Research Article Use of TBzTD as Noncarcinogenic Accelerator for ENR/SiO 2 Nanocomposites: Cured Characteristics, Mechanical Properties, Thermal Behaviors, and Oil Resistance Laksamon Raksaksri, 1 Saowaroj Chuayjuljit, 1 Phasawat Chaiwutthinan, 2 and Anyaporn Boonmahitthisud 1 1 Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Tailand 2 MTEC, National Science and Technology Development Agency (NSTDA), Tailand Science Park, Khlong Luang, Pathum Tani 12120, Tailand Correspondence should be addressed to Anyaporn Boonmahitthisud; anyaporn.b@chula.ac.th Received 6 April 2017; Accepted 7 June 2017; Published 31 July 2017 Academic Editor: Domenico Acierno Copyright © 2017 Laksamon Raksaksri et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tis study reported the use of tetrabenzylthiuram disulphide (TBzTD) as a noncarcinogenic accelerator in a traditional sulfur curing system of epoxidized natural rubber (ENR)/nanosilica (nSiO 2 ) composites. ENR used in this work was synthesized via in situ epoxidation of natural rubber (NR) in the presence of performic acid generated from the reaction of formic acid and hydrogen peroxide at 50 ∘ C for 8 h to acquire the epoxide content of about 40 mol%. Accordingly, the resulting ENR was referred to as ENR 40. Te curing characteristics, mechanical properties, thermal behaviors, dynamic mechanical properties, and oil resistance of ENR 40/nSiO 2 nanocomposites flled with three loadings of nSiO 2 (1, 2, and 3 parts per hundred parts of rubber) were investigated and compared with NR and neat ENR 40. Te results revealed that the scorch and cure times of ENR 40/nSiO 2 nanocomposites were slightly longer than those of NR but slightly shorter than those of ENR 40. Te tensile properties and tear strength for both before and afer aging of all ENR 40/nSiO 2 nanocomposites were higher than those of ENR 40, while the glass transition temperature, storage modulus at −65 ∘ C, thermal stability, and oil resistance of ENR 40/nSiO 2 nanocomposites were higher than those of NR and ENR 40. 1. Introduction Natural rubber (NR) is one of the most important natural biosynthesis polymers and renewable resources that pos- sesses excellent mechanical properties owing to its ability to crystallize upon stretching (strain-induced crystallization), but its thermal, oxidation, and oil resistance cannot compete with some special purpose synthetic rubbers [1–12]. Tis is a normal consequence of its highly unsaturated hydrocarbon chain structure and nonpolar nature [2–4]. However, the certain properties of NR can be improved via chemical modifcations at the carbon-carbon double bonds (C=C) in its isoprene unit to produce functionalized specialty rubbers with an expanded range of physical and chemical properties. Te controlled partial epoxidation of NR to form epoxidized NR (ENR) is one of the important methods that introduce a new reactive group into the NR backbone, leading to the new and useful properties. Tis involves the random introduction of polar epoxide (oxirane) groups onto the C=C in the repeat unit of NR by the two consecutive reactions. Te frst one included the “in situ” formed peracid generated from the endothermic reaction of hydrogen peroxide (H 2 O 2 ) and the acid, followed by the exothermic epoxidation reaction, lead- ing to an increased polarity and a reduction in the C=C in the rubber chains [5, 8, 9, 12–18]. As a consequence, ENR would have oil and oxidation resistance comparable to some of the synthetic rubbers, depending on the extent of epoxidation (mol% epoxidation) [5, 9, 10, 12]. It has been reported that ENR with 50 mol% epoxidation exhibits oil resistance similar to that of medium-acrylonitrile-content nitrile rubber and Hindawi International Journal of Polymer Science Volume 2017, Article ID 9721934, 11 pages https://doi.org/10.1155/2017/9721934