PCL／MDI／DEG体系聚氨酯水凝胶的制备及其亲水性能

Preparation and hydrophilicity of polyurethane hydrogel based on PCL/MDI/DEG

以聚己内酯(PCL)和二苯基甲烷二异氰酸酯(MDI)等为主要原料,分别采用二甘醇(DEG)、(2,2-二羟甲基丙酸(DMPA)、N-甲基二乙醇胺(MDEA)作为扩链剂合成聚氨酯预聚体,然后加入交联剂过氧化苯甲酰(BPO)进行自由基聚合,制备PCL/MDI/DEG新型聚氨酯水凝胶。研究扩链剂种类以及扩链剂DEG用量对聚氨酯水凝胶接触角、溶胀度、形貌等的影响,并研究扩链剂对聚氨酯水凝胶载氯霉素性能的影响。结果表明,以DEG为扩链剂制备的聚氨酯水凝胶亲水性最差,材料表面孔隙较少,氯霉素载药量最小,但前期药物释放速率比其它2种扩链剂制备的水凝胶更快。而以带有羧基的DMPA和带有叔氨基官能团的MDEA为扩链剂制备的聚氨酯水凝胶,亲水性较强,表面具有微孔结构,氯霉素载药量较大。随扩链剂DEG用量增加,聚氨酯水凝胶的溶胀度增大,接触角逐渐减小,表面形貌无明显变化。

A series of polyurethane （PU） prepolymers based on diphenyl-methane-diisocyanate （MDI） and polycaprolactam （PCL） were synthesized using diethylene glycol （DEG）, dimethylolpropionic acid （DMPA） and methyldiethanolamine （MDEA）, respectively, as the chain-extender, then the polyurethane hydrogels were obtained from the prepolymers using benzoyl peroxide （BPO） as crosslinking agent by free radical polymerization synthesis. The influences of the kind and the amount of chain-extender on the contact angle, swelling ratio and morphology of polyurethane hydrogel were investigated, and the influence of the kind of chain-extender on the release of chloromycetin in polyurethane hydrogel were also studied. The results show that the polyurethane hydrogel, using DEG as chain-extender, is preferably hydrophobic with no micropore on its surface, and the loading efficiency of cbloromycetin is the lowest; However, the release speed of chloromycetin is quicker than the hydrogel prepared by DMPA and MDEA. The polyurethane hydrogel, using DMPA and MDEA as chain-extenders, has higher hydrophilicity and micropouous structure on their surfaces due to their functional groups, and the loading efficiencies of chloromycetin are higher. The swelling ratio of PCL/MDI/DEG hydrogel increases and the contact angle decreases with increasing amount of DEG; however, the surface morphology has no obvious change.