ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
A study of a melt-spun threadline has been carried out to determine the effect of molecular weight on the elongational viscosity of the polymer being spun. Polymer chosen for this study was poly(ethylene terephthalate) having different molecular weights. Conventional nonisothermal spinning of the polymers was carried out with cooling by free convection. Threadline surface temperatures were measured by a null-balance technique. Threadline tension at the take-up device was measured, and samples of the threadline were taken to obtain linear density profiles. Nonlinear least-squares fits were applied to the linear density data to obtain equations for velocity and elongation rate. These measurements were then used to determine the threadline elongational viscosity. Least-squares fits were made to a polynomial relating absolute temperature and elongation rate to the elengational viscosity. These results were then used to determine an activation energy of elongational flow which was found to decrease with elongation rate. Elongational viscosity was found to increase with molecular weight.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1974.070180902
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