Epoxy composites/adhesives with silica
Ryszard Pilawka, Teofil Jesionowski
Quarterly No. 2, 2009 pages 112-116
DOI:
keywords: epoxy resin, epoxy composites, silica fillers, tensile and bending strength
abstract The epoxy compositions and composites hardened with 2-ethylimidazole (2EI) or 1-butylimidazole (1BI) with silica have been investigated. Epoxy resin used was Epidian 6 (product of Chemical Works ”Organika Sarzyna” in Nowa Sarzyna) and as filler was applied silica, product of precipitation reaction from solutions of sodium silicate and ammonium salts. The filler was introduced to the compositions in amounts 1; 2.5; 5 and 7 g per 100 g of the epoxy resin and the hardener was applied 1 g per 100 g of the resin. The time of dispergation of fillers was 120 minutes at 70°C. Epoxy composites were hardened in temperature 140°C for 4 hour. The particles size of the obtained powders using laser diffraction method (Mastersizer 2000, Malvern Instruments Ltd.) was determined. The investigations of viscosity of epoxy composition were carried out with the use the of rheometr ARES, Rheometric Scientific: the diameter of plates 25 mm, thickness between plates 1 mm. The tensile and bending strengths were measured with standards PN-EN ISO 527-1 (speed rate 5 mm/min) and PN-EN ISO178 (speed rate 1 mm/min) with using of testing machine Instron 4206, Instron Corporation. The particle size remains in interval 350 to 540 nm for silica. The addition of filler increases viscosities of epoxy composition (from 18.4 to 41.1 Pa•s). The epoxy compo-sites with filler have been higher tensile and bending strength that unfilled systems. The introduction of silica increased Young’s Modulus and modulus of elasticity and additionally tensile and bending strength of epoxy composites. Composites hardened with 1-buthylimidazole were characterized better mechanical properties than epoxy materials cured with 2-ethylimidazole.