Effect of Nano-Clay and Surfactant on the Biodegradation of Poly(Lactic Acid) Films.

Pooja C Mayekar,Ramani Narayan,Edgar Castro-Aguirre,Rafael Auras,Susan Selke

doi:10.3390/polym12020311

Abstract

This study examined the effect of nanoclays and surfactant on the hydrolytic degradation and biodegradation of poly(lactic acid) (PLA) and PLA nanocomposites. Organomodified montmorillonite (OMMT), unmodified montmorillonite (MMT) and an organomodifier (surfactant) for MMT (QAC) were extruded with PLA to produce PLA nanocomposites. The films were produced with the same initial molecular weight, thickness and crystallinity since these properties have a significant effect on the biodegradation process. The biodegradation experiments were carried out in an in-house built direct measurement respirometric system and were evaluated in inoculated vermiculite and vermiculite media for extended periods of time. Hydrolysis experiments were also conducted separately to decouple the abiotic/hydrolysis phase. The results showed no significant variation in the mineralization of PLA nanocomposites as compared to pristine PLA. The addition of nanoclays did not enhance the biodegradability of PLA when the initial parameters were strictly controlled. The hydrolysis test indicated that the nanoclays and surfactant did not aid in the degradation of PLA.

Highlights

Bio-based and biodegradable polymers have garnered great interest in the last decade as an alternative to the ever-growing demand for single-use petroleum based conventional polymers.Growing global concern regarding the environmental impacts and increasing awareness towards issues like plastic waste management and global climate change has led the consumers and in turn fueled governments and industries to adopt a greener or more sustainable approach [1]
The films were characterized for their initial molecular weight, thickness and crystallinity
The films were exposed to water media at 58 ± 2 ◦ C to determine how the nanoclays and surfactant affect the hydrolytic degradation

Summary

Introduction

Bio-based and biodegradable polymers have garnered great interest in the last decade as an alternative to the ever-growing demand for single-use petroleum based conventional polymers.Growing global concern regarding the environmental impacts and increasing awareness towards issues like plastic waste management and global climate change has led the consumers and in turn fueled governments and industries to adopt a greener or more sustainable approach [1]. Bio-based and biodegradable polymers have garnered great interest in the last decade as an alternative to the ever-growing demand for single-use petroleum based conventional polymers. Among the many waste management solutions, such as reducing, reusing, recycling and composting encouraged to reduce white pollution (i.e., single-use plastic contaminating the environment, reaching the oceans, nature and landfills), the development of biodegradable polymers has been a favorable one [2,3,4]. Poly(lactic acid)-PLA-a biobased and biodegradable plastic can provide an attractive solution to the waste disposal problem. PLA is a linear aliphatic polyester, which exhibits good stiffness, excellent barrier to flavor, good heat sealability, high clarity, ease of processing as well as grease and oil resistance comparable to conventional commodity plastics, such as polystyrene and poly(ethylene terephthalate) [7,8]

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