New Polylactic Acid Composites Reinforced with Artichoke Fibers

Luigi Botta,Vincenzo Fiore,Roberto ,Antonino Valenza,Tommaso Scalici

doi:10.3390/ma8115422

Abstract

In this work, artichoke fibers were used for the first time to prepare poly(lactic acid) (PLA)-based biocomposites. In particular, two PLA/artichoke composites with the same fiber loading (10% w/w) were prepared by the film-stacking method: the first one (UNID) reinforced with unidirectional long artichoke fibers, the second one (RANDOM) reinforced by randomly-oriented long artichoke fibers. Both composites were mechanically characterized in tensile mode by quasi-static and dynamic mechanical tests. The morphology of the fracture surfaces was analyzed through scanning electron microscopy (SEM). Moreover, a theoretical model, i.e., Hill’s method, was used to fit the experimental Young’s modulus of the biocomposites. The quasi-static tensile tests revealed that the modulus of UNID composites is significantly higher than that of the neat PLA (i.e., ~40%). Moreover, the tensile strength is slightly higher than that of the neat matrix. The other way around, the stiffness of RANDOM composites is not significantly improved, and the tensile strength decreases in comparison to the neat PLA.

Highlights

Over the last few decades, there has been a growing interest in using new and better performing materials, both in terms of intrinsic properties and from the environmental impact point of view
Natural fibers are considered as an alternative to conventional synthetic ones as reinforcement for polymer-based composites
In our previous work [12], artichoke fibers extracted from the plant stem were characterized in order to consider them as potential reinforcement of composite structures

Summary

Introduction

Over the last few decades, there has been a growing interest in using new and better performing materials, both in terms of intrinsic properties and from the environmental impact point of view. Increasing attention to ecological issues led the researchers to propose natural-based reinforcements with the aim to reduce the environmental impact and to optimize the efficiency of agricultural production, reducing disposal problems In this view, natural fibers are considered as an alternative to conventional synthetic ones as reinforcement for polymer-based composites. Composites reinforced with natural fibers often involved conventional oil-based polymers as matrices, with high environmental impact during the production process, service life, life-end and disposal phases. For this reason, matrices obtained from renewable sources were studied by paying particular attention to the material biodegradability. A theoretical model, i.e., Hill’s method, was used to fit the experimental Young’s modulus of the biocomposites

Materials

Composite Preparation

Findings

Hill’s Method for Tensile Modulus Prediction