Thermal and thermomechanical properties of rolivsan unsaturated resins co‐cured with bisphenol A dicyanate

Abstract

The present work discusses the experimental verification of the efficiency of a new method of chemical modification of thermosetting resins. The method is based on the use of (nano)micron-sized interlayers that appear between densely crosslinked grains of a glassy network polymer during threedimensional radical polymerization of unsaturated monomers (oligomers). These interlayers act as self-contained microreactors, into which different polyfunctional compounds can be introduced for carrying out the desired chemical reactions. Thermal and dynamic mechanical analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy were used to investigate the influence of regimes of thermocatalytic co-curing of rolivsan unsaturated resins (ROLs) with bisphenol A dicyanate (BADCy) on thermal and thermomechanical properties of the obtained crosslinked polymers. It was found that the cured ROL/BADCy blends with high (25-50 wt%) content of the BADCy component had less favorable thermal and mechanical parameters than the cured neat ROL. When the BADCy component of a ROL/BADCy blend played the role of a polyfunctional (modifying) additive (5-7.5 wt%) that migrated into "microreactors" and entered into ter-molecular and other reactions, the final cross-linked ROL-BADCy blends had better high-temperature strength, higher stability against thermo-oxidative and hydrolytic destruction than the individual components (i.e., the cured neat ROL and the cured neat BADCy). As the chemical structure may comprise two networks covalently bound to each other, they can be considered as block copolymers. The obtained results confirm the efficiency of the proposed method of chemical modification of unsaturated thermosetting resins, such as ROLs.