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 new criterion of phase separation of segmented polyurethaneureas. is found by comparing the relative crystallinity of the soft segment of polyurethaneurea. This criterion is more sensitive than the conventional thermal transition temperature measurements. The difference of crystallinity can be distinguished even if the thermal transition temperatures are the same. The polymers are synthesized by coupling a prepolymer consisting of poly(tetramethylene oxide) (PTMO) and 4,4′-diphenylmethane diisocyanate (MDI) with different chain extenders, ethylenediamine (ED), 1.6-hexanediamine (HD), and 4,4′-methylenedianiline (MDA). The degree of phase separation is found to relate to the structure of the chain extender and the hard-segment content as indicated by the relative crystallinity and initial modulus. Several explanations are proposed to discuss the relationship between these factors.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1982.070270627
Permalink