An innovative functional compatibility strategy for poly (lactic acid) and polypropylene carbonate blends to achieve superior toughness, degradability, and optical properties

Ying Jing; Weihan Chi; Wei Zhang; Ying Qiu; Meng Gao; Lingxiao Yu; Lixin Song; Xiangyi Wang; Zhe Liu; Jialu Gao; Jiangting Huang; Yongchao Li; Guangxu Gao; Yujuan Gao; Yuanxia Wang; Na Wang

doi:10.1016/j.ijbiomac.2024.135702

An innovative functional compatibility strategy for poly (lactic acid) and polypropylene carbonate blends to achieve superior toughness, degradability, and optical properties

Int J Biol Macromol. 2024 Sep 18;280(Pt 1):135702. doi: 10.1016/j.ijbiomac.2024.135702. Online ahead of print.

Authors

Ying Jing¹, Weihan Chi¹, Wei Zhang², Ying Qiu³, Meng Gao², Lingxiao Yu¹, Lixin Song⁴, Xiangyi Wang¹, Zhe Liu¹, Jialu Gao⁵, Jiangting Huang⁵, Yongchao Li¹, Guangxu Gao¹, Yujuan Gao¹, Yuanxia Wang⁶, Na Wang⁶

Affiliations

¹ Liaoning Provincial Key Laboratory for Synthesis and Preparation of Special Functional Materials, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China; College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China.
² Shenyang Research Institute of Industrial Technology for Advanced Coating Materials, Shenyang 110300, China.
³ College of Chemistry, Jilin University, Changchun 130012, China.
⁴ Liaoning Provincial Key Laboratory for Synthesis and Preparation of Special Functional Materials, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China; College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China. Electronic address: lxsong@syuct.edu.cn.
⁵ College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China.
⁶ Liaoning Provincial Key Laboratory for Synthesis and Preparation of Special Functional Materials, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China.

PMID: 39304048
DOI: 10.1016/j.ijbiomac.2024.135702

Abstract

This study, for the first time, unveils the potential of dibutyl itaconate (DBI) in enhancing the compatibility between PLA (poly (lactic acid)) and PPC (polypropylene carbonate), systematically investigating the effects of DBI amount on the thermal, optical, rheological, mechanical, and degradation properties and microstructure of the PLA/PPC/DBI blends. The results showed that DBI could chemically react with PLA and PPC, forming a PLA-co-DBI-co-PPC copolymer structure, thereby improving the compatibility between PLA and PPC. When the DBI amount reached 8 wt%, only one T_g was observed in the blend system, and no distinct phase interface was visible in the fracture surface of the blend specimens. This indicated that at this DBI amount, the PLA and PPC had transitioned from a partially compatible system to a fully compatible system. With the increase in DBI amount in the system, the elongation at break and notched impact strength of the blends initially increased and then decreased, while the storage modulus, loss modulus, and complex viscosity showed a gradual downward trend. When the DBI amount increased to 10 wt%, the flexibility of the blends reached its peak, with the values rising to 494.7 % and 8494.1 J/m², respectively, representing 13.7 times and 2.5 times those of the neat PLA/PPC blends. At this point, the impact specimens exhibited significant plastic flow in the direction of force, showing distinct ductile fracture characteristics. Meanwhile, the degradation performance of the PLA/PPC blends increased with the addition of DBI. The introduction of DBI effectively facilitated the penetration of water molecules into the PLA/PPC molecular chains, enhancing the hydrolysis of ester bonds, leading to a maximum mass loss rate of 84.1 %, which was significantly higher than the 20.3 % of the neat PLA/PPC blends. In addition, the addition of DBI significantly reduced the haze of the blends while maintaining high light transmittance, demonstrating excellent optical properties (light transmittance remained above 92.4 %, and haze decreased from 37.1 % to 11.1 %). In conclusion, this study provides a new approach for the development of high-performance PLA-based biodegradable composites. The resulting blends exhibit excellent toughness, degradation performance, and optical properties, significantly enhancing their application potential in fields such as disposable products, packaging, agriculture, and 3D printing materials.

Keywords: Compatibility; Degradation performance; Dibutyl itaconate; Ductile fracture; PLA/PPC blends.