Thermoresponsive and self-assembly behaviors of poly(oligo(ethylene glycol) methacrylate) based cyclodextrin cored star polymer and pseudo-graft polymer

Star polymers (CD-POEGMAs and CD-PNIPAMs), and pseudo-graft polymer (PADMA-(CD-POEGMAs) x ) formed from PADMA with adamantyl(Ad) pendants and CD-POEGMAs by host–guest inclusion complexation were prepared and characterized. This work compared the thermoresponsive and self-assembly mechanisms of the POEGMAs as branches to that of PNIPAMs branched cyclodextrin cored star polymers. In contrast to CD-PNIPAMs which behaved abrupt and intensive dehydration process near its LCST, CD-POEGMAs exhibited thermally induced aggregation process with consecutive conformation changes during the temperature increase process, and gradually self-assembled into cyclodextrin centered aggregates with hydrophobic methacrylate backbone and dehydrated POEGMAs side chains. Moreover, this work provided a supramolecular method controlling and adjusting the thermoresponsive properties of pseudo-graft PADMA-(CD-POEGMAs) x formed from CD-POEGMAs and PADMA via inclusion complexation, which underwent a reversible thermally induced transition from micelle to nano-aggregates. Pseudo-graft PADMA-(CD-POEGMAs) x behaved gradually conformation changes as temperature rising, and self-assembled into aggregates with hydrophobic methacrylate backbone, residual Ads, and dehydrated POEGMAs side chains.