Degradable alternating polyperoxides from poly(ethylene glycol)‐substituted styrenic monomers with water solubility and thermoresponsiveness.

Abstract

Water soluble alternating copolymers were prepared by oxidative free radical copolymerization of 4-vinylbenzyl methoxypoly(oxyethylene) ether (PEGSt) and molecular oxygen at 50 °C. NMR spectroscopy established alternate sequence of PEGSt and peroxy bonds (OO) along the polymer main-chain. The obtained polymers show temperature induced hydrophilic to hydrophobic phase separation, confirmed by UV-visible spectroscopy and dynamic light scattering. The cloud point temperature (TCP) of the polymers can be tuned by changing the chain length of side-chain poly(ethylene oxide) and incorporation of hydrophobic methyl methacrylate in the copolyperoxides. Exothermic degradation of these polyperoxides was confirmed by differential scanning calorimetry and the degradation products have been characterized by electron impact mass spectroscopy. Finally, N,N-dimethylacrylamide was polymerized in the presence of these polyperoxides in toluene, highlighting their potential as polymeric free radical initiator during polymerization of vinyl monomers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2030–2038