ISSN:
0022-3832
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
A simple and inexpensive instrument for measuring the osmotic pressure of polymer solutions has been designed. It consists of two 1-mm. I. D. Pyrex capillary tubes sealed into a flanged Pyrex sleeve, which is ground to fit snugly into a 19 × 60 mm. roundbased Alundum Thimble of medium porosity. A regenerated cellulose membrane is cast over the Alundum thimble, and the entire assembly is sealed in a test tube containing the polymer solution to be examined. This osmometer offers several unique advantages over others in current use. Its low cost and compact size permit inexpensive simultaneous measurement of many polymer solutions.A 1:3 copolymer of vinyltoluene and styrene monomers was separated into 24 cuts by fractional precipitation. On the basis of viscosity data these cuts were combined into 14 fractions. They were in the order of decreasing molecular weight, and infrared analysis indicated a uniform distribution of the ring methyl groups among the fractions. These two observations demonstrate that introduction of methyl groups into the benzene rings of a polystyrene molecule does not influence the polymer solubility appreciably.Osmotic molecular weights obtained with the Alundum thimble instruments and experimental limiting viscosity numbers gave values of 2.69 × 10-4 and 0.622 for K and α respectively in the Flory-Staudinger relation [η] = KMα. These results compare favorably with reported values for polystyrene samples prepared under similar conditions.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1953.120110507
