雷达罩用高性能氰酸酯树脂制备及性能

采用马来酸酐(MAH)改性低分子量聚苯醚(PPE),通过熔融共混法将改性聚苯醚(MAH–PPE)与氰酸酯(CE)树脂进行共混,分析研究MAH–PPE添加量对CE体系热性能、力学性能和介电性能的影响。研究结果表明,MAH–PPE对CE树脂的固化具有明显催化作用,动态热机械和热重分析表明,加入MAH–PPE对CE的耐热性影响不大,随着MAH–PPE添加量的增加,CE体系的玻璃化转变温度和最大热分解温度与纯CE相比基本保持不变。扫描电子显微镜分析表明,当MAH–PPE质量分数低于10%时,MAH–PPE与CE具有良好的界面作用,表现出典型的韧性断裂,随着MAH–PPE添加量的增加,CE/MAH–PPE体系呈现微观相分离。冲击强度测试结果表明,当MAH–PPE质量分数为10%时,CE/MAH–PPE体系的冲击强度达到43.36 kJ/m2,比纯CE提高140.9%,增韧效果达到最佳。介电性能测试结果表明,随着MAH–PPE质量分数的增加,CE/MAH–PPE体系呈现出较好的介电性能,当MAH–PPE质量分数为30%时,CE/MAH–PPE体系在10 GHz下的介电常数和介电损耗角正切值分别为2.84和9.35‰,比纯CE分别降低7.5%和30.8%。

Preparation and Properties of High Performance Cyanate Ester Resins for Radome

The low molecular weight polyphenylene ether(PPE)was modified by maleic anhydride(MAH),and then the modified PPE(MAH–PPE)was blended with cyanate ester(CE)resin by melt-mixing method.The effects of MAH–PPE content on the thermal stabilities,mechanical and dielectric properties of CE system were investigated.The results show that MAH–PPE can obviously catalyze the curing reaction of CE resin.The thermal performances of CE/MAH–PPE system were investigated by dynamic thermomechanical and thermogravimetric analysis.The results show that the addition of MAH–PPE has little effect on the thermal properties of CE/MAH–PPE system.Compared with pure CE,the glass transition temperature and the temperature of maximum degradation rate keep a relatively stable level with the increase of MAH–PPE content.SEM analysis shows that the fracture surface of CE/MAH–PPE system exhibits typical toughness fracture and good interface adhesion between MAH–PPE and CE.With the increase of MAH–PPE content,CE/MAH–PPE system exhibits microphase separation.The impact strength result shows that when the mass fraction of MAH–PPE is 10%,the toughening effect is the best and the impact strength is 43.36 kJ/m2 which increases by 140.9%in comparison to that of pure CE.The results of dielectric properties show that CE/MAH–PPE system exhibit better dielectric properties with the increase of MAH–PPE content,when the mass fraction of MAH–PPE is 30%,the dielectric constant and the tangent value of dielectric loss angle at 10 GHz are 2.84 and 9.35‰,which are 7.5%and 30.8%lower than those of pure CE,respectively.