The Motility of β-Cyclodextrins Threaded on the Polyrotaxane Based Triblock Polymer and Its Influences on Mechanical Properties

Abstract

Polyrotaxane (PR) has garnered increasing attention due to its unique structure and exceptional performance. In this study, a polypseudorotaxane (PPR) initiator was prepared through the self-assembly of bromine-capped Pluronic F68 and β-cyclodextrins (β-CD) in water. Polyrotaxane-containing triblock copolymers (PR copolymers) were successfully synthesized by atom transfer radical polymerization (ATRP) of butyl methacrylate (BMA) using the PPR initiator in the presence of Cu(I)Br/PMDETA. The structure of the PR copolymers was thoroughly characterized using infrared spectroscopy (IR), proton nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC). The mobility of β-CD in the PR copolymers was demonstrated through dielectric measurements. Mechanical tests, including tensile strength assessments, thermal mechanical analysis, and dynamic mechanical analysis, confirmed the excellent mechanical properties and good processability of the PR copolymer, attributed to the PBMA blocks. Furthermore, the mechanical properties were found to be modulated by the motility of the threaded β-CDs. Consequently, the superior mechanical properties and the high mobility of the threaded β-CDs suggest promising potential for the as-prepared PR polymer in various advanced applications.