Graphene-filled natural rubber nanocomposites: Influence of the composition on curing, morphological, mechanical, and electrical properties
Thananya Siriwas, Skulrat Pichaiyut
, Markus Susoff, Svea Petersen, Charoen Nakason
, Markus Susoff, Svea Petersen, Charoen NakasonVol. 17., No.8., Pages 819-836, 2023
DOI: 10.3144/expresspolymlett.2023.61
DOI: 10.3144/expresspolymlett.2023.61
Corresponding author: Charoen Nakason 
GRAPHICAL ABSTRACT
ABSTRACT
The properties of graphene (GP) filled rubber nanocomposites were investigated in functions of rubber type (unmodified natural rubber (NR) and epoxidized natural rubber with 25 mol% epoxides (ENR-25)) and filler content. The Fourier transform infrared spectroscopy (FTIR) spectrum indicated that GP surfaces contain polar hydroxyl and carbonyl functional groups. The ENR-25/GP compound exhibited higher maximum torque, torque difference, storage modulus, initial relaxation modulus, bound rubber, and degree of reinforcement with smaller GP aggregates dispersed in the rubber matrix than the NR/GP composites. Additionally, an increasing trend of tensile strength was observed in the ENR-25/GP composite, but the contrary trend was obviously seen in the NR/GP composites due to the interaction between polar functional groups in ENR-25 and GP surfaces. Furthermore, a higher Payne effect (filler-filler interaction) was found in the NR/GP composites, corresponding to larger GP agglomerates and voids dispersed in the NR matrix. Moreover, the ENR-25/GP composite had higher electrical conductivity and dielectric constant than the NR/GP composite due to the higher polarity of the ENR with the dipoles, leading to increasing orientation polarization and interfacial polarization.
