摘要
以3,3-双(叠氮甲基)环氧丁烷-四氢呋喃共聚醚(PBT)为软段,不同异氰酸酯和扩链剂为硬段,以一步法合成了不同硬段结构的聚氨酯弹性体。采用广角X射线衍射对其结构进行表征,表明刚性扩链剂(SR)制备的弹性体衍射峰强度比柔性扩链剂(DEG)制备的弹性体强,表明其硬段排列较规整。进一步采用常温拉伸、高温蠕变和低温动态力学分析等手段对其进行了不同温度的力学性能测试,结果显示SR扩链后弹性体拉伸强度达到5.36 MPa,较DEG扩链弹性体的2.29 MPa有很大提高,初始分解温度前者(208℃)也高于后者(198℃),高温蠕变量也从90.1%降到39.7%;与扩链剂相比,异氰酸酯结构对力学性能的影响较小,由包含对称结构的甲苯二异氰酸酯(TDI)固化的弹性体拉伸强度(5.36 MPa)比4,4’-二苯基甲烷二异氰酸酯(MDI)固化的弹性体(3.16 MPa)高,低温和高温性能相差不大。
The elastomers with different hard segment structure were synthesized by one-step method, using azido copolyethers of 3,3-bis（azidomethyl） oxetane （BAMO） and tetrahydrofuran （THF） as soft segment and different diisocyanate and chain extender as hard segment. The structure was characterized by WAXD and the results show the diffraction peak intensity of elastomer using rigid chain extender （SR） is higher than that of elastomer using flexible chain extender （DEG）, which means that the hard segment is ordered in this elastomer. The mechanical properties at different temperature were tested by room temperature tensile, high temperature creep and low temperature dynamic mechanical testing analysis. The results show that the room tensile strength of elastomer gets to 5.36 MPa in SR chain extender, compared to 2.29 MPa in DEG chain extender. The initial decomposition temperature of former reaches to 208 ℃ higher than the latter 198 ℃. The high temperature creep decreases from 90.1% to 39.7%. The mechanical property in symmetric structure of toluene diisocyanate （TDI） is higher than that of 4,4＇- diphenylmethane diisocyanate （MDI） cured elastomers. Except the room temperature tensile strength, less difference can be seen in low temperature and high temperature mechanical performance, despite TDI or MDI used as curing agent.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2017年第12期22-25,30,共5页
Polymer Materials Science & Engineering
基金
国家安全重大基础研究计划项目(613275)
国防科技项目基金(0106069)
