No additional plasticiser required. Poly(vinyl acetate), PVAc, with a degree of polymerisation Xn≈10 was produced by free radical chain transfer polymerisation with carbon tetrachloride and used as an oligomeric plasticiser for commercial PVAc. After H/Cl exchange at the chain ends, the product exhibits high thermal stability and excellent melt compounding properties. Blends of oligomeric and commercial PVAc show simple glass transition temperatures, which decrease with higher oligomer content, and exhibit small negative deviations from Fox’s linear additivity rule. This suggests that plasticisation and miscibility are mainly due to entropic effects. Injection moulded thick specimens show ductile behaviour at oligomer contents >10 wt%, while sheets with a thickness of 0.2-0.5 mm appear flexible already at 7.5 wt%. The oxygen permeability coefficients are an order of magnitude lower than those of low-density polyethylene. Due to the sum of their properties, the plasticised sheets represent a promising alternative for the production of barrier materials.
D. Heinze, T. Mang, K. Peter, M. Möller, O. Weichold
Synthesis of Low Molecular Weight Poly(vinyl acetate) and Its Application as Plasticizer
J. Appl. Polym. Sci. 2014, 40226. https://doi.org/10.1002/APP.40226
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