The Research On Polyamide And Nano-SiO₂ Modified Epoxy Resin

With the increase of traffic flows and over loading vehicles, the wear abrasion of the road surface of pavement is incresing greatly; which results that the pavements are damaged frequently within their service life. It is a current important subject that the various administer branches of highway face on how to prolong the highway lifespan, improve highway conditions and defend early disease of pavement. In this paper, using polyamide (PA) and nanometer-silica(nano-SiO2)as the modifiers of Epoxy Resin (EP), excellent innovative EP/PA/nano-SiO2 composite were parpared, and its preparing process, the mechanism of modification and main properties were studied. Furthermore, this composite has been used successfully for repairing pavement cracks on 107 national highway.Firstly based on a great deal of references and experiments, this paper optimizes the species and dosages of EP, curing agent, cure accelerator and diluent.Secondly, the effects of the dosage of PA on the shear strength, thermal property and Viscosity of composite are studied. The results show that the shear strength of composite materials firstly increases and then decreases when PA contents increase. When the loading of PA is 30%, the shear strength of composite comes up to the maximum(4.37Mpa), which is much higher than that of standard demand (2.0Mpa) of highway. Although PA improves the thermal stability of composite, it makes system viscosity increase greatly, which is disadvantage to actual workability.Thirdly, in order to improve the aging resistances of composite materials, based on above formulation, modified EP composites with nano-SiO2, which are embeded by coupling agents on its surface to improve its dispersion stability and compatibility with resin, were prepared. Functioned nano-SiO2 is characterized. The influence of three dispersion technologies on the preparation of composite materials were discussed and the result indicates the third dispersion method is the best of all, its shear strength increases by 90.7% and the glass transition temperature increase 7~8℃compared to pure EP. This paper tries to investigate the modification mechanism yet.Finally, the cause of common pavement distresses and the construction crafts of diseases treatment were discussed on the bases of field investigation in cement concrete pavement.