Reaction kinetics and heat transfer studies in thermoset resins

The differential scanning calorimetry technique is used to study the polyme rization 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 energ y balance, is used to predict the fractional conversion, the conversion rat e and the temperature profile for different thicknesses of the resin. In is othermal conditions, the conversion is less than 1, giving proof of the pre sence 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 i ntended for use in filling the gap between bone and metal prosthesis. For s uch cases, we have also noted that the prosthesis absorbs much heat and eff ectively cools the resin, whereas bone does not support a strong temperatur e elevation and is only locally in contact with hot cement at the bone-ceme nt interface, and for a short time period. In this respect, the proposition of a workable model for cement polymerization may help in determining prop er limits for cementation techniques. (C) 1999 Elsevier Science S.A. All ri ghts reserved.