Synthesis and properties of poly(ketone-co-alcohol) materials: Shape memory thermoplastic elastomers by control of the glass transition process

The well-controlled reduction of polyketone carbonyl functional group was performed without chain degradation by using NaBH₄ in tetrahydrofuran (THF)/MeOH solvent mixtures. Three different families of flexible polyketones (alternating propene/CO "PCO", hex-1-ene/CO "HxCO" copolymers, and "pulse feed" alternating olefin/ CO terpolymers from ethene and propene "EPCO") were investigated to achieve either a partial reduction, leading to poly(ketone-co-alcohol)s of corresponding composition, or a complete conversion into polyalcohols. Increasing the ratio of [OH]/[CO] functions allows continuous change of the T_g of the resulting polymers from below room temperature to about 75 °C. Properties of the synthesized materials, like thermal decomposition, glass transition temperature, surface tension, and mechanical performance, are described depending on the degree of reduction. Thermoplastic elastomers with an interesting "shape memory" effect result from the partially reduced, elastic EPCO terpolymers.