文档介绍：摘要
TDE-85是一种三官能度环氧树脂,其固化物拥有良好的热性能和机械性能性能,最为显著的是其高强度、高温承受能力和高粘接性能。大量研究表明,TDE-85与碳纤维(CF)界面结合较好。但TDE-85经固化后也存在着一些不足,如交联密度高、质脆以及耐疲劳性不够高等缺点。本论文针对TDE-85固化后存在的问题,采用热塑性树脂聚醚砜(PES)和CF对其的韧性、热性能和力学性能进行改性研究。
采用高性能热塑性树脂聚醚砜(PES)增韧改性TDE-85体系。固化剂选用4,4’-二氨基二苯砜(DDS)。采用差示扫描量热仪(DSC)、动态热机械分析仪(DMA)和机械性能测试探讨了不同PES含量对TDE-85/PES复合体系机械性能和热性能的影响。结果表明,添加一定量的PES可以提高TDE-85环氧体系的机械强度和耐热性,%时,冲击强度、%、%%;此外,采用扫描电子显微镜(SEM)对TDE-85/PES复合体系断裂面的微观形貌进行表征,分析表明TDE-85/PES复合体系为两相结构,分散相PES呈不规则的变形颗粒分散在环氧树脂中,研究证实,PES的增韧主要是通过PES与TDE-85环氧树脂在复合体系固化过程中,所形成的半互穿网络(S-IPN)和分散的PES微粒受压力作用引发的变形起作用。
采用短切碳纤维改性TDE-85/PES复合体系。对TDE-85/PES/CF复合体系的固化试样进行DMA和机械性能测试,结果表明,碳纤维的添加提高了复合体系的热性能与机械性能,%时,冲击强度、%、%%;采用SEM对复合体系冲击断面的微观形态进行分析,研究发现CF全部都以单丝状态均匀分布于树脂基体中。因此可以认为CF与TDE-85树脂相容性很好,界面粘结强度很高。与此同时,研究发现在CF与TDE-85的共混过程中,CF产生了一定的取向,当复合体系受到外力的突然冲击时,外力会由基体通过界面传递给高强度高韧性的CF,从而达到有效的分散外力的作用,增强了复合材料承受外力作用的能力,在宏观上表现为有效的改善了复合体系的机械性能。
关键词:TDE-85环氧树脂聚醚砜增韧机械性能微观形态
Abstract
TDE-85 was widely known as a kind of three-function epoxy resin. The cured TDE-85 epoxy resin has excellent thermo-mechanical properties, with high strength, good thermal stability, high adhesion of the most prominent, and the interface binding with carbon fiber (CF) is better, at the same time, it still has some disadvantages, such as a high crosslinking density ,very brittle after curing, and the fatigue resistance is not enough higher. In this work, TDE-85 epoxy resin was modified with thermoplastics and CF.
High-performance ductile thermoplastics polyether sulfone (PES) was used to tough TDE-85 epoxy resin systems . The curing agent used is 4,4’-diaminodiphenylsufone (DDS). The effects of PES content on the thermo-mechanical properties of the TDE-85/posite systems were studied by Differential scanning calorimetry (DSC)、Themomechanical analyzar (DMA) and mechanical property test. The results showed that the mechanical strength and glass transition temperature (Tg) of epoxy resin could be