Influence of Zirconia Nanofillers on Physical and Mechanical Characteristics of Palmyra Palm Fruit and Jackfruit Peel Fiber-Reinforced Polymer Composites

¹ Department of Mechanical Engineering, PSG Institute of Technology and Applied Research, Coimbatore, Tamil Nadu, India
² Department of Mechanical Engineering, Bannari Amman Institute of Technology, Sathyamangalam, Tamil Nadu, India
³ Department of Physics, Nandha College of Technology, Perundurai, Tamil Nadu, India
⁴ Department of Automobile Engineering, Rajalakshmi Engineering College, Chennai, Tamil Nadu, India
⁵ Department of Mechanical Engineering, Vinayaka Mission’s Kirupananda Variyar Engineering College, Vinayaka Mission’s Research Foundation (Deemed to be University), Salem, Tamil Nadu, India
⁶ Department of Mechanical Engineering, Nandha College of Technology, Perundurai, Tamil Nadu, India

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 29 May 2026

Abstract

This study seeks to examine the mechanical properties of epoxy composites reinforced with natural fibers derived from hybrid palmyra palm fruit waste and jackfruit (Artocarpus heterophyllus) peel waste fibers, as well as to evaluate the impact of varying zirconia (ZrO₂) nano filler loadings on their physical and mechanical attributes. A 5% NaOH solution was utilized to mercerize the fibers of the palmyra palm fruit, and X-ray diffraction (XRD) analysis verified the crystallinity of the treated fibers and ZrO₂ nanofillers. Three distinct loadings of ZrO₂ nano fillers (2.5 wt. %, 5 wt. %, and 7.5 wt. %) and three fiber fractions (20 wt. %, 25 wt. %, and 30 wt. %) were employed. Composites were manufactured via hand lay-up techniques, and evaluations were conducted in accordance with ASTM standards. The findings indicated that the incorporation of nZrO₂ markedly improved tensile strength (up to ~32 MPa), tensile modulus (up to ~1555 MPa), flexural strength (up to ~78 MPa), impact resistance (up to ~1.8 J), hardness (up to ~64 HV), and interlaminar shear strength (up to ~82 MPa) relative to unfilled composites, with optimal performance achieved at 25 wt. % fiber loading and moderate filler content (2.5–5 wt %). Excessive fiber or filler loadings (30 wt % fiber or ≥7.5 wt % filler) led to diminished characteristics due to agglomeration and an increase in voids (up to about 7 wt. %).