ISSN:
0098-1273
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Previously it was found that the lamellar thickness of solution-grown polyamide crystals as assessed by low-angle x-ray diffraction appeared to be unaffected by crystallization conditions. This point has now been re-examined in detail on nylon 6.6 with crystallization temperature Tc as the main variable. Over a very wide range of Tc the lamellar thickness was invariant; a notable increase could be produced only at the highest Tc. The “invariant” lamellar thickness occurs at larger supercoolings than can be realized in the much-studied polyethylene, which may explain why it has not yet been reported for polyethylene. The existence of this minimum invariant value raises important questions concerning the applicability of the current kinetic theories over such a wide range of supercoolings. Several other polyamides also revealed invariant long spacings after crystallization from solution. This provides the justification sought for comparing, in the paper which follows, the long periods observed for a large number of polyamides.
Zusätzliches Material:
4 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1973.180110201
