## Abstract Raman spectroscopy, which does not require a time‐consuming sample preparation, is described as an analytical tool for the high‐throughput characterization of polyethylenes. The content of comonomer and the amount of methyl groups per 1 000 carbon atoms of polyethylenes can be predicted
Structure–property relationships as a tool for the formulation of high-performance epoxy-amine networks
✍ Scribed by Antoine Chateauminois; Valérie Sauvant; Jean Louis Halary
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 151 KB
- Volume
- 52
- Category
- Article
- ISSN
- 0959-8103
- DOI
- 10.1002/pi.1074
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Inspection of the structure–property relationships already established for epoxy‐amine networks allows the design of some novel formulations leading to high‐performance materials. This was achieved by choosing an additive, miscible in the mixture of monomers, but which gives rise to phase nanoseparation along the network construction. As a result, small domains, consisting of additive molecules trapping some network chains, are dispersed in the polymer matrix which also contains residual additive molecules. The main effects of this special morphology on the properties of the networks are the depression of the main relaxation temperature, T~α~, of the matrix and the appearance of some damping (so‐called µ relaxation) in the temperature range intermediate between the secondary relaxation and T~α~. The networks prepared in this way exhibit a lower water uptake at equilibrium, and present higher modulus and higher toughness around room temperature than conventional systems without additive. Friction experiments showed that the increase in toughness drastically delays crack propagation within the contact and, in turn, can improve the wear resistance of the material.
© 2003 Society of Chemical Industry
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