Biodegradable Nanocomposite Films Based on Sodium Alginate and Cellulose Nanofibrils.

B Deepa,Nereida Cordeiro,Laly Pothan,Marisa Faria,Sabu Thomas,Eldho Abraham

doi:10.3390/ma9010050

Abstract

Biodegradable nanocomposite films were prepared by incorporation of cellulose nanofibrils (CNF) into alginate biopolymer using the solution casting method. The effects of CNF content (2.5, 5, 7.5, 10 and 15 wt %) on mechanical, biodegradability and swelling behavior of the nanocomposite films were determined. The results showed that the tensile modulus value of the nanocomposite films increased from 308 to 1403 MPa with increasing CNF content from 0% to 10%; however, it decreased with further increase of the filler content. Incorporation of CNF also significantly reduced the swelling percentage and water solubility of alginate-based films, with the lower values found for 10 wt % in CNF. Biodegradation studies of the films in soil confirmed that the biodegradation time of alginate/CNF films greatly depends on the CNF content. The results evidence that the stronger intermolecular interaction and molecular compatibility between alginate and CNF components was at 10 wt % in CNF alginate films.

Highlights

Bio-nanocomposite films developed from biopolymers have gained considerable attention due to their renewability, biodegradability, biocompatibility, low toxicity and their potential use in the packaging industry
Cellulose nanofibrils (CNF) isolated from sisal fiber by steam explosion coupled with the acid hydrolysis process was used to prepare nanocomposite films from alginate biopolymer
The similar chemical structures of the alginate matrix and the cellulose nanofibrils (CNF) led to strong adhesion between them through hydrogen bonding

Summary

Introduction

Bio-nanocomposite films developed from biopolymers have gained considerable attention due to their renewability, biodegradability, biocompatibility, low toxicity and their potential use in the packaging industry. In this context, studies based on two such biopolymers, namely cellulose and sodium alginate, have received renewed interest. The two novel forms of cellulose, namely cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC), appear to be attractive building blocks to produce high performance bionanomaterials They exhibit outstanding properties such as low density, low thermal expansion, high aspect ratio and important mechanical properties, which make them relevant in various applications [2,3,4,5,6]. Alginates and Materials 2016, 9, 50; doi:10.3390/ma9010050 www.mdpi.com/journal/materials alginate-based biocomposites have been used in food packaging, tissue engineering, biomedicine fields due to their fields non‐toxicity, biodegradability, biocompatibilitybiocompatibility and unique gel‐forming and pharmaceutical due to their non-toxicity, biodegradability, and unique characteristics [8]

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