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Sustainable cellulose reinforcement from Pithecellobium dulce fruit skin for performance enhancement of Grewia hirsuta fiber composites

V. R. Sivakumar, M. Vinothkumar, C. Chanakyan, and R. Ashok Raj

Department of Mechanical Engineering, RVS College of Engineering and Technology, Coimbatore, India

Received: 6 April 2026 Accepted: 5 May 2026

Abstract:

This study investigates the mechanical, wear, fatigue, and water absorption behavior of sustainable vinyl ester composites reinforced with Grewia hirsuta microfibers and cellulose particles derived from Pithecellobium dulce fruit outer skin. Cellulose particles (~ 3 μm) were extracted through alkali treatment, bleaching, and ball milling, and incorporated as a microfiller to enhance interfacial bonding and reduce void content. Composites were fabricated via manual layup followed by ultrasonication and room-temperature curing using vinyl ester resin with methyl ethyl ketone peroxide as catalyst. Five composite formulations were developed: V (100 vol% resin, VS0 (60 vol% + 40 vol% fiber), VS1 (30 vol% fiber, 1 vol% cellulose), VS2 (40 vol% fiber, 3 vol% cellulose), VS3 (40 vol% fiber, 5 vol% cellulose), with the remaining fraction being resin. Mechanical (tensile, flexural, compression, impact), tribological (wear rate, coefficient of friction), fatigue, and water absorption tests were conducted. Among all samples, VS2 (40 vol% fiber + 3 vol% cellulose) exhibited optimal performance with tensile strength of 142.1 MPa, flexural strength of 180.8 MPa, compressive strength of 159.9 MPa, and impact strength of 4.9 kJ/m². It also showed superior tribological performance (specific wear rate: 0.023 mm³/Nm, coefficient of friction: 0.25), extended fatigue life (35,920 cycles at 25% UTS), and reduced water absorption (1.45%). SEM analysis confirmed uniform dispersion of cellulose particles, improved fiber–matrix adhesion, and reduced voids. The enhanced performance is attributed to the dual reinforcement mechanism, where Grewia hirsuta microfibers provide load-bearing capacity, while cellulose particles act as microfillers that improve stress transfer, fill microvoids, and strengthen interfacial bonding. This study demonstrates that bio-derived cellulose from Pithecellobium dulce waste can effectively enhance the multifunctional performance of vinyl ester composites for structural applications.

Keywords: Biopolymers; Composites; Fibers; Fillers; Mechanical characteristics; Wear

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05023-w

Chemical Papers 80 (9) 10523–10536 (2026)

Saturday, September 05, 2026