Canadian Journal of Chemical Engineering, Vol.94, No.1, 46-52, 2016
Propargylated Novolac Resins for Fibre-Reinforced Plastics: Processing Aspects
Propargylated novolac resins (PN) are known polymer binders for fibre-reinforced plastic production. Unlike common phenolic resins, PNs are able to cure without volatiles, avoiding porosity formation in the final material. Otherwise, PN curing proceeds with a high exothermal effect (up to 1200 J/g), causing overheating that may result in destruction of material and equipment damage. The specific heat release limit was found with a curing kinetic study complemented with mathematical calculations to be 660 J/g for a quick and safe moulding process. A new commercially-available catalyst for PN curing based on Ni(II) salts is recommended for composite pressing. Use of this catalyst helps to spread exothermal effects and simplify the curing process. It was shown that by varying reaction conditions, it is possible to adjust material properties such as T-g, char yield, curing temperature, and processing time.