New Hyperbranched Poly(siloxysilanes):  Variation of the Branching Pattern and End-Functionalization

Abstract

The synthesis of new poly(siloxysilanes) by polyhydrosilation of AB2, AB4, and AB6 monomers using a solid-supported catalyst is described. Analysis of the polymers by gel permeation chromatography shows weight-average molecular weight values near 5−10 000 amu with polydispersities of ∼2. Addition of fresh monomer to the polymerized material only leads to a slight increase in molecular weight. In all cases, polymerization is accompanied by significant intramolecular cyclization side reaction. These results can be explained by considering factors such as the unequal reactivity of the different oligomeric species and their tendency to form cyclic species, but no clear evidence for a growth-limiting effect arising from steric crowding could be seen. End capping of the terminal silicon hydride groups by hydrosilation with a variety of reagents has been demonstrated, affording a diversity of functionalized poly(siloxysilane) materials.

Modification of Anodized Aluminum Film by Hyperbranched Poly(siloxysilane)s in Conductive Polymer Aluminum Solid Electrolytic Capacitor

“…HBPSi, therefore, offers intriguing possibilities for the materials especially as coatings, adhesives, and surfactants. [10][11][12] In this paper, we report that modification of aluminum anodized film by HBPSi increases contact area with PEDOT, and improves the capacitor's characteristics, such as capacitance and ESR.…”

“…HBPSi, therefore, offers intriguing possibilities for the materials especially as coatings, adhesives, and surfactants. [10][11][12] In this paper, we report that modification of aluminum anodized film by HBPSi increases contact area with PEDOT, and improves the capacitor's characteristics, such as capacitance and ESR.HBPSi with vinyl terminated groups was synthesized by the hydrosilylation of AB 2 monomer, 1,5-divinyl-1,1,3,5,5-pentamethyltrisiloxysilane, in the presence of platinum catalyst at room temperature for 3 h in bulk (Figure 1). Furthermore, we also used crosslinked type HBPSi that prepared with the crosslinking reaction of the resulting HBPSi and 1,1,3,3-tetramethyldisiloxane as a cross linker in the presence of platinum catalyst in toluene at room temperature for 1 h. Molecular weight of as prepared and cross linked polymers was determined by using gel permeation chromatography (GPC) with polystyrene standard.…”

Synthesis of hyperbranched polymers with controlled degree of branching

“…31 For example, 5-acetoxyisophthalic acid was used an AB 2 monomer in melt polymerization at 250 1C to prepare hyperbranched aromatic polyesters, which were insoluble in organic solvents because of the intermolecular dehydration between the carboxylic acid groups that occurred during melt polymerization. Hydrolysis of the crude product produced a soluble hyperbranched polyester having carboxylic acid groups as an end B function, as shown in Scheme 2.…”

Polyester Dendrimers

“…As the number of A functionalities in a monomer increases, the degree of branching tends to reduce for steric reasons. Examples include those of Mathias [122], Hunter [123], and Yoon [124] for the use of A 3 B monomers and the work of Miravet and Fréchet for the use of both A 4 B and A 6 B monomers [125]. This approach can be used without adding core molecules or with added core molecules.…”