The influence of glass fibers on the morphology of β-nucleated isotactic polypropylene evaluated by differential scanning calorimetry.

The presence of fillers/fibers can significantly affect the polymorphic behavior of semi-crystalline polymers. The influence of glass fibers on morphology of β-nucleated isotactic polypropylene (iPP) during isothermal and nonisothermal crystallization was analyzed in detail by differential scanning calorimetry (DSC), and the kinetics and thermodynamic parameters were determined for the systems containing 10-60 % glass fibers. The presence of glass fibers in the model composites with β-iPP had an insignificant effect on the morphology of the polymer. Thermodynamic and kinetics parameters of crystallization of iPP in model composites were similar to those obtained for the nucleated polymer. The relative content of β-crystalline phase was slightly affected by increasing glass the fiber content from 10 to 60 mas. % due to appearance of α-crystallites. Moreover, the stability of the β-crystalline phase was decreased with increasing glass fiber content and there appeared a certain amount of β1 and β2 phases, which are known to be disposed to recrystallization. [ABSTRACT FROM AUTHOR]