Novel thermoresponsive polymers having biodegradable phosphoester backbones

Thermoresponsive polyphosphoesters have been synthesized by the simple copolymerization of two cyclic phosphoester monomers components. Poly(IPP-co-EP) was prepared by ring-opening polymerization using triisobutyl aluminum (iBu3Al) as an initiator. The polymerization was homogeneously conducted by a solvent-free reaction. It was observed that lower critical solution temperature (LCST) of poly(EP) (PEP) linearly increased with an increase in the composition of IPP. It was also reported that the LCST of thermoresponsive polymers can be controlled by compositions of hydrophobic and hydrophilic units. The thermoresponsivity of polyphosphoesters could also be observed under physiological temperatures, proving the applicability of these polymers in biomedical field.