Synthesis and Properties of Two Kinds of CPVC Carboxylated Ionic Copolymers

In the present work, two kinds of CPVC carboxylated ionic copolymers were prepared by a new method. First, a graft copolymer (CPVC-cg-AA) comprising of polyacrylic acid (PAA) as branched chains and chlorinated polyvinyl chloride (CPVC) as backbone was synthesized by in-situ chlorinating graft copolymerization (ISCGC). Second, the acid groups of the graft copolymer were neutralized by sodium hydroxide and aluminium hydroxide, respectively in order to prepare carboxylated ionic copolymers. The carboxylated ionic copolymers have been studied by FTIR, 1H NMR, DSC, and DMA techniques and also their mechanical and swelling properties were determined. The results have confirmed the existence of the ionic copolymers by the characteristic peak at 1620 cm-1 in FTIR spectra and changes in chemical shift in 1H NMR. Compared with Al ionic copolymer, Na ionic copolymer has higher glass transition temperature (Tg) through DSC, DMA tests and it has shown better mechanical properties. Na ionic copolymer can be solved in tetrahydrofuran (THF) while Al ionic copolymer only swells in THF