Design and characterization of novel β-cyclodextrin based copolymer materials

Abstract

Reported herein are the systematic design and characterization of several novel polyurethane (PU) copolymers containing a macrocyclic porogen (β-cyclodextrin; β-CD). These copolymers were synthesized from the reaction between β-CD with different types of diisocyanate linker molecules (e.g., 1,6-hexamethylene diisocyanate (HDI), 4,4'-dicyclohexylmethane diisocyanate (CDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,4-phenylene diisocyanate (PDI) and 1,5-naphthalene diisocyanate (NDI)) at variable synthetic conditions. The copolymers were characterized using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), solid state (13)C CP-MAS NMR, (1)H/(13)C solution NMR spectroscopy, thermogravimetric analysis (TGA) and elemental analyses (CHN). The PU copolymers were generally insoluble in water and the optimal preparation of copolymer materials for sorption-based applications is for β-CD/linker synthetic mole ratios from 1:1 to 1:3. The practical upper limit of the crosslink density (approximately 1:7, β-CD/linker) depends on the steric bulk of the cross linker units.