Coupling Agents - HME Resin System.

摘要

Two approaches were taken to improve the SBS strength of HME/AS composites. First,attempts were made to react a number of organo-titanates,epoxides,and modified polybutadiene (PB) epoxides with reactive sites on the graphite fiber surface and then to react,or couple,with the matrix HME resin. Epon 834 (a bisphenol A type epoxy resin), allylglycidyl ether,and a reaction product of C-1000PB and ERE-1359epoxy resin produced very slight increases in SBS strengths of HME composites when used as AS fiber sizing. Second,attempts were made to reinforce the HME resin with three finely divided fillers: Vulcan 9A32carbon black, HiSil 233hydrated silica,and HR-600polyimide resin. However,these fillers severely degraded composite strengths. Low profile modifiers,developed to reduce cure shrinkage in polyester resins,were evaluated for this purpose in the HME resin system but were found to be incompatible. It is unlikely that all of the many approaches to form primary chemical bonds between the HME matrix and graphite fiber failed,yet no significant improvement in SBS was achieved over untreated fiber during this program. The possibility that a low cohesive strength in the HME matrix was the problem was briefly explored using fillers,also without success.