Mechanical properties, thermal behaviors and oil resistance of epoxidized natural rubber/multiwalled carbon nanotube nanocomposites prepared via in situ epoxidation

Abstract

Epoxidized natural rubber (ENR)/multiwalled carbon nanotube (MWCNT) nanocomposites were prepared via in situ epoxidation of natural rubber (NR) using a molar ratio of formic acid/hydrogen peroxide to isoprene unit at 0.75/0.75 with five loadings of MWCNTs, ranging from 0.5–2.5 parts per hundred parts of rubber (phr), at 50°C for 4 h. Based on Fourier transform infrared spectra, the epoxide content of ENR in the nanocomposites was about 32.5–33.2 mole%. Accordingly, the products were referred to ENR30/MWCNT nanocomposites. The curing characteristics, mechanical properties (tensile properties, tear strength, and hardness), glass transition temperature ( Tg), thermal stability, and oil resistance of these in situ ENR30/MWCNT nanocomposites were investigated and compared with NR and neat ENR30. The results showed that the scorch and cure times of ENR30/MWCNT nanocomposites were the longest followed by NR and ENR30. The incorporation of an appropriate amount of MWCNTs into the in situ epoxidation apparently improved the properties of NR. Among them, the nanocomposites filled with 2 phr MWCNTs exhibited the highest mechanical properties, Tg, thermal stability, and oil resistance. The mechanical properties of the in situ nanocomposites were also compared with those of the control nanocomposites prepared by adding MWCNTs directly in the prepared ENR30 latex. It was found that at similar MWCNT loadings, the in situ nanocomposites exhibited higher mechanical properties than the control nanocomposites.

Vinyl acetate ethylene copolymer and nanosilica reinforced epoxidized natural rubber: Effects of sulfur curing systems on cure characteristics, tensile properties, thermal stability, dynamic mechanical properties and oil resistance

“…To determine the mol% epoxidation from the 1 H‐NMR analysis, two characteristic peaks were considered in relation with Eq. 2 ; where A 2.7 and A 5.14 are the integrate areas under the 1 H‐NMR peaks at about 2.7 ppm, corresponding to the epoxide proton, and at about 5.14 ppm, representing an olefinic proton, respectively.…”

“…It is well established that many desirable properties of rubber products can be achieved through rubber/rubber blend , rubber/polymer blend and rubber composites . It has been reported that latex blending offers compatible or miscible blend without phase separation and flocculation .…”

“…In this study, the rubber/polymer blend and rubber/polymer blend nanocomposite were prepared from epoxidized natural rubber (ENR), vinyl acetate ethylene copolymer (VAE) and nanosilica (nSiO 2 ) in the latex stage. ENR in the latex form can be synthesized via in situ epoxidation of natural rubber (NR) latex by performic acid generated from the reaction between acetic acid (HCOOH) and hydrogen peroxide (H 2 O 2 ) . ENR with 50 mol% epoxidation exhibits oil resistance similar to that of medium‐acrylonitrile‐content nitrile rubber and superior to that of chloroprene rubber .…”

“…However, it is more beneficial to add filler and/or reinforcement into rubber. With the advance of nanotechnology, an inclusion of inorganic nanofillers at a very low loading level into rubbers has recently received much attention . Among the inorganic nanofillers, nSiO 2 has been extensively used as a nonblack nanofiller in the rubber products .…”

Chitosan and Natural Rubber Latex Biocomposite Prepared by Incorporating Negatively Charged Chitosan Dispersion

“…However, the products from NRL show some weaknesses such as low modulus, barrier properties and electrical properties that affect the quality of the natural rubber (NR) products. Consequently, many attempts have been made to use a reinforcing filler such as graphene oxide [ 5 ], multiwalled carbon nanotube [ 6 ], organoclay [ 7 , 8 ], carbon black [ 9 ], silica [ 10 ], cassava starch [ 11 ], and carbon fiber [ 12 ], to improve NR properties. The incorporation of bio-fillers from renewable resources into NRL could result in new biocomposites with enhanced features and biodegradability, so it is of interest to study the possibility of using chitosan (CT) as a reinforcing filler for NRL.…”