Design of Differential Pressure Detection System for Size Exclusion Chromatography and the Estimation of its Performance

当聚合物溶液通过毛细管时，毛细管入口和出口之间的压差与聚合物溶液的粘度成正比，聚合物溶液的粘度随分子量以及浓度而变化。设计了一种差压检测系统，并将该系统应用于从尺寸排阻色谱（SEC）柱上洗脱的聚合物溶液中，以聚苯乙烯（PS）样品构建log RpxM与保留体积的校准曲线，计算聚合物的平均分子量。这里，Rp是压差除以差示折射计（RI）的响应的值，M是分子量。提出了RI响应时滞的修正方法。为了将用PS构建的校准曲线应用于PS以外的聚合物，测定了这些聚合物的响应校正因子，准确测定了这些聚合物的平均分子量，并将该系统应用于几种共聚物的分子量分布和组成分布的测定。

When a polymer solution passes through a capillary tubing, pressure difference between the inlet and the outlet of the capillary tubing is proportional to the viscosity of the polymer solution which changes with molecular weight as well as the concentration. A differential pressure detection system was designed and the system was applied to the polymer solution eluted from size exclusion chromatography (SEC) columns.To calculate molecular weight averages for polymers, a calibration curve of log RpxM vs retention volume was constructed using polystyrene (PS) samples. Here, Rp is the value of the differential pressure divided by the response of a differential refractometer (RI) and M is molecular weight. A correction procedure of the time lag of the response of RI was developed. To apply the calibration curve constructed with PS to polymers other than PS, response correction factors for these polymers were measured and molecular weight averages of these polymers were determined accurately.This system was also applied for the determination of molecular weight distributions and composition distributions for several copolymers.