Controlling Miscibility of the Interphase in Polymer-Grafted Nanocellulose/Cellulose Triacetate Nanocomposites

Hiroto Soeta; Shuji Fujisawa; Tsuguyuki Saito; Akira Isogai

doi:10.1021/acsomega.0c02772

Controlling Miscibility of the Interphase in Polymer-Grafted Nanocellulose/Cellulose Triacetate Nanocomposites

ACS Omega. 2020 Sep 10;5(37):23755-23761. doi: 10.1021/acsomega.0c02772. eCollection 2020 Sep 22.

Authors

Hiroto Soeta¹, Shuji Fujisawa¹, Tsuguyuki Saito¹, Akira Isogai¹

Affiliation

¹ Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 113-8657 Tokyo, Japan.

Abstract

The miscibility at the interphase of polymer-grafted nanocellulose/cellulose triacetate (CTA) composite films was tailored using different casting solvents. The polymer-grafted cellulose nanofibrils were prepared by modifying surfaces of 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized nanocellulose with amine-terminated poly(ethylene glycol) (PEG). The PEG-grafted nanocelluloses were individually dispersed in dichloromethane, 1,4-dioxane, and N,N-dimethylacetamide. The PEG-grafted nanocellulose/CTA composite films were prepared by mixing the nanocellulose dispersion and CTA solution and subsequent casting-drying. The miscibility of PEG and CTA at the interphase of the composite was controlled by controlling the solvent, which was confirmed by dynamic mechanical analysis. All the composite films showed high optical transparency. However, the mechanical properties of the composites differed because of the difference in the PEG/CTA interfacial miscibility. The composite films with better PEG/CTA interfacial miscibility showed higher Young's modulus, strength, and toughness. This interfacial design technique paves the way to exploiting the reinforcing potential of highly transparent and hydrophobic surface-grafted nanocellulose/polymer composite materials.