Side-Loop Polymers Based on the Hydrosilylation of Polybutadiene

Abstract

Hydrosilylation of hydride-terminated poly(dimethylsiloxane) with polybutadiene in dilute solution yielded polysiloxane side-loops on a hydrocarbon base, a novel polymer architecture. When the ratio of silane to olefin was increased, the inherent viscosity of solutions dropped drastically, and polymer properties changed from tough rubbers to tacky materials. The results are rationalized on the basis of diminishing availability of olefin sites as the reaction proceeds. When one end of a difunctional silane attaches to an olefin site and no other olefin sites are available nearby, molecular motion eventually brings a remote olefin site in the molecule into proximity. Hydrosilylation then results in permanent ring folding. Subsequent hydrosilylations can then result in a dendrimer-like globular molecule. Contact angle measurements of side-loop adducts show temporal stability, indicating that the tendency of poly(dimethylsiloxane) side chains to migrate to or away from the surface, depending on the medium, is circumvented by anchoring both ends.

Controlled Interfacial Assembly and Transfer of Brushlike Copolymer Films

“…The probe liquid (water) can diffuse through the PBd to swell the underlying PEO, a process that would be facilitated if the topmost surface is not completely uniform in PBd coverage. In freshly prepared PBd dip‐coated surfaces,30 hysteresis is low and a value of θ A =108° agrees well with our highest‐density monolayers (Figure 4). Interestingly, at high densities, θ R approaches the value measured for PEO‐grafted silicon surfaces,31 suggesting penetration of the probe liquid (water) into the dried polymer film 32…”

Metal-Catalyzed Postpolymerization Strategies for Polar Group Incorporation into Polyolefins Containing C–C, C═C, and Aromatic Rings

“…Hydrosilylation of PBD with hydride-terminated poly-(dimethylsiloxane) using the same catalytic system afforded novel polymer architectures depending on the hydride-to-vinyl ratio. 80 For a low hydride-to-vinyl ratio, formation of side loops takes place from the hydrosilylation of adjacent vinyl groups (Scheme 14B). At higher ratios, hydrosilylation of distant vinyl groups may result in a compact, dendrimer-like molecule.…”

Syntheses of triblock polybutadiene–polydimethylsiloxane copolymers by coupling reactions

“…However, only a few studies have dealt with alkadiene–siloxane copolymers: side‐loop polymers have been obtained by the hydrosilylation of polybutadiene (PBd) with a hydride‐terminated PDMS,20 and a copolymer with alternating alkadiene and dimethylsiloxane (DMS) units has been prepared by the hydrosilylation of some α,ω‐alkadienes with 1,3‐dihydrotetramethyldisiloxane 21…”