Polymer Bulletin, Vol.78, No.4, 2009-2023, 2021
Cure characteristics and physico-mechanical properties of natural rubber/silica composites: effect of natural rubber-graft-poly(2-hydroxyethyl acrylate) content
The grafting of poly(2-hydroxyethyl acrylate) onto natural rubber (NRgPHEA) was used in order to compatibilize silica filler in NR composites. NR/silica compounds were prepared with various NRgPHEA contents from 0 to 12 phr, while the 14.5% grafting level in NRgPHEA and 20 phr silica content was held fixed. The cure characteristics of the compound were examined with a moving die rheometer. The physico-mechanical properties of NR/silica composites were analyzed by tensile testing, thermal gravimetric analysis, determination of bound rubber content and dynamic mechanical analysis. The results showed that scorch time and cure time decreased, while cure rate index increased with NRgPHEA content. The highest 100% modulus, 300% modulus, reinforcing index and tensile strength were obtained with 3 phr NRgPHEA. The addition of NRgPHEA can enhance wet skid resistance and thermal stability.
Keywords:Natural rubber;Poly(2-hydroxyethyl acrylate);Graft copolymer;Compatibilizer;Silica;Composite