摘要
用端异氰酸酯基聚醚型聚氨酯(PU)接枝改性环氧树脂(EP),通过FT-IR、DSC、DMTS、SEM分别研究了E51及其改性后分子链的基团变化、改性EP的热性能、动态性能以及断面形貌结构,并测试了其力学性能。结果表明,PU分子链已接枝到E51的分子链上;随PU链段含量的增加,EP的冲击强度明显提高,是未改性的两倍多,硬度和弯曲强度降低,玻璃化转变温度提高;改性后的EP不仅内耗峰高,而且内耗峰向高温方向拓展,温域变窄;改性EP的断面呈团状颗粒均匀分布。
EP was modified by the PU chains which grafted to the molecular chains of EP, and the PU chains were ended by isocyanate. The molecular structures of uncured samples were characterized by use of FT-IR. DSC, DMTS and SEM were used to study the post-cured of the EP thermal properties, dynamic mechanical properties and the morphology respectively. Their mechanical properties were also tested.
The results show that PU chains are grafted as branches to the EP; with the content of polyurethane pre-polymer is increased, the impact strength of modified EP （m-EP） is increased one times while the hardness and flexural strength is decreased; the Tg of the m-EP is increased; the m-EP has high internal friction peak which goes toward high temperature, and its temperature range becomes narrow.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2008年第12期66-69,共4页
Polymer Materials Science & Engineering
关键词
PU增韧环氧树脂
接枝改性
冲击强度
toughen epoxy resin by PU
graft modification
impact strength
