R6sum/~--Les copolym+res greff6s pr6par6s par grefl'age cationique de l'ind6ne sur du caoutchouc butyl chlor6 ont des structures r6guli+res en peigne. Leurs propri6tes m6caniques, qui peuvent ~tre reli6es au hombre de greffons par chaqne, sont conservaes en partie jusqu'/t 100 ° (~ 100 ° r6sistancc
Effet de la concentration sur la transition conformationnelle des copolymères séquencés et greffés
✍ Scribed by Dondos, Anastasios ;Benoît, Henri
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1977
- Weight
- 398 KB
- Volume
- 178
- Category
- Article
- ISSN
- 0025-116X
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✦ Synopsis
Abstract
In this paper we have been studying the effect of concentration c on reduced viscosity η~sp~/c for a triblock copolymer poly(methyl methacrylate)/polystyrene/poly(methyl methacrylate) and for a graft copolymer of the same nature.
The temperature of the experiments has been chosen in the range where the conformation changes from a segregated form to a pseudogaussian one. For this temperature range η~sp~/c is not a linear function of concentration but the points η~sp~/c vs. c are situated on two straight line segments with a well defined intercept.
We discuss the phenomenon in comparison to results obtained on mixtures of homopolymers. These results suggest a strong and anomalous dependance of molecular conformation on concentration.
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