Star-shaped cyclopolymers: A new category of star polymer with rigid cyclized arms prepared by controlled cationic cyclopolymerization and subsequent microgel formation of divinyl ethers

Abstract

The combination of living/controlled cationic cyclopolymerization and crosslinking polymerization of bifunctional vinyl ethers (divinyl ethers) was applied to the synthesis of core-crosslinked star-shaped polymers with rigid cyclized arms. Cyclopolymerization of 4,4-bis(vinyloxymethyl)cyclohexene (1), a divinyl ether with a cyclohexene group, was investigated with the hydrogen chloride/zinc chloride (HCl/ZnCl 2 ) initiating system in toluene at 0 C. The reaction proceeded quantitatively to give soluble poly(1)s in organic solvents. The content of the unreacted vinyl groups in the produced polymers was less than 3 mol%, and therefore, the degree of cyclization of the polymers was determined to be 97%. The numberaverage molecular weight (M n ) of the polymers increased in direct proportion to monomer conversion and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture, indicating that living cyclopolymerization of 1 occurred. The chain linking reactions among the formed living cyclopolymers with 1,4-bis(vinyloxy)cyclohexane (3) as a crosslinker in toluene at 0 C produced core-crosslinked star-shaped cyclopoly(1)s [star-poly(1)s] in high yield (100%). Dihydroxylation of the cyclohexene double bonds of star-poly(1) gave hydrophilic water-soluble starshaped polymers with rigid arm structure [star-poly(1)-OH] with thermo-responsive function in water. T g s of star-poly(1) and star-poly(1)-OH were 135 C and 216 C, respectively; these values are very high as vinyl ether-based star-shaped polymers. V C 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 00, 000-000

Cyclopolymerizations: Synthetic Tools for the Precision Synthesis of Macromolecular Architectures

“…Chain linking reactions among the formed cyclopolymers produced core-cross-linked star-shaped cyclopolymers, which could be dihydroxylated to give hydrophilic water-soluble starshaped polymers with rigid arm structures. 99 o-Phthalaldehyde is, to this day, the only aromatic aldehyde that can be homopolymerized through chain-growth polymerization. 100 Polyphthalaldehydes are cyclopolymeric structures obtained by anionic polymerization which have found application as one of the first chemically amplified photoresists (Figure 14).…”

“…The cationic cyclopolymerization of a divinyl ether with a cyclohexene group proceeded quantitatively to give soluble cyclopolymers in organic solvents. Chain linking reactions among the formed cyclopolymers produced core-cross-linked star-shaped cyclopolymers, which could be dihydroxylated to give hydrophilic water-soluble star-shaped polymers with rigid arm structures …”

Thermoresponsive star-shaped polymer with heteroarm type with methacrylates: preparation by living radical polymerization method and its topological effect

“…Some examples of a decrease in LCST with increasing number of branches in star-shaped polymers compared to linear polymers have been reported previously. 24,25…”

“…Some examples of a decrease in LCST with increasing number of branches in star-shaped polymers compared to linear polymers have been reported previously. 24,25 Synthesis of linear and star PTEGMA and their thermoresponsive properties Similar to DEGMA polymers, linear PTEGMA, block and statistical copolymers with MMA, and star-shaped PTEGMA were synthesized. The homopolymers and copolymers had M n values of 22 000-25 000 and a narrow polydistribution with Đ < 1.2 (Table 2).…”

“…The properties of star-shaped polymers with thermoresponsive moieties have been investigated. It has been reported that the LCST values can changed depending on the number of arms, 24,25 so it is important to design and control the polymer structures for thermoresponsive star-shaped polymers. By evaluating thermoresponsive star-shaped polymers obtained by multifunctional initiator methods, the effect of the number of branches on the LCST and the construction of precise thermoresponsive networks using these polymers has been reported.…”