Synthesis of high‐performance polyurethanes with rigid 5‐6‐5‐fused ring system in the main chain from naturally occurring myo‐inositol

Abstract

A bisketal of myo‐inositol was used as a diol‐type monomer for synthesis of polyurethanes. The monomer was obtained by treatment of myo‐inositol with 1,1‐dimethoxycyclohexane in the presence of p‐toluenesulfonic acid as a catalyst. The ketalization resulted in the formation of a 5‐6‐5‐fused ring system, which endowed the diol‐type monomer with high rigidity. The diol readily reacted with diisocyanate to give the corresponding polyurethane, which exhibited excellent heat resistance due to the rigid 5‐6‐5 system in the main chain. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3956–3963

Rigid diol bearing 6‐6‐6 fused ring system derived from naturally occurring myo‐inositol and its polyaddition with diisocyanates

“…The TG analysis confirmed the lower thermal stabilities of polyurethanes 4 than those of polyurethanes 2 : The T d5 values of 4 ranged from 233 to 266 °C, whereas those of 2 ranged from 283 to 302 °C.…”

“…Our research interest has been focused on the utilization of myo ‐inositol, a naturally occurring cyclic hexaol, as a starting material for polymer synthesis . myo ‐Inositol and its derivatives can be found abundantly in various plants and animal organs.…”

“…One of these efficient protection methods is bisketalization with 1,1‐dimethoxycyclohexane, which permits the ketalization of 2,3‐ cis ‐diol and 5,6‐ trans ‐diol to give a rigid diol, 1 , with a 5–6‐5 fused ring system . In our previous work, diol 1 was used as a monomer for polyurethane synthesis to afford polyurethanes 2 , the repeating units of which inherited the 5–6‐5 fused ring system from 1 (Scheme ) . Because of the rigidity of the repeating unit, the polyurethanes had high glass transition temperatures ( T g values), which in some cases were higher than those of the polyurethanes synthesized from isosorbide and some other monosaccharide‐derived diols.…”

Rigid triol and diol with adamantane-like core derived from naturally occurringmyo-inositol and their polyaddition with diisocyanates

“…In Table , the reported T g and T d10 values of the polyurethanes 5 (Fig. ), which were obtained by the polyaddition of CHD with diisocyanates, are also shown . T d10 values of 4 were comparable to 5 , suggesting that the orthoester moiety in the main chain of 4 is as thermally stable as the cyclohexane moiety in the main chain of 5 .…”

“…One of the derivatives obtained by the ketalization is DL‐1,2:4,5‐di‐ O ‐cyclohexylidene‐ myo ‐inositol, a rigid compound with a 5‐6‐5 fused ring system . We employed this compound as a diol‐type monomer for polyaddition with diisocyanates, leading to the successful synthesis of polyurethanes with high glass transition temperatures ( T g s) . Another functionalization method used frequently so far is orthoesterification, which allows protection of three hydroxyl groups of myo ‐inositol in one step .…”