致孔剂对聚乳酸多孔凝胶性能的影响

Influence of Porogen on the Performance of Porous Poly(lactic acid)Gel

以不同相对分子质量(M_w=1.0×10~5,2.0×10~5,3.0×10~5)的外消旋聚乳酸(PDLLA)为原料,三氯甲烷作溶剂,分别在去离子水和氯化钠作致孔剂条件下制备多孔凝胶。重点考察了致孔剂对多孔凝胶的力学性能影响。结果表明,用水作致孔剂的多孔凝胶(P_W),相比于用氯化钠作致孔剂的多孔凝胶(P_S),其压缩模量平均增加57%,拉伸强度提高60%,断裂伸长率增加5倍,柔韧性提高。并且,P_W表现出亲水性能。此外,通过溶剂置换法测定出相应孔隙率,P_S孔隙率为80%左右,P_W为40%左右。

Porous poly （lactic acid） （PDLLA） gel was prepared with different molecular weight （Mw=100000, 200000, 300000） of poly lactic acid which was used as raw material dissolved in chloroform under the condition of water or sodium chloride. The mechanical properties of porous gel were studied as important parts in the experiments. Results show that, compared with the porous gel with sodium chloride （Ps）, the compression modulus of porous gel with deionized water （Pw） increases by 57%, the tensile strength is improved by 60% on average and the elongation at break increases by about 5 times which means the improvement of toughness. The porous gel （Pw） performs hydrophilic properties. Additionally, the solvent displacement method was used to determine the corresponding porosity. The porosity of porous gel （Ps） is about 80% as well as porous gel （Pw） which is approximately 40%.