Preparation of low-crystalline POSS containing two types of alkylammonium groups and its optically transparent film

In this study, a low-crystalline POSS containing two types of alkylammonium groups was successfully prepared by hydrolytic condensation of a mixture of two types of amino group-containing organotrialkoxysilanes, i.e. 3-(2-aminoethylamino) propyltrimethoxysilane and 3-aminopropyltrimethoxysilane, using aqueous trifluoromethanesulfonic acid as the catalyst and solvent. Due to the low molecular symmetry of the resulting POSS compound containing two different randomly distributed side-chain groups, its crystallization was suppressed, leading to the formation of an optically transparent film.