Enhancing compatibility in epoxy/vulcanized natural rubber (VNR)/Graphene nano-platelets (GNP) system using epoxidized natural rubber (ENR-50). (1st October 2019)

• Record Type: Journal Article
• Authors: Ka Wei, Kam; Leng, Teh Pei; Keat, Yeoh Cheow; Osman, Hakimah; Ying, Lim Bee
• Is Part Of: Composites. Number 174(2019)
• Publication Date: 2019-10-01
• Subjects: ENR-50 -- Compatibilizer -- FE-SEM -- TGA -- XRD; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2019.107058
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: This paper reports the effect of epoxidized natural rubber (ENR-50) as a compatibilizer on the mechanical, thermal, and electrical performances of epoxy/VNR and epoxy/VNR/GNP systems. Fixed blend ratios at 95/5 and 80/20 vol% of epoxy/VNR were studied. Epoxy/VNR and epoxy/VNR/GNP systems were prepared using magnetic stirring method, with ENR-50 contents varied at 0, 5, and 10 vol%. Flexural strength and modulus of two systems have successfully improved with 5 vol% of ENR-50 content. With the incorporation of ENR-50, the distribution of VNR phases in epoxy matrix was more homogenous, thus improving the compatibility of the system. Nevertheless, the toughness properties of the compatibilized system were lower as compared to the non-compatibilized system, albeit higher than pure epoxy. Thermal stability (Tmax ) of the compatibilized system was lower as compared to non-compatibilized system, which was attributed to the low thermal stability of oxygen-containing groups (epoxide groups) on ENR-50. The incorporation of ENR-50 decreased the electrical conductivity of compatibilized system. This was supported by the d-spacing values, as obtained from the XRD results. The compatibilized system also shows high cross-link density as compared to the non-compatibilized system, where ENR-50 inhibited the penetration of non-polar solvent molecules into the cross-linked network structure. Highlights: The novelty of this study is to investigate the effectiveness of ENR-50 as a compatibilizer in epoxy/VNR and epoxy/VNR/GNP systems. Vulcanized NR phase acted as effective toughening agent and elastomer spacers in epoxy resins as compared to un-vulcanized NR phase. Commercial epoxy resins (with three-dimensional cross-linked structure) are classified as brittleness materials with poor resistance to crack propagation and low toughness. Natural rubber (NR) was widely used to reduce the brittleness properties of epoxy resin due to itis a renewable biological resources and easily available in Malaysia.