Reaction kinetics and heat transfer studies in thermoset resins

Abstract

The differential scanning calorimetry technique is used to study the polymerization kinetics of thermoset resins (bone cement), both under isothermal and dynamic conditions. A phenomenological kinetic model, which takes into account the diffusion effect, is proposed. The model, coupled with an energy balance, is used to predict the fractional conversion, the conversion rate and the temperature profile for different thicknesses of the resin. In isothermal conditions, the conversion is less than 1, giving proof of the presence of unreacted monomer in the resin. The results obtained under dynamic conditions indicate that the resulting temperature increase is responsible for the higher conversion and a better cure of the resin. Bone cement is intended for use in filling the gap between bone and metal prosthesis. For such cases, we have also noted that the prosthesis absorbs much heat and effectively cools the resin, whereas bone does not support a strong temperature elevation and is only locally in contact with hot cement at the bone–cement interface, and for a short time period. In this respect, the proposition of a workable model for cement polymerization may help in determining proper limits for cementation techniques.