Polypseudorotaxane-based multiblock copolymers prepared via in situ ATRP of NIPAAm initiated by inclusion complex having a feeding ratio of 4 β-CDs to ferrocene containing initiator

Abstract

A series of PPR-based multiblock copolymers were prepared by using a PPR self-assembled from a distal 2-bromoisobutyryl end-capped ferrocenyl containing derivative Br-TEG-Fc-TEG-Br with 4 β-CDs as initiator to initiate the in situ ATRP of NIPAAm in aqueous solution at room temperature. After the ATRP, about 2 β-CDs were resided on the polymeric backbone through a 7 day dialysing purification, but those β-CDs were all slipped off the polymeric chain through a further 7 day dialysing treatment. It suggested that the resulting multiblock copolymers are really the PPR-based instead of the PR-based ones showing an impeded dethreading behavior of β-CDs and the PNIPAAm blocks attached are not bulky enough as polymeric stoppers to end-cap the β-CD-TEG-Fc-TEG PPRs into the PR-based multiblock copolymers. A series of PPR-based multiblock copolymers were prepared by using a PPR self-assembled from Br-TEG-Fc-TEG-Br with 4 β-CDs as initiator to initiate the aqueous ATRP of NIPAAm. After the polymerization there are about 2 β-CDs still entrapped on the polymeric chain through a 7 day dialyzing purification. Those threaded β-CDs are all slipped off the polymeric backbone through a further 7 day dialyzing treatment.