Preparation of PMAM-B-PNVP and its Hydrolysate by RAFT Polymerization: Structure Characterization and its CO_2 Permeation Performance

摘要

Macromolecules chain transfer agents (MCTA) were synthesized through the reversible addition fragmentation chain transfer polymerization (RAFT) by using S-l-Dodecyl-S'-(α,α'-dimethyl-α-acetic acid) trithiocarbonate(MTTCD), S,S'-bis (2-hydroxyethyl-2'-dimethylacrylate) trihiocarbonate (BDATC), 2-cyanoprop-2-yl dithiobenzoate (CPDB) as the chain transfer agents, methacrylamide (MAM) as the first polymerization monomer. The results showed that the structures of the end-group of dithiocarbamates had significant effects on the activity of dithiocarbamates for the polymerization of PMAM. The derived block copolymer (PMAM-b-PNVP) was prepared by using the above mentioned polymer as macromolecular RAFT agent and NVP as the second polymerization monomer. N-vinyl-γ-sodium aminobutyrate-sodium methacrylate copolymer (VSA-MSA) containing -NH_2 and -COOH as the CO_2 facilitated carrier, a kind of new fixed carrier membrane material for CO_2 separation, was synthesized by hydrolysis of the resulted PMAM-b-PNVP. The chemical composition and structure of PMAM-CTA, PMAM-b-PNVP, MSA-VSA were analyzed by FTIR, ~1HNMR and DSC, the molecular weight and polydispersity index were analyzed by GPC. The Relative molecular mass of polymer was controllable. The polydispersity index (1.2~1.3) of the obtained polymer was narrow via using MTTCD and BDATC. The VSA-MSA/PS composite membranes were prepared. The CO_2 and N_2 permeation performance were tested at different pressure. The results showed that the resulted composited membrane had a CO_2 permeation rate of 1.2×10~(-4) cm~3 (STP) cm~(-2)s~(-1)cmHg~(-1) and a N_2 permeation rate of 8.57×10~(-7) cm~3 (STP) cm~(-2)s~(-1)cmHg~(-1) and an ideal CO_2/ N_2 selectivity of 140.02 at a feed gas pressure of 7.6 cmHg and 30 ?C.