前端聚合制备多孔聚丙烯酰胺水凝胶--溶剂和引发剂对反应和产物的影响

FRONTAL POLYMERIZATION OF ACRYLAMIDE FOR PREPARING POROUS POLYACRYLAMIDE HYDROGEL——EFFECTS OF INITIATOR AND SOLVENT ON PROPAGATION AND PRODUCTS

利用前端聚合结合发泡工艺制备了孔结构可调控的聚丙烯酰胺多孔水凝胶.研究发现溶剂和引发剂浓度变化对聚合前端的移动及形成的产物性能有重要影响.增加溶剂用量,聚合前端的移动速度和聚合前端最高温度下降,产物孔径增大,孔壁变厚,材料吸水溶胀性能降低;增加引发剂浓度,聚合前端移动速度显著加快,最高温度升高,产物的孔体积和溶胀率先增加后减小.

Porous polyacrylamide （PAM） hydrogels with tuned pore size were prepared by frontal polymerization （FP） combined with foaming process. Studies were conducted to investigate the effect of initiator concentration and reactant diluents on the most relevant parameters of FP and the performances of the final products. A dilution of the reactants resulted in an obvious decrease of the front velocity as well as the maximum temperature of front. The pore diameters and the wall thicknesses showed an uptrend when the water content increased, and the swelling properties of the final products reduced. A significant enhancement of the propagation velocity was noticed with increasing of initiator concentration. The size of pore and swelling degree were characterized by a constant increase when APS concentration increased,and then, a large decrease was noticed. At an initiator/monomer mass ratio of 0.022, the maximum pore volume was obtained.