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测定原理端羟基环氧丙烷-四氢呋喃共聚醚(POTHF共聚醚)是一种新型的“遥爪”型(Telechlic)预聚体,由它制备的聚氨酯具有较好的低温力学性能。由于预聚体的分子量及其分布,特别是官能度对成品材料的力学性质影响较大,故准确测定这些链结构参数是十分重要的. 测定数均官能度(了。)的常用方法川是通过测定样品的数均分子量(厕,)和怒基当量饮/equ)来计算的: 万。[g/equ〕(1) 当应用式(1)来测定PO一THF共聚醚的f,时,实验值总是要比理论值低得多(见表1).造成偏差的原因是由于样品中含有难以衰1常舰法润定po一THF共旅雌的,能度样品助催化剂数均官能度理论值实验值PTP(I)PTP(11)PTP(111) 甲醇l,2一丙二醇1,2,3一丙三醇
Determination principle Hydroxyl-terminated poly (propylene oxide) -tetrahydrofuran copolymer (POTHF) is a new type of “Telechlic” prepolymer. Polyurethane prepared from it has good low temperature mechanical properties. Because of the molecular weight of the prepolymer and its distribution, especially the functionalities of the finished material, the mechanical properties of a greater impact, so accurate determination of these chain structure parameters is very important to determine the number average functionality (). Calculated by measuring the number average molecular weight of the sample (WC) and ankle equivalent drink / equ. (1) When f (1) is used to determine the PO-THF copolyether, the experimental value is always much lower than the theoretical value (see Table 1). The reason for the deviation is that the sample Contains a hard-to-decay a ship the ship fixed-run a set of po THF total trip female, the degree of sample cocatalyst number average functionality theoretical value of the experimental value of PTP (11) PTP (11) methanol l, 2-propanediol 1 2,3-propanetriol