Vinylchloride-vinylacetate copolyme

The polymers used were polyvinylchloride (Sicron 230, Montedison, Italy) vinylchloride/vinylacetate copolymer (Sicron 822, Montedison, Italy) polytetrafluoroethylene (Fluon, I C.I, U.K ) polyethylene (Montedison,Italy) acrylic polymer (Paraloid K 120 N, Rohm Haas, Italy) acrylic/methacrylic acid esters copolymer with 10 % of quaternary ammonium groups (Eudragit RL, Rohm Pharma, Germany) and with S % of these groups (Eudragit RS, Rohm Pharma, Germany) ... 

PPG Poly(propylene glycol) VC-VA Vinylchloride-vinylacetate copolymer... 

The intensities of bands associated with particular monomer components of the copolymer can be measured relative to one another and a calibration graph constructed or the absorptivity of the bands can be used or determined. In the case of vinylchloride-vinylacetate copolymer, a band near 4650 cm" ( 2.15 pm), which may be associated with the carbonyl group, can be used for determining the proportion of vinylacetate. The absorptivity should be determined first or, alternatively, a calibration graph composed. This band may be used for the determination of the compositions of other copolymers involving esters. 

Ethylene-vinylacetate blends with PVC have been widely used in Europe as permanent polymeric plasticizers for PVC. Low cost and good weatherability of these blends permitted their use in window profiles, cable jacketing and other outdoor applications. Ethylene vinylacetate copolymer with 65-75% vinyl acetate content is quite miscible with PVC exhibiting a single T for the blend [Hammer, 1971 Ranby, 1975 Rellick and Runt, 1985]. Two phases are apparent when the vinylacetate is < 45%. Vinylchloride grafted ethylene-vinyl acetate copolymers have also been used for blending with PVC. 

Co2(CO)s Copolymer vinylchloride-vinylacetate spirit (91 6 3) Benzene chloride 75% 7-47 55... 

During an investigation of the thermal degradation of poly(vinylchloride - vinylacetate) blends, McNeill (14) observed acetyl chloride in the degradation products. We investigated this aspect by FTIR-EGA and found that the amount of acetyl chloride in the effluent decreased with increased residence time in the hot zone. This suggested that acetyl chloride is a primary decomposition product, rather than a product of reaction between HCl and acetic acid from pyrolysis of the copolymer. McNeill s work was performed by thermal volatilisation analysis and did not provide on-the-fly identification of the pyrolysis products. 

In the same way, Matsushima et al. [44] prepared block copolymers from styrene, vinylacetate, vinylchloride and acrylic monomers with the following initiators ... 

The rates of production of volatile material from polyvinylacetate, polyvinylchloride and vinylacetate vinylchloride copolymers, covering the entire composition range, have been compared by thermal volatilization analysis. It has been found that, at both extremes of the composition range, incorporation of the comonomer unit induces de-stabilization. Minimum stability occurs for composition of approximately 40—50 mole % vinylacetate. The rate of volatilization as a function of the composition of the copolymers is given in Fig. 74. The results were confirmed by a study of the thermal degradation in tritolylphosphate solution. The stability of the copolymers is a minimum at 30—40 mole % vinylacetate. HC1 and acetic acid catalyse the degradation of the... 

The usual concentration of plasticizers is 20% to 40%, but some systems (plastisols) have 50% to 60% plastification. The diffusion of plasticizers impairs flexibility, making the polymer rigid and brittle. It is important to eliminate the use of toxic additives, which adversely affect the environment through contact with food stock or other polymers. For these reasons a liquid-phase plasticizer may be replaced by a solid-state plasticizer which is mainly based on a short-chain polymer (polyester or epoxy) or a long-branched one. The most ideal plastification may be achieved by an appropriate copolymerization. A typical example is a copolymer made from vinylchloride and vinylacetate, in which a low Tg monomer is inserted into the main chain. 

One way to overcome such problems is to consider solvent(l)/polymer(2)/ polymer(3) ternary systems any method that determines either AG or its derivatives should make it possible to calculate Xi3- Thus, for example, osmotic pressure measurements were used to characterize PS/PVME blends dissolved in either toluene or ethylbenzene (Shiomi et al. 1985). The Xi3 was found to depend on the blends composition. Elimination of the solvent effects gave X23/E1 = —10 (7.41 — 11.0103). Thus, the system was expected to remain miscible up to a PVME volume fraction of 03 = 0.67. Osmotic pressure has also been used to determine X23 = 0.070 for PS with poly(p-chloro styrene) in toluene, 2-butanone, and cumene (Ogawa et al. 1986). For the same system, X23 = 0.087 was calculated from intrinsic viscosity measurements. Thus, the system is thermodynamically immiscible. More recently, osmotic pressure measurements in cyclohexanone of a ternary system resulted in X23ipoly(vinylchloride-co-vinylacetate) blends with a series of acrylic copolymers (Sato et al. 1997). 

They observed that protonated emeraldine using these dopants has a good solubility in cresol, which is a excellent solvent for many classical polymers such as poly(methyl methacrylate). This methodology of using a dopant having a surfactant group led to the preparation of polyblends with following polymers. Nylon, polycarbonate, polystyrene, polysultone, poly(-vinylacetate) polypropylene, poly(vinylchloride), acrylonitrile butadiene-styrene copolymer (ABS) and poly methyl (methacrylate). 

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