Four samples of copolymeix of -&enzyl bgliitamic (BLG) and 0-benzyl-L-wrine (BLS) were syntheriized by changing the mixing ratio of two monomer anhydrides. The conformations of these copolymers in CHCb, containing very small amount of dichloroacetic acid (DCA) necessary to dissolve the sample, were
The rate of γ-benzyl-L-glutamate NCA polymerizations
✍ Scribed by Fred D. Williams; Ronald D. Brown
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1973
- Tongue
- English
- Weight
- 393 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
Abstract
The primary amine initiated homopolymerization of γ‐benzyl‐L‐glutamate NCA in dioxane at 25°C, 35°C, 50°C, and 65°C has been investigated. The reactions were virtually independent of temperature indicating an activation energy of less than 1 kcal/mole. The entropy of activation was estimated to be −65 entropy units at 300°K. The reaction proceeded in two stages. The first stage was zero‐order with respect to monomer, whereas the second was first‐order with respect to monomer. Both stages were first‐order with respect to initiator. These results were interpreted by assuming that the rate constant for propagation was not independent of the degree of polymerization up to the point where a conformational transition to α‐helix occurred.
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