Abstract
Glass fiber reinforced plastics (GFRP) are extensively used in many kinds of industry fields. Matrixs used are commonly unsaturated polyester resin, epoxy resin and phenolic resin. Especially, phenolic resin is expected as a matrix because of its good heat resistance, high mechanical properties and flame resistance.We have studied a new type of phenolic resin, which released no volatiles and needed no catalysts. Our objective in this study is to develop a new type of high-performance phenolic GFRP, which releases no volatiles and needs no catalysts. Bisphenol-A, based benzoxazine (B-a) as a new type of phenolic resin precursor was prepared from bisphenol-A, formaline and aniline. Matrix used was a molten mixture from B-a and bisoxazoline. Bisoxazoline is well known as a compound that can improve in interfacial bonding between matrix and fiber. GFRP laminate was reinforced by E-glass woven cloth fabric of 10 plies by hand-layup method. The surface treatment of fiber was acrylic silane-treatment. As a result, GFRP using B-a and bisoxazoline as a matrix showed higher heat resistance, tensile strength, flexural strength and especially impact strength than GFRP using a conventional bisphenol-A type novolac (BisA-N) and bisoxazoline as a matrix. The reason of this high strength of GFRP using B-a and bisoxazoline as a matrix was considered as follows: interfacial bonding strength of GFRP using B-a and bisoxazoline as a matrix was slightly weaker than that of GFRP using BisA-N and bisoxazoline as a matrix, and so stress concentration in matrix was relaxed by interfacial delamination.
