Biomass Modifiers for Low Dielectric Bismaleimides at High-Frequency

Two fluoro-containing monomers M1 and M2 derived from bio-based eugenol and estragole were designed and successfully synthesized via a facile one-step reaction. These monomers were copolymerized with commercial bismaleimide (BMI) in different molar ratios to give a series of BMI polymers. The properties of polymers were investigated to explore the effects of the modifiers on the thermostability, hydrophobicity, and dielectric properties of the BMIs. The BMI polymer incorporated with M2 showed a low dielectric content ( D k ) of 2.89 and a dielectric loss ( D f ) of 6.1 × 10 –3 at a high frequency of 10 GHz. Moreover, it displayed good hydrophobicity with a water uptake of 0.88% and excellent thermostability with a high 5% weight loss temperature ( T 5d ) of 468 °C and a glass transition temperature ( T g ) higher than 400 °C. The comprehensive properties are better than those of the allyl-modified maleimide resins (bismaleimide modified by diallyl bisphenol A, referred to as DABPA-BMI ), which are widely used in the industry. This work provides a method to improve the properties of BMIs. The biomass monomers can be potentially used as modifiers to achieve low dielectric BMIs for high-frequency technology.