Universität zu Köln

Wenning, Christian, Schmidt, Annette M. and Leimenstoll, Marc C. (2018). Reaction-induced phase separation in hexamethylene diisocyanate-based poly(propylene oxide)/poly(ethylene oxide) bi-soft segment oligomers. Polym. Int., 67 (4). S. 481 - 490. HOBOKEN: WILEY. ISSN 1097-0126

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Abstract

Oligomeric bi-soft segment isocyanate-terminated polyurethanes (ITPUs) are semi-finished materials crucial for the synthesis of various PU products like foams, thermoplastic parts, dispersions or elastomers. Incompatibilities and thus phase separation phenomena play an essential role in tailoring the properties of the final products. Therefore, a detailed knowledge of these phenomena is mandatory in order to design products with properties meeting the requirements of a given application. In this study the reaction-induced phase separation during the formation of ITPUs by application of two partially miscible soft segments is presented. The physicochemical basics of this process as well as the extent of the resulting phase separation are discussed on the basis of the initial phase diagram of the reactants. Reaction monitoring by NCO content titration and UV-visible spectroscopy reveals a dependency between the onset of phase separation and conversion. It is found that an increase of the initial content of hexamethylene diisocyanate delays the onset of phase separation. Differential scanning calorimetry reveals further that the phase separation is a direct consequence of the incompatibility of the soft segments. Overall, the findings support the hypothesis that the mechanism and the extent of phase separation are closely related to the ternary phase diagram of the reactants. (c) 2018 Society of Chemical Industry

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Wenning, Christian UNSPECIFIED UNSPECIFIED UNSPECIFIED Schmidt, Annette M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Leimenstoll, Marc C. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-192133
DOI:	10.1002/pi.5539
Journal or Publication Title:	Polym. Int.
Volume:	67
Number:	4
Page Range:	S. 481 - 490
Date:	2018
Publisher:	WILEY
Place of Publication:	HOBOKEN
ISSN:	1097-0126
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language HARD BLOCK CONTENT; MICROPHASE SEPARATION; URETHANE/UREA POLYMER; LINEAR POLYURETHANES; ETHYLENE-OXIDE; MORPHOLOGY; COPOLYMERS; MEMBRANES; BLENDS; KINETICS Multiple languages Polymer Science Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/19213