Crystallization of isotactic polypropylene from prequenched mesomorphic phase
Crystallization of isotactic polypropylene from prequenched mesomorphic phase
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DOI：
10.1021/ma060191b
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发表时间：
2006-11-14
期刊：
影响因子：
5.5
通讯作者：
Kanaya, Toshiji
中科院分区：
文献类型：
--
作者：
Konishi, Takashi;Nishida, Koji;Kanaya, Toshiji
用广角X射线衍射、小角X射线散射和光学显微镜研究了等规聚丙烯（iPP）从预冷介晶相加热结晶的过程。淬火的介晶iPP显示出众所周知的约100 nm的结节状结构。100埃在加热过程中，结核在保持自相似性的情况下长大，部分介晶相转变为结晶相。在达到等温过程之后，取决于退火温度，结节停止生长在一定的准平衡尺寸。在长时间退火过程中，纳米尺度的颗粒间的界面变得模糊不清，并逐渐融合成微米尺度的纯α相结构。准平衡结节的大小和退火温度之间的关系导致外推熔化温度的介晶相，这是位于以上的α-晶体的平衡熔化温度。
The crystallization process of isotactic polypropylene (iPP) by heating from the prequenched mesomorphic phase has been studied using wide-angle X-ray diffraction, small-angle X-ray scattering, and optical microscopy. Mesomorphic iPP as quenched shows the well-known nodular structure of ca. 100 angstrom. In heating process the nodules grew larger keeping self-similarity, with the mesomorphic phase partially transforming into the crystalline phase inside the nodules. After reaching the isothermal process, the nodules stopped to grow at a certain quasi-equilibrium size depending on the annealing temperature. During the long annealing, the interface among the nodules became obscure, and the nodules in nanometer scale merge into larger structure of pure alpha-phase in micrometer scale. The relation between the quasi-equilibrium nodule size and the annealing temperature leads an extrapolated melting temperature of the mesomorphic phase, which is located above the equilibrium melting temperature of the alpha-crystal.