Reactive Compatibilization of a Nitrile Rubber/Phenolic Resin Blend:Effect on Adhesive and Composite Properties

摘要

Resole phenolic resins containing various p-cresol (PC) to phenol (P) mol ratios were prepared and characterized.These phenolic resins were blended with nitrile rubber (NBR) and the measurements of adhesive joint strength,stress-strain properties,DSC,TGA,DMA,TEM,and SEM were performed using a 50:50NBR/phenolic resin blend.It was observed that the adhesive joint strength and the mechanical properties of the blend enhanced significantly on incorporation of p-cresol into the phenolic resin,and the optimum p-cresol/phenol mol ratio was in the vicinity of 2:1.Observation of a more continuous phase and the increase in T_g of the rubber region in the blend indicated increased reactivity and compatibilization of NBR with phenolic resin as p-cresol was incorporated.The effect of silica filler on the properties of the nitrile rubber/phenolic resin blend was also studied without and with p-cresol modification and the results suggest that silica filler take not only the role of a reinforcing filler in the nitrile-phenolic-silica composite,but also a role as surface compatibilizer of the blend components.