Abstract

Influence of nature and concentration of silica on swelling (in water/acid environments) and structure of polyepoxy composites

Author(s): Starokadomsky Dmitro, Telegeev Igor

It was determined that silica addition in epoxypolymer is able to activate swelling process in 1Ì solutions of the hydrochloric and nitric acids, and to reduce in water and concentrated nitric acid. By nature of influence on the swelling process silica are divided on coarsely dispersed (specific surface 50-100m2/g),middle dispersed (100-300m2/g) and finely dispersed (300-500 m2/g). It was define that the swelling process of composites in 2-5 times intense in acids solutions than in water, and in nitric acid in 1,5-2 times is more intense than in the hydrochloric (5-10%against 3-6%after 100 days). The swelling curve does not reach saturation in acids unlike of water medium. It was explained by the processes of decomposing (dissolution), and in concentrated nitric acids the swelling reach 40-60%and concludes for 6- 8 days of decomposing producing foam solution. It is shown that the swelling of the filled composite material can be weaken noticeably in the field of 5 wt.%(comparing both with others concentrations, and with unfilled composites), in particular for water, solution of the hydrochloric and concentrated nitric acids. Bymicroscopic techniques (SEM, AFM) it is shown that silica influence on the swelling process can be related to decrease in an amount of pores and its distribution and also appearance of a structure