Rheological and topological characterizations of electron beam irradiation prepared long-chain branched polylactic acid

Authors

  • Yongbin Wang,

    1. CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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  • Liang Yang,

    1. CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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  • Yanhua Niu,

    Corresponding author
    1. CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
    • CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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  • Zhigang Wang,

    Corresponding author
    1. CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
    2. CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China
    • CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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  • Jun Zhang,

    1. CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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  • Fengyuan Yu,

    1. Advanced Rheology Institute, Department of Polymer Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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  • Hongbin Zhang

    1. Advanced Rheology Institute, Department of Polymer Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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Abstract

In this study, a series of linear- and long-chain branched polylactic acid (PLA) samples was prepared by electron beam irradiation without or with addition of a trifunctional monomer, trimethylolpropane triacrylate (TMPTA). The chain structures of the PLA samples were characterized by size-exclusion chromatography coupled with a light scattering detector (SEC-MALLS) and shear and extensional rheology. PLA tends to degrade while keeps linear structures with increasing irradiation dose and without addition of TMPTA, as evidenced by decreased molecular mass Mw and reductions of storage modulus G′ and the zero shear viscosity η0. Long-chain branched PLA samples were successfully prepared with irradiation and addition of TMPTA, which shows prominent higher η0 and apparent flow activation energy, longer characteristic relaxation time τ, and pronounced strain-hardening behaviors. With increasing amount of TMPTA, Mw dependences of η0 and the root mean square radius of gyration Rg obviously deviate from the scaling relation of linear PLA samples, which strongly indicates the increased long-chain branching degree for the branched PLA samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

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