Protocol for nonisothermal cure analysis of thermoset composites

Abstract

Thermoset composites are elements of advanced devices, and their properties depend on their crosslinking state. Unsurprisingly, reports on the effect of addition of micro- and nanoparticles, pigments, additives, and reinforcing agents on the thermal, mechanical, thermomechanical, and anti-corrosion prioerties of thermoset systems include cure analysis-both qualitatively and quantitatively. The poor knowledge about cure state makes interpretations about ultimate properties of thermoset composites prone to criticism of crosslinking density consideration. There is a general agreement that a complete cure is the result of appropriate dispersion of particles in a highly-viscous system in which the state of filler-polymer interaction determines the efficiency of crosslinking. Typically, an external filler can facilitate or hinder curing reaction depending on the shape, size, content and surface chemistry of particles. This short communication proposes a protocol for either qualitative or quantitative analysis of cure in thermoset systems based on nonisothermal differential scanning calorimetry measurements. The proposed instruction allows taking a full image of crosslinking in terms of Cure Index, cure behavior, and cure kinetics in thermoset composites to understand/predict correlation between microstructure and properties.