The Structure and Mechanical Properties of Hemp Fibers-Reinforced Poly(ε-Caprolactone) Composites Modified by Electron Beam Irradiation

Rafał Malinowski,Wojciech Głuszewski,Aneta Raszkowska-Kaczor,Volodymyr Krasinskyi,Krzysztof Moraczewski,Lauren Wedderburn

doi:10.3390/app11125317

Abstract

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.

Highlights

One of the most important biodegradable polymers, produced from petroleum resources, is poly(ε-caprolactone) (PCL) [1,2,3,4,5]
The structure and mechanical properties of the investigated materials depended on three main factors: (i) processing conditions, (ii) qualitative and quantitative contribution of dispersed phase and (iii) the magnitude of the electron radiation dose
The final fibers’ structures in the obtained composites were closely linked to processing conditions, which depended on the percentage filling of these fibers in the polymer matrix

Summary

Introduction

One of the most important biodegradable polymers, produced from petroleum resources, is poly(ε-caprolactone) (PCL) [1,2,3,4,5]. The PCL properties need to be modified for some applications. PCL mechanical properties can be modified with the use of mineral or vegetable fillers that simultaneously lower the price of the polymer. It is important because PCL in its pristine form is generally more expensive than conventional polymers and even some biodegradable ones such as PLA [9,10,11,12,13] or TPS [14,15,16,17]

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Conclusion