Let’s know more about polyvinyl alcohol (CAS 9002-89-5)
Main uses of polyvinyl alcohol
The CAS No. of polyvinyl alcohol is 9002-89-5, PVA is its abbreviation. Polyvinyl alcohol is mainly used in manufacturing of polyvinyl acetal, gasoline resistant pipeline, vinylon synthetic fiber, fabric treatment agent, emulsifier, paper coating, adhesive and etc.
A water-soluble polyvinyl alcohol fiber and the preparation method, it is characterized by adding 100 parts of polyvinyl (the polymerization degree is 500-2000 and the hydrolysis degree is 75-99 mol%.) and 200-400 parts of mixed solvent (dimethyl sulfoxide: water=90-70: 10-30) into the stainless steel dissolving kettle. Under 80-120 °C temperature and -0.01-0.08 MPa pressure, dissolving for 3-4 hours in a stirring, the paired spinning solution is filtered, defoamed, wet-dry spun and post-treated to obtain water-soluble polyvinyl alcohol fiber. The fiber water solubility temperature is 10-90 ℃, the intensity≥3.5 cN/dtex, a single fiber fineness is 1.5-10 dtex, an elongation at break is 15%-30%. Its filaments are processed into tops and blended with wool, sliver, hemp and chemical fibers to form high counts or hollow yarns, or cut into short fibers for a variety of uses in non-woven fabrics, embroidery backings and paper making.
Polyvinyl alcohol possess good natures as follows:
Soluble polyvinyl alcohol is dissolved in water, the higher the water temperature and the greater the solubility, but almost insoluble in organic solvents. Polyvinyl alcohol solubility varies with degree of alcoholysis and degree of polymerization. Partial alcoholysis and low degree of polymerization of PVA dissolve extremely fast, and complete alcoholysis and high degree of polymerization PVA dissolves slowly. In general, the degree of alcoholysis has greater effect on the solubility of PVA than the degree of polymerization. Polyvinyl alcohol dissolution process is carried out in stages, namely: affinity wetting-swelling-infinite swelling-dissolution.
- Film-forming. Polyvinyl alcohol is easy to film, the mechanical properties of the film is excellent. With the degree of polymerization and the degree of alcoholysis increased, tensile strength of the film is stronger.
- Adhesion. Polyvinyl alcohol and hydrophilic cellulose have good adhesion. In general, the higher the degree of alcoholysis and the degree of polymerization, the stronger the bond strength.
- Thermal stability. When polyvinyl alcohol powder is heated to about 100 ℃, the appearance of the powder changes gradually. The partially alcoholized PVA begins to melt at around 190 °C and decomposes at 200 °C. The completely alcoholized PVA begins to melt at around 230 °C and decomposes at 240 °C. Thermal cracking experiments show that the lower the degree of polymerization, the faster the weight decrease; the higher the degree of alcoholysis, the shorter the decomposition time.
Medical polyvinyl alcohol has PVA05-88, PVAl7-88, PVA-124 and other specifications, the alcoholysis degree of the first two specifications both are (88 ± 2) (mol)%, the average degree of polymerization (n) is 500-600 and 1700-1800, respectively. PVA-124 alcoholysis degree is 98-99(mol)%, the average degree of polymerization (n) is 2400-2500.
The development of new pharmaceutical excipients and the promotion of dosage form optimization are one of the strategic tasks for developing Chinese traditional medicine in line with international standards. Polyvinyl alcohol (CAS 9002-89-5) has the advantages of convenient synthesis, safe and low toxicity, easy product quality control, low price and convenient use. Therefore, PVA is an excellent pharmaceutical excipient that has the potential to be re-developed.
Market analysis and suppliers of polyvinyl alcohol
After more than 40 years of development, China has become the largest producer of polyvinyl alcohol in the world, possessing such technical routes as petroleum ethylene method, natural gas acetylene method and calcium carbide acetylene method. Anyang General Chemical Co., Ltd. is a PVA supplier from China, we provide high quality polyvinyl alcohol (CAS 9002-89-5). Contact us to get price now!