动态渗透压法测定水溶性聚电解质的分子量

用动态渗透压法,在适量含盐的水溶液中测量聚电解质——尿素改性磺化酚醛(SPU)的分子量。选取预计平衡点附近所作H-dv/dt的上升线为基准来测定溶液的平衡渗透压。从陶南渗透压求得SPU和第二维利系数A_2,比一般统计线团的A_2大,由A_2算得的Z~2/C'_s值,表征聚离子上有效荷电情况,其大小次序与样品处理钻井泥浆的降失水性能相一致,即Z~2/C'_s数值大则泥浆失水量小。因此, Z~2/C'_s值是聚电解质特性的一个有意义的量。

DETERMINATION OF MOLECULAR WEIGHT OF WATER-SOLUBLE POLYELECTROLYTE BY DYNAMIC MEMBRANE OSMOMETRY

The molecular weight of Urea Modified Sulfonated Phenol Formadehyde Resin (SPU) was determined in its aqueous solution by dynamic membrane osmometry. Considering the properties of water, the raising line of H-dV/dt, which was drawn out near the estimated equilibrium point, was chosen as a standard for obtaining the molecular weight of the sample.The second virial coefficients A2 of SPU found by this method were larger than that of the statistical coil. Z2/Cs' calculated from A2 is a parameter characterizing the effective charge of the polyion. The value of Z2/Cs' were consistent with the depressions of the water-loss of the SPU-treated drilling mud, i.e., the greater the Z2/Cs', the better the depression is. The value of Z2/Cs' may have certain meaning.