Morphology and properties of polypropylene/ethylene-dimethylaminoethyl methacrylate copolymer blends

Blends of polypropylene (PP) with an ethylene-dimethylaminoethyl methacrylate (E-DAM) copolymer with 27 wt% dimethylaminoethyl methacrylate content were prepared. Mechanical properties, morphology and compatibility are described. Blends of various compositions were studied using tensile tests, differential scanning calorimetry, small-angle X-ray scattering and optical and scanning electron microscopy. The polymers were found to be incompatible and the blends have a two-phase structure. Negative deviations from simple additivity for the strengths at yield and break as well as the modulus were observed. With increasing E-DAM content, the blends tend to show characteristic brittle rather than ductile frature. The interfaces between PP and E-DAM are weakly bonded. © 1990.