Calix[4]arenes Used as a New Type of Chain Extender in the Preparation of Polyurethanes

Abstract

A series of polyether-or polyester-polyurethanes based on tetrahydrofuran-propylene oxide copolyether diol (PTMG/PPG) or poly(ethylene terephthalate) diol (PET), toluene diisocyanate (TDI), and three kinds of chain extenders including two calix[4]arene derivatives and 3,3 -dichloro-4,4 -diaminodiphenylmethane (MOCA) were synthesized in toluene. The thermal stability and mechanical properties of solvent-type polyurethanes were investigated. Incorporation of calixarenes into polyurethane backbones improved the thermal properties of the polyurethane as a result of the residual phenol hydroxy groups of the calix[4]arene units. Compared with polyurethane chain-extended by MOCA, the polyurethanes with calix[4]arene derivatives had higher elongation at break, lower elastic modulus, and lower yield strength, as a result of the larger steric cubage of calix[4]arene units and relatively large free volume of the polymer.

Synthesis and Characterization of Functionalized Calix[4]arene Derivatives and Preparation of Rigid Polyurethane Foams by the Incorporation of Calixarene

“…The PU‐calixarene composite ability to separate alkaline metal cations has been studied . Calixarene based synthesis of PU and enhancement pf mechanical and structural properties of PU have been widely reported at literature . Zheng et al have used calix[4]arene as chain extender at PU preparation .…”

“…[16,[25][26][27][28] Calixarene based synthesis of PU and enhancement pf mechanical and structural properties of PU have been widely reported at literature. [29][30][31][32] Zheng et al have used calix [4]arene as chain extender at PU preparation. [31] Yadav et al have studied the mechanical and structural properties of calix [4]arene-segmented polyurethane and its nanocomposites with single-walled carbon nanotubes.…”

“…[29][30][31][32] Zheng et al have used calix [4]arene as chain extender at PU preparation. [31] Yadav et al have studied the mechanical and structural properties of calix [4]arene-segmented polyurethane and its nanocomposites with single-walled carbon nanotubes. [30] Mohammadi et a. have investigated the synthesis and properties of thiacalix [4] arene-based polyurethane elastomers.…”