Optical, rheological, and thermal properties of hollow glass bead filled isotactic polypropylene

Abstract Hollow glass beads (HGB) were mixed into isotactic polypropylene (iPP) by an internal mixer and the effect of HGB concentration on optical, rheological, and thermal properties of iPP/HGB composites was studied. The dispersion of treated and nontreated HGB in the iPP matrix and the crystal habit of iPP in the composites were examined by phase contrast microscopy. Dynamic rheological measurements were carried out in the melt state in the oscillatory shear mode. The data were analyzed to yield the variations of rheological properties of the composites when the HGB were added. The influence of HGB concentration on the thermal properties including the crystallization and melting behaviors of the composites was studied by means of differential scanning calorimeter and wide angle X‐ray diffraction. It was found that the addition of HGB had effect on the crystallization and melting behaviors of the composites, including that HGB had a weak nucleating effect in the matrix and promoting the formation of β‐crystals of iPP. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers