Preferential Association of Segment Blocks in Polyurethane Nanocomposites
Submitted to Macromolecules
| Main Authors: | , , , , |
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| Format: | Preprint |
| Language: | en_US |
| Published: |
2007
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1721.1/35769 |
| _version_ | 1811081232070475776 |
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| author | James-Korley, LaShanda T. Liff, Shawna M. Kumar, Nitin McKinley, Gareth H. Hammond, Paula T. |
| author_facet | James-Korley, LaShanda T. Liff, Shawna M. Kumar, Nitin McKinley, Gareth H. Hammond, Paula T. |
| author_sort | James-Korley, LaShanda T. |
| collection | MIT |
| description | Submitted to Macromolecules |
| first_indexed | 2024-09-23T11:43:32Z |
| format | Preprint |
| id | mit-1721.1/35769 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:43:32Z |
| publishDate | 2007 |
| record_format | dspace |
| spelling | mit-1721.1/357692019-04-10T09:58:41Z Preferential Association of Segment Blocks in Polyurethane Nanocomposites James-Korley, LaShanda T. Liff, Shawna M. Kumar, Nitin McKinley, Gareth H. Hammond, Paula T. Polyurethane nanocomposite block copolymer polarity Preferential segregation Submitted to Macromolecules Controlling the level of dispersion of silicate layers in polymer matrices through intermolecular interactions and exploiting these interactions to enhance thermomechanical behavior are key challenges in the field of polymer nanocomposites. In this investigation, unmodified Laponite platelets are dispersed in a segmented polyurethane containing polar, hydrophilic soft segments and a hydrophobic hard segment using a novel solvent exchange method and compared to polyurethane nanocomposites containing more hydrophobic hard and soft domains. It was determined that the silicate layers were preferentially, but not exclusively, attracted to the hydrophilic, polar soft domains. An apparent micro-phase segregated morphology was observed in transmission electron microscopy for this system, revealing regions of exfoliation and intercalation. According to polarizing optical microscopy, strain-induced alignment is inhibited for this polyurethane nanocomposite, which is reflected in dramatic reductions in tensile strength and ultimate extensibility. In comparison, the Laponite discs appear to be preferentially, but not exclusively, embedded to the hard domains in the segmented polyurethanes containing more hydrophobic hard and soft domains. Exfoliation of the clay platelets leads to enhanced modulus and toughness without a reduction in extensibility. This study provides clues for exploiting silicate-polymer interactions to tune material properties without chemical modification. Institute for Soldier Nanotechnology (ISN) at MIT 2007-01-23T12:03:41Z 2007-01-23T12:03:41Z 2007-01-23T12:03:41Z Preprint http://hdl.handle.net/1721.1/35769 en_US 06-P-07 2367674 bytes application/pdf application/pdf |
| spellingShingle | Polyurethane nanocomposite block copolymer polarity Preferential segregation James-Korley, LaShanda T. Liff, Shawna M. Kumar, Nitin McKinley, Gareth H. Hammond, Paula T. Preferential Association of Segment Blocks in Polyurethane Nanocomposites |
| title | Preferential Association of Segment Blocks in Polyurethane Nanocomposites |
| title_full | Preferential Association of Segment Blocks in Polyurethane Nanocomposites |
| title_fullStr | Preferential Association of Segment Blocks in Polyurethane Nanocomposites |
| title_full_unstemmed | Preferential Association of Segment Blocks in Polyurethane Nanocomposites |
| title_short | Preferential Association of Segment Blocks in Polyurethane Nanocomposites |
| title_sort | preferential association of segment blocks in polyurethane nanocomposites |
| topic | Polyurethane nanocomposite block copolymer polarity Preferential segregation |
| url | http://hdl.handle.net/1721.1/35769 |
| work_keys_str_mv | AT jameskorleylashandat preferentialassociationofsegmentblocksinpolyurethanenanocomposites AT liffshawnam preferentialassociationofsegmentblocksinpolyurethanenanocomposites AT kumarnitin preferentialassociationofsegmentblocksinpolyurethanenanocomposites AT mckinleygarethh preferentialassociationofsegmentblocksinpolyurethanenanocomposites AT hammondpaulat preferentialassociationofsegmentblocksinpolyurethanenanocomposites |