Block copolymerization of vinyl ether with cyclic imino ether: synthesis of a new cleavable, nonionic polymer surfactant

Abstract

Block copolymers from vinyl ether and cyclic imino ether monomers were synthesized by successive cationic copolymerization of each monomer in a one-pot procedure. The resulting copolymers had a hydrophobic polylvinyl ether) segment and a hydrophilic poly(JV-acylalkylenimine) segment from the cyclic imino ether. Vinyl ethers used for construction of a hydrophobic segment are n-butyl, ¿-octyl, and n-cetyl vinyl ethers. Cyclic imino ethers used for construction of a hydrophilic segment are 2-methyl-and 2-ethyl-2-oxazolines and 2-methyl-5,6-dihydro-4H-l,3-oxazine. These block copolymers exhibit good surface activities and, hence, are a family of nonionic polymer surfactants. The surface activities reflected by the surface tension ( ) in water were high. The lowest value reached 27.6 dyn/cm for the copolymer from n-butyl vinyl ether/ 2-methyl-2-oxazoline. The C-N bond between the polylvinyl ether) segment and poly(TV-acylalkylenimine) segment was readily cleaved under acidic conditions to give a mixture of both homopolymers having no surface activities.was formed by the reaction of iodine with a vinyl ether at the initiation stage.

Molecular iodine in monomer and polymer designing

“…Kobayashi et al [75] took advantage of this strategy to synthesize a block copolymer, poly(viny1 ether)-blockpoly(N-acylethylenimine), as depicted in Scheme 16. (R 1 = n-butyl, R 2 = methyl).…”

Block copolymers of poly(vinyl ethers) and poly(ethylene glycol) by means of the living cationic polymerization of vinyl ethers

“…A hemiacetal can be formed by acid hydrolysis of an acetal [5] or by a direct reaction of the living polymer with water [2] or ammonia [3]. These reactions are well-known from the chemistry of low molcular weight acetals.…”

Poly(cyclic imino ether)s Beyond 2‐Substituted‐2‐oxazolines

“…[35] First, the vinyl Scheme 6. Methylation of PTMI and P-2-unsubstituted-2-OZI by the Leuckardt method.…”

“…[35] THF was first polymerized using EtOTf as the initiator followed by the addition of the 2-Me-2-OZI to obtain an oxazolinium group at the polymer terminus. After polymerization of 2-Me-2-OZI, the block copolymer was obtained (Scheme 8).…”

“…The BAB-type triblock copolymer was synthesized starting with a bifunctional initiator, trifluoromethanesulfonic anhydride (Tf 2 O), followed by propagation at both ends via a two-stage copolymerization in one pot. [35] The initiation of THF was fast and the length of the polymer was very close to the initial feed ratio with a low PDI value (M n ¼ 1 280 g Á mol À1 ;…”