Poly(lactic acid) Toughening through Chain End Engineering

Li, Kai; Wang, Yu; Rowe, Matthew; Zhao, Xianhui; Li, Tianyu; Tekinalp, Halil; Ozcan, Soydan

doi:10.1021/acsapm.9b00888

Title: Poly(lactic acid) Toughening through Chain End Engineering

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Abstract

The intrinsic brittleness of poly(lactic acid) (PLA) has hindered its widespread use in many structural applications. Various strategies have been developed to toughen PLA; however, most of the methods lead to a trade-off in strength or modulus. In this study, a chain end engineering strategy was developed to toughen PLA via an industry-friendly melt processing method. Green acids with multifunctional groups, such as 1,2,3,4-butanetetracarboxylic acid (BTCA), were used to modify PLA chain ends/tails via a melt reaction. We report a remarkable improvement in toughness (16×) was achieved by the addition of a minimal amount of BTCA (0.5%). At the same time, the toughened PLA samples maintained the tensile strength and Young’s modulus of neat PLA, suggesting a unique toughening mechanism that is different from the plasticizing effect. Other acid–based modifiers with different numbers of functional groups were also studied in this work. To understand the toughening, we propose a chain end engineering picture that can improve the toughness via a reduction in the number density of chain ends or defects of entanglement and the formation of long-branch topological structures. This study demonstrates a unique and cost-effective strategy for toughening PLA via scalable melt reaction without sacrificing other mechanical properties ofmore »« less

Authors:

^[1];

^[1]; Rowe, Matthew ^[2]; Zhao, Xianhui ^[1]; Li, Tianyu ^[3]; Tekinalp, Halil ^[1];

^[2]

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Univ. of Tennessee, Knoxville, TN (United States)

Publication Date:: 2019-12-06

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Advanced Manufacturing Office

OSTI Identifier:: 1606924

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: ACS Applied Polymer Materials

Additional Journal Information:: Journal Volume: 2; Journal Issue: 2; Journal ID: ISSN 2637-6105

Publisher:: ACS Publications

Country of Publication:: United States

Language:: English

Subject:: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; poly(lactic acid); chain end engineering; molten state functionalization; toughening; polyesters

Citation Formats


                    Li, Kai, Wang, Yu, Rowe, Matthew, Zhao, Xianhui, Li, Tianyu, Tekinalp, Halil, and Ozcan, Soydan. Poly(lactic acid) Toughening through Chain End Engineering.  United States: N. p., 2019. 
Web.  https://doi.org/10.1021/acsapm.9b00888.

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                    Li, Kai, Wang, Yu, Rowe, Matthew, Zhao, Xianhui, Li, Tianyu, Tekinalp, Halil, & Ozcan, Soydan. Poly(lactic acid) Toughening through Chain End Engineering.  United States.  https://doi.org/10.1021/acsapm.9b00888

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                    Li, Kai, Wang, Yu, Rowe, Matthew, Zhao, Xianhui, Li, Tianyu, Tekinalp, Halil, and Ozcan, Soydan. Fri .  
"Poly(lactic acid) Toughening through Chain End Engineering".  United States.  https://doi.org/10.1021/acsapm.9b00888.  https://www.osti.gov/servlets/purl/1606924.

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@article{osti_1606924,

  title        = {Poly(lactic acid) Toughening through Chain End Engineering},

  author       = {Li, Kai and Wang, Yu and Rowe, Matthew and Zhao, Xianhui and Li, Tianyu and Tekinalp, Halil and Ozcan, Soydan},

  abstractNote = {The intrinsic brittleness of poly(lactic acid) (PLA) has hindered its widespread use in many structural applications. Various strategies have been developed to toughen PLA; however, most of the methods lead to a trade-off in strength or modulus. In this study, a chain end engineering strategy was developed to toughen PLA via an industry-friendly melt processing method. Green acids with multifunctional groups, such as 1,2,3,4-butanetetracarboxylic acid (BTCA), were used to modify PLA chain ends/tails via a melt reaction. We report a remarkable improvement in toughness (16×) was achieved by the addition of a minimal amount of BTCA (0.5%). At the same time, the toughened PLA samples maintained the tensile strength and Young’s modulus of neat PLA, suggesting a unique toughening mechanism that is different from the plasticizing effect. Other acid–based modifiers with different numbers of functional groups were also studied in this work. To understand the toughening, we propose a chain end engineering picture that can improve the toughness via a reduction in the number density of chain ends or defects of entanglement and the formation of long-branch topological structures. This study demonstrates a unique and cost-effective strategy for toughening PLA via scalable melt reaction without sacrificing other mechanical properties of PLA, potentially broadening the applications.},

  doi          = {10.1021/acsapm.9b00888},

  journal      = {ACS Applied Polymer Materials},

  number       = 2,

  volume       = 2,

  place        = {United States},

  year         = {2019},

  month        = {12}

}

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