Spatially Controlled Highly Branched Vinylsilicones
| Autor: | Michael A. Brook, Yang Chen, Mengchen Liao |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Steric effects
Polymers and Plastics Piers–Rubinsztajn reaction Hydrosilylation dendritic branches 02 engineering and technology 010402 general chemistry Elastomer 01 natural sciences Article lcsh:QD241-441 chemistry.chemical_compound Silicone lcsh:Organic chemistry Polymer chemistry chemistry.chemical_classification technology industry and agriculture hydrosilylation General Chemistry Polymer 021001 nanoscience & nanotechnology Grafting 0104 chemical sciences chemistry Polymerization Reagent 0210 nano-technology silicone polymers |
| Zdroj: | Polymers Volume 13 Issue 6 Polymers, Vol 13, Iss 859, p 859 (2021) |
| ISSN: | 2073-4360 |
| DOI: | 10.3390/polym13060859 |
| Popis: | Branched silicones possess interesting properties as oils, including their viscoelastic behavior, or as precursors to controlled networks. However, highly branched silicone polymers are difficult to form reliably using a “grafting to” strategy because functional groups may be bunched together preventing complete conversion for steric reasons. We report the synthesis of vinyl-functional highly branched silicone polymers based, at their core, on the ability to spatially locate functional vinyl groups along a silicone backbone at the desired frequency. Macromonomers were created and then polymerized using the Piers–Rubinsztajn reaction with dialkoxyvinylsilanes and telechelic HSi-silicones molecular weights of the polymerized macromonomers were controlled by the ratio of the two reagents. The vinyl groups were subjected to iterative (two steps, one pot) hydrosilylation with alkoxysilane and Piers–Rubinsztajn reactions, leading to high molecular weight, highly branched silicones after one or two iterations. The vinyl-functional products can optionally be converted to phenyl/methyl-modified branched oils or elastomers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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