温度敏感性P(NtBA-co-AAm)聚合物和水凝胶的合成及表征

Synthesis and Characterization of Poly( N-Tert-Butylacrylamide-co-Acrylamide)Linear Copolymer and Hydrogels

以N-叔丁基丙烯酰胺(Nt BA)和丙烯酰胺(AAm)为反应单体,过硫酸铵(APS)为引发剂,在50℃时通过自由基聚合反应合成了具有温度敏感性的聚(N-叔丁基聚丙烯酰胺-co-丙烯酰胺)(P(Nt BA-co-AAm))线型聚合物及水凝胶。为提高凝胶的溶胀性能,以硅胶微粒和聚乙二醇400(PEG400)为造孔剂,合成了一系列大孔P(Nt BA-co-AAm)水凝胶。用差热分析仪分析了P(Nt BA-co-AAm)共聚物的热力学性能,通过红外光谱、扫描电镜表征了P(Nt BA-co-AAm)凝胶的结构。研究了进料中单体配比和交联剂用量对水凝胶溶胀性能的影响以及不同温度下水凝胶的溶胀动力学。结果表明,进料中Nt BA与AAm的摩尔比越高,共聚物及水凝胶的相转变温度越低;增加交联剂的用量,水凝胶的溶胀率降低;大孔凝胶的溶胀率和去溶胀率较传统凝胶有较大提高,同时对外界温度变化的响应更迅速。

Temperature-sensitive poly( N-tert-butylacrylamide-co-acrylamide) [P( NTBA-co-AAm) ]linear copolymer and hydrogels were prepared by radical polymerization with N-tert-butylacrylamide( NTBA) and acrylamide( AAm)as comonomer,ammonium persulfate( APS) and N',N-methylenebisacrylamide( MBA) as initiator and crosslinking agent respectively. In order to improve the swelling properties of hydrogels,a series of macroporous hydrogels were synthesized using silica particles and PEG400 as pore-forming agent. The thermal properties of P( NTBA-co-AAm) linear copolymers were evaluated by utilizing differential scanning calorimeter( DSC). The structures of hydrogels were characterized by FT-IR. The surface and interior morphologies were observed by SEM. The influences of n( Nt BA) / n( AAm),the amount of MBA and reaction temperature on the swelling properties of hydrogels were also studied. From the results of the experiments,it is found that an increase of n( Nt BA) / n( AAm) in feed cause decrease of transition temperature of linear copolymers and hydrogels; the swelling ratios of hydrogels decreases with increase of the MBA concentration; the macroporous P( NTBA-co-AAm) hydrogels exhibit faster response rate to temperature changes and higher swelling-deswelling properties compared with traditional hydrogels.