Synthesis of Hydroxyl‐Terminated Poly(vinylcarbazole‐ran‐styrene) Copolymers by Nitroxide‐Mediated Polymerization

Abstract

A series of poly(vinylcarbazole‐ran‐styrene) copolymers with terminal hydroxyl groups were synthesized using nitroxide mediated polymerization (NMP) with the hydroxyl‐functional initiator VA‐086 and TEMPO as the mediator at 130 °C. Polymerizations were studied as a function of vinylcarbazole feed content, target molecular weight, and VA‐086/TEMPO ratio. The characterization of the copolymers was done by GPC and NMR. For feed concentrations of 40 mol‐% vinylcarbazole, copolymers with vinylcarbazole concentration up to 33 mol‐% could be obtained with narrow molecular weight distributions (PDI = 1.35) and exhibit pseudo‐“living” character up to conversions of about 20% if the target molecular weight was >100 kg · mol−1. 1H NMR indicated that the hydroxyl group was retained sufficiently with a functionality typically of about 0.7 hydroxyl groups per chain. Copolymers synthesized with higher vinylcarbazole feed content exhibited slower kinetics and were less controlled, resulting in much broader molecular weight distributions. The absence of control could be attributed to the absence of thermal initiation by vinylcarbazole which is advantageous toward controlling the radical concentration during the polymerization.magnified image

Polymerization Mechanism in the Presence of 1,1‐Diphenylethylene Part 2: Synthesis and Characterization of PMA and PSt

“…In recent years, controlled/“living” free radical polymerization has attracted increasing attention due to its capacity to prepare polymers with well‐defined structure. Various controlled radical polymerization systems are available, such as, atom transfer radical polymerization (ATRP), nitroxide‐mediated polymerization (NMP), and reversible addition‐fragmentation transfer polymerization (RAFT) . These three techniques have been intensively investigated and successfully applied for the controlled polymerization of various monomers, but some drawbacks and limitations hinder their industrial application.…”

Titanium Dioxide Photocatalytic Polymerization of Acrylamide for Gel Electrophoresis (TIPPAGE) of Proteins and Structural Identification by Mass Spectrometry

“…This work is aimed to investigate the polymerization reaction of acrylamide and bis-acrylamide initiated by hydroxyl radicals in acidic condition. Compared with Azo-based initiator such as VA-086 which is also used for introducing hydroxyl group into terminal of polymer 23 24 25 , semiconductor nanoparticles not only speed up the polymerization process under light irradiation but also improve the mechanical properties because of the formation of cross-linked nanocomposites. The so called TIP PAGE approach ( ti tanium dioxide p hotocatalytic p olymerization of a crylamide for g el e lectrophoresis) should be able to provide an alternative approach for proteomics.…”