Synthesis of highly branched polymers via three-dimensional radical polymerization in the presence of oxygen

Abstract

It is shown that branched and highly branched vinyl polymers can be prepared by three dimen sional radical polymerization in the presence of dissolved oxygen, as exemplified by the oxidative copolymer ization of styrene and divinylbenzene. The conditions of synthesis of highly branched polymers with a high yield-the ratio between monovinyl and divinyl comonomers and the rate of oxygen bubbling-are deter mined. The kinetics of formation of branched polystyrenes and the features of their molecular mass distribu tion are studied. Elemental analysis data show that the polymeric product contains 22-24 wt % oxygen, which, according to the IR data, enters into the composition of carbonyl, hydroxyl, and peroxide groups. The thermal decomposition of polymeric products is investigated via the TGA-DSC method. The main exother mal peak at ~145°C is associated with the decomposition of peroxide groups, which is accompanied by the evolution of formaldehyde.

Degradable Crystalline Polyperoxides from Fatty Acid Containing Styrenic Monomers

“…They also show unique properties like highly exothermic degradation, in contrast to common polymers which commonly undergo endothermic degradation. Polyperoxides find academic and technological importance as polymeric initiators during the free radical polymerization of vinyl monomers, autocombustible polymeric fuel, curators in coating and molding compositions, dismantlable adhesive, branched polymer synthesis precursor, , drug carrier, etc.…”

“…Generally, polyperoxides do not form crystalline structures owing to their low molecular weight and highly flexible backbone because of the main-chain peroxy links. Cais and Bovey demonstrated the effect of heteroatom unit on the transmission of configurational information in poly(styrene peroxide) by chain dynamics study using 13 C NMR spectroscopy, compared to the corresponding hydrocarbon-backbone counterpart poly(styrene). 25 In general, polymer chains form a crystalline domain when certain symmetry requirements are met in addition to regularity in structure, strong intermolecular forces, and an optimum flexibility.…”

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

“…Since polyperoxides exhibit unusual phenomenon of auto‐pyrolysis, they are potential candidates as an auto‐combustible fuel . Moreover, this class of polymers have great utility in the field of coating, dismentable adhesion, synthesis of branched polymer, as thermal and photo‐initiator for vinyl monomers to prepare homopolymers and block copolymers, and so on. Also, polyperoxides are biodegradable and biocompatible polymers …”

N‐Hydroxyphthalimide‐Mediated Oxidation of Styrene by Molecular Oxygen

“…Polymerization of vinyl monomers in the presence of molecular oxygen produces polyperoxides, which are strictly alternating copolymers of vinyl monomers and oxygen . The main chain repeating weak‐link peroxide group (OO) containing polymers are biodegradable, find usefulness as polymeric macroinitiators, curators in coating and molding applications, autocombustible polymeric fuel, drug carrier, dismantlable adhesive, branched polymer precursor, etc. The main drawbacks for the oxidative polymerization of vinyl monomers are their slow rate of polymerization and low polyperoxide yields due to their facile degradation and chain transfer reactions during their synthesis …”