High-Strength Bio-Degradable Polymer Foams with Stable High Volume-Expansion Ratio Using Chain Extension and Green Supercritical Mixed-Gas Foaming

Autor: Haoyu Long, Hongsen Xu, Jingwen Shaoyu, Tianchen Jiang, Wei Zhuang, Ming Li, Junyang Jin, Lei Ji, Hanjie Ying, Chenjie Zhu
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Polymers
Volume 15
Issue 4
Pages: 895
ISSN: 2073-4360
DOI: 10.3390/polym15040895
Popis: The preparation of biodegradable polymer foams with a stable high volume-expansion ratio (VER) is challenging. For example, poly (butylene adipate-co-terephthalate) (PBAT) foams have a low melt strength and high shrinkage. In this study, polylactic acid (PLA), which has a high VER and crystallinity, was added to PBAT to reduce shrinkage during the supercritical molded-bead foaming process. The epoxy chain extender ADR4368 was used both as a chain extender and a compatibilizer to mitigate the linear chain structure and incompatibility and improve the foamability of PBAT. The branched-chain structure increased the energy-storage modulus (G’) and complex viscosity (η*), which are the key factors for the growth of cells, by 1–2 orders of magnitude. Subsequently, we innovatively used the CO2 and N2 composite gas method. The foam-shrinkage performance was further inhibited; the final foam had a VER of 23.39 and a stable cell was obtained. Finally, after steam forming, the results showed that the mechanical strength of the PBAT/PLA blended composite foam was considerably improved by the addition of PLA. The compressive strength (50%), bending strength, and fracture load by bending reached 270.23 kPa, 0.36 MPa, and 23.32 N, respectively. This study provides a potential strategy for the development of PBAT-based foam packaging materials with stable cell structure, high VER, and excellent mechanical strength.
Databáze: OpenAIRE
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