Synthesis and characterization of low‐molecular‐weight poly(2,6‐dimethyl‐1,4‐phenylene oxide) in water

Abstract

Low-molecular-weight poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) with unimodal polydispersity was synthesized by oxidative polymerization of 2,6-dimethylphenol in the presence of Cu-ethylene diamine tetraacetic acid catalyst in water. A series of low-molecular-weight PPO oligomers with M n ranged from 360 to 3500 were obtained. It was found that the molecular weight and polydispersity were affected by reaction time, reaction temperature, and catalyst concentration. Based on the detector response-elution volume curve and the molecular weight from gel permeation chromatography, a possible molecular weight growth mechanism was proposed. The structure and properties of low-molecular-weight PPO oligomers were characterized by atomic absorption spectroscopy, differential scanning calorimetry, Ubbelohde viscometer, and nuclear magnetic resonance spectroscopy. Compared to the commercial low-molecular-weight PPO, PPO oligomers synthesized in water had a much lower residual copper content. The relationships between T g and M n at relatively low-molecular weight are in good agreement with the equation proposed by Fox and Loshack. V C 2012Wiley Periodicals, Inc. J. Appl. Polym. Sci.

Evaluation of electrochemical properties and reverse electrodialysis performance for porous cation exchange membranes with sulfate-functionalized iron oxide

“…Poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) is a viable candidate for IEMs because it possesses excellent membrane-forming properties, good mechanical and chemical properties, high thermal stability, and low moisture uptake at low cost [27][28][29][30]. To enhance the hydrophilicity and IEC of the PPO, a sulfonation reaction was carried out that functionalized the aromatic rings of the polymer chains with charged groups, typically from sulfonic acid.…”

Synthesis and properties of cured epoxy mixed resin systems modified by polyphenylene oxide for production of high‐frequency copper clad laminates

“…Figure shows a schematic diagram of the redistribution reaction of PPO promoted by BPA, using BPO as a free radical initiator. The resultant free radicals attack the PPO molecules, causing it to fragment into smaller radical chains that are then terminated by reaction with BPA to afford hydroxyl‐terminated rPPO .…”

Oxidative coupling copolymerization for synthesis of poly(phenylene oxide) containing allyl groups in water

“…Although the oxidative coupling copolymerization of DMP with AMP to synthesize allyl-PPO was reported before, 5,6 the copolymerization of these two monomers in aqueous solution has not been investigated so far. On the other hand, the oxidative coupling polymerization of DMP in alkaline aqueous solution using copper complexes as catalyst has been studied before, [7][8][9][10][11][12] and PPO with lower molecular weight and narrow polydispersity was successfully synthesized which is acceptable from the viewpoint of green chemistry.…”