ABSTRACT
This chapter describes research on the preparation, modification, and hybridization of one-dimensional ionic ladder-like polysilsesquioxanes (PSQs). It also describes the preparation of various ionic ladder-like PSQs with hexagonally stacked structures by hydrolytic polycondensation of the corresponding organotrialkoxysilanes. Ladder-type PSQs are representative soluble PSQs with regular molecular structures, and their structures are classified into two types: “perfect ladder structure” and “ladder-like structure.” The ladder-like PSQs are soluble, rigid, and anisotropic in addition to having the superior physical properties of SQs, as described, because they are one-dimensional structures. The ladder-like structure is a representative molecular structure of soluble PSQs with high molecular weight. Polymer electrolyte fuel cells have attracted much attention recently because of their excellent potential as power devices with high-energy conversion efficiencies and no emission of pollutants. The side-chain groups of the soluble ladder-like PSQs prepared by the hydrolytic condensation of organotrialkoxysilanes or organotrichlorosilanes are often restricted.
