Effects of catalysts and post-curing conditions in the polymer network of epoxy and phenolic resins: Preliminary results

In the earlier study about polymer network of phenolic and epoxies resins mixed with linseed oil, only Phencat 15 was used as the catalyst for the phenolic resin. In this study, Phencat 382 and UH (a urea hydrochloride solution based on a 1:1 mole ratio of urea: hydrochloric acid 32%) will be used as catalysts to study their effects on the polymer network of phenolic and epoxy resins mixed with epoxidized linseed oil (ELO) (58%). The effect of each one of these catalysts on the curing and the properties of the formed network were investigated. It was discovered that Phencat 382 was the best catalyst for the composites. It was also discovered that ELO can play its role as plasticiser in the blends of epoxy and phenolic resins and does improve the flexural strength and other mechanical properties of the prepared resins. The storage modulus, flexural modulus, stress at peak and glass transition temperature decreased with increasing percentage by weight of ELO added irrespective of the catalysts used, while the strain yield increased. The cross-link density decreased with the increasing amount of ELO in the resins. The best properties were obtained for the 80/20 epoxy/phenolic resin blends after post-curing for 4 h.