Influence of the quenching temperature on the crystallization of the trans-planar mesomorphic form of syndiotactic polypropylene

The crystallization from the melt of the trans-planar mesomorphic form of syndiotactic polypropylene is investigated at different quenching temperatures. The formation of the trans-planar mesomorphic form at -5, 0 and 6 degreesC is followed as a function of the residence time at these temperatures by X-ray diffraction and FTIR spectroscopy. The quenching temperature influences the rate of formation of the mesomorphic form as well as the maximum amount of the obtained mesomorphic form. By increasing the quenching temperature, in the examined range between -5 and +6 degreesC, an increase in the rate of formation of the mesomorphic form is observed. The maximum amounts of mesomorphic form obtained at 6 and -5 degreesC are lower than the amount achieved at 0 degreesC, which corresponds to nearly 100% of the total crystalline phase. (C) 2003 Elsevier Ltd. All rights reserved.