Influence of mesophase–crystal transition on thermal and mechanical properties of stretched poly(L-lactide)

Authors

  • Ruihua Lv,

    1. Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, School of Biology, Chemistry and Material Science, East China Institute of Technology, Nanchang 330013, People's Republic of China
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  • Shufen Zou,

    1. Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, School of Biology, Chemistry and Material Science, East China Institute of Technology, Nanchang 330013, People's Republic of China
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  • Bing Na,

    Corresponding author
    1. Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, School of Biology, Chemistry and Material Science, East China Institute of Technology, Nanchang 330013, People's Republic of China
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  • Huiyu Deng,

    1. Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, School of Biology, Chemistry and Material Science, East China Institute of Technology, Nanchang 330013, People's Republic of China
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  • Zhiwei Yu

    1. Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, School of Biology, Chemistry and Material Science, East China Institute of Technology, Nanchang 330013, People's Republic of China
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Abstract

The mesophase in the as-stretched poly(L-lactide) (PLLA) exhibits low thermal stability and undergoes melting around Tg. As a consequence, without constraints as-stretched PLLA can recover to its original (unstretched) length while being held above Tg. Upon constrained annealing at 70°C mesophase is transformed into highly oriented crystals, responsible for little free shrinkage and superior dimensional stability. At the same time, molecular orientation in the amorphous phase first decreases significantly due to thermodynamic relaxation, and then increases moderately with the advent of cold crystallization. It correlates well with the change of yield strength with respect to annealing time. POLYM. ENG. SCI., 53:2568–2572, 2013. © 2013 Society of Plastics Engineers

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