Low Dielectric Thermoset from Redistributed Poly(phenylene oxide)

A curable low-molecular-weight poly(phenylene oxide) (PPO) was prepared by the redistribution of regular PPO with bisphenol-A (BPA) followed by etherification of the redistributed-PPO (BPA-PPO) with N,N-diallyl-2-chloroacetamide. The redistributed-PPO with allyl group (AL-PPO) was characterized by proton nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The AL-PPO oligomers with reactive double bounds were cured with triallylisocyanurate (TAIC) and/or phosphorus-containing allyl-functionalized monomer (allyl-DOPO). The glass transition temperatures were measured by dynamic mechanical analysis (DMA). Electrical properties of cured resins were studied using dielectric analyzer (DEA). The flame retardancy was determined by a UL-94 vertical test. The effects of curing accelerator, amount of TAIC and allyl-DOPO incorporated into the network on the glass transition temperatures, dielectric properties, and flame retardancy of the resulting systems were investigated. The results indicated t...