A Facile Synthetic Route To Ether Diols Derived From 1,1-Cyclopentylenylbisphenol For Robust Cardo-Type Polyurethanes

An efficient scheme for the synthesis of 1,1-cyclopentylenylbisphenol (bisphenol CP) has been developed starting from dicyclopentadiene, a C5 byproduct from the petroleum cracking process. The synthetic steps leading to bisphenol CP consist of mostly isomerization and addition reactions, which are higher in their atom-economy efficiencies than those based upon condensation reactions. In addition, alkoxylation by cyclic carbonates converted bisphenol CP into ethoxylated and propoxylated ether diols. The transformation of hydroxyl functional groups from bisphenols to alkoxylated alcohols increased the reactivity of their hydroxyl groups toward isocyanates, as evidenced by achieving >3 times higher molecular weights of the segmented polyurethanes (PUs) in GPC analysis using alkoxylated diols as chain extenders instead of bisphenols. In addition, the incorporation of five-membered cardo-type groups onto the PU side chains through alkoxyl diols of bisphenol CP also significantly enhances the phase mixing of the resulting hard and soft segments, leading to a series of robust PUs.