MICROMECHANICAL DEFORMATION PROCESSES IN TOUGHENED AND PARTICLE-FILLED SEMICRYSTALLINE POLYMERS - PART 1 - CHARACTERIZATION OF DEFORMATION PROCESSES IN DEPENDENCE ON PHASE MORPHOLOGY

Relationships between morphology and micromechanical deformation proce sses in various toughened and particle-filled semicrystalline polymers with different types of modifier particles have been investigated by high voltage electron microscopy and scanning electron microscopy usin g in situ tensile techniques. From the study of phase structure of mod ifier particles, two morphological standard types are classified: the binary system (homogeneous modifier particles are dispersed in the mat rix), and the ternary system (heterogeneous modifier particles are dis persed in the matrix). Taking into account these categories and the ph ase adhesion between the modifier particles and the matrix, micromecha nical deformation processes have been characterized. As initiation sit es of plastic deformation the microvoid formation is considered, which plays an important role for the activation of further plastic deforma tion of matrix material during deformation processes. According to the morphology of modifier particles this microvoid formation is caused b y either cavitation in the stretched rubbery shell/inside particles or debonding at the interface between particles and matrix. (C) 1998 Els evier Science Ltd. All rights reserved.