The phase transition of deformed mesophase of isotactic polypropylene  by in situ synchrotron radiation WAXD studies

ZHAO Baijin; MA Zhe; HONG Zhenfei; LI Liangbin

doi:10.3969/j.issn.0253-2778.2011.10.005

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The phase transition of deformed mesophase of isotactic polypropylene by in situ synchrotron radiation WAXD studies

1.
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
2.
School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026, China

Cite this:

https://doi.org/10.3969/j.issn.0253-2778.2011.10.005

Received Date: 14 October 2010
Rev Recd Date: 20 December 2010
Publish Date: 31 October 2011

Abstract Full text PDF

Abstract

Abstract

The phase transition of quench-induced mesophase and deformed mesophase which was prepared by stretching the quench-induced mesophase during heating and isothermal annealing process was studied by in situ synchrotron radiation WAXD. The results show that though the temperature at which the phase transition of the two mesophase taken place is same, the temperature at which the phase transition has a slope increase is higher with deformed mesophase than quench-induced mesophase, and it indicates that the former one is much more stable. It is found that the regular conformation of 31 helices along stretching direction has a larger long-range order in deformed mesophase. That reason is used to explain why the deformed mesophase has a higher melt point.

Abstract

The phase transition of quench-induced mesophase and deformed mesophase which was prepared by stretching the quench-induced mesophase during heating and isothermal annealing process was studied by in situ synchrotron radiation WAXD. The results show that though the temperature at which the phase transition of the two mesophase taken place is same, the temperature at which the phase transition has a slope increase is higher with deformed mesophase than quench-induced mesophase, and it indicates that the former one is much more stable. It is found that the regular conformation of 31 helices along stretching direction has a larger long-range order in deformed mesophase. That reason is used to explain why the deformed mesophase has a higher melt point.