HDPE/Chitosan Composites Modified with PE-g-MA. Thermal, Morphological and Antibacterial Analysis.

Poliana S. Lima,Suédina M. L. Silva,Marcus V. L. Fook,Rossanna Trocolli,Renate M. R. Wellen,Luis Rojo,Miguel A. Lopez-Manchado

doi:10.3390/polym11101559

Poliana S. Lima, Suédina M. L. Silva + Show 5 more

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https://doi.org/10.3390/polym11101559

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Abstract

In this work, composites of high density polyethylene (HDPE) with chitosan were prepared by melt compounding in a laboratory internal mixer. Maleic anhydride grafted HDPE (PE-g-MA) in a concentration up to 25 phr was used as a compatibilizer to enhance the dispersing effect of chitosan in the HDPE matrix. The degree of crystallinity was investigated by X-ray diffraction (XRD) and the thermal properties were analyzed by differential scanning calorimetry (DSC) and thermogravimetry (TG). The morphology was investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The integrity of composites was evaluated by mechanical properties and antibacterial properties were assessed against Escherichia coli (DH5a). Neither crystallinity nor HDPE’s melting parameters changed upon addition of chitosan and PE-g-MA. Chitosan aggregates were observed, which were dispersed upon addition of PE-g-MA, which also provided improved mechanical performance. Chitosan significantly improved the bacteriostatic effect of HDPE compounds preventing bacteria to colonize thus reducing the number of viable colony-forming units (CFU). This study revealed that HDPE/chitosan composites could be obtained by melt compounding, at lower cost and additionally having antibacterial properties, which might provide a new formulation option for developing antimicrobial film for food packaging.

Highlights

IntroductionFossil fuel used for both energy production and plastic manufacturing has finite availability
Polymers have supplied most of the common materials in modern society because they present several desired features like versatility, lightness, easy processability, softness and low cost being suitable for multiple uses such us packaging, automotive, medical devices fabrication, construction and electro-electronics industries among many others [1,2,3].Fossil fuel used for both energy production and plastic manufacturing has finite availability.Approximately 6–8% of the global production of fossil fuel goes into the synthesis of plastic materials such as polyolefin, polystyrenes, polyesters or polyamides
The environmental concerns about the lack on biodegradability have led to an increased interest in the development of green plastics and composite materials derived from renewable natural resources with distinct or superior physical and chemical properties [4,5,6]

Summary

Introduction

Fossil fuel used for both energy production and plastic manufacturing has finite availability. 6–8% of the global production of fossil fuel goes into the synthesis of plastic materials such as polyolefin, polystyrenes, polyesters or polyamides. The environmental concerns about the lack on biodegradability have led to an increased interest in the development of green plastics and composite materials derived from renewable natural resources with distinct or superior physical and chemical properties [4,5,6]. Polythene shares about 64% among the synthetic plastics waste produced, and it is considered as the most commonly found solid waste that has been recognized as a major threat to marine life [7,8].

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