ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The damping, resonant frequency, and dynamic elastic storage modulus of five polyamides have been investigated at resonant frequencies ranging from 100 to 2000 cycles/sec. at temperatures in the 100 to 450°K. region. Specimens of poly(hexamethyleneadipamide) containing 0, 0.9, 3.3, and 6.4 wt.-% water were studied and it was found that with increasing water content: the loss peak and associated modulus dispersion at 170°K. in the dry material decreased; the loss peak and modulus dispersion at 370°K. in the dry material shifted to lower temperatures reaching a value of 280°K. for 6.4% water; a third damping peak appeared at 240 to 245°K. and the modulus in the 150 to 250°K. region increased while above and below this range the reverse was true. A poly(hexamethylene adipamide) specimen containing 10.5 wt.-% methanol exhibited one broad peak at about 255 to 260°K. Dry specimens of poly(hexamethylene sebacamide), poly(decamethylene sebacamide), 17% N-methylated poly(decamethylene sebacamide), and 58% N-methylated poly(decamethylene sebacamide) were also investigated. For the latter three specimens the principal amorphous transition shifted from 340 to 285°K. and the area under the loss peak increased greatly in going from 0 to 58% N-methylation, while the low temperature transition remained at 160 to 170°K. essentially unchanged. Of the five polymers studied the 17% N-methylated poly(decamethylene sebacamide) exhibited the highest apparent modulus in the 110 to 160°K. region; and at all temperatures below the principal amorphous transition this material had a higher modulus than the unmethylated parent polymer.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1960.1204414303
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