Work

Rapid-cycle epoxy prepreg for automotive composites: thermal behavior and unconventional cure kinetics

Year: 2025

Type: article

Abstract: Fast-curing prepregs are increasingly gaining attention for high-throughput composite manufacturing, especially in the automotive industry where cost, cycle time, and scalability are critical. In this work, we investigated the thermal and mechanical behavior of a commercial fast-cure carbon/epoxy prepreg processed via hot compression molding in a 13-minute cycle. Thermogravimetric analysis (TGA) showed thermal stability up to 300 °C, while differential scanning calorimetry (DSC) revealed an atypical dual-mechanism curing behavior. Both dynamic and isothermal DSC analyses demonstrated deviations from conventional kinetics, including non-linear Arrhenius behavior and a shift in activation parameters depending on the method employed. The prepreg achieved a glass transition temperature of 153 °C and delivered tensile, compressive, and interlaminar shear strengths of 786 MPa, 276 MPa, and 42 MPa, respectively. With a low void content (2.8 vol%) and full cure completion experimentally confirmed within 13 minutes, this material demonstrates strong potential for structural automotive applications. The study provides new insights into the kinetic complexity of snap-cure epoxy systems and supports their applicability in fast-cycle composite manufacturing.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.06.042

Authors: Celson Luiz Homem de Mello Junior, Manoel Cleber de Sampaio Alves, Marcos Valério Ribeiro, Marcel Yuzo Kondo, Edson Cocchieri Botelho, Michelle Leali Costa

Institution: Universidade Estadual Paulista (Unesp)

Language: English

Topic: Epoxy Resin Curing Processes

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $1,640