Evaluation on Structural Properties and Performances of Graphene Oxide Incorporated into Chitosan/Poly-Lactic Acid Composites: CS/PLA versus CS/PLA-GO.

Siti Noor Kamilah Mohamad,Nor Hasimah Mohamed,Nor Shafizah Ishak,Irmawati Ramli,Nor Azowa Ibrahim,Md Saiful Islam,Luqman Chuah Abdullah

doi:10.3390/polym13111839

Siti Noor Kamilah Mohamad, Nor Hasimah Mohamed + Show 5 more

Open Access

https://doi.org/10.3390/polym13111839

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Abstract

In this work, to fabricate a novel composite consisting of chitosan/poly-lactic acid doped with graphene oxide (CS/PLA-GO), composites were prepared via solution blending method to create various compositions of CS and PLA (90/10, 70/30 and 50/50CS/PLA-GO). Graphene oxide (GO) was added into a PLA solution prior to blending it with chitosan (CS). The surface morphology and structural properties of synthesized composites were characterized using FT-IR, SEM and XRD analysis. The performances of synthesized composites on thermal strength, mechanical strength, water absorption, and microbial activity were also evaluated through standard testing methods. The morphology of 70/30CS/PLA-GO became smoother with the addition of GO due to enhanced interfacial adhesion between CS, PLA and GO. The presence of GO has also improved the miscibility of CS and PLA and has superior properties compared to CS/PLA composites. Moreover, the addition of GO has boosted the thermal stability of the composite, with a significant enhancement of Td and Tg. The highest Td and Tg were accomplished at 389 °C and 76.88 °C, respectively, for the 70/30CS/PLA-GO composite in comparison to the CS and PLA that recorded Td at 272 °C and 325 °C and Tg at 61 °C and 60 °C, respectively. In addition, as reinforcement, GO provided a significant influence on the tensile strength of composites where the tensile modulus showed remarkable improvement compared to pure CS and CS/PLA composites. Furthermore, CS/PLA-GO composites showed excellent water-barrier properties. Among other compositions, 70/30CS/PLA revealed the greatest decrement in water absorption. From the antibacterial results, it was observed that 90/10CS/PLA-GO and 70/30CS/PLA-GO showed an inhibitory effect and had wide inhibition zones which were 8.0 and 8.5 mm, respectively, against bacteria Bacillus Subtillis B29.

Highlights

Chitosan (CS) is a natural biopolymer and has great potential as an antimicrobial packaging material, coating or blending with a wide array of pathogenic bacteria and fungi that are inhibited on direct contact with CS [1]
A blend of composite films composed of CS/poly-lactic acid (PLA) and CS/PLA-graphene oxide (GO) with various compositions were successfully prepared using a solution-blending technique
The results successfully showed that the incorporation of GO into CS/PLA indicated some level of attractive interaction between CS, GO and PLA

Summary

Introduction

Chitosan (CS) is a natural biopolymer and has great potential as an antimicrobial packaging material, coating or blending with a wide array of pathogenic bacteria and fungi that are inhibited on direct contact with CS [1]. According to recent studies, adding graphene-based materials GO, GO modified with silane, GO modified with stearic acid and GO modified with poly(ethylene glycol) (PEG) to a PLA matrix significantly improved the mechanical efficiency, thermal properties, gas barrier and water vapor permeability of the resulting final product. In this regard, the appropriate functionalization of the GO surface becomes a critical factor in achieving compatible interfaces that facilitate good compatibilizer dispersion into the PLA matrix, resulting in improved final product properties. SSchheemme e1. 1Sc.hSecmhaetimc foarttihcefsoyrntthheseissoyfnCthhiteossains/oPfolCylhacitticoascaidnc/Pomoplyosliatecstaicndacchiidtoscaonm/ppoloylsaictteics and ch taiccida-gcriadp-hgernaepoxhideenceomoxpoidsiteescvoiambpleondsiintgesmvetihaodb.lending method

Materials and Methods

Composite Characterizations

Results

Water Absorption Analysis

Conclusions