柔性透明聚氨酯弹性体制备及性能

采用不同聚醚软段,醇扩链剂和胺扩链剂,分别与二环己基甲烷二异氰酸酯(HMDI)反应,用浇注工艺制备了系列透明聚氨酯弹性体,考察了不同软段和扩链剂对弹性体的透光性、力学性能、耐屈挠性和折叠恢复性的影响。结果表明,由数均分子量为3 000的聚氧化丙烯二醇软段制备的弹性体拉伸强度较低;而由数均分子量为1 000的聚四氢呋喃醚二醇软段制备的弹性体耐屈挠性较差;由数均分子量为2 000的聚四氢呋喃醚二醇软段制备的弹性体透光率显著下降;与醇扩链剂相比,由胺扩链的弹性体的拉伸强度更高、耐热性和折叠恢复性更好。当软段采用低不饱和度聚醚223–060LM、扩链剂为二乙基甲苯二胺时,制备的透明聚氨酯弹性体综合性能最佳,其拉伸强度、断裂伸长率、透光率、耐屈挠循环次数和折叠恢复时间分别为25.6 MPa,567%,91%,2 100次和20 s。

Preparation and Properties of Flexible Transparent Polyurethane Elastomer

:Different polyether soft segments,alcohol chain extenders and amine chain extenders were respectively reacted with dicyclohexylmethane diisocyanate(HMDI),and a series of transparent polyurethane elastomers were prepared by casting process.The effects of different soft segments and chain extenders on light transmittance,mechanical properties,flexural resistance and folding recovery of the elastomers were investigated.The results show that the elastomer prepared from the soft segment of polyoxypropylene diol(Mn=3 000)has a low tensile strength,while the elastomer prepared from the soft segment of polytetrahydrofuran(Mn=1 000)has poor flexural resistance,the light transmittance of the elastomer prepared from the soft segment of polytetrahydrofuran(Mn=2 000)decreases significantly.Compared with an alcohol chain extender,the elastomer extended by amine has higher tensile strength,better heat resistance and folding recovery.When low unsaturation polyether 223–060LM is adopted as the soft segment and diethyltoluenediamine is selected as the chain extender,the prepared transparent polyurethane elastomer has the best comprehensive performance,tensile strength,elongation at break,transmittance,cycle times of flexural resistance and folding recovery time are 25.6 MPa,567%,91%,2 100 times and 20 s,respectively.