硬段对聚酯型聚氨酯弹性体微相分离的影响

以聚己二酸-1,4-丁二醇酯二醇(PBA)、4,4′-二苯基甲烷二异氰酸酯(MDI)、乙二醇(EG)、1,4-丁二醇(BDO)和1,6-己二醇(HD)等为主要原料,采用预聚体法制备了一系列热塑性聚氨酯弹性体(TPU)。通过对TPU流变性能、结晶性能、硬度与力学性能的研究,考察了不同扩链剂及不同硬段含量对TPU体系内部微相分离的影响。结果表明,HD-TPU与BDO-TPU微相分离情况相当,均大于EGTPU,且HD-TPU具有较好的结晶性能、拉伸强度及断裂伸长率;随TPU体系硬段含量增加,硬度和拉伸强度增加,断裂伸长率减小,相分离发生越早越快,结晶熔融温度越高,但相分离程度并不高。

Effect of hard segment on microphase separation property of polyester-polyurethane elastomer

A series of polyurethane elastomers were synthesized from polyol PBA which was synthesized in our lab,MDI and different chain extenders EG/BDO/HD,by using prepolymer method.The effects of different extenders and different hard segment contents on the microphase separation properties of the elastomer were studied through the rheological property,crystallization and mechanical property.The results showed that,under the same hard segment content,the HD-TPU and BDO-TPU almost had the same microphase separation which was better than the EG-TPU.The HD-TPU had the best crystallization,tensile strength and elongation at break.In the BDO-TPU system,with the increase of the hard segment content,the hardness and tensile strength increased,the elongation at break descended,the microphase separation occured much earlier and faster,but the ultimate content was low.