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Oxidation assisted new reaction of glycerol
Author(s) -
Kimura Hiroshi
Publication year - 2001
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.91
Subject(s) - polymerization , cationic polymerization , polymer chemistry , decarboxylation , catalysis , chemistry , ketone , reagent , polymer , organic chemistry
Catalytic oxidation of tartronic acid (TA) in water over a BiPt/C catalyst generates ketomalonic acid (KM) which polymerizes via ketone‐carbonyl to form the corresponding polyether, poly(ketomalonate) (PKM), preventing the competitive formation of KM‐hydrate available as reagent. Formation of the polyether (I) and of the hydrate (II) constitute the relaxation processes of generated active KM (keto‐form). Polymerization of KM proceeds cationically or anionically depending on pH, which shows that ketone‐carbonyl of KM is a dipole. TA, which can be prepared by catalytic oxidation of glycerol (GLY), functions as a precursor for KM as well as initiators such as proton or TA‐carbanion for cationic and anionic polymerization of KM, respectively. Perchloric acid and zinc chloride are effective promoters for polymerization of KM. The CeBiPt/C is an excellent multi‐functional catalyst which has three functions; (a) oxidation of the two primary hydroxy groups of GLY to form TA; (b) oxidation of the secondary hydroxy group of TA to generate KM; (c) polymerization of generated KM. PKM prepared by anionic polymerization of KM has no hydrogens bonded to the carbon atoms of the polyether chain. Decarboxylation of PKM can be easily performed by adding mineral acid. This shows that PKM is a polymer of carbon dioxide which is bonded to carbon of the polyether chain and is stabilized by sodium ion. Excess oxidation of PKM formed by pure oxygen accelerates complete decarboxylation to form poly(oxymethylene). These observations, assisted by catalytic oxidation, demonstrate new chemistry of GLY as a renewable resource. TA‐carbanion can also be used as an initiator for the anionic polymerization of glyoxylic acid (GOA) in a basic aqueous media to form poly(glyoxylate). Zinc chloride, a Lewis acid, can be an initiator for cationic polymerization of half‐neutralized GOA in water. GOA, which has been generally used as an ester for polyether synthesis, can be polymerized in water by controlling pH‐dependent hydration equilibrium of GOA to aldehyde‐form. Copolymer of KM and pyruvic acid prepared by anionic copolymerization initiated by TA‐carbanion shows excellent Ca‐sequestrancy as a detergent builder. Polymerization of a substituted ketone, generated by catalytic oxidation of a corresponding precursor, polymerizes via ketone‐carbonyl even in water to form the corresponding polyether. Oxidative polymerization in water of an aliphatic hydroxy compound is a new methodology for the advancement of fine chemistry and functional polymers. Copyright © 2001 John Wiley & Sons, Ltd.