Effect of interface on the morphology and properties of composites comprising poly(propylene) and short organic fibers

The effect of the fiber surface modification with an azide derivative on th e morphology and properties of composites based on poly(propylene) (PP) and short poly(ethylene terephthalate) (PET) and nylon 66 (PA) fibers, has bee n investigated. Both organic fibers act as reinforcement of the PP, and the reinforcing effect increases with the introduction of azide groups on the chemical structure of the fibers. This effect is more sensible in PP/short PET fiber composites although PA fibers gives rise to higher improvements i n toughness. Scanning electron microscopy (SEM) has shown that the azide tr eatment of PET fibers gives rise to a better wettability and adhesion at th e fiber/matrix interface. A good correlation between SEM and mechanical beh avior of the composites has been observed.