Effect of Starch Plasticization on Morphological, Mechanical, Crystalline, Thermal, and Optical Behavior of Poly(butylene adipate-co-terephthalate)/Thermoplastic Starch Composite Films

Xiaoyan He; Fuhong Zhang; Congcong Li; Weiwei Ding; Yuanyuan Jin; Lisheng Tang; Ran Huang

doi:10.3390/polym16030326

Effect of Starch Plasticization on Morphological, Mechanical, Crystalline, Thermal, and Optical Behavior of Poly(butylene adipate-co-terephthalate)/Thermoplastic Starch Composite Films

Polymers (Basel). 2024 Jan 25;16(3):326. doi: 10.3390/polym16030326.

Authors

Xiaoyan He¹, Fuhong Zhang², Congcong Li³, Weiwei Ding², Yuanyuan Jin¹, Lisheng Tang¹, Ran Huang^{1

4}

Affiliations

¹ Department of Material Science and Engineering, Taizhou Institute of Zhejiang University, Taizhou 318000, China.
² Sanmen Megatron Tech. Co., Ltd., Taizhou 318000, China.
³ Center for Biotechnology and Biomedical Engineering, Yiwu Research Institute of Fudan University, Yiwu 322000, China.
⁴ Academy for Engineering and Applied Technology, Fudan University, Shanghai 200433, China.

Abstract

Starches plasticized with glycerol/citric acid/stearic acid and tributyl 2-acetylcitrate (ATBC), respectively, were processed with poly (butylene adipate-Co-terephthalate (PBAT) via extrusion and a film-blown process. All the composite films were determined for morphology, mechanical, thermal stability, crystalline, and optical properties. Results show that the most improved morphology was in the 30% glycerol plasticized PBAT/thermoplastic starch (TPS) composite films, characterized by the smallest and narrowest distribution of TPS particle sizes and a more uniform dispersion of TPS particles. However, the water absorption of PBAT/TPS composite films plasticized with glycerol surpassed that observed with ATBC as a plasticizer. Mechanical properties indicated insufficient plasticization of the starch crystal structure when using 10% ATBC, 20% ATBC, and 20% glycerol as plasticizers, leading to poor compatibility between PBAT and TPS. This resulted in stress concentration points under external forces, adversely affecting the mechanical properties of the composites. All PBAT/TPS composite films exhibited a negative impact on the initial thermal decomposition temperature compared to PBAT. Additionally, the haze value of PBAT/TPS composite films exceeded 96%, while pure PBAT had a haze value of 47.42%. Films plasticized with 10% ATBC, 20% ATBC, and 20% glycerol displayed lower transmittance values in the visible light region. The increased transmittance of films plasticized with 30% glycerol further demonstrated their superior plasticizing effect compared to other PBAT/TPS composite films. This study provides a simple and feasible method for preparing low-cost PBAT composites, and their extensions are expected to further replace general-purpose plastics in daily applications.

Keywords: PBAT; biodegradable films; optical property; plasticized starch.

Grants and funding

This work is financially supported by the Postdoctoral fellows of Taizhou (275104), Taizhou Municipal Science and Technology Program (21gya24, 22gya19), the National Key Research and Development Program China (2022YFC2009500), the Medical Engineering Fund of Fudan University (yg2021-005, yg2022-008), Guangdong Provincial Science and Technology Program (2023A0505050146), and the RIZT Industrial Program (2021ZSS04, 2022ZSS09, 2023ZM01, 2023CLG01, 2023CLG01PT).