Synthesis and characterization of hyperbranched polymer consisting of silsesquioxane derivatives

Abstract

Hyperbranched polysiloxanes were synthesized by polyhydrosilylation of silsesquioxane derivatives and vinyl derivatives in the presence of Karstedt's catalyst. The hyperbranched polymers (HBPs) with M n ¼5.2Â10 3 -9.8Â10 4 were soluble in common solvents and exhibited good thermal stability. HBPs based on double-decker-shaped silsesquioxane showed a large thermal-optical coefficient compared with the corresponding linear polymer. The refractive index values of the polymers obtained tended to decrease with the increasing structure size of the co-monomers.

Tripodal polyhedral oligomeric silsesquioxanes as a novel class of three-dimensional emulsifiers

“…Although the incompletely condensed POSS derivatives have generally been used as precursors for mono-functionalized POSSs, 51,52 they can also serve as three-dimensional scaffolds of tripodal molecules such as initiators, 53 ligands for transition metals 54 and cross-linking agents. 42,55 Hence, precisely defined POSS emulsifiers with multiple hydrophobic and hydrophilic substituents would exploit the threedimensional structure of POSS to its fullest extent. Additionally, it is expected that incompletely condensed POSSs can effectively restrict crystallinity by lowering the rigidity to gain solubility, without losing thermal stability, in comparison with completely condensed POSSs, which could result in aggregation (aggregation formation due to the high crystallinity has been utilized for construction of micro-structures; e.g., see Hayakawa et al 28 , Hirai et al 29 , , Hirai et al 30 , Ishida et al 31 ).…”

“…From this point of view, polyhedral oligomeric silsesquioxanes (POSSs) [17][18][19][20][21] are one of the most suitable candidates because of their precisely defined three-dimensional structure. POSSs have been widely used as fillers, [22][23][24][25][26][27] cross-linkers, 28-33 monomers [34][35][36][37] and substituents to polymer side chains, [38][39][40][41][42][43] to attain high performance. To obtain a POSS emulsifier, the basic strategy is the construction of amphiphilic POSS derivatives.…”

Multi-Alkenylsilsesquioxanes as Comonomers and Active Species Modifiers of Metallocene Catalyst in Copolymerization with Ethylene

“…Di-functional POSS derivatives have attracted considerable attention in recent years. Depending on the types of reactive substituents, they have been successfully incorporated into such macromolecules as polyimide [9][10][11], polysiloxane [12], polyamide [13], polyurethane [14], polysulfone [15], vinylidene-arylene copolymer [16], and polyethylene [17], via the polyethylene [17], via the step-growth polymerization process [9][10][11][13][14][15][16]18], or as pendant groups and cross-linkage sites through the coordination copolymerization [17].…”

Synthesis of Dialkenyl-Substituted Double-Decker Silsesquioxanes as Precursors for Linear Copolymeric Systems

“…Si-H, Si-HC=CH 2 are of special interest as there are reports on efficient catalytic reactions used for synthesis of copolymeric DDSQ based systems (e.g. hydrosilylation, cross-metathesis or silylative coupling) [9][10][11][12][13]. The macromolecular DDSQ-based systems are of specific importance as the silsesquioxane is embedded in the linear chain of the copolymer.…”