Synthesis of Multiblock Copolymers of Poly(2-vinylpyridine) and Polyoxyethylene and their Application as Compatibilizers for Epichlorohydrin Rubber/Poly(Vinyl Chloride) Blends

Multiblock copolymers of poly(2-vinylpyridine) (P2-VP) and polyoxyethylene (PEO) were synthesized by condensing telechelic dihydroxy poly(2-vinylpyridine) (THPVP) and PEO with dichloromethane in the presence of potassium hydroxide. The copolymers were purified by extraction with water and toluene successively and characterized by Fourier Transform Infrared Spectroscopy and nuclear magnetic resonance spectroscopy. The block copolymers behave as good compatibilizers for the blending of epichlorohydrin rubber (CHR) with poly(vinyl chloride) (PVC). The addition of approximately 2-3% block copolymer to the blends evidently improves their mechanical properties and causes the two glass transition temperatures (T_g) to become closer. The blends with a weight ratio PVC/CHR of 4/6 and the addition of 2-4% block copolymer show mechanical properties consistent with those of a thermoplastic elastomer.