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Isotactic poly(butene‐1) trigonal crystal growth in the melt
Authors:Motoi Yamashita  Akitaka Hoshino  Minoru Kato
Affiliation:1. Department of Applied Chemistry, Ritsumeikan University, Noji‐higashi, Kusatsu, Shiga 525‐8577, JapanDepartment of Applied Chemistry, Ritsumeikan University, Noji‐higashi, Kusatsu, Shiga 525‐8577, Japan;2. Faculty of Liberal Arts and Sciences, Osaka Prefecture University, 1‐1 Gakuencho, Sakai, Osaka 599‐8531, Japan;3. Department of Applied Chemistry, Ritsumeikan University, Noji‐higashi, Kusatsu, Shiga 525‐8577, Japan
Abstract:Crystal growth of the trigonal form of isotactic poly(butene‐1) (it‐PB1) was successfully observed in the melt at atmospheric pressure. The growth rate of trigonal crystals was obtained by in situ optical microscopy. It is one hundredth that of it‐PB1 tetragonal crystals. The growth rate of trigonal crystals, as well as that of tetragonal crystals, shows supercooling dependence derived from the nucleation theory. The value of the kinetic constant K of trigonal crystals is about 3.3 times larger than that of tetragonal crystals. The value of the pre‐exponential factor G0 of trigonal crystals was found to be 41 times as large as that of tetragonal crystals. The difference between these K values can be attributed to the conformational entropy of the ethyl side groups in a nucleating stem. The discrepancy found in the values of G0 could be explained by introducing pinning and nucleation barriers, which originate from the crystal thickness δlc, which does not depend on the crystallization temperature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 684–697, 2007
Keywords:atomic force microscopy (AFM)  barrier  crystallization  disorder  growth interfaces  isotactic polyolefins  melt  surfaces  TEM  thin films
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