CRYSTALLIZATION BEHAVIOR AND MECHANICAL-PROPERTIES OF POLYPROPYLENE-BASED COMPOSITES

The influence of glass fibers on the primary nucleation process, isothermal radial growth rate of spherulites and overall kinetic rate constant of isotactic polypropylene (iPP) has been examined. The polypropylene was also modified by means of acrylic acid (iPP*) in order to improve the adhesion between the matrix and the fibers, and the relative properties were compared with those concerning the composites having as matrix plain iPP. Moreover the mechanical properties of injection-moulded composites containing iPP and iPP* have been studied. These properties improved on increasing the fiber content. It was found that for the same glass-fiber content better values of the elongation at break and creep are observed in the case of reinforced polypropylenes having as matrix acrylic acid modified polypropylene.