The Usage of Polyvinyl Alcohol(PVA)

The Usage of Polyvinyl Alcohol(PVA)

Firstly, let’s introduce the physical and chemical properties of polyvinyl alcohol. Polyvinyl alcohol, also known as PVA, is a water-soluble organic compound, white or cream-colored solid. According to Chemsource.com, its chemical structural formula is [C2H4O]n, and its relative molecular weight is 44.053. Soluble in water, slightly soluble in dimethyl sulfoxide, insoluble in various organic solvents such as gasoline, petroleum ether, vegetable oil, benzene, toluene, dichloroethane, ethylene glycol, carbon tetrachloride, acetone, ethyl acetate, methanol, etc.

Secondly, polyvinyl alcohol is widely used. Currently, as a chemical raw material, it can be used to manufacture polyvinyl acetal, gasoline-resistant pipes and vinylon, paper coatings, fabric treatment agents, adhesives, emulsifiers, glues, etc. According to a 2019 study, it was found that the polyvinyl alcohol contained in the glue can be used in the culture medium of hematopoietic stem cells, allowing the hematopoietic stem cells from experimental mice to proliferate hundreds of times, thereby greatly reducing the cost of hematopoietic stem cell culture, which can help treat diseases such as leukemia.

Finally, the main industrial uses of polyvinyl alcohol are:

1. Construction adhesives: Adhesives for building groups made of polyvinyl alcohol include putty adhesives, paint adhesive base materials, etc., and their scale accounts for more than 40% of the total. Currently the most widely used are PVA 17-99, PVA 20-99, these two medium-viscosity adhesives, and PVA 24-99, PVA 26-99, these two high-viscosity adhesives. In addition to construction glue, polyvinyl alcohol can also be used as an adhesive for paper, wood, textiles, office glue and high-grade paint bases, mainly used as bases in paper, wood, textiles, office glues and high-grade paint. These glues have relatively high technical content and require a high level of compounding.

2. Textile size and fiber: adhesives made of polyvinyl alcohol has very good adhesion and film-forming properties, and is cheap and high-quality. It is mainly used for pulping pure polyester or polyester-cotton yarn, and sometimes it is also used for pulping together with acrylic size. Polyvinyl alcohol is the main raw material of vinylon fiber, which is used to make short fiber, long fiber, medium-strength medium-mode, high-strength high-modulus, water-soluble fiber and other varieties. Among them, high-strength and high-modulus vinylon fiber is considered to be a "green and environmentally friendly" high-tech material.

3. Polyvinyl butyral (PVB): Polyvinyl alcohol can also be used to make PVB films. High-end PVB films can be used not only to make windshields for cars, but also for bulletproof glass in military industries. With the rapid development of green energy, PVB films have also begun to be widely used in the photovoltaic industry.

4. Papermaking: In order to improve the wear resistance, tear resistance and folding resistance of paper, paper surface sizing agents, pigment binders and beater additives made of polyvinyl alcohol are widely used in the paper industry.

5. Biodegradable PVA film: The film-forming property, biodegradation and water degradation of polyvinyl alcohol make it the darling of new packaging products. Its industrial research and development is gradually expanding and deepening.