Concurrent Cationic Vinyl-Addition and Ring-Opening Copolymerization Using B(C₆F₅)₃ as a Catalyst: Copolymerization of Vinyl Ethers and Isobutylene Oxide via Crossover Propagation Reactions

Abstract

Alkyl vinyl ethers and isobutylene oxide were concurrently copolymerized through cationic vinyl addition and ring opening using B(C6F5)3 as a catalyst. NMR analyses and acid hydrolysis of the products demonstrated that the copolymerization successfully proceeded through crossover reactions between vinyl and cyclic monomers to yield multiblock-like copolymers. Appropriate catalyst and monomer combinations with suitable reactivities were key for copolymerization.

Zwitterionic Copolymerization of β‐Butyrolactone with Styrene

“…Therefore, the hydrolysis experiment confirmed that crossover reactions between styrene and β‐BL occurred. The existence of non‐degradable segment in copolymer chains is also reported by Aoshima and coworkers in the copolymerization of vinyl ethers with isobutylene oxide and aldehydes . The long sequence of non‐degradable segment was attributed to the reactivity difference between monomers.…”

“…Although the hybrid copolymerization of polar vinyl monomers with cyclic esters have been reported based on anionic or cationic polymerization mechanism, the copolymerization of cyclic esters with non‐polar vinyl monomers remains a challenge because of the dramatically different monomer reactivities. Styrene‐based polymers are a major class of commercial polymers, which also contribute for white waste .…”

“…Hybrid copolymerization of vinyl monomers and cyclic esters provide the formed copolymer with new features, such as biodegradability and functionality . Based on anionic polymerization mechanism, Zhang and coworkers reported that acrylates/methacrylates could copolymerize with cyclic esters, namely ε‐caprolactone (ε‐CL), lactide as well as trimethylene carbonate (TMC) to afford random copolymers using (1‐ tert ‐butyl‐4,4,4‐tris‐(dimethylamino)‐2,2‐bis[tris(dimethylamino)phosphoranylidenamino]‐2Λ 5 ,Λ 5 ‐catenadi(phosphazene) ( t ‐BuP 4 ) as the catalyst .…”

“…Aoshima et al. reported that oxiranes and vinyl ethers copolymerized via the concurrent cationic vinyl addition and ring‐opening on the basis of cationic polymerization mechanism utilizing B(C 6 F 5 ) 3 as the catalyst . They demonstrated that the crossover reactions between the vinyl and cyclic monomers were successful and yielded multi‐block‐like copolymers.…”

Anionic Hybrid Copolymerization via Concurrent Oxa‐Michael Addition and Ring‐Opening Polymerizations

“…For example, Saegusa et al found that oxazolines and maleimides could undergo hybrid copolymerization via a zwitterionic mechanism . Aoshima’s group reported a series of hybrid copolymerizations between vinyl ethers and oxetane monomers . Polymerizations of this type rely on a long‐lived cationic propagating species and are based on a cationic mechanism.…”