不同软段结构聚氨酯-酰亚胺嵌段共聚物的合成及热性能研究

用二步法合成了不同软段 (PPO ,PEG ,PEPA)聚氨酯 酰亚胺 (PUI)嵌段共聚物 ,FTIR光谱表征了所有合成PUI分子主链均含有酰亚胺链段 ,并研究了PUI嵌段共聚物的热性能受软段类型及长度的影响 .DSC研究表明聚酯型PUI的软硬段之间的相容性比聚醚型PUI好 ,随相同软段分子量的增加 ,PUI体系的软硬段兼容性变差 ,并显示了相分离的特征 ;热失重 (TGA)研究得出不同软段的PUI样品的热稳定性大小顺序为 :PEPA PUI >PEG PUI>PPO PUI ;动态力学 (DMTA)研究给出了所合成的PUI样品在 5 0～ 2 0 0℃范围内均出现了较长的模量平台显示出有较好的耐热性 ,且随硬段含量的升高其储能模量不断增强

STUDIES ON THERMAL PROPERTIES OF POLYURETHANE-IMIDE BLOCK COPOLYMERS WITH DIFFERENT SOFT SEGMENTS

PUI block copolymers with three different soft segments were synthesized and characterized. FTIR spectroscopy studies confirmed the characteristic absorption of polyurethane imide main chain structure of all PUI samples. DSC analysis revealed that the values of the glass transition temperature of hard segments rich phase ( T gh ) were increased with an increase of soft segments length for the same kind soft segment. DSC results additionally support that with an increase of soft segment length, the soft and hard segments phase compatibility was decreased and the soft hard block phase was more separable. TGA revealed that the thermal stability of different soft segment PUI was in the order of PEPA PUI>PEG PUI>PPO PUI, and dynamic mechanical thermal analysis (DMTA) of PUI samples also showed that the storage energy modulus platform dropping is not remarkable from 50～200℃, this result proved that thermo plastic PUI elastomer samples may have good thermal mechanical properties, which was found to be improved by increasing the hard segments content of PUI systems.