ISSN:
0887-6266
Keywords:
polyurethanes
;
cationomers
;
morphology
;
thermal properties
;
tensile properties
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Diphenylmethane-4,4′-diisocyanate based polyether polyurethane cationomers were synthesized using 3-trialkylammonium-(1,2-propanediol)iodide (TAPI) as the chain extender. The ionic content was varied by substituting up to 100% of 3-dialkylamino-1,2-propanediol (DAP) for TAPI. Cationomers with bromine and chlorine ions were prepared from the iodine-based polymer via ion exchange. The morphology and properties of the cationomers were studied as a function of alkyl group, ion content, and anion type using small-angle x-ray scattering, tensile testing, dynamic mechanical thermal analysis, and differential scanning calorimetry. The bulky side groups of DAP and TAPI prevented crystallization in the hard domains, and consequently little or no phase separation was evident in the unionized materials. Polyurethanes with cationic functionality showed dramatic improvements in phase separation and tensile properties. Results suggest tht while ionic interactions are the primary driving force for phase separation, they produce a morphology not typical of ionomers, but rather akin to that of a conventional polyurethane with semicrystalline hard segments. © 1994 John Wiley & Sons, Inc.
Additional Material:
14 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/polb.1994.090320827
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