Highly heat-resistant polymers with good dielectric properties at high frequency derived from a bio-based resveratrol

Abstract

Starting from a bio-based resveratrol, a new monomer (M1) without oxygen atoms and having thermocrosslinkable benzocyclobutene groups and a double bond has been obtained. Thermally cured M1 displays excellent heat resistance with a 5% weight loss temperature (T5d) of 532 °C, a glass transition temperature (Tg) of higher than 400 °C, a very high char yield of 79% at 1000 °C and a very low coefficient of thermal expansion (CTE) of 18.2 ppm/°C. For comparison, a control monomer (M2) has been prepared by hydrogenating the double bond of M1. Thermally cured M2 exhibits excellent dielectric properties with dielectric constant (Dk) of 2.75 and dielectric loss (Df) of 7 × 10−4 at a high frequency of 5 GHz. These results mean that the double bonds in the molecule endow the polymers with higher thermostability, while the alkyl group makes the Dk and Df polymers decreased. In contrast, the polymers containing oxygen atoms derived from resveratrol (cured M3 and cured M4) exhibit increased Dk and Df, and lowered thermostability. This work provides a helpful way to design the materials with high heat-resistance and low dielectric properties for the application in aerospace and microelectronic industry.