Significantly improving strength and oil-adsorption performance of regular porous polydimethylsiloxane via soft template approach

Abstract

A soft template, polyethylene glycol (PEG), was used for the preparation of polydimethylsiloxane (PDMS) oil absorbent. The preparation can be finished does not involve special equipment that normally required by conventional duplicating processes base on hard template. PEG/PDMS ratio, the key synthesis parameter, was systematically optimized in terms of both oil capacity and mechanical strength. Compared with previously reported PDMS materials developed using hard template, the optimized absorbents have comparable capacities of various oils in the range of 4.5–21.5 g/g, faster absorption rate and significantly improved mechanical strength with elongation at break significantly enhanced from 60 to 97% to greater than 200%. These improved properties can be explained by the regular distribution of macropore size that exhibits a signature twin-head peak dominated at about 120 and 200 μm. That fractional distribution is not affected by increased PEG/PDMS ratio until a structural collapse occurs at the ratio of 6 suggests specific and uniform interactions between PEG soft template and PDMS. Also examined are recyclability, anti-deformation property and oil-keeping performance, which are of practical importance under realistic storage and application conditions were also examined.