Cooperative Effects of Cellulose Nanocrystals and Sepiolite When Combined on Ionic Liquid Plasticised Chitosan Materials.

Pei Chen,Tony Mcnally,Fengwei Xie,Fengzai Tang

doi:10.3390/polym13040571

Pei Chen, Tony Mcnally + Show 2 more

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https://doi.org/10.3390/polym13040571

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Abstract

Cellulose nanocrystals (CNCs) and/or sepiolite (SPT) were thermomechanically mixed with un-plasticised chitosan and chitosan/carboxymethyl cellulose (CMC) blends plasticised with 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]). Examination of the morphology of these materials indicates that SPT aggregates were reduced when CNCs or [C2mim][OAc] were present. Inclusion of CNCs and/or SPT had a greater effect on material properties when the matrices were un-plasticised. Addition of SPT or CNCs altered the crystalline structure of the un-plasticised chitosan matrix. Moreover, a combination of SPT and CNCs was more effective at suppressing re-crystallisation. Nonetheless, the mechanical properties and surface hydrophobicity were more related to CNC/SPT–biopolymer interactions. The un-plasticised bionanocomposites generally showed increased relaxation temperatures, enhanced tensile strength, and reduced surface wettability. For the [C2mim][OAc] plasticised matrices, the ionic liquid (IL) dominates the interactions with the biopolymers such that the effect of the nanofillers is diminished. However, for the [C2mim][OAc] plasticised chitosan/CMC matrix, CNCs and SPT acted synergistically suppressing re-crystallisation but resulting in increased tensile strength.

Highlights

Natural biopolymers have attracted tremendous interest in creating new and functional materials due to their renewability, biodegradability, and biocompatibility
The goal of this work is to understand the effects of inclusion of cellulose nanocrystals (CNCs) and SPT on the structure and properties of chitosan and chitosan/carboxymethyl cellulose (CMC) materials prepared by thermomechanical processing
While it is widely accepted that for composites of polymers and nanomaterials, material properties are largely determined by the level of dispersion of the nanomaterial and polymer crystallinity, we propose that interactions between the biopolymer, plasticiser, and nanofillers play a more dominant role in determining material properties here

Summary

Introduction

Natural biopolymers have attracted tremendous interest in creating new and functional materials due to their renewability, biodegradability, and biocompatibility. Among these polymers is, cellulose composed of D-anhydro-glucopyranose joined together by β-1,4-glycosidic bonds [1]. Cellulose composed of D-anhydro-glucopyranose joined together by β-1,4-glycosidic bonds [1] It is widely available in plants and constitutes the most abundant renewable polymer resource. Regenerated cellulose has found wide application such as in food, biomedicine, agriculture, packaging, water treatment, textiles, and in optical/electrical devices [2]. Chitosan has been widely studied for application in areas as diverse as food, biomedical treatment, pharmaceutics, cosmetics, water treatment, agriculture, and textiles [3,4,5,6]

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