Mechanical properties of polypropylene filled with calcium carbonate

The tensile behavior of polypropylene (PP) filled with calcium carbonate particles has been studied using a tensile test. In particular, the effect of strain rate, filler content, and filler size upon the elastic modulus, yield stress, and strain of surface‐modified and unmodified particles‐filled PP were investigated. The results indicated that the elastic modulus and yield stress of an unmodified system were increased with an increase of strain rate and filler content, and with a decrease of filler size. The yield strain was decreased with an increase of filler content, and with a decrease of filler size, but did not depend on the strain rate. Although the dependence of elastic modulus on the filler size was maintained even by the surface‐modified fillers, that dependence on the strain rate and filler content was decreased by such fillers. This may be because the modifier is present at the interface of filler and polymer matrix.