STRUCTURE AND PROPERTIES OF THE β NUCLEATED INJECTION MOLDED POLYPROPYLENES: TIME STABILITY OF β PHASE AND IMPACT STRENGTH

摘要

It is known that β-phase of isotactic polypropylene (iPP) can improve toughness of samples. Notch impact strength of samples containing different amounts of novel β-nucleating agent NU100 has been measured. Injection molding, WAXD, DSC, optical microscopy and Charpy impact tests were used to prepare samples and characterize the structure and impact strength. For the first time, measurements of the impact strength and the β-phase content were carried out immediately after injection molding and then the same values were determined after 2 years. It was found that β-phase is not time-dependent and also notch impact strength of samples does not change with time.