N. S. Akhila, Vipin G. Krishnan, Jefin Parukoor Thomas and E. Bhoje Gowd*,
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引用次数: 0
Abstract
Thermally induced crystal structure changes in semicrystalline polymers involve solid-to-solid transition or melting of the starting crystal form followed by the recrystallization into different crystal forms. Understanding such crystal-to-crystal transitions by controlling the chain mobility of amorphous chains is rarely studied. Herein, we chose poly(3-hydroxybutyrate) (PHB) to investigate the temperature-induced structural changes in the bulk and aerogel samples and present the role of amorphous chain mobility on structural reorganization during heating. Aerogels of PHB were prepared by freeze-drying the thermoreversible gels and the films were prepared by hot pressing the PHB pellets. Both aerogels and films crystallized into the α form. We observed a major structural reorganization in aerogels upon heating prior to the melting and such a transition was not observed in the melt-crystallized PHB α form. We speculate that the enhanced mobility of the tie chains that are present between the α lamellar crystals during the heating of the aerogel triggered the conformational change from T2G2 helical chains to all-trans conformation (T′TT̅′T̅) within the crystal lattice resulted in the crystal-to-crystal (α to α + β) transition.
期刊介绍:
ACS Applied Polymer Materials is an interdisciplinary journal publishing original research covering all aspects of engineering, chemistry, physics, and biology relevant to applications of polymers.
The journal is devoted to reports of new and original experimental and theoretical research of an applied nature that integrates fundamental knowledge in the areas of materials, engineering, physics, bioscience, polymer science and chemistry into important polymer applications. The journal is specifically interested in work that addresses relationships among structure, processing, morphology, chemistry, properties, and function as well as work that provide insights into mechanisms critical to the performance of the polymer for applications.