THE EFFECT OF CHEMICAL STRUCTURE OF VINYL CHLORIDE BASED POLYMERS ON ITS THE COMPATIBILITY WITH POLYURETHANEUREA ELASTOMER

Abstract

The effect of the chemical structure of vinyl chloride-based polymers, such as poly(vinyl chloride) (PVC), chlorinated PVC (cPVC), vinyl chloride/vinylidene chloride copolymer VCVD-40TM, vinyl chloride/vinyl acetate copolymer А-15TM on its compatibility with poly(ether-urethane)urea elastomer (PUU) was studied by DSC and FTIR spectroscopy. The segmented PUU was synthesized by prepolymer approach in N,N-dimethylformamide (DMF) solution using poly(propylene glycol) of number-averaged molecular weight (Mn) of 1000 Da, 2,4-tolylenediisocyanate and tolylene 2,4-diamine as a chain extender at a molar ratio of 1:2:1. PUU/vinyl chloride-based polymer blends was prepared by solution casting technique vie DMF solution. It was found a compatibility of PUU based blends containing 30 % PVC (PUU/30PVC blend) or cPVC (PUU/30cPVC) were initiated by strong hydrogen bonding. As a result, the blends are characterized by single wide relaxation transition. A glass transition temperature (Тс) of PUU/30PVC composite is similar to the theoretical one (ТFс), which is calculated using the Flory-Fox equation, whereas Тс value of PUU/30cPVC composite is higher than ТFс. Introducing polar vinyl acetate or vinylidene chloride fragments into vinyl chloride-based polymer macrochains suppresses the compatibility of components of the polymer blends and initiates the formation of a biphase microheterogeneous structure. The formation of intermolecular hydrogen bonding network at the interface in polymer-polymer blends is confirmed by FTIR spectroscopy. Comparative analysis of experimental and theoretically calculated (additive) tensile characteristics of polymer blends demonstrates their substantial dependence on interface interactions between the constituents. The highest strengthening effect was observed for cPVC or PVC-containing nanocomposites.