A comparative study of rice husk ash and siliceous earth as reinforcing fillers in epoxidized natural rubber composites

Abstract

Rice husk ash (RHA) and siliceous earth (SE) were compared as alternative reinforcing fillers in epoxidized natural rubber (ENR) vulcanizates. The effects of RHA and SE on processability, curing characteristics, mechanical, thermal and morphological properties, and thermoelastic behavior of vulcanizates were studied, in the presence and absence of bis(triethoxysilylpropyl) tetrasulfide (TESPT) silane coupling agent. The results indicated that the RHA offers processing advantages over the commercial SE. The filled ENR vulcanizates without TESPT provided higher tensile strengths than the unfilled ENR vulcanizates, but had lower elongations at break. This is attributed to physical interactions between filler particles and rubber matrix, which affects the reinforcement by the filler. The modification of filler surfaces with TESPT resulted in further improved properties of the rubber vulcanizates. This is attributed to the coupling of polymer matrix and filler particles via TESPT linkages that increased the polymer–filler interactions. It was also found that the RHA filler, a renewable resource, exhibited similar reinforcement to the conventional SE. This indicates that the RHA has great potential as a reinforcing filler that can substitute for conventional SE in polymer composites. POLYM. COMPOS., 39:414–426, 2018. © 2016 Society of Plastics Engineers

Thermodynamically and kinetically favored locations of rice husk ash particles in the phase structure, and the properties of epoxidized natural rubber/thermoplastic polyurethane blends

“…To increase oil resistance, heat resistance, and due to reasons of compatibility epoxidized natural rubber (ENR) was used as a blend rather than simple NR. The improvement of damping property and hardness of TPU by blending with ENR has been reported in our previous work . It is well established that TPUs drawbacks of high damping properties and hardness can be compensated by blending it with ENR, especially with dynamic curing.…”

“…The RHA powder from burning of agricultural waste rice husk was supplied by Thunyakit Nakhorn Pathom Rice Mill Co., Ltd. (Nakhon Pathom, Thailand). The RHA particles were first ground finely and further heat treated at 700 °C for 6 h to burn off the carbonaceous materials, with procedures described in our previous work …”

“…Rice husk ash (RHA) is a renewable resource with silicon dioxide (SiO 2 ) as its major component, similar to the conventional silica filler used in rubber industry. The physical properties of RHA used in the work have been reported elsewhere . It has been found out that silica is the predominant component of RHA with trace amounts of various elements such as potassium, phosphorus, alumina, iron, sodium, magnesium, and calcium also present.…”

“…The physical properties of RHA used in the work have been reported elsewhere. 14,15 It has been found out that silica is the predominant component of RHA with trace amounts of various elements such as potassium, phosphorus, alumina, iron, sodium, magnesium, and calcium also present. The topography of RHA which was characterized by scanning electron microscope (SEM) is irregular in shape with smooth surface.…”

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

“…It is well established that many desirable properties of rubber products can be achieved through rubber/rubber blend [1][2][3], rubber/polymer blend [4][5][6][7][8] and rubber composites [9][10][11][12][13][14][15][16][17][18][19][20]. It has been reported that latex blending offers compatible or miscible blend without phase separation and flocculation [9,13].…”