Abstract
Fracture behavior of unfilled (N-PP) and short glass fiber filled polypropylene (GF-PP) has been studied with compact tension specimens by varying annealing temperature and loading rate. The crystallinity measurements and the dynamic mechanical analysis were also carried out. The filled specimens exhibited an increase in the maximum load at a temperature below -30°C, and an increase in the fracture toughness (Jm) in a temperature range between -30°C and 0°C corresponding to the glass transition region of PP. They showed ductile fracture behavior beyond 0°C. The fracture toughness of N-PP exhibited a decrease with increasing loading rate. On the other hand, GF-PP showed little change in the fracture toughness. The annealing of the specimens just below the melting temperature of PP resulted in an increase in the crystallinity and the dynamic modulus. However, it induced a decrease in the maximum load and the fracture toughness.
