Direct synthesis of carboranylpolystyrene and their applications for oxidation resistance of graphene oxides and catalyst support

Abstract

Radical polymerization reaction of carborane monomer closo-1-R-2-(4vinylbenzyl)-1,2-C 2 B 10 H 10 (R=Me (1), Ph (2)) produced carboranyl-functionalized polystyrenes, poly(1-R-2-(4-vinylbenzyl)-1,2-closo-C 2 B 10 H 10) (R=Me (3), Ph (4)), in a yield of 56.3% and 85.0%, respectively. The polymers 3 and 4 were used to coat graphene oxides (GO) and the resulting products exhibited high oxidation resistance property when compared with pristine GO. Polymer 3 was also used to stabilize palladium nanoparticles (Pd-NPs) to form catalyst composite Pd-NPs/3. Composite Pd-NPs/3 was found to be efficient catalyst for selective oxidation of glycerol. All new compounds were fully characterized.

Carborane-Containing Polymers: Synthesis, Properties, and Applications

“…Other synthetic methods included: an ethylene-α-olefin polymerization between ethylene gas and octenyl methyl- closo -1,2-carborane ( 57 ) using a Group 4 organometallic complex Me 2 Si­(η 5 C 5 Me 4 )­(η 1 - N - t Bu)­TiCl 2 /methylaluminoxane (CGC/MAO) catalyst system to afford II-15 , and free radical polymerizations of methyl- or phenyl-substituted closo -1,2-carboranylmethylstyrenes ( 53 and 58 ) initiated by AIBN that gave carborane-appended polystyrenes II-16a and II-16b . (Scheme )…”

“…86 (Scheme 19) It should be noted that in chain-growth polymerization reactions, the bulkiness and low polarity of pendant carborane groups caused some difficulties in the polymerization reaction, leading to reaction inefficiency, low yields and low molecular weights, as described in some publications. 35,80,86 Also, from the yields and SEC results, it appears that closo-1,2-carboranecontaining vinyl monomers behaved poorly in reactions compared to closo-1,7-carborane-appended monomers, however it is difficult to know if there are indeed synthetic differences involving the two isomeric carborane cages due to the limited number of publications in this area. Furthermore, in living-like polymerizations (RAFT, ATRP, and ROMP), closo-1,12carborane monomers and unprotected monosubstituted closo-1,2-carborane monomers were not reported in these publications.…”

“…Other synthetic methods included: an ethylene-α-olefin polymerization between ethylene gas and octenyl methyl-closo-1,2-carborane (57) using a Group 4 organometallic complex Me 2 Si(η 5 C 5 Me 4 )(η 1 -N-tBu)TiCl 2 /methylaluminoxane (CGC/ MAO) catalyst system to afford II-15, 85 and free radical polymerizations of methyl-or phenyl-substituted closo-1,2carboranylmethylstyrenes (53 and 58) initiated by AIBN that gave carborane-appended polystyrenes II-16a and II-16b. 86 (Scheme 19) It should be noted that in chain-growth polymerization reactions, the bulkiness and low polarity of pendant carborane groups caused some difficulties in the polymerization reaction, leading to reaction inefficiency, low yields and low molecular weights, as described in some publications. 35,80,86 Also, from the yields and SEC results, it appears that closo-1,2-carboranecontaining vinyl monomers behaved poorly in reactions compared to closo-1,7-carborane-appended monomers, however it is difficult to know if there are indeed synthetic differences involving the two isomeric carborane cages due to the limited number of publications in this area.…”

“…Other than the properties and applications mentioned above, carborane polymers have also been studied as catalyst supports, nanoparticle coatings for stabilization improvement, graphene oxide coatings for microwave absorption enhancement, hydrophobic coatings for nanopapers, responsive materials to nucleophiles, , shape-memory materials, and as chain-scission sites during ultrasonication of mechanomaterials . In terms of analysis, some carborane-containing polymers were found to have unique spectroscopic handles in their characterization.…”