In Situ Polycondensation of p-tert-Butylphenol in the Presence of Poly(ethylene glycol)s for Preparation of Polyrotaxanes

Abstract

A new polyrotaxane was formed by the polycondensation of p-tert-butylphenol (BP) with paraformaldehyde in the presence of poly(ethylene glycol)s, (PEG)s, of various molecular weights. The polyrotaxane of BP oligomers with PEG was obtained when the PEG of average molecular weights between 1000 and 10 000 were used in the polycondensation. The polyrotaxane yield and the composition were dependent on the molecular weight of PEG. The molecular structure was determined by FT-IR and 1 H NMR spectroscopies and the thermal properties by DSC measurements. 1 H NMR spectra of the complexes showed a pair of doublets in the methylene region, which correspond to the methylene protons between phenolic rings in p-tert-butylcalixarenes. The FT-IR spectra and DSC curves were different from those of the blend of linear p-tert-butylphenolic resins with PEG and pure p-tert-butylcalix[8]arene, respectively. Calixarenes slipped off the backbone PEG by heating the polyrotaxane in ethylene glycol at 180 °C. The structure of the dethreaded calixarenes was determined by 1 H NMR, and they were found to be p-tertbutylcalix[8]arenes and a few p-tert-butylcalix [4]arenes. From the characteristic results it was found that the polyrotaxane obtained by the in situ polycondensation of BP was composed of p-tert-butylcalix[8]arenes penetrated by PEG; that is, this was a calix[8]arene-based polyrotaxane.

One Pot Synthesis of a Polyisoprene Polyrotaxane and Conversion to a Slide‐Ring Gel

“…A great variety of cyclic host molecules have been already assembled to polyrotaxanes, such as crown ethers, cucurbit[ n ]urils, calixarenes, and cyclodextrins. Among them, cyclodextrins (CDs, or cycloamyloses) have received the most attention, because CDs are nontoxic, biodegradable, and readily available starting materials, which can easily be functionalized …”

“…[ 7,[13][14][15] Because of this unique topology, much higher degrees of swelling and elongations at break are reachable for SRGs than for conventional gels. [ 16 ] A great variety of cyclic host molecules have been already assembled to polyrotaxanes, such as crown ethers, [ 12,[17][18][19][20] cucurbit[ n ]urils, [21][22][23] calixarenes, [ 24,25 ] and cyclodextrins. Among them, cyclodextrins (CDs, or cycloamyloses) have received the most attention, because synthesis and costly purifi cation procedures.…”

Polyrotaxanes

“…A water-soluble, nanometer-scale metallocapped polyrotaxane was prepared by the inclusion complexation of azocalixarenes with metallo-bridged CD dimers, displaying highly selective binding for Ca 2+ (156). A polyrotaxane formed by the polycondensation of p-tert-butylphenol with paraformaldehyde in the presence of PEGs was reported (157).…”

Polyrotaxanes and Polycatenanes: Recent Advances in Syntheses and Applications of Polymers Comprising of Interlocked Structures

“…Yamagishi et al carried out the condensation of p-tert-butylphenol with paraformaldehyde in the presence of poly(ethylene glycol) (PEG), pseudopolyrotaxane consisting of PEG axle and calixarene wheel was obtained [189] (Scheme 32). The wheel components removed from pseudopolyrotaxane were found to be mainly calix [8]arene which was accompanied with a small amount of calix [4]arene.…”