Hybridized reinforcement of natural rubber with silane‐modified short cellulose fibers and silica

Abstract

Natural-rubber-based hybrid composites were prepared by the mixture of short cellulose fibers and silica of different relative contents with a 20-phr filler loading with a laboratory two-roll mill. The processability and tensile properties of the hybrid composites were analyzed. The tensile modulus improved, but the tensile strength and elongation at break decreased with increasing cellulose fiber content. The scorch safety improved with the addition of 5-phr cellulose fiber in the composites. The Mooney viscosity significantly decreased with increasing cellulose fiber content. To modify the surface properties of the cellulose fiber and silica fillers, a silane coupling agent [bis(triethoxysilylpropyl)tetrasulfide, or Si69] was used. The effects of Si69 treatment on the processing and tensile properties of the hybrid composites were assessed. We found that the silane treatment of both fillers had significant benefits on the processability but little benefit on the rubber reinforcement. The strength of the treated hybrid composite was comparable to that of silica-reinforced natural rubber. Furthermore, to investigate the filler surface modification and to determine the mixing effects, infrared spectroscopic and various microscopic techniques, respectively, were used. From these results, we concluded that the fillers were better dispersed in the composites, and the compatibility of the fillers and natural rubber increased with silane treatment. In conclusion, the hybridized use of short cellulose fibers from a renewable resource and silica with Si69 presented in this article offers practical benefits for the production of rubber-based composites having greater processability and more environmental compatibility than conventional silica-filler-reinforced rubber.

Phenolic resin‐crosslinked natural rubber/clay nanocomposites: Influence of clay loading and interfacial adhesion on strain‐induced crystallization behavior

“…Considering the TEM images shown in Figure , the PhOH‐crosslinked NR/clay nanocomposite containing 10 phr clay (PhOH‐NRNC10) showed that the dispersion of clay was relatively poor. It was well accepted that the good dispersion of filler in NR matrix prevented the formation of structural defects, as a result of aggregated filler, which weakened the NR network . Thus, the poor dispersion of clay layer in the NR matrix filled with 10 phr clay caused a decrease of tensile strength.…”

Effect of Silane Treatment Methods on Physical Properties of Rice Husk Flour/Natural Rubber Composites

“…ey suggested that the prolonged scorch time and cure time of NR composites resulted from the better interaction between the filler and rubber matrix. In addition, the increase in scorch time and cure time of NR composites containing TESPT was also reported in natural rubber reinforced with short cellulose fiber/silica [22], natural rubber filled with fly ash [28], and natural rubber reinforced with silica [28].…”

“…e small band that occurred at 2931 cm −1 was the stretching vibration of the -CH 2 groups of the attached TESPTon UW-STand W-STsurface [22]. Another absorption band that emerged at 1037 cm −1 was related to the Si-O-Si stretching of the siloxane groups of TESPT on UW-ST and W-STsurface [23].…”

Natural Rubber with Polyhedral Oligomeric Silsesquioxane, Nanocomposites, and Hybrids Compared by Molecular Modeling

“…The use of nanofillers to reinforce NR has high expectation because nanofillers have shown in many cases an enhancement of the mechanical properties; conventional inclusion of inorganic fillers by dispersion is more widely used over organic fillers, where carbon black and silica are the most used that have comparable tensile strength, but lower tensile modulus ( E ) than exhibited by silica composites . With the current demand for fillers from renewable resources, organic fillers have become more widely used, especially in the form of fibers, although lower performance than the inorganic fillers has been reported . There are several studies where a synergetic contribution using hybrid fillers (organic–inorganic) appears to enhance mechanical properties as well as increase thermal and physico‐chemical properties …”