ISSN:
0032-3888
Schlagwort(e):
Chemistry
;
Chemical Engineering
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
The extraordinary physical properties exhibited by block polymers have been ascribed to the presence of a multiphase microstructure in which the higher modulus phase acts as a quasi-crosslink or filler particle. Recently, the optical examination of these materials combined with mechanical testing has given investigatiors new insight into this complex morphology. In this investigation, simultaneous stress, strain, and birefringence data have been collected on a block polyester urethane elastomer. Stress-softening is observed in cyclic stress-strain experiments, giving rise to significant hysteresis in the stressstrain and birefringence-stress curves. In these tests, prestrain causes a large increase in the stress-optical coefficient, but has little effect on the strain-optical coeffcient. As the temperature is increased, the strain-optical coefficent decreases while the stress-optical coefficient increases with the latter exhibiting a larger temperature dependence than predicted by the kinetic theory of rubber elasticity. The good agreement between the mechanical-optical response of polyester urethanes and that of other block polymer systems provides further evidence of their morphological similarity.
Zusätzliches Material:
7 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pen.760090602
