硬段微区结构与聚氨酯脲弹性体力学性能及耐热性的相关性  

Correlation Among the Structure of Hard Segment Micro-Phase,Mechanical Properties and Heat Resistance for PUU Elastomers

作　　者：赵洪祥[1] 蒋玉湘[1] 赵天宝[1] 罗明艳[1] 周京福 李再峰[1] 

机构地区：[1]青岛科技大学生态化工国家重点实验室培育基地,山东青岛266042

出　　处：《高分子材料科学与工程》2017年第6期100-104,112,共6页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(21676150);山东省自然科学基金资助项目(ZR2013EMM007)

摘　　要：以聚四氢呋喃醚二醇(PTMG)为软段,甲苯二异氰酸酯(TDI)、二苯基甲烷二异氰酸酯(MDI)、混合异氰酸酯(n(TDI)∶n(MDI)=1∶1)分别为硬段,采用预聚体法合成了一系列不同硬段微区结构的聚氨酯脲弹性体,并通过红外光谱、热重分析、差示扫描量热以及力学表征等方法,研究了不同硬段微区结构与聚氨酯脲(PUU)体系内部微相分离、热稳定性及力学性能的相关性。结果表明,TDI型聚氨酯脲的NH官能团伸缩振动谱带出现在较低位置(3270cm^(-1)),MDI型NH官能团伸缩振动谱带出现在相对较高的位置(3285cm^(-1)),前者的T_g(-57.6℃)低于后者T_g(-49.5℃),而初始降解温度前者(294℃)高于后者(268℃),混合型的均位于两者之间。因此,TDI型PUU表现出较高的微相分离程度和硬段微区有序度,而MDI型微相混合程度较高、且微相混合程度有助于力学性能的改善。随着温度的升高,PUU内部氢键化NH官能团伸缩振动吸收强度逐渐减弱,谱带吸收位置由低波数向高波数移动,力学性能逐渐下降,当温度处于70℃左右时,其波数出现轻微的突越,力学性能也表现出较快的下降趋势。A series of polyurethane urea （PUU） elastomers were prepared, based on polytetramethyleneether glycol（PTMG） used as soft segment, tolylene diisocyanate（TDI）, diphenyl methane diisocyanate（MDI） and mixture of TDI/MDI for their mole ratio of 1∶1 as hard segment. The mechanical properties and heat resistance of PUU were investigated through correlation among the structure of hard segment micro-phase. The results show that the NH group stretching vibration band of TDI-based appears at 3270 cm-1, and that of MDI-based appeares at the higher wave number （3285 cm-1）. Additionally, Tg （-57.6 ℃） of TDI-based（-57.6 ℃） is lower than that of the MDI-based （-49.5 ℃）, and the initial degradation temperature instead. Mixture-based is located between them. Compared with MDI-based, the TDI-based shows the higher micro-phase separation degree, but exhibits worse mechanical properties. And with the temperature increasing, the absorption intensity of hydrogen bonded NH stretching vibration band is gradually weakened, and the band site shifts from the lower wave number to the higher wave numbers, and the mechanical properties of the PUU decrease gradually. When the temperature is 70 ℃, the slightly jump of wave numbers is observed , and the mechanical properties drop quickly.

关 键 词：聚氨酯脲 氢键 微相分离 耐热性 力学性能 

分 类 号：TQ323.8[化学工程—合成树脂塑料工业]