Abstract

The objective of this work was to examine the effect of inorganic additives on thermal behavior of homo- and hetero-polymeric hydrogel. Nano SiO2 and TiO2 doped acrylic acid (AA) based homo-polymeric and acrylic acid/vinyl pyrrolidone (AA/VP) based hetero-polymeric hydrogels were synthesized by using in-situ free radical polymerization technique. Additives were used in the ratio of 0.005, 0.5 and 1 (wt %) on AA based homo-polymeric hydrogels. Hetero-polymeric hydrogels were prepared in ratios of 1:3, 2:2 and 3:1 (AA/VP). Additives were used in only AA/VP (3:1) and they were added 0.5 and 1 (wt %). Thermal behaviour of hydrogels, were investigated by TGA-DTA analysis. The effect of doping on pore structure of hydrogels was demonstrated by SEM analysis. SEM/EDX measurements confirmed the presence of additives in the hydrogels. The dispersions of SiO2 and TiO2 on hydrogel were indicated by elemental mapping and their amounts were compared with EDX analysis.

Key words: Nano-SiO2; TiO2; poly(acrylic acid) (PAA); thermal behavior; hydrogels.