Abstract:

In this paper , first , a novel phenolic resin internally toughened by epoxidized soybean oil (ESO) with good toughness and thermal stability was prepared as the matrix resin of copper clad laminate (CCL). Next , IT-IR was adopted to characterize the molecular structure of the modified phenolic resin and SEM was used to observe the micro morphology of the resin intersections with impact. Then , the properties of CCLs prepared with the modified phenolic resin were studied to determine the optimal processing conditions. Finally , the corresponding toughening mechanism was investigated. It is demonstrated that the toughening relies mainly on the triethanolamine-catalyzed etherification reaction between phenol hydroxyl and ESO and the chain extension polymerization between ESO and multi-amine , which presents long-chain ESO epoxy grafting on the phenolic resin prepolymer. Moreover , it is foundthat the ESO-toughened phenolic resin possesses optimal performance at an ESO content of 30% and a curing agent content of 7 % , and that the flexible ESO epoxy possessing significant toughening effect can crosslink with the phenolic resin to form an internally toughened network for improving the solderleaching resistance of the CCL prepared with the modified phenolic resin.

Key words: phenolic resin, toughness, epoxidized soybean oil, copper clad laminate, solderleaching resistance;synthesis, application