Attempted equilibration of an insoluble spiran polymer with monomers and oligomers through reversible chemical reactions: transketalization route to spiropolymers from 1,4-cyclohexanedione and pentaerythritol
✍ Scribed by Roger W. Alder; B.S.R. Reddy
- Book ID
- 104164068
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 747 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0032-3861
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✦ Synopsis
Transketalization reactions between the diketals of 1,4-cyclohexanedione and the diketonides of pentaerythritol yield a spiropolymer which is insoluble in all solvents tried, but which can be hydrolysed to 1,4-cyclohexanedione and pentaerythritol. At short reaction times, oligomers such as 3,3,21,2 l-tetrameth yl-1, 5,10,14,19,23,26,29-octaoxapentaspiro['5.2.2.2.2.5.2.2.2.2] untriacontane can be isolated. However, all attempts to achieve a genuine equilibrium between the monomers, oligomers and polymer were fruitless. The 13C cross-polarization/magic angle spinning (CP/MAS) n.m.r, spectrum of the polymer shows extra lines relative to those of soluble model compounds; this is probably due to a slow ring inversion of the 1,3-dioxane rings in the solid polymer.