Open Access

ARTICLE

Influence of Processing Route on the Mechanical Properties of Poly(Lactic Acid)-Poly(Caprolactone)-Basalt Fiber Composites Prepared via Planetary Extrusion

Declan Mary Colbert^1,*, Eyman Manaf¹, Zeeshan Ali¹, Steven Rowe², Chris Doran², Trevor Howard², Vlasta Chyzna³, Evan Moore³, Alan J. Murphy³, Patrick Doran⁴, Golnoosh Abdeali¹, Declan M. Devine¹
1 PRISM Research Institute, Technological University of the Shannon, Athlone, Ireland
2 Applied Polymer Technology Gateway, Technological University of the Shannon, Athlone, Ireland
3 CISD, Technological University of the Shannon, Athlone, N37 HD68, Ireland
4 Department of Polymer and Mechanical Engineering, Technological University of the Shannon, Athlone, Ireland
* Corresponding Author: Declan Mary Colbert. Email:
(This article belongs to the Special Issue: Development and Application of Biodegradable Plastics)

Journal of Polymer Materials https://doi.org/10.32604/jpm.2026.076318

Received 18 November 2025; Accepted 12 January 2026; Published online 23 January 2026

Abstract

A comparative analysis was performed on poly(lactic acid) (PLA), poly(caprolactone) (PCL), basalt fiber (BF) composites produced using two distinct approaches: direct blending and masterbatching. The limitations of PLA-BF composites with regard to distribution and adhesion are well-documented, as are chemical treatment methods (addition of compatibilisers, surface treatments, silanization). This work aimed to study an industrially relevant potential solution of utilising a PCL-BF masterbatch, prepared as a 50/50 wt.% blend using planetary roller extrusion (PEX) to both improve the distribution and homogeneity of the fibers as well as provide a secondary adhesion site to facilitate improved mechanical properties of the final PLA-PCL-BF composite. The resultant materials were injection moulded to prepare ISO standard test specimens and tested on the basis of their physical properties via tensile testing, impact strength testing, flexural analysis, Fourier transform infrared spectroscopy and water absorption capability. The results displayed that the incorporation of PCL and BF led to an increase in ductility of the composite materials, allowing for improvements in the inherent brittleness of virgin PLA. Major increases in the impact strength were achieved with the utilisation of a 25% PCL/BF masterbatch, allowing for a greater than 50% increase. As an overall observation, the use of a masterbatching process, opposed to direct blending of the constituent materials allows for a greater consistency of composite to be achieved at the expense of increased gains.

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Keywords

PLA; natural fibers; composites; planetary extrusion

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