Fabrication of nanostructured polycarbonate/poly(methyl methacrylate) blends with improved optical and mechanical properties by high‐shear processing

The structure and properties of polycarbonate (PC)/ poly(methyl methacrylate) (PMMA) blends fabricated using a high-shear extruder at different shear rates were investigated. It was found that the morphologies of the blends were greatly dependent on the shear rate exerted during melt processing. High-shear processing leads to a nanostructured PC/PMMA blend, in which PMMA domains with a size of less than 50 nm are homogeneously dispersed in the PC matrix. The prepared nanostructured blends exhibit not only excellent optical properties with a transmittance of more than 90% in the visible region but also a higher modulus than pure PC. In contrast, the PMMA domain size ranges from submicron to micrometer for the same blends processed at a low-shear rate. These blends are opaque and display much lower elongation at break compared with the blends processed at a high-shear rate. POLYM. ENG. SCI., 51:1437–1445, 2011. a 2011 Society of Plastics Engineers