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1、INTERNATIONAL STANDARD IS0 1628-6. First edition 1990-02-01 Plastics - Determination of viscosity number and limiting viscosity number - Part 6: Methyl methacrylate polymers Plastiques - D . . (II q is the dynamic viscosity of the test solution, in millipascal seconds; q. is the dynamic viscosity of
2、 the solvent, in millipascal seconds; c is the concentration, in grams per millilitre, of polymer in the solution. NOTE - If the solvent and solution densities e. and Q are substantially equal, t in equation (I) may be replaced by v and q. by vo, where v and v. are the kinematic viscosities, in squa
3、re millimetres per second, of the solution and the solvent, respectively (see clause 10). 4 Principle Determination of the efflux time at 25 OC If: 0,05 OC of a sol- vent and of a polymer solution, having a specified concen- tration, in that solvent. Calculation of the viscosity number and the limit
4、ing viscosity number from the above measurements and the known concen- tration of the solution. 5 Measurements The data needed to calculate the function defined in clause 3 are obtained by means of a capillary tube viscometer, as explained in clause 4 of IS0 1628-1 : 1984. 1 Copyright International
5、Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 19:08:48 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 1628-6 : 1990 (E) The efflux time of a liquid is related to its vis
6、cosity by the 7 Solvent and test solution (see also Poiseuiile-Hagenbach-Couette equation: IS0 1628-1 : 1984, clause 6) v = f- = k(t - At) = kt - + . * . (2) where k is the viscometer constant, in square millimetres per second squared; 7.1 Solvent Chloroform, recognized analytical grade, stabilized
7、with less than 1 % (Vl VI of ethanol, kept in a brown bottle and stored in the dark. t is the efflux time, in seconds; 7.2 Sample At is the kinetic energy correction (Hagenbach It is important that the sample is representative of the material correction), in seconds; to be tested. Q is the density,
8、in grams per cubic oentimetre, of the liquid; 7.3 Test solution concentration A is a kinetic energy correction parameter, as defined in The solution concentration shall be 2,6 g of polymer per litre of IS0 1628-I. solution. NOTE - The kinetic energy correction At becomes insignificant if it is less
9、than 0,2 % of 1. For Ubbelohde type OC apparatus, At can be neglected if the efflux time t is greater than 270 s; for micro-Ubbelohde type Ml apparatus, At can be neglected if t is greater than 70 s. 6 Apparatus (see also IS0 1628-1 : 1984, clause 5) 7.4 Preparation of the test solution Weigh, to th
10、e nearest 0,l mg, 0,26 g f 0,005 g of the sample into the volumetric flask (6.4). Add 50 ml of chloroform (7.1) and dissolve the sample completely with shaking. Then make up to the mark with chloroform at 20 OC v. is the viscosity of the solvent; t is the arithmetic mean of the values obtained for t
11、he efflux time, in seconds, of the test solution; fc is the arithmetic mean of the values obtained for the efflux time, in seconds, of the solvent: c is the concentration, expressed in grams per millilitre, of the test solution; At is the kinetic energy correction for t (see annex A); At, is the kin
12、etic energy correction for tc (see annex A). The equation for the viscosity number given in IS0 1628-1: t - t(J V.N. = tc s . * 0 (4) may be used to give results of similar accuracy if a viscometer with a smaller capillary diameter is used so that the kinetic energy correction is less than 0,2 % of
13、the efflux time. 11 Test report See IS0 1628-1 : 1964, clause 10. 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 19:08:48 MDTNo reproduction or networking permitted without li
14、cense from IHS -,-,- IS0 1626-6 : 1990 (E) Annex A (normative) Calibration of the viscometer A.1 Experience has shown that the required high accuracy of the viscosity number determination of MMA homopolymer and copolymer solutions cannot always be achieved with com- mercially available Ubbelohde vis
15、cometers because of minor irregularities in the capillary. It is therefore advisable to check the accuracy of the viscometer by means of calibrating liquids whose kinematic viscosity 111 is known. A.2 Viscometer constant k Using n-undecane of recognized analytical grade at 25 OC, make three to five
16、passages with the same viscometer and determine the mean efflux time t in accordance with IS0 3105 : 1976, clause 5. Calculate the viscometer constant k from the equation : k=+ where v for n-undecane at 25 OC is 1,467 5 mmz/s. NOTE - The density Q of n-undecane at 25 OC is 0,736 5 g/ml, A.3 Kinetic
17、energy corrections At, and At The energy correction can be neglected if it is less than 0,2 % of the efflux time. The Ubbelohde type OC viscometer complies with this require- ment if the = t,; - 2 * . . (A.21 where t. Sl is the efflux time, in seconds, of the ith standard liquid; vi is the kinematic
18、 viscosity, in second, of the ith standard liquid; k is the viscometer constant, in second squared. square millimetres per square millimetres per Linear interpolation, using the following equations, between the two efflux times t, and fQ for the standard liquids i = 1 and i = 2 (see figure A.11 give
19、s the kinematic energy correction At, for the efflux time to of the solvent (chloroform) : 41 K12= 1 - At, At, - At0 = 1 1 1 . . . (A.31 (A.41 - _- t sl ts2 t Sl t0 In the same manner, linear interpolation, using the following equations, between tQ and td gives At for the efflux time t of the test s
20、olution: . I . KB = 42 - Ata At fto is the dynamic viscosity, in millipascal seconds, of the solvent; c is the concentration of polymer, in grams per millilitre of solution. Annex C (informative) Bibliography ill BAUER, H., and MEERLENDER, G., Precise viscosity measurements of Newtonian liquids with
21、 v 1 mm2/s for the selection of suitable standards. Rheologica Acte 23: 514-521 (1994). 121 BILLMEYER, F.W., Jr., Journal of Polymer Science 4: 83 W49). UDC 678.744.336 : 632.13.08 Descriptors: plastics, polymers, methylmethactylate, tests, physical tests, determination, viscosity, viscosity index. Price based on 6 pages 6 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 19:08:48 MDTNo reproduction or networking permitted without license from IHS -,-,-