摘要
采用二环己基甲烷二异氰酸酯(HMDI)与聚四氢呋喃二醇(PTMEG)预聚,用三羟甲基丙烷(TMP)和1,4-BDO扩链,合成系列透明聚氨酯弹性体,研究了原材料配比、扩链剂配比对力学性能的影响,并通过加温老化、DMTA、TGA等方法对其热力学性能进行研究,结果表明:随着PU弹性体中硬段含量的增加,材料的硬度、拉伸强度、撕裂强度均有明显增加,断裂伸长率下降。PU弹性体在150℃时表面开始变黄以至黏流;硬段含量高的PU弹性体耐热性略有提高。随硬段含量增加,PU弹性体的玻璃化转变温度逐渐移向高温。PU弹性体的起始热分解温度均为320℃,交联结构及氨酯键的断裂破坏是第一阶段质量损失的主要原因。
A series of transparent polyurethane elastomers were synthesized with HMDI-PTMEG as prepolymer,1,4-BDO and TMP as chain-extender.The effect of proportion of raw materials and chain-extenders on mechanical properties was studied.Thermal and mechanical properties had been investigated by thermal ageing,DMTA and TGA.The results showed that the hardness,tensile and tearing strength of PU increased evidently with the hard-segments concentration of PU increasing,while the elongation at break decreased.The surfaces of PU specimens turned to be sticky and yellow at 150 ℃.When hard-segments concentration increased,the heat resistance of PU elastomer increased slightly and Tg shifted to high temperature as well.The initial decomposition temperature of the PU elastomer was 320 ℃,the break of the cross linking structure and urethane bound was the main cause of the mass loss in the first stage.
出处
《塑料工业》
CAS
CSCD
北大核心
2010年第10期6-8,12,共4页
China Plastics Industry
