Abstract
Nucleation effects of a novel nucleating agent, bicyclic [2,2,1] heptane di-carboxylate (commercial product name: HPN-68), in isotactic polypropylene (iPP) were studied by using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The results showed that HPN-68 is a typical nucleating agent for α-iPP and has high nucleation efficiency. Crystallization peak temperature and mechanical properties of iPP nucleated with HPN-68 can be greatly increased with only a low concentration of HPN-68. However, increased concentration of HPN-68 has a saturation value and properties of iPP, which tend to plateau when the concentration of HPN-68 exceeds the saturation value. When the concentration of HPN-68 was 0.2 wt%, the crystallization peak temperature was increased by about 15°C, and the tensile strength and flexural modulus of iPP were increased by 13% and 18%, respectively.
Acknowledgments
The authors are grateful for financial supports from the Ministry of Science and Technology of the People's Republic of China (Grant No. 2008AA05Z405) and Scientific Research Fund of Human Provincial Education Department (Grant No. 10B004) and Changsha University of Science and Technology.