Toward Fully Bio-based and Supertough PLA Blends via in Situ Formation of Cross-Linked Biopolyamide Continuity Network

Liu, Hongzhi and Chen, Ning and Shan, Pengjia and Song, Pingan ORCID: https://orcid.org/0000-0003-1082-652X and Liu, Xuying and Chen, Jinzhou (2019) Toward Fully Bio-based and Supertough PLA Blends via in Situ Formation of Cross-Linked Biopolyamide Continuity Network. Macromolecules, 52 (21). pp. 8415-8429. ISSN 0024-9297


Abstract

Dynamic vulcanization has been demonstrated to be a versatile and efficient way of improving impact toughness of PLA. However, the existing vulcanization routes usually suffer from complicated presynthetic procedures and use of nonrenewable modifiers as well as markedly enhanced melt-viscosity. Herein, using both biomass-derived hydrogenated dimer acid (HDA) and an excess molar amount of l-lysine ethyl ester diisocyanate (LDI) as toughening monomers, we have developed a facile yet highly effective diisocyanate method for the design of fully bio-based PLA blends with excellent impact toughness and melt-flowability. The in situ formation and self-cross-linking of flexible biopolyamide (HDAPA) toughener, as well as its reactive compatibilization with PLA, were accomplished in a single melt-blending step. When incorporating the amount of HDAPA from 15 to 20 wt % or higher, the resulting blends evolved from the network-like morphology to the bi-continuous one with the cross-linked HDAPA network. At HDAPA content higher than 10 wt %, a sharp and persistent brittle–ductile transition occurred with an equilibrium impact strength of over 1200 J/m, and elongation-at-break was over 400%. Moreover, such a tremendous toughening effect was accompanied by low melt-viscosity and enhanced PLA crystallization. The matrix yielding triggered by internal cavitation of percolated HDAPA domains, together with the pull-out of many in situ formed block copolymers located at the interfaces, was found to be the major impact-toughening mechanism. This work offers a novel and facile strategy for fabricating high-performance and fully bio-based polymeric materials.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 25 Jan 2021 05:55
Last Modified: 31 Jan 2021 23:26
Uncontrolled Keywords: Brittle ductile transitions; Dynamic vulcanization; Elongation at break; In-situ formations; Internal cavitation; Reactive compatibilization; Toughening effects; Toughening mechanisms
Fields of Research (2008): 09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
03 Chemical Sciences > 0303 Macromolecular and Materials Chemistry > 030306 Synthesis of Materials
09 Engineering > 0912 Materials Engineering > 091209 Polymers and Plastics
09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
40 ENGINEERING > 4016 Materials engineering > 401609 Polymers and plastics
40 ENGINEERING > 4016 Materials engineering > 401602 Composite and hybrid materials
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
E Expanding Knowledge > 97 Expanding Knowledge > 970103 Expanding Knowledge in the Chemical Sciences
Socio-Economic Objectives (2020): 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280105 Expanding knowledge in the chemical sciences
28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280110 Expanding knowledge in engineering
Identification Number or DOI: https://doi.org/10.1021/acs.macromol.9b01398
URI: http://eprints.usq.edu.au/id/eprint/40604

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