ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The weight average molecular weights, Mu, of some unfractionated Alfin polybutadienes ranged from 5 to 20 million. The ratio of the mean-square radius of a linear polybutadiene molecule to its molecular weight in a thermodynamically neutral solvent is estimated to be R2/M = 2.2 (±0.3) × 10-17 cm.2g.-1 mole. The relationship [η] = 0.125 Mv0.77 between intrinsic viscosity and molecular weight is estimated for linear polybutadiene in cyclohexane at 25°. The average value of Φ′, the parameter in the Flory-Fox theory of intrinsic viscosity, is found to be 3.6 × 1024 mole-1 (or Φ = 2.5 × 1023 mole-1) for linear molecules and appears to increase with branching. Branching is found to decrease with increasing conversion for this polymer. Values of the osmotic second virial coefficient, A2, are discussed in connection with theoretical predictions. Various corrections to measured quantities required because of polydispersity in polymer samples are presented.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1958.1202711528
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