Polymer blends with polyfvinyl chloride

The broadening of the dielectric spectra for miscible polymer blends is not only observed for the PS/PVME system. This further demonstrated by Fig. 12.16 where the normalized dielectric loss is plotted for a blend poly(ethylene-co-vinyl acetate) (EVA70, 70 % vinyl acetate) with polyfvinyl chloride) (PVC). With increasing concentration of PVC in the blend, the loss peak systematically broadens in comparison to that of both components (Rellick and Runt 1988). 

Modulus-temperature behavior of amorphous polymers is also affected by admixture with plasticizers. These are the soluble diluents described briefly in Section 12.3.2. As shown in Fig. 11-11, the incorporation of a plasticizer reduces Tg and makes the polymer more flexible at any temperature above Tg. In polyfvinyl chloride), for example, T can be lowered from about 85°C for unplaslicized material to —30°C for blends of the polymer with 50 wt % of dioctyl phthalate plasticizer. A very wide range of mechanical properties can be achieved with this one polymer by variations in the type and concentration of plasticizers. 

TG-DTA-MS has obvious synthetic polymer applications. TA-MS has been appHed to study the thermal behavior of homopolymers, copolymers, polymeric blends, composites, residual monomers, solvents, additives, and toxic degradation products. In the latter context, FICl evolution from heated polyfvinyl chloride) materials is readily quantified by TA-MS and such data are of major significance in the design of fire-resistant polymeric materials. Pyrotechnic materials have been studied by TA-MS. A complex sequence of thermal events relates to the decomposition of these materials involving interactions between the nitrocellulose, perchlorate, and metal components with periodic release of carbon dioxide and oxygen. Only by EGA is it possible to rationalize the thermal behavior of such materials. TA-FTIR has also been applied extensively to study the thermal characteristics of synthetic polymers... 

C.M. Nunez, A.L. Andrady, R.K. Guo, J.N. Baskir, and D.R. Morgan, Mechanical Properties of Blends of PAMAM Dendrimers with Poly( vinyl chloride) and Polyfvinyl acetate), J. Polymer ScL, Part A - Polym. Chem., 36,2111-2117 (1998). 

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