POS9-0102
Evaluation of Physical Property and Biodegradability of Immiscible PBAT/PHBH Blend Films
Topic
S9. Polymer Technology for Sustainability
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Atsunori Ishida (Graduate School of Agricultural and Life Sciences, The University of Tokyo)
Co-Author(s)
Abstract
The biodegradation rate of biodegradable plastics varies depending on the material type and can be controlled by blending polymers with different degradation rates. In this study, to control the degradation of PBAT (poly[butylene adipate-co-terephthalate]), what exhibits poor biodegradability in non-composting environments, immiscible PBAT/PHBH (poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate]) blend film was investigated. Selective enzymatic degradation of PHBH by PHB depolymerase did not proceed when PHBH content was 20% or less, indicating that the surface was covered by PBAT. Enzymatic etching revealed that the phase-separated structure changes from sea-island to co-continuous as PHBH increased. Biodegradation tests in seawater showed that low-PHBH-content films were not degraded like PBAT pure-film, while 40% PHBH film showed accelerated degradation. These results indicate that biodegradability depends not only on blend ratio but also on phase-separated structure and surface composition and is hindered when surface contains a large amount of poorly degradable PBAT.
