Silica gel

In general, the silicone can be divided according to their nature and composition of organic and inorganic silicone silicone two categories. Shape into its component silicone extrusion and molded silicone .
Inorganic silica is a highly active adsorption material , usually with sodium silicate and sulfuric acid , and after a series of aging process , acid bulbs , etc.

Obtained. An amorphous silica material , its chemical formula is mSiO2. nH2O. Insoluble in water and any solvent , non-toxic , odorless , chemically stable, does not react with any substance except alkali, hydrofluoric acid . Various types of silica are formed in different manufacturing methods of different pore structure . Chemical composition and physical structure of silica gel , and determines that it has many other similar materials difficult to replace characteristics: high adsorption properties, good thermal stability, chemical stability, high mechanical strength.
Silicone is an organosilicon compound containing a Si-C bond means , and at least one organic group is directly bonded to silicon atoms compound , and those on the regular habits through an oxygen , sulfur, and nitrogen, the organic silicon group compound atom is attached as an organic silicon compound . Among them, the silicon- oxygen bond (-Si-O-Si-) for the skeleton consisting of silicones, silicone compounds are the most numerous , most studies , the most widely used class of more than 90% of the total amount .
Extruded silicone relatively common , such as household electric cooker ring , called the rice cooker silicone seals .
Molded silicone bit more complicated , irregular shape, including silicone bowls, silicone ice tray , silicone bakeware and more.
Inorganic silicone
About inorganic silicone
Name: Silicone
Alias: silica gel or silicic acid gel
Name : Silica gel; Silica
MF : xSiO2 · yH2O
Weight: 60.08
CAS Registry Number : CAS # 112926-00-8
EINECS No. :231 -545-4
Word explanation : Chemical Formula xSio 2 · yH2O. Transparent or white granular solid . Has an open porous structure , strong adsorption, can absorb a variety of substances. Dilute sulfuric acid ( or hydrochloric acid ) in an aqueous solution of sodium silicate and allowed to stand , it will become hydrous silicate gel and solid-state technology . Washed with water electrolyte dissolved therein remove Na + and SO4 2 – (Cl-) ions, a silica gel can be dried . As absorb moisture , moisture is about 40% . For gas drying , gas absorption, liquid dewatering , color layer , but also used as catalysts. Such as cobalt chloride , dry blue, and red absorption . Repeated use of renewable .
Safety performance
The main ingredient is silica, silica gel , chemically stable , does not burn . Silica gel is an amorphous silica dust content of the workshop should be controlled less than 10 mg / cubic meter, the need to enhance ventilation, wear a mask when operating .
Silicone has a strong adsorption capacity, can produce human skin drying effect , therefore , the operation should wear good clothes. If the silicone into the eyes , flush with lots of water and seek medical treatment as soon as possible .
Blue silicone because it contains small amounts of cobalt chloride , toxic, should avoid contact and inhalation of the mouth and food , such as the occurrence of poisoning should immediately seek medical treatment.
Silica in the course of the medium due to the adsorption of water vapor or other organic substances , the adsorption capacity decreased after regeneration can be reused.
Security terms :. S22 Do not breathe dust Do not breathe dust.
Silicone regeneration
A reproduction after absorbing silica
Silica gel adsorption of water , thermal desorption way through the water to remove heat in different ways , such as electric heaters , heating and hot flue heat drying . Desorption temperature control in heating 120 – 180 ℃ is appropriate, for the blue gel indicator , color gel , DL -type blue silicone control at 100 – 120 ℃ appropriate. The maximum temperature of various industrial silicone regeneration should not exceed the following limits :
Coarse pore silica shall not exceed 600 ℃;
Pore ​​silica shall not exceed 200 ℃;
Blue plastic indicator agent ( or color gel ) shall not exceed 120 ℃;
Silica-alumina gel shall not exceed 350 ℃.
Silicone regeneration , the general control 2% moisture or less back into use .
Renewable two , silica gel adsorption of organic impurities
⒈ roasting method
For coarse -pored silica gel , gradually warming up to 500 can be placed within the roaster – 600 ℃, after about 6-8 hours to

Particles can be white or brown . Of silica gel pores , the firing temperature should not exceed 200 ℃.
⒉ rinsing method
After the silica gel in the saturated water vapor adsorption heat saturated water immersion rinsing detergent to remove oils or other organic impurities can be combined , dried and then dehydrated by washing water .
⒊ solvent flushing method
According to silica gel adsorption of organic species , the choice of an appropriate solvent adsorbed organic matter dissolved in the silica , silica gel is then heated to remove the solvent .
Third, the silicone should pay attention to the problem of regeneration
⒈ drying regeneration should be careful to gradually raise the temperature , so as not to cause severe drying particles burst, lower recoveries .
⒉ silicone baking for regeneration when the temperature is too high will cause changes in the pore structure of silica gel adsorption effect of significantly reducing the impact value. For blue or discoloration silica gel indicator , desorption regeneration temperature should not exceed 120 ℃, otherwise they will be gradually oxidized color developing agent and lose color effect.
⒊ regenerated by silica gel should generally screened to remove fine particles, so the particles evenly.
Storage and Packaging
Silicone has a strong capacity to absorb moisture and should therefore be stored in a dry place , packaging, between the ground and have a shelf . There packaging drums , drum , cardboard boxes, plastic bottles, polyethylene plastic bags, flexible container bags and so on. During transportation to avoid rain, moisture and sunlight .
The use of inorganic silica
Wide pore silica is generally used as a catalyst carrier, a matting agent , abrasive toothpaste . Therefore, different varieties should be selected depending on the purpose.
Silica gel desiccant can be used for , and can be reused. Silica is silica gel mSiO2 · nH2O made ​​suitable dehydrating porous materials of different particle sizes . An open porous structure having a specific surface area ( surface area per unit mass ) is large , many substances can be adsorbed , is a good desiccant, an adsorbent and a catalyst carrier. Silica gel adsorption is mainly physical adsorption, can be regenerated and used repeatedly. Adding an acid to an alkali metal silicate ( such as sodium ) solution, and acidified , and then added with stirring for a certain amount of electrolyte , the silicic acid gel ; acid or sodium silicate solution is added in the thick or silicic acid salts can also generate gel. The silica gel was allowed to stand for several hours so that the aging of soluble salts and washed with hot water at 60 ~ 70 ℃ the dried and activated at about 300 ℃, silica gel can be obtained . The silica gel with cobalt chloride solution and then drying and soaking activation , available color gel . When it is used as a desiccant, is blue before absorption , the absorption becomes red, the color change can be seen from the water absorption degree , and the need for regeneration processing . Silicone is also widely used in the vapor recovery areas , and preparing the oil refining catalyst, etc.
Inorganic silica used as a drying agent , the following aspects may be embodied
1 is mainly used for equipment, instruments, equipment, and other moisture absorption in confined conditions rust .
2 in conjunction with ordinary silica gel desiccant , indicating desiccant to absorb moisture and relative humidity to determine the extent of the environment . As packing silica gel desiccant, widely used in precision instruments , leather, clothing, food , medicines and household appliances.
3 use food-grade silicone because it can be used for baby pacifiers and other supplies in direct contact with the human body , in addition , can also be used to produce silicone skin .
Silicone regeneration should pay attention to the issue
1 , drying regeneration should be careful to gradually raise the temperature , so as not to cause severe drying particles burst, lower recoveries .
2, when the silicone baking regeneration , the temperature is too high will cause changes in the pore structure of silica gel adsorption effect of significantly reducing the impact value. For blue or discoloration silica gel indicator , desorption regeneration temperature should not exceed 120 ℃, otherwise they will be gradually oxidized color developing agent and lose color effect.
3, after the regenerated silica should generally screened to remove fine particles, so the particles evenly.
3 related jargon
Specific surface area : means per g of silica gel has a surface area , including internal and external surface area of ​​the micropores and . – Unit : m / g
Pore ​​volume : Each gram of silica gel inside the pores of the total volume . – Unit: ml / g (ml / g)
Aperture: refers to the internal diameter of the silica pores . – Unit: Angstroms (A 0) or nanometers (nm) 1nm = 10A 0
Adsorption amount : silica gel adsorption at a relative humidity of saturated water vapor , when said amount of the adsorbed amount of adsorption of water vapor . – Unit :%
Bulk density: the quality and volume of the silicone they heap space ratio . – Unit : g / liter (g / l)
PH: PH value is the silica gel after a certain processing conditions , PH value of the aqueous solution containing a proportion of silica gel .
Specific resistance : silica is an indicator of purity . Than the resistance itself is defined as the solution resistance at 1cm distance. Is the specific resistance of the silica gel after a certain processing conditions , the silica gel eluted soluble electrolyte , the electric conductivity than the resistance was measured . Resistance higher than reflected lower water-soluble silica contained in the electrolyte . – Unit : ohm cm (Ω.cm)
Attrition rate : is an indicator of the strength wear-resistant silicone . Refers to silica gel under conditions of loss of abrasion . – Unit :%
Water does not burst rate : is an indicator of the degree of water-resistant silicone water . – Unit :%
4 inorganic silica classification
Silicone based on its pore size is divided into: large pore silica , silica coarse holes , B -type silica gel , silica pores . Due to the different pore structure , adsorption properties so they have their own characteristics . Coarse pore silica gel in the case of high relative humidity has a higher adsorption capacity , pore silica gel in the case of low relative humidity higher than the coarse pore silica gel adsorption , while the B -type silica gel due to the pore structure between the coarse and fine between holes , its adsorption capacity between thick, between pore .
Depending on the use of inorganic silica , silica gel can also be classified into beer , silicone PSA , medical silica gel, indicating silica gel , silica gel desiccant, silica opening agent , such as silica gel toothpaste .
Pores of silica gel
Pore ​​silica gel is colorless or slightly yellow transparent vitreous, its basic quality parameters are as follows : average pitch 2.0-3.0nm, surface area 650-800

M / g, pore volume 0.35-0.4ml / g, the specific heat 0.92KJ/kg. ℃, thermal conductivity 0.63KJ / m. Hr. ℃.
Usage: Apply to dry , moisture, rust . Prevents equipment, instruments, weapons, ammunition, electrical equipment, pharmaceuticals , food , textiles and various other packaging items damp, can also be used as catalyst carrier and dehydration of organic compounds refined . Because of its high bulk density and low humidity absorption effect is obvious characteristics that can be used as an air purifying agent to control air humidity. In the ocean the way there are a wide range of applications , because the goods during transport often deteriorate due to high humidity and moisture , the product can be effective desiccant moisture, so that the quality of the goods is guaranteed . Pore ​​silica is also commonly used in two parallel plates between the sealing window dehumidifier can maintain transparency of the layers of glass .
B -type silica gel
Characters : B -type silica as a milky transparent or translucent pellets or lumps . B -type glue between the pore structure of coarse -pored silica gel , silica pores .

The basic quality parameters : pore volume of 0.60-0.85ml / g, average pore diameter of 4.5-7.0nm, specific surface area of ​​450-650m2 / g.
Uses: mainly used for air humidity regulators, raw materials and catalyst carriers, pet litter, and as chromatography on silica gel and other chemical products.
Coarse pore silica gel
Coarse pore silica called C -type silicone is a silicone , is a highly active adsorption material , is

Amorphous material , its chemical formula is mSiO2 · nH2O. Insoluble in water and any solvent , non-toxic , odorless , chemically stable, does not react with any substance except alkali, hydrofluoric acid . Chemical composition and physical structure of the coarse pore silica , and determines that it has many other features too difficult to replace similar materials : high adsorption properties, good thermal stability, chemical stability, high mechanical strength.
Coarse pore silica white in appearance , there are massive, spherical and spherical micro three products . Coarse -porous spherical silica and the like is mainly used to remove acid gas purification , drying agents , and the insulating oil ; coarse pore silica gel is mainly used for the catalyst carrier block , drying , gas and liquid purification agents .
5 silicone
Silicone Performance
The basic structural unit of the silicone product is made ​​of a silicon – oxide chain section composed of a silicon atom through a side chain with various other organic groups . Thus, in the structure of organic silicon products containing both ” organic group” , but also contain ” inorganic structure” , this particular composition and molecular structure makes it features organic and inorganic feature set in one. Compared with other polymers, silicone products

The most outstanding performance are:
1 . Temperature characteristics
Silicones are silicon – oxygen (Si-O) bond of the main chain structure , C-C bond energy of 82.6 kcal / mol , the bond energy Si-O bond in the organic silicon is 121 kcal / mole , so the high thermal stability of silicone products , high temperature ( or radiation ) molecular bond is not broken , do not break down . Silicone is not only to high temperature , low temperature resistance, but also can be used in a very wide temperature range . Whether it is physical or chemical properties and mechanical properties, temperature dependence is very small.
2 . Weatherability
Silicones of the main chain is -Si-O-, unparalleled key exists , it is not easy to be decomposed by ultraviolet light and ozone. Better than other silicone polymer material thermal stability and resistance to radiation and weathering capabilities . Silicone natural environment life of up to several decades.
3 . Electrical insulating properties
Silicones have excellent electrical insulating properties , dielectric loss , resistance, voltage, resistance, arc resistance, corona , volume resistivity and surface resistivity of the top in the insulating material etc. , and their performance is affected by temperature and frequency electrical little effect . Therefore, they are a stable electrically insulating material , are widely used in electronics and electrical industry. Silicones have excellent heat resistance in addition , it also has excellent water repellency , the electrical equipment which is used under wet conditions having a high reliability protection .
4 . Physiologically inert
Silicone compounds are known in the least one active compound . They are extremely resistant to biological aging , and animal body without rejection , and has better anti- clotting properties.
5. Low surface tension and low surface energy
Main chain of the silicone is very soft, the force between molecules is much weaker than the hydrocarbon , therefore , lower viscosity than the same molecular weight hydrocarbons , weak surface tension , surface energy is small, the film forming ability . This low surface tension and low surface energy which is the main reason for many applications to obtain : the excellent performance of the hydrophobic , anti-foaming , foam stability, release , lubrication, coating and the like.
Use of silicone
Since these silicones excellent properties , it is very wide range of applications . It

Not only as aviation, cutting-edge technology, special materials used in military technology sector , but also for the various sectors of the national economy , its scope of application has been extended to : construction, electrical and electronics, textiles, automobiles, machinery , leather, paper, chemicals , light industry, metal and paints, pharmaceuticals and medical .
Category 6 silicone
Silicone divided into silicone rubber, silicone resin, silicone three categories.
Depending molding silicone products can be divided into three categories Department
Molded silicone products
Molded silicone products are usually placed in the mold by adding high-temperature vulcanizing agent solid vulcanized silicone raw materials by applying pressure machines, high temperature sulfur of forming a solid , molded silicone hardness is usually 30 ° C-70 ° C. Raw materials in accordance with creams recall Pantone color card color, shape of the mold determines the shape of the molded silicone products , molded silicone products silicone industry is currently the most widely used one . Mainly used only silicone industrial parts, buttons, silicone gifts , silicone wristbands , silicone watches, key cases, mobile phone sets , silicone kitchenware, silicone pad, Ice Cube , cake and so on.
Extruded silicone products
Extruded silicone products usually through extrusion machine extrusion molding silicone , silicone extrusion shapes are generally long , tubular free to cut, but there are limitations shape silicone extrusion , medical equipment, food machinery in a wide range of to use.
Liquid silicone products
Liquid silicone injection molding silicone products through injection molding , product flexibility , hardness can reach 10 ° C-40 ° C, because of its soft features , in emulation of human organs , medical Guijiaoxiongdian , and other widely used.
Specialty Silicone Products
Specialty silicone products is based on the chemical properties of silicone or some add auxiliary materials , specialty silicone products also have a high temperature ( up to 330 degrees ) , food grade ( full compliance with U.S. FDA, LFGB standard ) , medical grade, flame retardant by adding auxiliary materials can also have , luminous , negative ions, color, and other characteristics.
7 Silicone Rubber classified edit
Silicone RTV silicone is mainly divided into high-temperature vulcanized silicone
RTV silicone Introduction and classification
RTV silicone (RTV) is a sixties advent of a new type of silicone elastomer , the most significant feature of this rubber is at room temperature without heating , such as pressure can be cured in situ , extremely easy to use . Thus , came on fast become an important part of the silicone products . Today, RTV silicone has been widely used as adhesives , sealants, protective coatings, potting and molding materials , in all walks of life has its purpose.
RTV silicone its packaging can be divided into single -component and two -component RTV silicone, by curing mechanism can be divided into condensation and molding. Therefore , by component RTV silicone , curing mechanism and the use of technology can be divided into three types, namely single-component RTV silicone, two-component RTV silicone condensation-type and two-component RTV silicone molding added . These three series RTV silicone has its own characteristics : the advantages of one-component RTV silicone is easy to use, but deep curing speed more difficult ; advantages of two-component RTV silicone that hold heat curing , shrinkage is small, no swelling, no stress, curing can be performed on both the inside and the surface, deep cure ; plus RTV curing time mainly depends on the temperature of the silica gel , and therefore , can be controlled by temperature adjustment cure rate .
Among the many synthetic rubber , silicone is a leader in it. It has a non-toxic , tasteless , not afraid to withstand cold temperatures and characteristics , in the ninety degrees below zero Celsius Baidu and ” poised “, ” without blinking an eye ,” still lose the original strength and elasticity. There are good electrical insulation silicone , resistance to oxygen aging resistance , light resistance to aging and mildew resistance , chemical stability. Because of these excellent properties , making silicone get a very broad and important uses in modern medicine . In recent years, the hospitals, research institutes and factories work together successfully trial a variety of silicone medical supplies .
Silicone Earplugs : wear comfortable, noise can be a good barrier to protect the eardrum.
Silicone vacuum extraction device : easy to operate , safe to use , according to the size of the fetal head deformation , fetal scalp will not be sucked up attracting avoid damage to the scalp and intracranial hematoma and other ills , can greatly reduce the pain of childbirth in pregnant women during childbirth .
Silicone artificial blood vessel : a particular physiological function, and the body can be ” intimacy ” , it does not exclude the human body , after a certain time, it will complete with the body tissue is extremely good stability up case .
Silicone tympanic membrane repair piece : its thin, flexible film , finish and good toughness . Is an ideal material for repair of the eardrum , and easy to operate , the effect is quite good.
There are also artificial trachea silica , artificial lung, artificial bone , duodenum silicone tube, the effect is very good.

Barium Carbonate

Barium carbonate, barium BaCO3 is an important compound of the formula BaCO3, molecular weight 197.35 .
Barium carbonate
Hexagonal crystal or fine white powder, orthorhombic , hexagonal , cubic three kinds of crystal. Due to the different conditions of preparation , the bulk density of the obtained products are different , generally 0.80 ~ 2.11g/cm3, the particle size of 0.1 ~ 10μm. Density 4.43 g / cm 3, melting point 1740 ℃ (8820 kPa -90 atm ) . Good thermal stability, at 1400 ℃, about 0.1MPa decomposition and emit carbon dioxide. Slightly soluble in water containing carbon dioxide , carbonic acid or an ammonium salt when in the presence of a concentrated solution of sodium sulfate and magnesium sulfate , zinc sulfate, calcium nitrate , calcium chloride , potassium chloride or the like, to increase its solubility . Soluble chloride or ammonium nitrate solution to generate complex, dissolved in hydrochloric acid , nitric acid to release carbon dioxide. Toxic . Barium component prepared carburizing agent is used at a high temperature carburizing a steel member ( hardening ) . Manufacturing cathode tube used to do screening agent . Also used as rat poison , water clarifying agents and fillers. In addition, for the instrumentation, metallurgy industry, for the preparation of fireworks, flares system , ceramic coatings, optical glass materials such as enamel system . Natural barium carbonate ore , barite from the chemical processing system, or carbon dioxide pass into the barium hydroxide solution , sodium carbonate solution or mixed with barium nitrate solution was prepared .
Barium carbonate – the main purpose
Analysis of calcium, magnesium, manganese and zinc iron, measured organic halogen . Used for making barium salts , pigments , fireworks and flares , optical glass, rodenticides , pottery , porcelain, and used as filler and water clarifying agent.

Barium – Toxicity

Barium carbonate is a virulent , can cause acute and chronic poisoning. Because heavy metals barium , barium carbonate reacts with hydrochloric acid in gastric juice , the release of barium ions , causing toxic reactions.
Barium carbonate, barium poisoning poisoning
Barium carbonate into the body through the respiratory tract and digestive tract can cause acute and chronic poisoning , severe cases can be fatal. About the health hazards of barium more such as: occupational exposure to barium carbonate on human lungs, blood, serum potassium and cholinesterase and so on.

Barium – Chronic poisoning
Barium carbonate accumulates in the bones, causing bone marrow leukosis , which occurred in chronic poisoning.
Barium – acute poisoning
When severe acute poisoning occurs when acute gastrointestinal disease, muscle tendon reflexes , convulsions, muscle weakness and other symptoms.
Barium carbonate, barium carbonate Structure Structure

Toxicity:
Oral
Rat LD50: 418mg/kg
Mouse LD50: 200mg/kg
Barium – emergency treatment
For patients with acute barium poisoning , usually taken gastric lavage, enema, taking measures to make the barium emetic agents excreted .
By the administration of potassium can also react with the barium carbonate , barium can become toxic insoluble barium sulfate precipitation , reduce toxicity. The reason for using potassium sulfate , barium poisoning because may cause hypokalemia .

Barium – rescue and care
1 Clear poison vomiting, gastric lavage , catharsis to clear toxins, preventing the absorption of toxins is the primary rescue measures . In this group of patients , 35 cases after eating poison nausea , vomiting 25 cases , 10 cases of diarrhea, there are two cases of tongue to induce vomiting at home to take the pressure method , five cases with 5% sodium carbonate oral vomiting or gastric lavage , oral sulfate and then sodium 20g catharsis , and the remaining patients with mild symptoms , not gastric lavage or induce vomiting. Close observation of the patient’s consciousness , pale , breathing , pulse, blood pressure and other changes, while in the treatment of patients collected vomit timely submission to identify the poison .
2 As the barium ions potassium supplementation agents can activate the cell membrane, so that from the extracellular potassium ions into the cell and lead to lower serum potassium , and potassium in the pathogenesis of course there will be progressively decreased , so in order to prevent hypokalemia, timely potassium chloride treatment is very important . The group of 49 patients given potassium chloride and VitC, VitB 6 infusion, for the temperature more than 38 ℃, poisoning symptoms are relatively heavier ( 9 cases ) to be potassium chloride 5 ~ 6g / d intravenously treated 1 ~ 2d symptoms, body temperature returned to normal. 9 cases of patients had lower serum potassium four cases before the normal use of potassium chloride , potassium and in the process it produces reduced to varying degrees , by potassium 5 ~ 6g / d, 2d after the review properly. 40 cases with normal serum potassium be potassium 4 ~ 5g / d after the review of potassium were within the normal range.
3 Application role thiosulfate thiosulfate is absorbed with the body undigested insoluble barium carbonate , barium sulfate is generated , thereby reducing the toxicity of barium carbonate , sodium thiosulfate , but must pay attention to the slow intravenous injection or infusion, and fully diuretic , so insoluble barium sulfate particles generated composure in the renal tubules . There are nine cases in this group of critically ill patients to be 0.64g of sodium thiosulfate 20ml 0.9% sodium chloride intravenous , Q4H × 3 times.
4 As the group closely observed in 9 cases of hypokalemia , including four cases appear to reduce serum potassium in potassium process, and potassium chloride intravenous overdose can cause peripheral circulatory failure , heart rate to cardiac arrest , so must be diligent blood pressure , pulse , good monitoring and serum potassium, sodium , chlorine content review electrocardiogram , prevent arrhythmias induced hypokalemia or hyperkalemia . The group, 4 patients with abnormal ECG in potassium are converted to normal after the rest have not exception. For the four cases of pregnant patients , with particular attention to the amount of fluid can not be too much speed not too fast, but also to observe whether the pain intensified and the availability of contractions, see red. After treatment and observation , four cases of pregnant women is not bad to happen.
5 good psychological care in this group of patients suffer a sudden illness , mental activity is very complex , expressed as emotional stress , fear , anxiety, worry prognosis until after symptoms , fear has consequences, affecting work , live, learn, especially 4 pregnant women are more worried about the health and safety of the fetus, which we take the following measures:

Caring, comforting patients with cordial words , more with their talk, communicate ideas , distracted.

In calm , warm , full of attitude and emotional impact of infection , thereby enhancing their self-confidence .

Patients given patiently answered questions raised , and treatment measures , the effect , the prognosis for the necessary explanations to eliminate worries.

Noble ethics and skilled business technology to win the trust of patients, so that they are in the best state of mind, and actively cooperate with the treatment and examination.

Strengthening the fetal heart rate monitoring for pregnant patients , observed changes in fetal heart rate , with or without contractions , see red , once there is a change promptly notify the obstetrician , explained in therapy to do , pay attention to the total amount of drug safety and rehydration , speed.

Paraquat use

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sodium metabisulphite

A detailed description editor
Basic Information
Name
English / Latin names
Sodium Pyrosulfite
Jiaoya Liusuanna
English Name

Supplies: http://www.lubonchem.com
: SODIUM BISULFITE; disodiummetabisulfite; disodiumpyrosulphite; fertisilo; metabisulfitedesodium; Sodiummetabisufite; sodiummetabisulfite (na2-s2o5); sodiumpyrosulfite (na2s2o5); Sodium dissulfite; Sodium disulphite; Sodium pyrosulphite; SODIUM METABISULFITE, PH EUR; SODIUM DISULFITE DRY TECHNICAL; SODIUM METABISULFITE ACS REAGENT ;… SODIUM DISULFITE DRY, RG, REAG ACS, REAG PH EUR;. SODIUM METABISULFITE, 97 +%, ACS REAGE NT; SODIUM METABISULFITE 97 +% ACS REAG &; SODIUM METABISULFITE REAGENT GRADE 97%; SodiumMetabisulphiteA.R;. SodiumMetabisulphiteFcc
Chinese alias
Sodium metabisulfite ; dipropylene sulfite ; weight thioredoxin ; pyrogallol sulfite ; sodium metabisulfite ; metabisulfite ; edible metabisulfite .
CASRN :7681-57-4
EINECS No. :231 -673-0
InchI Code : InChI = 1/2Na.H2O5S2/c;; 1-6 ⑵ 5-7 ⑶ 4 / h;; (H, 1,2) (H, 3,4) / q2 * +1 ;/ p-2
Formula : Na2S2O5
Molecular Weight : 190.09
Appearance: white or light yellow crystalline powder or small crystals ..
Specification: ≥ 65% of sulfur dioxide
Iron ≤ 0.005%
Water insoluble ≤ 0.05%
PH value of 4.0-4.6
Chemical Name
Chinese chemical name : sodium metabisulfite
Chemical Name : sodium metabisulfite
Chinese Name 2 : sodium metabisulfite
Name 2: sodium pyrosulfite / sodium metabisulphite
Technical Manual Code : 1333
CAS No. :7681-57-4
Formula : Na2S2O5
Molecular Weight : 190.09
Ingredients and composition
Hazardous components CAS No.
Sodium metabisulfite 7681-57-4
Category : Antioxidants .
Properties and Applications
Summary
Sodium metabisulfite ; sodium metabisulfite ; heavy thioredoxin ; Sodium metabisulfite; Sodium pyrosulfite formula Na2S2O5 Molecular Weight 190.10 CAS No. 7681-57-4
Physical and chemical properties
The main ingredients: pure
Appearance: colorless prismatic crystals or white powder ; has sulfur smell , sour, salty , ; Storage falling yellow color gradient .
pH:
300（fen jie） “>Melting point (℃):> 300 ( decomposition )
Boiling Point (℃): Not available
Relative density ( water = 1 ) : 1.48
Solubility: soluble in water , acidic aqueous solution ( at 20 ℃ to 54g/100ml water ; 100 ℃ when 81.7g/100ml water ) . Soluble in glycerol, slightly soluble in ethanol. The relative density of 1.4 . Soluble in water soluble in glycerine , slightly soluble in ethanol. Damp decomposition, exposed in air easily oxidized sodium . Contact with acid emit sulfur dioxide and generate the corresponding salts. Heated to 150 ℃ decomposition.
Stability and reactivity
Materials to avoid : strong acids, strong oxidizing agents.
Avoid contact conditions : moist air.
Physical and chemical properties
Sodium metabisulfite is white or yellow crystalline powder or small crystals , with a strong smell of SO2 , the proportion of 1.4 , dissolved in water , acidic aqueous solution , with a strong acid contact with the release SO2 and generates the corresponding salts, long home air, the oxidation into Na2S2O6, so the product can not go far. Higher than 150 ℃, namely decomposition SO2.
Security terms
S26In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S39Wear eye / face protection.
Wear goggles or masks.
S46If swallowed, seek medical advice immediately and show this container or label.
If swallowed , seek medical advice immediately and show this container or label.
Risk Phrases
R22Harmful if swallowed.
Harmful if swallowed .
R31Contact with acids liberates toxic gas.
Contact with acids liberates toxic gas.
R41Risk of serious damage to the eyes.
Serious damage to eyes .
Determination
Thiosulfate
Take this product 1.1g, slowly add dilute hydrochloric acid 10ml, dissolved in a water bath for 10 minutes , let cool, relocated colorimetric tube , add water to 20ml, as was muddy , and sodium thiosulfate solution ( 0.1 control solution mol / L) 0.20ml comparison is made using the same method , no thicker ( 0.2% ) .
Iron
Take this product 1.0g, 5ml of water and hydrochloric acid 2ml dissolved , evaporated on a water bath , the residue with water 15ml 2ml hydrochloric acid , dissolved , add the amount of bromine test solution and the solution of microscopic yellow , heated to remove excess bromine , let cool , add water to 25ml, according to inspection , 2.0ml solution compared with standard control solution made ​​of iron , not deeper ( 0.002% ) .
Heavy Metal
Take this product 1.0g, 10ml water dissolved, add 5ml of hydrochloric acid , evaporated on a water bath , the residue water 15ml, slowly boil for 2 minutes, filtered , and the filtrate was added so that the amount of bromine test solution clarified , heated to remove excess bromine , let cool, add 1 drop of phenolphthalein indicator solution and the amount of ammonia solution until the solution was pink , vinegar salt buffer (pH3.5) 2ml with water to make a 25ml, according to inspection , containing no heavy metals per million dated .
Arsenic

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Barium chloride

Name: Barium chloride
Formula: BaCl2
Molecular Weight: 208.23
Risk: Toxic
CAS No.: 10361-37-2
Control Type: Unregulated
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1 Physical and Chemical Properties
Physical Properties
White crystalline or granular powder. Bitter and salty. Slightly hygroscopic . At 100 ℃ loses crystal water , but placed in the wet air again absorb two molecules of water of crystallization . Soluble in water , soluble in methanol , insoluble in ethanol, ethyl acetate and acetone. The relative density of 3.86 . Melting point 963 ℃, boiling point 1560 ℃, refractive index 1.635 . Barium yellow- green flame reaction
Chemical properties
Barium chloride is commonly used laboratory analytical reagents , mainly for precipitation sulfate , barium sulfate to produce insoluble precipitate .
2 Preparation Method Editor
Reduction on industrial carbon barite get barium sulfide , barium sulfide dissolved in concentrated hydrochloric acid or calcium chloride that was saturated barium chloride . This is the method commonly used , calcium and strontium can be easily removed impurities
3 Use the Edit Profile
Mainly used for metal heat treatment, barium salt manufacturing, electronic instruments , also used for machining heat treatment agent. Determination of sulfate and selenium salts , etc. , chromatography, drip Determination of platinum , water softener . Fabric dyeing .
4 Storage Condition
Store in a cool , ventilated warehouse. Keep away from fire and heat. Packing seal. Should oxidants , acids, food chemicals stored separately and avoid mixing reservoir.
5 hazardous editor
Barium is a virulent , 0.2 ~ 0.5g ingestion can cause poisoning, lethal dose of 0.8 ~ 0.9g. If found poisoned , magnesium or sodium -speed service , taking gastric lavage , enema, vomiting and other measures. Rapid medical treatment, barium poisoning obvious symptoms of hypokalemia .  LD50 approximately 118mg/kg.

Sulfamic acid

Name : Sulfamic acid
English Name : ACETO ACID; AMIDOSULFONIC ACID; AMIDOSULFURIC ACID; AMINOSULFONIC ACID; BETZ 0254; SULFAMIDIC ACID; SULFAMINIC ACID; SULPHAMIC ACID; aminosulfuricacid; Imidosulfonic acid; Jumbo; Kyselina amidosulfonova; Kyselina sulfaminova; kyselinaamidosulfonova; kyselinaamidosulfonova (czech); kyselinasulfaminova; kyselinasulfaminova (czech); sulfamic; sulphamidic acid
Grade : AR
CAS No. :5329 -14-6 [ 1 ]
Formula : H3NO3S
Weight: 97.09

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No. MDL: MFCD00011603
EC Number: 226-218-8
2 Products
Raw materials : urea, fuming sulfuric acid, chlorosulfonic acid
Preparation Products : cobalt sulfamate , nickel sulfamate , Acid Green 20 , cyclamate, detergents, alkali superplasticizer , affinity of the toner , ammonium sulfamate , strong detergents , cleaning agents
Characters
Colorless or white crystals , soluble in water, slightly soluble in ethanol and methanol, slightly soluble in acetone, ether insoluble in aqueous solution gradually break down into ammonium bisulfate , water solubility :. 146.8 g / l (20 ℃)
Physical parameters
Melting point : 215-225 ℃
Storage and transportation
Sealed dry place.
Instructions for use
Standard amount of the base titration , complexation masking agents , organic trace analysis of nitrogen and sulfur determination criteria .
Hazard statement
Dangerous code : Xi
Hazard Class : R36/38- R52/53
Security Level : S26-S28-S61
3 Synthetic Method
An amino acid produced in many ways, sulfur dioxide or acetone oxime with hydroxylamine as raw material hydroxylamine , sulfite or sulfate and ammonia as raw materials ammoniting , urea and chlorine acid as raw materials sulfochlorination law , fuming sulfuric acid and urea as raw fuming sulfuric acid , urea , sulfur trioxide and sulfuric acid as raw materials and fuming sulfuric acid method (also known as liquid phase ) and ammonia via gasification and sulfur trioxide in Gas under vapor phase reaction conditions and the like. Domestic and industrial significance of the process has to send two amination with ammonia and direct synthesis of sulfur trioxide fuming sulfuric acid method. Urea is sulfonated with fuming sulfuric acid to form an amino acid in the crude 40-70 ℃, and then water was added for crystallization to obtain the amino acid product. Consumption of raw materials fixed: Urea 2000kg / t, oleum 1500kg / t.
2 , there are two main methods synthesis gas and liquid method. Fumed harsh operating conditions , equipment material requirements . Byproducts and more easily adhere to the amino acids and the reactor wall need regular cleaning. High production costs . The advantage is the high product purity. Manufacturers use mostly liquid phase .
3 excess fuming sulfuric acid in the reaction vessel , cooled with stirring to 20 ~ 40 ℃, start adding the mixed proportion of urea and sulfuric acid . After completion of the addition , stirring at about 20 ℃ 8 h. Then gradually warmed to 70 ~ 90 ℃, distilled sulfur trioxide , cooling crystallization . The crude obtained after the solid-liquid share amino acid, and recrystallized from water , dehydrated and dried to obtain a high-purity quality amino acid.
Four amino acid is a strong Lewis acid and a strong Lewis base NH3 SO3 adduct , prepared a small amount of high purity when the amino acid , in a completely anhydrous conditions , with high purity directly by reaction with ammonia SO3 . If a larger amount of urea is available with fuming sulfuric acid reaction to the system. The round bottom flask equipped with a mechanical stirrer was placed in the water bath , to which was added 560g 100% sulfuric acid under vigorous stirring to 100g of urea times ( about 45min plus End ) was slowly added to sulfuric acid , being careful not the temperature exceed 40 ℃. Then thereto was added 309g of fuming sulfuric acid ( containing 65 % free SO3), and 16h is placed at a temperature of 42 ~ 45 ℃ . Filtered through a glass frit funnel the reaction mixture was washed first with pure sulfuric acid , washed with 50% sulfuric acid , washed with cold methanol and finally with .
5 heating oleum 20% to 30 ℃, urea was slowly added , the temperature controlled at 60 ~ 65 ℃, after adding heat 3H, then warmed to 80 ~ 85 ℃, incubated 2h, after the reaction was cooled to 5 ℃, filtration, drying the obtained crystals by centrifugation , washed with 5% ethanol and recrystallized with distilled water and drained after purification to obtain pure amino acid .

Polyvinyl alcohol

Polyvinyl Alcohol

Chemicals Name : polyvinyl alcohol, vinylalcohol polymer, poval, referred to as PVA
CAS No. :9002-89-5
Formula : [C2H4O] n
Molecular weight:  44.05
Structure:Non-toxic
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1,Security terms : S24/25 Avoid contact with skin and eyes Avoid contact with skin and eyes.
S26In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37Wear suitable protective clothing and gloves.
Wear suitable protective clothing and gloves.
S24/25Avoid contact with skin and eyes.
Avoid contact with skin and eyes.
S45In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)
In case of accident or feel unwell, seek medical advice immediately ( if possible show the label ) .
Risk Phrases R23/24/25Toxic by inhalation, in contact with skin and if swallowed.
Inhalation , in contact with skin and if swallowed poisonous.
2, Technical indicators
Polyvinyl alcohol product standards (cp2010)
No.                      Index Name                    Standard
1                         Exterior                       White powder
2                      Viscosity                        3-70
3                     PH value                        4.5 ~ 6.5
4                   Loss on drying                  ≤ 5.0
5             Residue on ignition                 ≤ 0.5
6                    Acid value                        ≤ 3.0%
7                Alcoholysis                          85 ~ 89
8             Heavy Metal                       ≤ 10PPM
Polyvinyl alcohol product standards (USP25)
Low viscosity
No.                       Index Name                       Standard
1                              Exterior                         White powder
2                          Viscosity                           4.0 ~ 7.0
3                         PH value                           5-8
4       The average molecular weight        16000 to 20000
5                  Loss on drying                         ≤ 5.0
6               Residue on ignition                     ≤ 2.0
7           Water- insoluble impurities              ≤ 0.1%
8             The degree of hydrolysis                +
9              Organic volatile impurities              +
10                 Content                             85.0% ~ 115.0%
Medium viscosity
No.                              Index Name                       Standard
1                                      Exterior                    White powder
2                                    Viscosity                       21.0 ~ 33.0
3                                  PH value                              5-8
4                 The average molecular weight           110000 ~ 130000
5                           Loss on drying                           ≤ 5.0
6                       Residue on ignition                       ≤ 2.0
7                Water- insoluble impurities                 ≤ 0.1%
8              The degree of hydrolysis                    +
9         Organic volatile impurities                      +
10                  Content                               85.0% ~ 115.0%
High viscosity
No.                                 Index Name                                            Standard
1                                      Exterior                                             White powder
2                                    Viscosity                                               40.0 to 65.0
3                                  PH value                                                     5-8
4                   The average molecular weight                       180000 to 200000
5                            Loss on drying                                                  ≤ 5.0
6                  Residue on ignition                                                    ≤ 2.0
7               Water- insoluble impurities                                           ≤ 0.1%
8                  The degree of hydrolysis                                         +
9                 Organic volatile impurities                                        +
10                         Content                                                     85.0% ~ 115.0%
3, Pharmaceutical Grade
Pharmaceutical grade and specifications with EG , EG system uses. Pharmaceutical grade polyvinyl alcohol , polyvinyl alcohol level is different from the chemical industry , it is a very safe organic polymer , non-toxic to humans , no side effects, biocompatible , water-based gel , especially if he ‘s in medical in ophthalmology , wound dressings and artificial joints aspects are widely used in pharmaceutical polyvinyl alcohol film while the film , an artificial kidney film also has to use. Its security can be used to repair skin wounds , eye drops and eye products visible in general. Some models are also often used in cosmetics mask, cleanser , lotion and emulsion , is a commonly used security into film.

4,Risk
Health hazard : inhalation , ingestion or absorption through the skin harmful to eyes and skin

Stimulation.
Explosion hazard: The product is flammable , irritating.

5,Aid measures
Skin contact: Remove contaminated clothing, mobile water rinse .
Eye contact: Did eyelid, mobile water or saline. Doctor.
Inhalation: from the scene to fresh air. If breathing is difficult , give oxygen. Doctor.
Ingestion : drink plenty of water, induce vomiting . Doctor.
6, Fire-fighting measures
Hazardous characteristics : powder can form explosive mixtures with air , when it reaches a certain concentration, when Mars will explode. The thermal decomposition of flammable gases.
Hazardous combustion products : carbon monoxide, carbon dioxide.
Fire fighting methods : firefighters are required to wear gas masks, body wear firefighting suits , fire in the wind . Extinguishing Media: Water spray, foam, dry powder , carbon dioxide , sand.
7 leak handling
Emergency treatment: isolation leak contaminated areas, restricting access. Cut off the fire source . Recommended emergency personnel wearing a dust mask ( full cover ) , wear protective clothing. To avoid dust, carefully scan, bag placed transfer to a safe place . You can also rinse with plenty of water , wash water diluted into the wastewater system . If large spills, using plastic sheeting, canvas cover . Recycling or collection shipped to the waste disposal sites.
8, Handling
Handling Precautions: provide good natural ventilation.

The operator must go through specialized training , strict adherence to rules . Proposed operators wear self-absorption filter respirators , wearing chemical protective safety glasses , wear protective overalls on infiltration , wear rubber gloves. Away from fire , heat, workplace smoking . Use explosion-proof ventilation systems and equipment. Avoid generating dust . Avoid contact with oxidizing agents . Handling of light when light unloading , packaging and containers to prevent damage . Corresponding with the variety and quantity of fire equipment and emergency equipment leakage . Empty containers may be harmful residues .
Storage: Store in a cool , ventilated warehouse. Keep away from fire and heat. Oxidants should be stored separately and avoid mixing reservoir . Corresponding with the variety and quantity of fire equipment . Storage areas should be equipped with suitable material spill .

Diazolidinylurea information

1 Basic information Chinese Name: Diazolidinyl Urea Chinese alias: N- (1,3- 2,5-bis (hydroxymethyl)-dione-4-imidazolyl group) -N, N’- two methylol urea; two azo Lee Ting urea; two dual chlorine alkyl urea; Pierre B; N- hydroxymethyl -N- (1,3- dimethylol-2,5-dione-4-imidazolyl group) -N’- methylol urea; diazo imidazolidinyl urea; Pierre A; bis (hydroxymethyl) imidazolidinyl urea; Pierre 115 (imidazolidinyl urine) English Name: Diazolidinyl urea English Synonyms: DIAZOLIDINYL UREA; N- (1,3-Bis (hydroxymethyl) -2,5-dioxo-4-imidazolidinyl) -N, Asics Pas Cher N’-bis (hydroxymethyl) -urea; germall11; hyl) -; imidazolidinylurea11; n – (1,3-bis (hydroxymethyl) -2,5-dioxo-4-imidazolidinyl) -n, n’-bis (hydroxymethyl; n- (hydroxymethyl) -n- (1,3-dihydroxymethyl-2,5- dioxo-4-imidazolidinyl) -n ‘- (hyd; N- (Hydroxymethyl) -N- (1,3-dihydroxymethyl-2,5-dioxo-4-imidazolidinyl) -N’ – (hydroxymethyl) urea; roxymethyl) urea ; urea, n- (1,3-bis (hydroxymethyl) -2,5-dioxo-4-imidazolidinyl) -n, n’-bis (hydroxymet; urea, nike tn requin pas cher n- [1,3-bis (hydroxymethyl) -2 , 5-dioxo-4-imidazolidinyl] -n, nike air max 2016 blauw n’-bis (hydroxymet; Urea, N- [1,3-bis (hydroxymethyl) -2,5-dioxo-4-imidazolidinyl] -N, N’-bis (hydroxymethyl) -; 1- [1,3-bis (hydroxymethyl) -2,5-dioxoimidazolidin-4-yl] -1,3-bis (hydroxymethyl) urea; MicrocideIvtm; Germall; N- (HYDROXYMETHYL) -N- (1,3-DIHYDROXYMETHYL-2,5-DIOXO-4-IMIDA .; DIAZOLIDINYLUREA (GERMALL II); 1,3-Bis (hydroxymethyl) -5- [1,3-bis (hydroxymethyl) ureido] hydantoin; Germall Ⅱ CAS: 78491-02-8 Formula: C8H14N4O7 Molecular Weight: 278.22 2 Physical and chemical properties Appearance: white powder, hygroscopic, nike air max pas cher odorless or with a characteristic odor. Storage condition: 2-8 ° C 3 uses Diazolidinyl Urea Used in cosmetics, food processing and animal feed industries,

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U.S. new ethylene cracker production will reach 10

American Plastics News Network News, The Dow Chemical Company executives said, thanks to shale gas in North America to bring the advantages of raw material supply, the U.S. petrochemical market is being ushered in four wave of investment wave.
Dow Jim Fitterling at IHS World Petrochemical Conference, held March 26 in Houston, said: “Investing tide may be much larger than we expected.”, Former U.S. announced at least 120 energy-related chemical expansion project an investment of over 100 billion U.S. dollars.
Petrochemical companies in the United States have announced new production of ethylene cracker reached 10, including a unit of Dow’s Freeport, Texas in the United States. Fitterling estimated that 6 will be completed as scheduled. He added that this investment demonstrates the range of investment theory investors. Dow’s Freeport project will add a lot of polyethylene capacity.(chemicals offer)