Rubber-toughening in polypropylene

摘要: To deformation and fracture behavior of several polypropylene (PP) rubber-modified PP materials have been investigated. Plastic mechanisms these systems depend upon the test rate temperature with high rates low temperatures being in favor crazing. The ductility toughness are explained light competition between crack formation degree plastic through crazing shear yielding. second phase morphology smaller average rubber particle diameter D appears to be more efficient than that larger toughening PP. Theoretical calculations indicate stresses imposed particles due volume shrinkage during crystallization sufficient compensate for differential thermal contraction cooling from solidification end-use temperature. difference two is small, therefore they provide very little contribution interfacial adhesion matrix, insufficient effective controlling craze propagation. particles, addition promoting yielding, can also improve resistance by varying crystalline structure (e.g., reducing spherulite dimensions).