Effect of dicarboxy terminated polystyrene on strengthening immiscible polystyrene/poly(methyl methacrylate) interface

Abstract

The fracture toughness between polystyrene (PS)/poly(methyl methacrylate) (PMMA) reinforced with reactive polymers, poly(glycidyl methacrylate) (PGMA) and dicarboxy or monocarboxy terminated PS (dcPS and mcPS), was measured by the asymmetric fracture test. Molecular weight effect of mcPS, although the molecular weight distribution is rather polydisperse, on the maximum achievable fracture toughness, Gmax qualitatively agreed with the results of the monodisperse case4,5). In the case of dcPS with Mw 142 K, Gmax reached ca. 170 J/m2 which is nearly 8 times higher than that of mcPS of molecular weight of about 150K. From the mechanical point of view, dcPS with a degree of polymerization (N) greater than the ratio of chain breaking force to monomeric friction force (fb/fmono) is more effective in enhancing the interfacial adhesion than mcPS since it provides two stitches to the interface. It was also shown by Monte Carlo simulation on reactive polymer system that the di-endfunctional polymers are more effective than mono-endfunctional polymers in reinforcing the week interface between immiscible polymers.