Advanced method to determine the curing-induced evolutions of chemical shrinkage and modulus

A novel method is proposed to simultaneously measure the effective chemical shrinkage and modulus evolutions of polymeric materials during polymerization. The glass fiber Bragg grating (FBG) sensors are embedded in two different uncured cylindrical polymer configurations and the Bragg wavelength (BW) shifts are documented continuously during the polymerization process. The configurations are designed for optimum measurement sensitivity while minimizing the effect of polymerization-induced heat generation. The two evolution properties are determined from the theoretical relationship between the BW shifts and the evolution properties. The method is successfully implemented for a high-temperature curing thermosetting polymer.