Modification of poly(lactate) via polymer blending with microbially produced poly[(R)-lactate-co-(R)-3-hydroxybutyrate] copolymers

Yusuke Imai; Yuichi Tominaga; Shinji Tanaka; Masaru Yoshida; Sho Furutate; Shunsuke Sato; Sangho Koh; Seiichi Taguchi

doi:10.1016/j.ijbiomac.2024.130990

Modification of poly(lactate) via polymer blending with microbially produced poly[(R)-lactate-co-(R)-3-hydroxybutyrate] copolymers

Int J Biol Macromol. 2024 Mar 19;266(Pt 1):130990. doi: 10.1016/j.ijbiomac.2024.130990. Online ahead of print.

Authors

Yusuke Imai¹, Yuichi Tominaga², Shinji Tanaka³, Masaru Yoshida³, Sho Furutate⁴, Shunsuke Sato⁴, Sangho Koh⁵, Seiichi Taguchi⁶

Affiliations

¹ Multi-Material Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 4-205, Sakurazaka, Moriyama-ku, Nagoya, Aichi 463-8560, Japan. Electronic address: y-imai@aist.go.jp.
² Multi-Material Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 4-205, Sakurazaka, Moriyama-ku, Nagoya, Aichi 463-8560, Japan.
³ Interdisciplinary Research Center for Catalytic Chemistry, AIST, Tsukuba, Ibaraki, Japan.
⁴ Kaneka Corp., Takasago, Hyogo, Japan.
⁵ Graduate School of Science, Technology and Innovation, Kobe University, Nada, Kobe 657-8501, Japan.
⁶ Graduate School of Science, Technology and Innovation, Kobe University, Nada, Kobe 657-8501, Japan; Engineering Biology Research Center, Kobe University, Nada, Kobe 657-8501, Japan. Electronic address: staguchi86@people.kobe-u.ac.jp.

PMID: 38508553
DOI: 10.1016/j.ijbiomac.2024.130990

Abstract

This study investigated the effect of polymer blending of microbially produced poly[(R)-lactate-co-(R)-3-hydroxybutyrate] copolymers (LAHB) with poly(lactate) (PLA) on their mechanical, thermal, and biodegradable properties. Blending of high lactate (LA) content and high molecular weight LAHB significantly improved the tensile elongation of PLA up to more than 250 % at optimal LAHB composition of 20-30 wt%. Temperature-modulated differential scanning calorimetry and dynamic mechanical analysis revealed that PLA and LAHB were immiscible but interacted with each other, as indicated by the mutual plasticization effect. Detailed morphological characterization using scanning probe microscopy, small-angle X-ray scattering, and solid-state NMR confirmed that PLA and LAHB formed a two-phase structure with a characteristic length scale as small as 20 nm. Because of mixing in this order, the polymer blends were optically transparent. The biological oxygen demand test of the polymer blends in seawater indicated an enhancement of PLA biodegradation during biodegradation of the polymer blends.

Keywords: Biodegradable; Plasticization; Poly(hydroxyalkanoate); Poly(lactic acid); Tensile elongation.