Rapid Self-healing and Strong Adhesive Elastomer via Supramolecular Aggregates from Core-shell Micelles of Silicon Hydroxyl-functionalized cis-Polybutadiene

Liquid trimethoxy silane-functionalized cis-polybutadiene(cis-PB-Si(OMe)3),possessing number-average molecular weights of cis-PB segments(Mn,PB)ranging from 1800 g/mol to 5400 g/mol,with cis-1,4 content of ca.80%and high functionality(>96%)could be synthesized by coordination copolymerization of living cis-PB chain ends with ethenyltrimethoxy-silane with neodymium-based catalytic system.The silicon hydroxyl-functionalized cis-polybutadiene(cis-PB-Si(OH)_(3))-based micelles in water have been achieved by in situ hydrolysis of cis-PB-Si(OMe)_(3)in hexane/water mixture(pH=6.8)at 70℃and by sequential removal of residue hexane.The size of the above micelles with soft elastic cis-PB cores could be remarkably enlarged by loading SiO_(2)nanoparticles on their surfaces via hydrogen bonding interaction.Giant supramolecular long chain aggregates or networks formed by hydrogen bonding interaction and possible O—Si—O chemical bonds between cis-PB-Si(OH)3-based micellar surfaces had relatively large size and thus precipitated from water after several months of storage,leading to production of cis-PB-Si(OH)_(3)solid elastomer with extremely low T_(g)at−107.0℃.The left cis-PB-Si(OH)_(3)-based micelles in water with relatively small size gradually formed the water-insoluble cis-PB-Si(OH)_(3)-based supramolecular aggregates or networks.The cis-PB-Si(OH)_(3)-based supramolecular elastomer exhibited excellent self-healing property within 60 s at 25℃.The elastomer(20 mg)in a joint of 25 mm×30 mm(2.7 mg/cm^(2))provided very strong adhesion for two pieces of glass and the bound glass keep unchanged at room temperature for 98 h even hung with 100 g of steel column below.The cis-PB-Si(OH)3-based supramolecular elastomer would have potential applications in adhesives,self-healing materials,damping materials and elastic materials.