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    • 6. 发明授权
    • Method for determining chloroformate concentration
    • 测定氯甲酸盐浓度的方法
    • US5100804A
    • 1992-03-31
    • US669161
    • 1991-03-14
    • Daniel J. BrunelleDavid K. BonautoEugene P. Boden
    • Daniel J. BrunelleDavid K. BonautoEugene P. Boden
    • C08G64/26G01N31/16
    • C08G64/26G01N31/164Y10T436/19Y10T436/196666
    • The molar concentration of chloroformate in an organic chloroformate solution is determined by adding an excess of a monohydroxyaromatic compound, water and a catalytic amount of a 4-dialkylaminopyridine such as 4-dimethylaminopyridine, titrating with aqueous base and taking as the end point the volume of base which achieves complete conversation of chloroformate groups to monoaromatic carbonate groups, as shown by a rapid rise in the pH of the aqueous phase of more than two points to a value in the range of 7-9. This method is particularly applicable to the determination of bischloroformate molar concentration in systems to be converted to cyclic polycarbonate oligomers. Conversion may be effected by condensation in the presence of a trialkylamine and aqueous base in the amount of about 3 moles per mole of bischloroformate.
    • 氯甲酸酯在有机氯甲酸酯溶液中的摩尔浓度通过加入过量的单羟基芳族化合物,水和催化量的4-二烷基氨基吡啶如4-二甲基氨基吡啶来测定,用碱水溶液滴定,并以作为终点的体积 碱性化合物可使氯甲酸酯基团完全与单芳族碳酸酯基团进行通讯,如水相pH值的快速上升超过两点所示,为7-9。 该方法特别适用于待转化为环状聚碳酸酯低聚物的体系中双氯甲酸酯摩尔浓度的测定。 转化率可以通过在三烷基胺和碱水溶液的存在下以每摩尔二氯甲酸酯约3摩尔的量进行缩合来进行。