Hydrolysis poly phenylene oxide

More than 100 polymers, both synthetic and natural, have been successfully electrospun into nanofibers, mostly from polyma solutions, as any polymer may be electrospun into nanofibers, provided that the polymer molecular weight is sufficiently high and the solvent can be evaporated in the time during the jet transit period, over a distance between the spinneret and the collector. Standard polymers successfully electrospun into nanofibers include polyacrylonitrile (PAN), poly(ethylene oxide) (PEO), poly(ethylene terephthalate) (PET), polystyrene (PS), poly(vinyl chloride) (PVC), Nylon 6, PVA, poly(8-caprolactone), Kevlar (poly[p-phenylene terephthalamide]), poly(vinylidene fluoride) (PVDF), polybenzimidazole, polyurethanes (PUs), polycarbonates, polysulfones, poly(vinyl phenol) (PVP), and many others [36,37]. Electrospinning has also been used to produce nanofibers from natural biomacromolecules, including cellulose [either electrospun from cellulose acetate (CA) with subsequent hydrolysis or directly electrospun from cellulose solutions in Af,Af-dimethylacetamide with lithium chloride], collagen and gelatin, modified chitin, chitosan, and DNA. 

RS+ electrophiles that are electrogenerated in a CH2CI2/BU4NCIO4 solution readily attack even less reactive triple bonds of terminal alkynes [123] and result, after further oxidation and hydrolysis, in a-oxo-thioesters (Scheme 33). Under acidic conditions, it is possible to direct the reaction to the formation of an oligomer, cyclohexa-1,4-phenylene sulfide, or a conductive poly(p-phenylene)sulfide [131,132]. 

TPA amide is formed by thermo-oxidation in melt and at low-temperature solid-phase oxidation. Light yellow crystals of TPA amide and TPA mixture occur and accumulate on the surface of mould samples during accelerated heat ageing at temperatures of 150-200 °C. TPA is a typical product of hydrolysis by macrochain ends. From our point of view, TPA amide product is of greater interest. Recall that analogous products (relative to polymer structure) were already observed in investigation of thermo-oxidative transformations of other APH. For example, pyromellite diimide, was identified in thermooxidation of PAI [7, 21] and classical polyimide Capton , and 2,2 -(l,4-phenylene)-bis-(phenylpyrazine), is formed by poly(phenylquinoxaline) ageing [7]. 

A chemoenzymatic way to produce poly(hydroquinone) was achieved by enzymatic oxidative polymerization of 4-hydroxyphenyl benzoate, followed by alkahne hydrolysis of the resulting polymer [45]. HRP and SBP were used as enzymes. The molecular weight of the resulting poly(4-hydroxyphenyl benzoate) varied between 1100 and 2400 g/mol. The structure was said to consist of phenylene and oxyphenylene moieties, which was found by IR analysis and titration of the residual amount of phenolic groups in the polymer. Other phenol polymers have shown their potential for electronic applications as well. Besides hydroquinone, catechol has also been used as substrate for peroxidase-catalyzed polymerization. The molecular weights of the reac-... 

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