Vinyl alcohol polymer

Poly(vinyl alcohol) (PVA), a polyhydroxy polymer, is the largest-volume synthetic, water-soluble resin produced in the world. It is commercially manufactured by the hydrolysis of poly(vinyl acetate), because monomeric vinyl alcohol cannot be obtained in quantities and purity that makes polymerization to poly (vinyl alcohol) feasible (1—3). 

Poly(vinyl alcohol) [9002-89-5] was discovered through the addition of alkali to a dear alcoholic solution of poly (vinyl acetate), which resulted in the ivory-colored poly (vinyl alcohol) (4). The same discovery has been made by studying the reversible transformation between poly (vinyl alcohol) and poly(vinyl acetate) via esterification and saponification (5). The first scientific reports on poly (vinyl alcohol) were published in 1927 (6,7). 

The excellent chemical resistance and physical properties of PVA resins have resulted in broad industrial use. The polymer is an excellent adhesive and possesses solvent-, oil-, and grease-resistant properties matched by few other polymers. Poly(vinyl alcohol) films exhibit high tensile strength, abrasion resistance, and oxygen barrier properties which, under dry conditions, are superior to those of any other known polymer. The polymer s low surface tension provides for excellent emulsification and protective colloid properties. 

The physical properties of poly(vinyl alcohol) are highly correlated with the method of preparation. The final properties are affected hy the polymerization conditions of the parent poly(vinyl acetate), the hydrolysis conditions, drying, and grinding. Further, the term poly(vinyl alcohol) refers to an array of products that can be considered copolymers of vinyl acetate and vinyl alcohol. 

Increased flexibility Increased water sensitivity Increased ease of solvation 

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PVA resins as piNYL POLYMERS - VINYL ALCOHOL POLYMERS] pol 24)... 

Vinal fibers, or poly(vinyl alcohol) fibers, are not made in the United States, but the fiber is produced commercially in Japan, Korea, and China where the generic name vinylon is used. These materials are the subject of this article (see also Vinyl polymers, vinyl alcohol polymers). 

Functional derivatives of polyethylene, particularly poly(vinyl alcohol) and poly(acryLic acid) and derivatives, have received attention because of their water-solubility and disposal iato the aqueous environment. Poly(vinyl alcohol) is used ia a wide variety of appHcations, including textiles, paper, plastic films, etc, and poly(acryLic acid) is widely used ia detergents as a builder, a super-absorbent for diapers and feminine hygiene products, for water treatment, ia thickeners, as pigment dispersant, etc (see Vinyl polymers, vinyl alcohol polymers). 

Poly(vinyl alcohol) used to manufacture the poly(vinyl acetal)s is made from poly(vinyl acetate) homopolymer (see Vinyl polymers, vinyl alcohol polymers Vinyl POLYMERS, vinyl acetate polymers). Hydrolysis of poly(vinyl acetate) homopolymer produces a polyol with predominandy 1,3-glycol units. The polyol also contains up to 2 wt % 1,2-glycol units that come from head-to-head bonding during the polymeri2ation of vinyl acetate monomer. Poly(vinyl acetate) hydrolysis is seldom complete, and for some appHcations, not desired. For example, commercial PVF resins may contain up to 13 wt % unhydroly2ed poly(vinyl acetate). Residual vinyl acetate units on the polymer help improve resin solubiHty and processibiHty (15). On the other hand, the poly(vinyl alcohol) preferred for commercial PVB resins has less than 3 wt % residual poly(vinyl acetate) units on the polymer chain. 

Poly(vinyl alcohol) Polymer derived from the hydrolysis of polyvinyl esters. 

A flow injection optical fibre biosensor for choline was also developed55. Choline oxidase (ChOX) was immobilized by physical entrapment in a photo-cross-linkable poly(vinyl alcohol) polymer (PVA-SbQ) after adsorption on weak anion-exchanger beads (DEAE-Sepharose). In this way, the sensing layer was directly created at the surface of the working glassy carbon electrode. The optimization of the reaction conditions and of the physicochemical parameters influencing the FIA biosensor response allows the measurement of choline concentration with a detection limit of 10 pmol. The DEAE-based system also exhibited a good operational stability since 160 repeated measurements of 3 nmol of choline could be performed with a variation coefficient of 4.5%. 

TABLE III. A STUDY OF THE SPECIFIC VISCOSITY OF SOME MODIFIED POLY(VINYL ALCOHOL) POLYMERS IN DMSO SOLUTION AT 30°C ... 

Figure 3.19 Theophylline in blood serum on vinyl alcohol polymer column. Conditions column, Asahipak GS320 (vinyl alcohol copolymer gel), 50 cm x 7.6 mm i.d. eluent, 0.01 M sodium acetate buffer pH 4.0 in 10% aqueous acetonitrile flow rate, 2 ml min-1 detection, UV 280 nm. Peaks 1, protein 2, low Mr impurity and 3, theophylline.

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