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V. Ravi Raj,
Deiveegan Ramasamy,
Nishanth P,
Ashokkumar P,
Mary Zerlin. J,
P. Uma,
M M Nandakumar,
A. Parvathi Priya,
M. Saraswathi,
- Associate Professor, Department of Mechanial Engineering, Sri Sairam Engineering College, Chennai, Tamil Nadu, India
- Lecturer, Department of Civil and Architectural Engineering, University of Technology and Applied science, Salalah, , Oman
- Professor & Head, Department of Aeronautical Engineering, Gopalan College of Engineering and Management, Bengaluru, Karnataka, India
- , Department of Civil Engineering, Sona College of Technology, Salem, Tamil Nadu, India
- PG Scholar, Department of Orthopaedic Conditions, Sri Balaji Vidyapeeth, Pillayarkuppam, Puducherry, India
- Assistant Professor, Department of Chemistry, Prathyusha Engineering College, Tiruvallur, Tamil Nadu, India
- UG scholar, Department of Mechanical Engineering, St. Joseph’s College of Engineering, OMR, Chennai, Tamil Nadu, India
- Assistant Professor, Department of Chemistry, R.M.K. Engineering College, Kavaraipettai, Chennai, Tamil Nadu, India
- Associate Professor, Department of Electronics And Communication Engineering, Panimalar Engineering College, Chennai, Tamil Nadu, India
Abstract
This study develops a multifunctional natural-fibre-reinforced polymer composite based on alkali-treated jute fabric, bio-based epoxy, kraft lignin and a small amount of multiwalled carbon nanotubes (MWCNTs), with particular emphasis on polymer-matrix modification, fibre–matrix interfacial behaviour and intrinsic damage sensing. Kraft lignin was incorporated at 0, 2, 4 and 6 wt.% to examine its influence on polymer-chain mobility, interfacial morphology, thermal stability and mechanical response, while 0.5 wt.% MWCNTs was introduced into the selected 4 wt.% lignin formulation to impart piezoresistive functionality. FTIR results indicated enhanced hydrogen-bonding interactions within the polymer–lignin–fibre system, with the O–H band shifting from 3338 cm⁻¹ for JE to 3325 cm⁻¹ for JE-L4. SEM observations showed reduced fibre pull-out and improved polymer adhesion at 4 wt.% lignin, whereas 6 wt.% lignin promoted agglomeration, microvoid formation and incomplete fibre wetting. The JE-L4 composite exhibited a flexural strength of 118.6 MPa and flexural modulus of 5.12 GPa, corresponding to improvements of 28.4% and 22.5%, respectively, relative to the reference JE composite. Its storage modulus increased to 3.31 GPa and glass-transition temperature to 87.6 °C, confirming greater restriction of epoxy-chain mobility. The JE-L4C composite further increased flexural strength and modulus to 121.9 MPa and 5.36 GPa, respectively, while providing an effective gauge factor of approximately 18.7. Overall, 4 wt.% lignin provided the most favourable balance between polymer-network modification, interfacial reinforcement and processability, while MWCNT incorporation transformed the modified bio-epoxy matrix into an electrically responsive phase capable of monitoring strain and progressive damage.
Keywords: bio-epoxy; jute fibre; kraft lignin; polymer composites; fibre–matrix interphase; MWCNT; piezoresistive sensing; structural health monitoring.
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Journal of Polymer & Composites
| Volume | 14 | |
| 05 | ||
| Received | 21/09/2026 | |
| Accepted | 29/09/2026 | |
| Published | 01/10/2026 | |
| Publication Time | 10 Days |