Monitoring of Epoxy Curing by a Thermal-Conductivity Sensor Based on the Hot-Ball Transient Method

Abstract

Epoxy resins are materials capable of polymerizing under certain conditions, i.e., a temperature and the presence of a hardener, yielding a three-dimensional net formed by the crosslinking of the chains. This polymerization is also called the curing process. During the curing, different physical processes can be detected, namely, formation of polymer chains and their crosslinking. Thermodynamic and transport characteristics change markedly. A new thermal-conductivity sensor was used for monitoring of the curing process. The principle of the sensor is based on the hot-ball method for measuring the thermal conductivity. The sensor recognizes the processes operating during polymerization. This paper deals with the monitoring of the curing process of diglycidylether of bisphenol A (DGBA) epoxy resin modified with aromatic reactive diluent, where the curing rate is controlled by the temperature and boron trifluoride (BTF) hardener. A short description of the measurement method is given.