| EPSRC Reference: |
GR/R92295/01 |
| Title: |
Self-Poisoning Crystallization and Polymer Morphology |
| Principal Investigator: |
Ungar, Professor G |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
Materials Science and Engineering |
| Organisation: |
University of Sheffield |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
02 December 2002 |
Ends: |
01 June 2006 |
Value (£): |
183,291
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| EPSRC Research Topic Classifications: |
| Complex fluids & soft solids |
Materials Characterisation |
| Materials Synthesis & Growth |
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Summary on Grant Application Form |
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The main aim of the proposed research is to understand the causes of the dependence of polymer crystal morphology on crystallization temperature. Tc dependence of lamellar thickness has been studied extensively and explained theoretically. In contrast, although experimental data exist on Tc dependence of the crystal shape, there is almost no understanding of what causes this dependence, e.g. why polyethylene lamellae grow along b-axis from the melt and primarily along a-axis from solution at low Tc, why some faces are rounded at high Tc and flat at low Tc; the one-time suggestion of a roughening transition has not been upheld. Preliminary results on Tc-induced changes in habits of long n-alkane crystals suggest that the alkanes may provide the clue to the factors determining crystal morphology in polyethylene. For this reason morphology and detailed growth kinetics (step initiation and propagation rates) will be investigated for pure alkane and selected mixtures, as well as for the polymer where necessary. Furthermore, the effect of chain tilt on crystal morphology and growth kinetics will be studied and related to lamellar surface disorder determined spectroscopically. Finally, the effect of permanent and transient cilia on crystal and spherulite morphology and growth kinetics will be studied using the new asymmetrically branched and Y-shaped long alkanes.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.shef.ac.uk |