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Effect of environments on the thermal properties of epoxy adhesives modified with nano- and micro-particles for in-situ timber bonding

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Abstract

This paper reports the investigation made on the effect of nano and micro-particles additions on the thermal properties of epoxy based adhesives when exposed to different environmental conditions. The thermal behaviors of the adhesives are measured using dynamic mechanical thermal analysis (DMTA) following exposure to different temperatures and humidities which include temperatures of 20, 30 and 50°C, relative humidities of 65, 75 and 95% RH and soaking in water at 20°C and placed in the oven at 50°C. The dynamic thermal properties reported include storage modulus and loss modulus, the loss tangent and the glass transition temperature, Tg. For nano-and micro-particles filled adhesives, the glass transition temperature increases with increase in temperature even though the adhesives are subjected to high humidity and this is due to further cross-linking. The results show that room temperature cured epoxies are only partially cured at room temperature.

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