Polyisobutylene model elastomers prepared using demonstrably complete end-linking reactions
Sung, P. -H. ; Pan, S. -J. ; Mark, J. E. ; Chang, V. S. C. ; Lackey, J. E. ; Kennedy, J. P.
Springer
Published 1983
Springer
Published 1983
| ISSN: |
1436-2449
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|---|---|
| Source: |
Springer Online Journal Archives 1860-2000
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| Topics: |
Chemistry and Pharmacology
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Physics
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| Notes: |
Summary Linear polyisobutylene (PIB) molecules with either hydroxyl or isopropenyl groups at the chain ends were prepared using cationic polymerizations with bifunctional initiator-chain transfer agents. Extensive spectroscopic analyses confirmed the essentially perfect difunctionality of the two types of polymers. The former polymers were end-linked using an aromatic triisocyanate, and the latter by means of a tetrafunctional silane. The resulting trifunctional and tetrafunctional model PIB networks were found to have absolutely negligible sol fractions, which demonstrates that the end-linking reactions used to prepare them were essentially complete. The networks were studied with regard to their equilibrium stress-strain isotherms in uniaxial extension at 25 °C. The results thus obtained are in satisfactory agreement with theory and yield no evidence whatever for significant elastic contributions from inter-chain entanglements.
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| Type of Medium: |
Electronic Resource
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| URL: |