Preparation and Characterization of Bio-Based PLA/PBAT and Cinnamon Essential Oil Polymer Fibers and Life-Cycle Assessment from Hydrolytic Degradation.

Zormy Nacary Correa-Pacheco,Alfonso Barajas-Cervantes,Pedro Ortega-Gudiño,José Jesús Benítez-Jiménez,Liliana Beyalith Hurtado-Colmenares,Jaime Daniel Black-Solís,Silvia Bautista-Baños,Marcos Antonio Sabino-Gutiérrez

doi:10.3390/polym12010038

Abstract

Nowadays, the need to reduce the dependence on fuel products and to achieve a sustainable development is of special importance due to environmental concerns. Therefore, new alternatives must be sought. In this work, extruded fibers from poly (lactic acid) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) added with cinnamon essential oil (CEO) were prepared and characterized, and the hydrolytic degradation was assessed. A two-phase system was observed with spherical particles of PBAT embedded in the PLA matrix. The thermal analysis showed partial miscibility between PLA and PBAT. Mechanically, Young’s modulus decreased and the elongation at break increased with the incorporation of PBAT and CEO into the blends. The variation in weight loss for the fibers was below 5% during the period of hydrolytic degradation studied with the most important changes at 37 °C and pH 8.50. From microscopy, the formation of cracks in the fiber surface was evidenced, especially for PLA fibers in alkaline medium at 37 °C. This study shows the importance of the variables that influence the performance of polyester-cinnamon essential oil-based fibers in agro-industrial applications for horticultural product preservation.

Highlights

In the last few decades, there has been a growing interest in the use of biodegradable materials for food packaging instead of conventional petroleum-based plastics [1]
In relation to the Differential Scanning Calorimetry (DSC) results, this blend was selected because showed the lowest melting peak value and because its crystallization temperature was intermediate between values reached for the other blends, which guarantees that it can solidify quickly, which in turn is favorable for the subsequent flexibility and extrusion process of the fibers
The disperse phase (PBAT) was observed in the form of spherical particles that leave some pores in the PLA matrix because of incompatibility between the two phases, which has been demonstrated in related papers of compatibility/miscibility in PLA/PBAT polymer blends [36,37]

Summary

Introduction

In the last few decades, there has been a growing interest in the use of biodegradable materials for food packaging instead of conventional petroleum-based plastics [1]. Poly (lactic acid) (PLA) is one of the most promising [2]. It is a biocompatible, biodegradable, and FDA (Food and Drug Administration)-approved and generally recognized as safe (GRAS) for Polymers 2020, 12, 38; doi:10.3390/polym12010038 www.mdpi.com/journal/polymers. Polymers 2020, 12, 38 use in contact with food, making it a good alternative as an environmentally friendly packaging material to extend the shelf life of fruit and vegetables [3]. PLA has the disadvantage of being brittle [4] It has been blended with other polymers of high elasticity such as poly (butylene adipate-co-terephthalate) (PBAT). PLA/PBAT blends have demonstrated excellent physico-chemical and mechanical properties, being employed for different applications in medicine, industry, and packaging [6,7,8,9,10,11]

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Conclusion