Diglycerol bisacetonide was synthesized and isolated from acetone and diglycerol, which is renewable and available in large scale. DGA was directly used in polytransacetalization with 1,4-cyclohexanedione or 4,4-bicyclohexanone as diketone monomers. Polycycloacetals were obtained with molecular weights (M-n) of up to 28 kg mol(-1), broad dispersities (D = 1.5-4.0) and as semi-crystalline polymers with high melting points (T-m = 210-241 degrees C) and glass transition temperatures (T-g) of 48 degrees C or 65 degrees C. Introducing di(trimethylolpropane) (di-TMP) in the polymerization of DGA and 1,4-cyclohexanedione resulted in copolymers as confirmed by H-1-NMR and C-13-NMR spectroscopy. Increasing the di-TMP content from 10 to 50 mol% reduces the crystallinity of the polycycloacetals and increases the T-g, eventually yielding amorphous polymers (T-g = 60-71 degrees C). For the amorphous polycycloacetals, Young's moduli could be determined by tensile strength testing (E = 1.1-1.4 GPa). The polycycloacetals with renewable carbon contents in the range of 33-100% cover a wide range in material properties and are stable against hydrolysis at pH > 1-3, depending on the polycycloacetal composition.
- ACETAL METATHESIS POLYMERIZATION
- DELIVERY VEHICLE
- POLYKETAL MICROPARTICLES