Effect of Pre-Existed Form I' on the Phase Transition of Isotactic Poly-1-butene Form III under High Pressure CO2 |
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Authors: | Lei Li Tao Liu Ling Zhao |
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Institution: | State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China |
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Abstract: | The CO2 plasticization effect on the isotactic poly-1-butene (iPB-1) form III with pre-existed minority form I' was investigated by using high-pressure differential scanning calorimetry (DSC). The results showed that the form III melting peak moved to a lower temperature and the melting peak area of form II generated during heating decreased with the increased CO2 pressure. The solid-solid transition of form III to I' in the iPB-1 was mainly studied by fourier transform infrared spectroscopy (FTIR). It was claimed that the phase transition was a thermodynamic process and the pre-existed form I' in form III inhibit the phase transition of form III into I'. The influence of the pre-existed form I' on the melting behavior of the iPB-1 was also studied by DSC. It was found that the form I' also suppressed the recrystallization of form II. |
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Keywords: | form III form I' isotactic poly-1-butene polymorphous transitions |
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