![]() (1) the experimental values of qsp and C, and also the proper value of 21' taken from the graph. Intrinsic viscosity may then be calculated from one specific viscosity measurement by substituting in eq. ~ Hart3 suggested therefore a graphic method for single- point determination of intrinsic viscosity based on the arranged equation of Schulz and Blaschke :įor polymer-good solvent system, it is possible to establish a graph of N (reciprocal of k) versus specific viscosity. This constant is, however, dependent on specific viscosity (polymer- good solvent system) or, moreover, on intrinsic viscosity (polymer-poor solvent ~ y s t e m ). Using the equation of Schulz and Blaschke for single-point determination of intrinsic viscosity, it is necessary to know the value of constant k. For this reason, when smaller precision is sufficient, a quicker method of calculation of intrinsic vicosity from a single specific viscosity measurement is ad- vantageous. This procedure is precise but rather lengthy as specific viscosities have to be measured a t several concentrations. In the extrapolation procedure for the determination of intrinsic viscosity of polymer solutions, the equations of Huggins' or Schulz and Blaschke2 are usually used. POLACEK, Institute of Physical Chemistry, Czechoslovak Academy of Sciences, Prague, CzecFoslovakia It is necessary to stress that the initial concentrations (about 0.4 g./100 ml.) 469 During the study of molecular weight distributions in fresh, naturally, and artificially aged Svitprene K (polychloroprene polymerized in emulsion at 35☌.),4 the extrapolation of reduced specific viscosities to zero con- centration, according to Huggins' equation, was used for the determination of intrinsic viscosities of benzene solutions of the samples and their frac- tions, and on the experimental data obtained the precision of Hart's method was verified. An approximative value of is then calculated by using an average N curve the result is used to determine the proper N curve and in the same way the definite value of the intrinsic viscosity is calculated. For polymer-poor-solvent system, it is necessary to establish several N versus qsp curves covering the required range of in- trinsic viscosities. This constant is, however, dependent on specific viscosity (polymer- good solvent system) or, moreover, on intrinsic viscosity (polymer-poor solvent ~ystem).~ Hart3 suggested therefore a graphic method for single- point determination of intrinsic viscosity based on the arranged equation of Schulz and Blaschke : For polymer-good solvent system, it is possible to establish a graph of N (reciprocal of k) versus specific viscosity. ![]() POLACEK, Institute of Physical Chemistry, Czechoslovak Academy of Sciences, Prague, CzecFoslovakia In the extrapolation procedure for the determination of intrinsic viscosity of polymer solutions, the equations of Huggins' or Schulz and Blaschke2 are usually used. ![]() XXXIX, PAGES 469-473 (1959) Single-Point Determination of Viscosity J.
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