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Kamatani, Hiroyoshi

doi:10.1246/nikkashi.1978.1271

Cited by 4 publications

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“…Diethylene glycol, obtained by the ethanolysis of PET, was determined by gas chromatography as described previously. 13 Determination of Acetaldehyde. Acetaldehyde, generated by the side reaction in the polycondensation, was collected in a cold trap together with ethylene glycol.…”

Section: Discussionmentioning

confidence: 99%

Effect of Phosphoric Acid on the Polycondensation of Bis(2-hydroxyethyl) Terephthalate Catalyzed by Sb(III) Compounds

Kamatani

Konagaya

Nakamura

1980

Polym J

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The influence of phosphoric acid on the activity of Sb(III) catalyst was studied in the catalytic polycondensation of bis(2-hydroxyethyl) terephthalate (BHET). Although the rate of polycondensation in the initial stage was depressed by the addition of phosphoric acid to the Sb(III) catalyst, subsequent polycondensation was accelerated to give a higher-molecular-weight poly(ethylene terephthalate) as compared with that obtained in the absence of phosphoric acid. The yield of by-products in the polycondensation was also affected by the addition of phosphoric acid; the formation of acetaldehyde decreased, and that of the diethylene glycol unit increased. It was made clear from studies of 31 P NMR that the phosphoric acid was converted into phosphate (0= P(OC2H4 0R)3) in the early stage of the polycondensation by reaction with BHET or ethylene glycol which was generated in the polycondensation ofBHET. It is assumed that the modification of the polycondensation reaction caused by the addition of phosphoric acid is due to the complexation of Sb(III) catalyst with the phosphate. The mechanism for the polycondensation of BHET catalyzed by Sb(III) compounds in the presence of phosphoric acid was proposed on the basis of these findings. KEY WORDS Bis(2-hydroxyethyl) Terephthalate I Poly(ethylene !erephthalate) I Polycondensation I Sb(III) Catalyst I Phosphoric Acid I 31p NMR I

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Section: Discussionmentioning

confidence: 99%