Citation
Allen G., . Molecular mobility in rubbers. pp. 51-57. ISSN 0127-7065
Abstract
Neutron beams can be obtained in pulsed beams of virtually monochromatic character at wavelengths of about 5 A. The momentum associated with the beam is high and the energy low. Thus neutrons are ideal for studying the diffusional motions of liquids in scattering experiments. In the past ten years neutron scattering has been used to determine the average dimensions of individual chains in bulk rubbers and plastics to study the dynamics of polymer chains in raw rubbers and melts and cross-linked networks and to measure the rotation of side groups. Results show that the Rouse model of molecular chain dynamics is more appropriate than the Zimm model for rubber. In networks the sections of chain between cross-links form essentially the same chain motion as in the raw rubber but the junction points move more slowly. The energy barrier to internal rotation of the methyl side groups in polypropylene oxide is found to be approximately 15 kJ mol-1 in line with the expected value.
Download File
Full text available from:
Official URL: http://vitaldoc.lgm.gov.my:8060/vital/access/servi...
|
Abstract
Neutron beams can be obtained in pulsed beams of virtually monochromatic character at wavelengths of about 5 A. The momentum associated with the beam is high and the energy low. Thus neutrons are ideal for studying the diffusional motions of liquids in scattering experiments. In the past ten years neutron scattering has been used to determine the average dimensions of individual chains in bulk rubbers and plastics to study the dynamics of polymer chains in raw rubbers and melts and cross-linked networks and to measure the rotation of side groups. Results show that the Rouse model of molecular chain dynamics is more appropriate than the Zimm model for rubber. In networks the sections of chain between cross-links form essentially the same chain motion as in the raw rubber but the junction points move more slowly. The energy barrier to internal rotation of the methyl side groups in polypropylene oxide is found to be approximately 15 kJ mol-1 in line with the expected value.
Additional Metadata
| Item Type: | Article |
|---|---|
| AGROVOC Term: | Rubber |
| AGROVOC Term: | Experiments |
| AGROVOC Term: | Neutron activation analysis |
| AGROVOC Term: | Diffusion |
| AGROVOC Term: | Cross-linking |
| AGROVOC Term: | Liquids |
| AGROVOC Term: | Polymers |
| AGROVOC Term: | Polypropylene |
| AGROVOC Term: | Energy value |
| Depositing User: | Ms. Suzila Mohamad Kasim |
| Last Modified: | 24 Apr 2025 06:28 |
| URI: | http://webagris.upm.edu.my/id/eprint/23595 |
Actions (login required)
 |
View Item |
