Living cationic polymerization of isobutyl vinyl ether by the diphenyl phosphate/zinc iodide initiating system

A phosphonium intermediate for cationic RAFT polymerization

“…Particularly, in Lewis acid-catalyzed living cationic polymerization, phosphoric and phosphinic acids can be employed as the initiator that forms an adduct with vinyl ether, where the resulting phosphorus ester bonds are activated by metal-halide Lewis acids, such as ZnX 2 (X = Cl, Br, I), to induce living cationic polymerization of vinyl ethers. 49,50 Furthermore, bulky phosphoric acids are effective for stereospecific cationic polymerization of vinyl ethers in the presence of SnCl 4 as the Lewis acid catalyst to result in isotactic rich poly(vinyl ether)s with relatively high glass transition temperatures. 51 In this study, we employed adducts of phosphoric or phosphinic acid with vinyl ether as the novel phosphorus-based RAFT agent to the PvO bond of which the growing carbocationic species is supposed to add to form the stable phosphonium intermediate and then undergo the RAFT process to induce the controlled cationic polymerizations.…”

Polymerization of Glycidyl Phenyl Ether with Phosphonic Acid Esters as Novel Thermally Latent Initiators

“…Phosphonic acid esters can be easily synthesized and are expected to generate phosphonic acid as an initiation species. Higashimura et al have succeeded in living polymerization of a vinyl ether with the adduct of the vinyl ether and phosphoric acid in the presence of zinc iodide . To develop a new non-salt-type latent initiator, we have employed phosphonic acid esters having a labile C−O bond.…”

“…Higashimura et al have succeeded in living polymerization of a vinyl ether with the adduct of the vinyl ether and phosphoric acid in the presence of zinc iodide. 11 To develop a new non-salt-type latent initiator, we have employed phosphonic acid esters having a labile C-O bond. This article deals with the possibility of phosphonic acid esters (1, 2, and 3) as thermally latent initiators in the polymerization of GPE.…”

Synthesis of phosphate end‐functional polymers and application to thermally latent polymeric initiators

“…Biela and colleagues4 have reported that the phosphorus‐acid‐initiated polymerization of ethylene oxide affords the oligomers via the activated monomer mechanism. Sawamoto et al5 have reported the living cationic polymerization of isobutyl vinyl ether by the diphenyl phosphate with zinc iodide initiating system. Recently, we have reported6 that phosphonates can serve as latent initiators that show no activity under certain temperatures in the polymerization of glycidyl phenyl ether (GPE) but do above the temperatures to afford poly(GPE).…”