Polyurethanes from renewable resources. III: synthesis and characterisation of low molar mass polytetrahydrofuran diols and their glucosides

Polytetrahydrofuran diols are polyurethane precursors obtainable from carbohydrate feedstocks. A range of commercial diols of different molecular weights were selected and supplemented by synthesised diols of lower molecular weights. To increase the carbohydrate content of derived polymers each diol was reacted with 1 or 2 moles of glucose and converted to a glucoside in high yield using a solution reaction. Complex products resulted, which approximately may be represented by mono‐ or bisglucoside structures. The parent diols and the glucosides were characterised using a wide range of techniques including acetylation equivalent weight, functionality towards diisocyanate, GPC, DSC, GLC, IR, HPLC, viscosity determinations and various wet chemical analyses. Relative to the parent diols, the properties of the glucosides (such as high viscosity, wider range of functionality towards MDI, and the relationships between transition temperatures and (diol) molecular weight) are explained as due to the rigidity and large free volume of the terminal glucose unit, its potential for increasing hydrogen bonding, and its ability to cause disruption of polytetramethylene oxide chain ordering.