Amphiphilic Silicon Hydroxyl-Functionalized cis-Polybutadiene: Synthesis, Characterization, and Properties

A series of living cis-polybutadiene (cis-PB) chains with desired molecular weights could be successfully synthesized during the polymerization process at different monomer conversions or by sequential addition of an extra monomer at every polymerization stage. The amphiphilic silicon hydroxyl-functionalized cis-PB (cis-PB-Si(OH)(3)) could be further achieved via copolymerization of the above living cis-PB chains with ethenyltrimethoxy-silane to obtain trimethoxy silane-functionalized cis-PBs and hydrolysis of these polymers. It is found that the star-shaped cis-PBs were formed by self-assembly via hydrogen bonding interaction from the end-functional groups of -Si(OH)(3). The surface of cis-PB-Si(OH)(3) films transformed from hydrophobic to hydrophilic after water induction at 50 degrees C when the M-n of cis-PB segments was lower than 9.1 kg.mol(-1). The above hydrophilic cis-PB-Si(OH)(3) films exhibit good self-healing behavior at 25 degrees C owing to a great contribution from -Si(OH)(3) hydrophilic terminals. The amphiphilic cis-PB-Si(OH)(3) and its aggregates would have potential application in recyclable elastomers or self-healing elastic coatings with low-temperature resistance.

Automated summary

The study demonstrates the successful synthesis of living cis-polybutadiene chains with desired molecular weights through polymerization process or sequential addition of an extra monomer, leading to the formation of amphiphilic silicon hydroxyl-functionalized cis-PB. Star-shaped cis-PBs are formed through self-assembly via hydrogen bonding from -Si(OH)3 groups, with surface transformation from hydrophobic to hydrophilic observed after water induction in lower molecular weight cis-PB segments. The hydrophilic cis-PB-Si(OH)3 films show good self-healing behavior, suggesting potential applications in recyclable elastomers and self-healing elastic coatings with low-temperature resistance.