Enhancing Mechanical and Thermal Properties of Natural Rubber Grafted Poly(Ethyl Acrylate) Using Glutaraldehyde as a Curing Agent

Authors

  • Rawiporn Promsung
  • Nussana Lehman
  • Ekwipoo Kalkornsurapranee

DOI:

https://doi.org/10.48048/siam.2025.68004

Abstract

Ethyl acrylate (EA) monomer was successfully grafted onto natural rubber (NR) via redox polymerization, which enhanced the grafting efficiency to 91%. The grafted-NR was clarified using ATR-FTIR. This study focuses on enhancing the mechanical and thermal properties of the grafted-NR vulcanized by using a low-temperature curing system of glutaraldehyde (GA). It was found that the mechanical properties of grafted-NR were superior to those ungrafted-NR, with a 35% increase in modulus, 145% increase in tensile strength, and 17% increase in elongation at break. Moreover, oil resistance properties and thermal stability of NR were significantly improved after graft copolymerization owing to the presence of functional groups in the molecular chain. It was also demonstrated that the grafted-NR exhibited improved crosslinking, elucidated through swelling and temperature scanning stress relaxation (TSSR) measurements. The relaxation behavior was evaluated through TSSR, revealing two significant peaks in chemical and physical relaxations. According to these findings, it can be summarized that the properties of grafted-NR improved by using a GA curing agent with several possibilities of interaction, including GA-rubber crosslinks, GA-protein crosslinks, GA-ester crosslinks, and polar-polar interactions facilitated by the presence of carbonyl groups on grafted-NR molecules. Therefore, this current work is beneficial for future flexible material applications requiring high mechanical properties, oil resistance, and thermal stability.

 

Keywords: Natural rubber latex, Graft copolymerization, Glutaraldehyde

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Published

2025-01-02

Issue

Section

Original Research Articles