Fly ash particles and precipitated silica as fillers in rubbers. I. Untreated fillers in natural rubber and styrene–butadiene rubber compounds

Abstract

ABSTRACT:In this study, we investigated the effects of untreated precipitated silica (PSi) and fly ash silica (FASi) as fillers on the properties of natural rubber (NR) and styrenebutadiene rubber (SBR) compounds. The cure characteristics and the final properties of the NR and SBR compounds were considered separately and comparatively with regard to the effect of the loading of the fillers, which ranged from 0 to 80 phr. In the NR system, the cure time and minimum and maximum torques of the NR compounds progressively increased at PSi loadings of 30 -75 phr. A relatively low cure time and low viscosity of the NR compounds were achieved throughout the FASi loadings used. The vulcanizate properties of the FASi-filled vulcanizates appeared to be very similar to those of the PSi-filled vulcanizates at silica contents of 0 -30 phr. Above these concentrations, the properties of the PSi-filled vulcanizates improved, whereas those of the FASi-filled compounds remained the same. In the SBR system, the changing trends of all of the properties of the filled SBR vulcanizates were very similar to those of the filled NR vulcanizates, except for the tensile and tear strengths. For a given rubber matrix and silica content, the discrepancies in the results between PSi and FASi were associated with fillerfiller interactions, filler particle size, and the amount of nonrubber in the vulcanizates. With the effect of the FASi particles on the mechanical properties of the NR and SBR vulcanizates considered, we recommend fly ash particles as a filler in NR at silica concentrations of 0 -30 phr but not in SBR systems, except when improvement in the tensile and tear properties is required.

Mechanical Properties of Epoxy Resin – Fly Ash Composite

“…The demand for the light weight materials such as for surfaces of ships had led to the development of fly -ash based thermosetting resins [2][3][4][5][6]. In fibre epoxy composites the addition of fly ash led to a reduction of the density and increase in modulus of composites [4].…”

Static and Dynamic Mechanical Properties of Vinylester Resin Matrix Composites Filled with Fly Ash

“…The physical properties of silanized and unsilanized fly ash filled unsaturated polyester composites in both uncured and cured states were reported by Sen et al [10] They observed a lower cure rate in case of silanized fly ash filled composites and a higher cure rate in case of unsilanized flyash-filled composites compared to the neat resin. Sombatsompop et al [11] reported a comparative study on the use of fly ash and precipitated silica as fillers in rubbers. They observed discrepancies in the results between precipitated silica and fly ash silica for different rubber matrix systems and concluded that the filler-filler interactions, actual rubber content in the vulcanizates and particle size of the fillers were responsible for such discrepancies.…”

Optimizing the Properties of Vulcanized Compounds for Foodstuff Conveyor Belts in Industrial Microwave Per-Heating

“…Next, the other substances were added to reduce the silica crystallization and improve the filler dispersion. During this procedure, the siloxane (-Si-O-Si) and silanol (-Si-OH) on the silica surfaces easily react with silane and PEG, reducing the surface polarity (by breaking the cross-linking agents, especially polysulfide), and hence increasing their hydrophobicity [12]. This chemical change improves the compatibility with rubber and reduces the silica absorption that otherwise prolongs vulcanization in the MgCO 3 Fig.2 vulcanizates.…”