Cellulose nanofiber reinforced poly (lactic acid) with enhanced rheology, crystallization and foaming ability

Qian Ren; Minghui Wu; Long Wang; Wenge Zheng; Yuta Hikima; Takeshi Semba; Masahiro Ohshima

doi:10.1016/j.carbpol.2022.119320

Cellulose nanofiber reinforced poly (lactic acid) with enhanced rheology, crystallization and foaming ability

Carbohydr Polym. 2022 Jun 15:286:119320. doi: 10.1016/j.carbpol.2022.119320. Epub 2022 Mar 5.

Authors

Qian Ren¹, Minghui Wu², Long Wang³, Wenge Zheng¹, Yuta Hikima⁴, Takeshi Semba⁵, Masahiro Ohshima⁴

Affiliations

¹ Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; Advanced Materials and Composites Department, University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315000, China.
³ Ningbo Key Lab of Polymer Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: wanglong@nimte.ac.cn.
⁴ Department of Chemical Engineering, Kyoto University, Katsura, Kyoto 6158510, Japan.
⁵ Polymer Materials Laboratory, Kyoto Municipal Institute of Industrial Technology and Culture, 91 Chudoji Awata-cho, Shimogyo-ku, Kyoto, Japan.

PMID: 35337523
DOI: 10.1016/j.carbpol.2022.119320

Abstract

The incorporation of micro-/nano-particles is one of the most efficient approaches to reinforce poly (lactic acid) (PLA). However, introducing the inorganic particles which can compromise the green nature of PLA. Herein, we proposed a green strategy to add biodegradable cellulose nanofibers (CNFs) into the PLA matrix for eliminating its low melt strength and slow crystallization rate. Well-dispersed hydrophobic-modified CNFs in the PLA matrix were obtained through the combination of acetylation surface modification and the melt-compounding technology. The PLA/CNF composites notably improved crystallization properties and melt elasticity, compared with the neat PLA. Additionally, the foaming behavior of PLA was dramatically enhanced by introducing 2 wt% modified CNFs. At an ultralow pressure of 1.5 MPa, the prepared PLA/CNF nanocomposite foams exhibited the highest expansion ratio approximately 20.4. These results demonstrated that CNFs were extraordinarily helpful in enhancing the foamability of PLA, which are expected to be applied as a sustainable packaging material.

Keywords: Cellulose nanofibers; Crystallization; Foams; Poly (lactic acid); Rheological behavior.