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

Transketalization reactions between the diketals of 1,4-cyclohexanedio ne and the diketonides of pentaerythritol yield a spiropolymer which i s insoluble in all solvents tried, but which can be hydrolysed to 1,4- cyclohexanedione and pentaerythritol. At short reaction times, oligome rs such as aoxapentaspiro[5.2.2.2.2.5.2.2.2.2.2]untriacontane can be i solated. However, all attempts to achieve a genuine equilibrium betwee n the monomers, oligomers and polymer were fruitless. The C-13 cross-p olarization/magic angle spinning (CP/MAS) n.m.r. spectrum of the polym er shows extra lines relative to those of soluble model compounds; thi s is probably due to a slow ring inversion of the 1,3-dioxane rings in the solid polymer.