In recent years, there exists a rapid development in china's paper industry. At present, many foreign-funded enterprises mainly import the paper mandrel plastic pipes, while some domestic companies are also stepping up the research and development of high-rigidity and high toughness plastic pipes. Based on our early research, two PP pipes made with different catalysts were analysed, and the results showed that there wasα-βtransition in the Ziegler-Natta isotactic polypropylene (ZNPP) pipe after cyclical fat...