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Structure–property relationship of shape memory polyurethane cross-linked by a polyethyleneglycol spacer between polyurethane chains.
- Source :
- Journal of Materials Science; Nov2007, Vol. 42 Issue 21, p9045-9056, 12p, 1 Color Photograph, 2 Diagrams, 5 Charts, 11 Graphs
- Publication Year :
- 2007
-
Abstract
- Shape memory polyurethane (SMPU) cross-linked by a polyethyleneglycol (PEG) spacer at its side was compared with a linear SMPU and the one randomly cross-linked by glycerol. The SMPU was composed of 4,4′-methylenebis(phenylisocyanate) (MDI), polytetramethyleneglycol-2000 (PTMG-2000), 1,4-butanediol (BD), glycerol, and PEG-200 as a spacer. PEG-200 connected the glycerol hydroxyl groups of two polyurethane chains via the connecting agent, MDI. T<subscript>m</subscript> of the soft segment increased with the increase of cross-linking content. Cross-link density measured by the swelling experiment increased in proportion to the glycerol content. A surprising increase in maximum stress compared to the linear SMPU was attained without any sacrifice in strain. Remarkably, the stress–strain curve revealed that the PEG cross-linked SMPU exhibited a similar behavior and superior tensile mechanical properties to natural rubber. Storage modulus also increased and loss tangent became broad in distribution over the temperature range after PEG cross-linking. Shape recovery rate went up to 96.8%, and shape recovery speed was three times faster than that of linear SMPU. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00222461
- Volume :
- 42
- Issue :
- 21
- Database :
- Complementary Index
- Journal :
- Journal of Materials Science
- Publication Type :
- Academic Journal
- Accession number :
- 26430201
- Full Text :
- https://doi.org/10.1007/s10853-007-1824-2