环氧基POSS催化固化苯并恶嗪树脂的结构与性能

Structure and properties of benzoxazine resin catalyzed by epoxidized POSS

采用八乙烯基笼型倍半硅氧烷合成了环氧基倍半硅氧烷(EPPOSS),将其与双酚A型苯并恶嗪(BA-a)熔融共混制备了系列BA-a/EPPOSS共混树脂。通过红外光谱、示差扫描量热分析、热机械性能分析、热重分析、扫描电镜、介电性能及冲击性能测试等研究了共混树脂的结构和性能。结果表明,共混树脂的固化温度降低,EPPOSS在低温开环后催化恶嗪环开环,并与BA-a发生共聚,生成复合材料。EPPOSS的质量分数在15%以下时,可在复合材料中均匀分散。EPPOSS的中空笼型结构可显著提高复合材料的介电性能,EPPOSS的质量分数为15%时,介电常数最小为2.72。随着EPPOSS的用量的增加,复合材料在高温下的耐热性和热稳定性提高,这是EPPOSS的无机骨架和体系交联密度增加所致。由于醚键的引入以及无机纳米粒子的增强作用,复合材料的韧性增强,冲击强度提高1倍。

The epoxy-silsesquioxane(EPPOSS) was synthesized using octavinyl cage silsesquioxane,and it was melt blended with bisphenol A benzoxazine(BA-a) to prepare series BA-a/EPPOSS blend resins. Through infrared spectroscopy,differential scanning calorimetry analysis,thermomechanical performance analysis,thermogravimetric analysis,scanning electron microscopy,dielectric properties and impact performance testings,the structure and performance of the blended resin were studied. The results showed that the curing temperature of the blended resin was lowered,and EPPOSS catalyzed the opening of the oxazine ring after low-temperature ring opening,and copolymerized with BA-a to form a composite material. When the mass fraction of EPPOSS was below 15%,it could be uniformly dispersed in the composites The hollow cage structure of EPPOSS could significantly improve the dielectric properties of composites. When the mass fraction of EPPOSS was 15%, the minimum dielectric constant was 2.72. With the increase of EPPOSS amount,the heat resistance and thermal stability of the composites at high temperatures were increased. This was due to the inorganic framework of EPPOSS and the increase of crosslinking density of the system. Due to the introduction of ether bonds and the reinforcement of inorganic nanoparticles,the toughness of the composite was enhanced,and the impact strength was doubled.