Effect of Composition and Type of Phenolic Resin on Mechanical Properties andMorphology of Phenolic Nanocomposites

Nanocomposites based on phenolic resol and novolac resins and Cloisite 30B were prepared. Different kinds of phenolic resins and clay content were studied with respect to the morphology and mechanical properties of the polymer silicate layers. The phenolic resins, namely resol, novolac and their mixture and four different percentages of clay contents, 0.5, 1, 2 and 5 wt% have been considered. XRD analysis has been used to investigate clay distribution in the prepared polymer matrices. Chopped strand mat glass fiber was impregnated with each phenolic resin solution and after hand-lay-up, specimens were prepared by hot press compression molding. The mechanical properties of the nanocomposites were assessed by tensile, flexural and Izod impact tests. XRD results show that the degree of clay distribution in resol type phenolic resin is more satisfactory than novolac resin. Based on mechanical properties evaluations, the novolac nanocomposites showed better mechanical properties than other systems under study. The mixture of novolac resin and resol showed improved mechanical properties relative to each phenolic system. The final results indicate that nanocomposites with 2 wt% clay content show maximum modulus and tensile strength increased by 23%. Impact test results also show that optimum properties can be achieved with 2 wt% clay content.