Chain-extended epoxy-functionalised poly-(2-ethylhexylacrylate) as impact and adhesive modifier for epoxy resin

摘要

Epoxy resin is widely used for coatings,adhesives,casting,electrical insulation materials and other applications.However,unsolved problems still remain in its applications.The main problem is low toughness:cured epoxy resin is rather brittle with poor resistance to the propagation of cracks,derived from the internal stress generated by shrinkage in the cooling process from cure temperature to room temperature.The objective of this study was to improve the flexibility of diglycidyl ether of bisphenol-A based epoxy resin by using a liquid rubber.For this purpose,epoxy functionalised poly-(2-ethylhexylacrylate) (EFPEHA) and chain extended poly-(2-ethylhexylacrylate) (CEEFPEHA) based on the EFPEHA and Tris-2,4,6-(N,N-dimethyl amino methyl) phenol have been synthesised.The products were characterised by IR spectroscopy,non-aqueous titration,viscosity measurement and solubility characteristics.The developed CEEFPEHA was incorporated as a modifier into the epoxy matrix and its effect was studied by impact and adhesive strength measurements.Fractographic examinations under scanning electron microscope indicated the formation of rubber domains in the epoxy matrix.