Thermosetting epoxidized polybutadiene/low‐molecular weight polyphenylene oxide compatible system with quite low‐dielectric constant and loss prepared through co‐curing reaction

Abstract Through the redistribution reaction of PPO, the hydroxyl‐terminated low molecular weight PPO (PPO‐OH) was prepared. Furthermore, after the reacting of PPO‐OH with methacrylic anhydride, the double‐bond‐terminated low‐molecular weight PPO (R‐PPO) were synthesized, its M n was 2631 g/mol. The R‐PPO were co‐cured with epoxidized polybutadiene (JP‐100) to prepare JP‐100/R‐PPO cured systems. The JP‐100/R‐PPO cured systems showed single‐phase morphology. The co‐curing reaction with R‐PPO could effectively improve the thermal performance of JP‐100, the glass transition temperature ( T g ) of cured JP‐100/R‐PPO systems raised greatly. For the cured JP‐100/R‐PPO (100/30) system, its T g was 192°C. The dielectric constant and dissipation factor of cured JP‐100/R‐PPO systems were both decreased and showed good frequency stability. The dielectric constant and dissipation factor at 1 MHz of cured JP‐100/R‐PPO (100/30) system were 2.61 and 0.0038, respectively, were obviously lower than those of cured JP‐100 system (which were 3.10 and 0.0099, respectively). The JP‐100/R‐PPO systems exhibited an excellent thermal stability. The 5% weight loss temperature ( T 5% ) of cured JP‐100/R‐PPO system was around 340°C.