2014年6月12日星期四

Polyvinyl Alchol PVA 1788 and PVA 1799

Architectural coatings commonly use Polyvinyl Alcohol PVA 1788 and PVA 1799. Polyvinyl Alcohol is derived from the hydrolysis of Polyvinyl Acetate, and can not derived by the polymerization of Vinyl Alcohol. Because Vinyl Alcohol is very unstable, there can be no free Vinyl Alcohol Monomer. The formula of Polyvinyl Alcohol is (CH2CH)OH, wherein the degree of hydrolysis and degree of polymerization has a great influence on the physical properties of Polyvinyl Alcohol. The polymerization degree of the Polyvinyl Alcohol can be divided into a high polymerization degree, medium polymerization degree and low degree of oligomerization, and recently, the development of an ultra-high degree of polymerization products.
There are three typically kinds of alcoholysis, namely, 78 %, 88 % and 98 %. The complete alcoholysis of Polyvinyl Alcohol is 98 % to 100 %, partial alcoholysis of alcoholysis typically is 87 % to 89 %. For convenience, we often fetching thousands of polymerization degree, rounded at the front, percentages in the back alcoholysis. Therefore, PVA 1788 means that polymerization is 1700, with diethylene glycol 88 %, PVA 1799 means that polymerization is 1700, with diethylene glycol 99 %.
PVA 1788 is with good water solubility, whether in cold water, was quickly dissolved in hot water, but PVA 1799 only dissolves in hot water at 95 or above. Due to Polyvinyl Alcohol PVA to neutral, at the time of dissolution does not need special corrosion requirements, but it’s best to use stainless steel or enamel reaction kettle, because these materials will not rust and contamination of the solution.

PolyvinylAlcohol PVA 1788 and PVA 1799 can be used for emulsion polymerization of Vinyl Acetate emulsion stabilizer. Polyvinyl Alcohol can be used in the manufacturing of water-soluble adhesives, and can be used as modification of starch adhesive agents. And also can be used to preparation of photosensitive adhesive and benzene class solvent resistant sealant. Polyvinyl Alcohol also can be used as release agents, dispersants and so on.

2014年5月12日星期一

What is Sodium Ascorbate?

Sodium Ascorbate is a kind of white to yellowish white crystalline powder or granules, odorless, slightly salty flavor. The decomposition temperature of it is of 218 , in the dry conditions are more stable, light color burn, after moisture absorption and slow oxidation and decomposition in aqueous solution. Sodium Ascorbate can be much easier to be soluble in water than Ascorbic Acid, 10 % aqueous solution PH is about 7.5.
First aid measures:
Ingestion: Do not induce vomiting. If the victim is conscious, instead of convulsions, give 1 or 2 glasses of water to dilute the chemicals, and to make a hospital or poison control center immediately.
Breath in: Leave the contaminated area immediately and take deep breath of fresh air. If the symptoms (such as wheezing, coughing, shortness of breath, or in the mouth, throat, or chest burning), call the doctor, and was prepared to transport victims to hospitals.
Skin: It can cause skin irritation. Symptoms may include redness and burning of the skin and other skin damage. Gently and thoroughly wash all affected skin areas with soap and water. If you develop symptoms such as redness or irritation, immediately call a doctor, and be prepared to transport the victim to a hospital for treatment.
Eyes: First check the victim of contact lenses, if present removed. While calling a hospital or poison control center for 20 to 30 minutes of water or saline solution flush eyes of the victims. Do not put any ointments, oils, or medication in the victim 's eyes, the doctor did not specify. If symptoms ( such as redness or irritation ) development, please transported the victim to a hospital immediately.
The stability of Sodium Ascorbate:

Aqueous solution is unstable, and the air is greater than pH 6.0 by the relative stability when exposed to rapid oxidation of Ascorbic Acid gradually darken light it is exposed to light in the air is gradually dimmed, but not damage, slight coloration therapeutic activity Ascorbic acid injection. Solution of Ascorbic Acid is rapidly oxidized in the air, the drug in an alkaline medium should be protected, air and light. Ascorbic Acid at concentrations greater than 100 mg/ml may undergo decomposition and the production of carbon dioxide. Due to the increased pressure may develop after prolonged storage, carefully open the ampoule containing Ascorbic Acid injection.

2014年3月3日星期一

The application of Vanadate

Vanadate is a general term for the pentavalent Vanadium oxy acid salts. It is similar to the situation of phosphate. Vanadate from solution crystallization, Vanadate ions sometimes has a structure similar to the solution, sometimes also have some changes, such as partial Vanadate VO in solution to form V3O ion triangle. In the anhydrous potassium Vanadate is formed by VO4 tetrahedra is an infinite chain structure unit. When there are other ions in solution, such as oxygen radical containing silicon, phosphorus, arsenic, tin, molybdenum, tungsten, vanadium ion VO can also become the corresponding heteropoly acid and their condensation. As with the Vanadium Pentoxide, vanadium acid salt can also be used as catalyst for oxidation reaction. Dissolved Vanadium Pentoxide in the concentrated solution of Sodium Hydroxide, Sodium Vanadate solution can be obtained which is colorless, Vanadium in Vanadate VO from. In aqueous solution,with the increase of the acidity of the solution, Vanadate in different degree of condensation and the formation of multi anion different.
Vanadate can be used as a chemical reagent and catalysts, mordant as well as manufacture of Vanadium Pentoxide or vanadium, iron and other raw materials. Vanadate pigments not only color and decoration, with increased strength, corrosion-resistant coating, light, weather and other special properties, such as temperature indicating paint to indicate that the surface temperature.
The development and application of vanadium bismuth yellow pigment in foreign countries is quite active, attract people's attention. Using Ammonium Vanadate pigment in black leather and ink dye, durable and non corrosive nib. In order to YVO4 europium activated for imaging, color TV tube.
Vanadate also has some applications in glass and ceramic industrial, such as:

Vanadate can be made of a variety of colored glass, with semiconductor properties of glass, utraviolet radiation absorbing glass, porcelain like coating color enamel and so on. Vanadate also developed for photosensitive agent and colorant, in photography and film industry.

2014年1月25日星期六

What is Polyvinyl Alcohol Resin?

Polyvinyl Alcohol Resin products is white solid, the appearance can be divided into three kinds: flocculent, granular and powder. PVA Resin is non-toxic, tasteless, non-polluting, and can be dissolve in water at the temperature of 80 to 90 . The aqueous solution of Polyvinyl Alcohol Resin has good adhesion and film forming properties, it has resistant to oil, lubricants and most organic solvents such as hydrocarbons. Polyvinyl Alcohol PVA has the properties of long-chain polyol esters, ethers, acetals and other chemical properties.
At the same time of preparation of aqueous solutions, this product is not bubbling, but in high concentration, speed faster and also produce small amounts of foam in order to contain the bubble, we should add defoamer: 0.01-0.05% (PVA as a benchmark) octanol, phosphoric acid tributyl ester or 0.2-0.5% (PVA as a benchmark) silicone emulsion.
Anti-corrosion: If the Polyvinyl AlcoholResin has been long-term storage, the water in aqueous solution will have a corruption, but it does not affect the performance of this product. At this point, we should add 0.01-0.05% (PVA as a benchmark) of formaldehyde, salicylic acid or other preservatives.
Rust prevention: Storage in tools, you should add traces of weak bases, should be added when meat is used 0.02-0.05% (PVA as a benchmark) of sodium nitrite, the best use of stainless steel, plastic containers.
And the Polyvinyl Alcohol Resin should be stored in ventilated, cool and dry place, away from sources of ignition. And should handle with care during transport, and prevent damage to the packaging.

Polyvinyl acetate emulsion (PVAC) is mainly based on vinyl acetate monomer, polymer, commonly known as the white LaTeX. The latex-free environment, the price is cheap, easy to use, are porous materials such as wood, paper, fiber adhesive ideal for. It is widely used in printing, bonding, wood construction, leather, tobacco processing, paper processing, fiber composite, aluminum foil paper, Emery cloth, sand paper adhesive industry, can also be used for insulating plates for interior wall paint, steel processing and so on.

2014年1月15日星期三

The Characteristics of PVC Resin.


PVC Resin is one of the most important organic synthetic materials. The full name of it is Polyvinyl Chloride Resin. This product has good physical properties and chemical properties, and is widely used in industrial, construction, agriculture, daily life, package, electric power and public utilities and many other fields.
The physical appearance of PVC Resin is white powder, non-toxic and odorless. The relative density of it is 1.35 to 1.46, the refractive index of it is 1.544 (20 ). PVC Resin is insoluble in water, gasoline, alcohol and vinyl chloride, but it can be soluble in acetone, ethylene dichloride, xylene solvent and so on. PVC Resin has high chemical stability and good plasticity.
Except for a few organic solvent, it can resistant to any concentration of hydrochloric acid, concentration below 90 % of nitric acid, concentration about 50 % to 60 % of sulfuric acid and concentration below 20 % caustic soda at the room temperature. In addition to these, it is fairly stable for the salt. PVC and burns on the flame and release HCl, but leave the flame self-extinguishing, is a kind of self-extinguishing and fire products. PVC start to break down and slowly release HCl when the temperature is above 100 . As the temperature rises, the speed of decomposition and release HCl rising, the PVC color start to change.
PVC is made by free radical polymerization of vinyl chloride synthesis. By suspension polymerization and emulsion polymerization method and polymerization method, dominated by suspension polymerization, accounted for about 80% of PVC production. PVC production in the industry based on vinyl chloride monomer acquisition method to distinguish, can be divided into calcium carbide method, ethylene method, imports (EDC and VCM) simplex method.
According to the different methods of production, PVC pure powder can be divided into general purpose PVC Resin, high degree of polymerization PVC Resin, crosslinked PVC Resin. General purpose PVC Resin is made of vinyl chloride monomer in the initiator role of aggregation formation. High degree of polymerization of PVC Resin is in the vinyl chloride monomer polymerization system include chain growth agent in polymer made of resin. Crosslinked PVC Resin is added in the vinyl chloride monomer polymerization system containing diene and polyene resins, crosslinking agent aggregation. 

2013年12月30日星期一

What is copper corrosion inhibitor?


Copper corrosion inhibitor can be adsorbed to form a thin film on the surface of metal, copper and other metals from corrosion protection of the atmosphere and harmful medium. Copper corrosioninhibitor BTA in circulating cooling water system with a variety of scale inhibitor, biocide used in conjunction, circulating cooling water system of good corrosion inhibition. It also can be used as anti tarnish agent, coolant, lubricant additive copper silver.
Generally, there are two kinds of copper corrosion inhibitors: one is Benzotriazole (BTA), the other is Tolyltriazole(TTA).
In China, there are four shape of Benzotriazole: granular, flake, needle and powdery. And in foreign, most are particles and flakes. United States production Benzotriazole is mostly granular. However, granular, hard to dissolve, triazole-need p-parallel domestic manufacturers often need to use solvent after the dissolution of placed inside the product. In recent years, more and more manufacturers use Germany producing Benzotriazole, Germany p-triazole-parallel export in accordance with EU REACH and needles, water and oil soluble. Either directly can also be dissolved in the solvent dissolve in water, and very easy to use. Benzotriazole can be used as rust preventive oil (grease) products, copper and its alloys, silver and copper alloy corrosion effect is particularly evident, usually used in vapor corrosion inhibitor for copper and copper alloys, circulating water treatment chemicals, automobile antifreeze, photographic antifogging agent, macromolecule stabilizer, plant growth regulator, lubricating oil additives. And Benzotriazole can also be used as chrome fog contain agents for chromium plating industry, prevent chrome fog and damage. It can increase the brightness of coated parts.
The abbreviation of Tolyltriazole is TTA. The chemical formula of it is C7H7N3. And the molecular weight of it is 133.15. It is of white granular or powder, can be processed into a large form, small particles,-like, fine particle-like, powder.
Tolyltriazole is mainly used for metals (such as silver, copper, lead, nickel, zinc, etc) and inhibition agent of antirust, widely used in antirust oil (grease) product, usually used in vapor corrosion inhibitor for copper and copper alloys, lubricant additive, water treatment agents, automobile antifreeze. This product is also available with a variety of scale inhibitor, algicide sterilization is used especially for closed-loop cooling system corrosion inhibitor effectiveness well.

2013年12月25日星期三

Oxygen supply system of Vanadium extraction technology of BOF blowing


Oxygen consumption:
Refers to the 1t oxygen blowing into molten iron containing vanadium for semi steel oxygen consumption, the unit is m3/t. According to the general basis: hot metal composition, different blowing mode supply intensity and stirring. Converter re-vanadium oxygen consumption of per ton iron is within 14 to 18m3, 16000 to 18000m3/h.
The intensity of oxygen supply:
The intensity of oxygen supply of oxygen consumption per ton of metal refers, in unit time unit is m3/ (t.min).
The oxidation reaction of v-extraction process affects the intensity of oxygen supply intensity, big splash seriously, over an hour slow reaction, converting time is long, will cause the temperature of the molten pool increase, over temperature, leading to decarburization reaction dramatically accelerated, semi steel residue from the new increasing vanadium content.
General in the early oxygen can improve oxygen supply intensity, decreased at the later stage.
Oxygen pressure and the gun position
Oxygen pressure: under the same oxygen supply conditions, oxygen pressure can strengthen the bath stirring strengthen dynamics conditions for vanadium and other elements of the oxidation rate. Oxygen pressure control is more suitable in the range of 0.7 to 0.8MPa.
Gun: gun position refers to the oxygen lance nozzle end from the pool surface height. Such as vanadium Russia Nizhny tagil 160t oxygen top blown converter, blowing lance height control in early 2.0m to late lance position is reduced to 1m. When the silicon content in molten iron is higher, the gun position remained lower limit.
In general, the primary product of vanadium is a by-product in with other metals and oil extraction or use to produce (V2O3or V2O5). In iron ore by smelting vanadium is dissolved into molten iron, molten iron by oxidation, slag (10% to 25% V2O5), and then through the processing production of calcination / leaching process for vanadate or vanadium oxide of the final product. In the roasting / reached 1.8% on the V2O5 content in leaching process of mineral processing production of vanadate or vanadium oxide directly. Power plant fly ash recycling, waste catalyst and other residue contain vanadium. The process is the roasting / leaching process generates vanadate or vanadium oxide.