羟丙基纤维素RAFT聚合温敏性聚（N异丙基丙烯酰胺）水凝胶的合成及表征

Synthesis and Characterization of Hydroxypropyl Cellulose Grafted Thermosensitive Poly(N-Isopropylacrylamide) Hydrogel by Raft Polymerization

摘要:

以羟丙基纤维素（HPC）接枝的大分子RAFT试剂作链转移剂，用RAFT聚合制备了HPC大分子接枝聚（N-异丙基丙烯酰胺）（PNIPAM）水凝胶，研究了HPC分子量、RAFT分子接枝密度以及HPC和NIPAM用量比对水凝胶微观形貌、低临界溶解温度（LCST）以及溶胀性能的影响。结果表明，RAFT聚合使凝胶层壁变薄，一定量HPC组分的引入使水凝胶具有褶皱、通孔和网状超孔结构，能提高水凝胶的溶胀性能和去溶胀性能；同时不影响水凝胶的LCST和敏感度，HPC分子的刚性还能提高水凝胶的力学强度，弥补梳状接枝PNIPAM水凝胶强度低的缺点，具有较好的应用前景。

Abstract:

Hydroxypropyl cellulose(HPC) with RAFT agents were used to synthesize a grafted poly(N-isopropylacrylamide) (PNIPAM) hydrogel via reversible addition-fragmentation chain transfer (RAFT) polymerization. The influences of HPC molecular weight, density of RAFT molecule on the HPC chain and the component ratio of HPC over NIPAM, to the properties of hydrogels were investigated. It was found that the hydrogels from RAFT polymerization show the fold, thin wall, porous and super-porous net structure, which led to the improved swelling and deswelling properties; Meanwhile HPC didn’t show the influence on the lower critical solution temperature (LCST) and the sensitivity but improved the hydrogels’ mechanical property by the rigidity of HPC molecule compare to the comb grafted PNIPAM hydrogels and conventional hydrogels, and made an attractive future in applications.