Synthesis and investigation of properties of thiacalix[4]arene-based polyurethane elastomers

Abstract

A series of polyurethane elastomers (PUEs) derived from three thiacalix[4]arene derivatives (TC4As), namely p-tert-butylthiacalix[4]arene, tetrasodium thiacalix[4]arenetetrasulfonate and thiacalix[4]arenetetrasulfonic acid, as a portion of chain extender in a mixture with glycerol were synthesized. The effects of the chemical structure of TC4As used as chain extenders on the various properties of the prepared PUEs were investigated and compared with PUE extended with only glycerol as chain extender using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy and a universal tensile tester. Moreover, the effect of the introduction of TC4As as a portion of chain extender on the hydrophobicity of the PUEs was also evaluated. DSC, FTIR spectroscopy and XRD revealed that the degree of phase separation and crystallinity in TC4A-based PUEs was much higher than that of the glycerol-based ones. Thus, it was concluded that the presence of TC4As in TC4A-based PUEs seems to favour the formation of a more ordered structure due to an increase in the degree of phase separation. The TGA results also showed that, with incorporation of TC4As into the polyurethane backbone, the thermal stability of PUEs was improved.

Synthesis and characterization of super dye adsorbent hydrogels based on acrylic acid and acryloyl tetrasodium thiacalix[4]arene tetrasulfonate

“…Several adsorbents have been proposed in the literature for MG removal from aqueous solutions, e.g. iron humate, freshwater algae, chitosan beads, prosopis cineraria , bagasse fly ash, cyclodextrin‐based adsorbent, seashell powder, degreased coffee bean, vinyl‐modified mesoporous poly(acrylic acid)/SiO 2 composite nanofiber membranes, pine sawdust, bentonite clay, chitin hydrogel and polyurethane foams …”

“…The fact that the adsorption obeys the Freundlich isotherm well indicates that the adsorbent surface is heterogeneous in nature . According to the Langmuir isotherm, the maximum adsorption capacity of the hydrogel toward MG is estimated as 120.5 mg g −1 which is much higher than previous reported adsorbents, such as polyurethane (58.8 mg g −1 ), magnetite/reduced graphene oxide (22 mg g −1 ), chitin hydrogel (26.8 mg g −1 ), chitosan bead (93.5 mg g −1 ), cyclodexterin based adsorbent (91 mg g −1 ), iron humate (19.20 mg g −1 ), Arundo donax root carbon (8.69 mg g −1 ), bentonite clay (7.72 mg g −1 ) and organically modified clay (40.48 mg g −1 ) …”

Swelling behavior and characterization of alcohol-specific superabsorbing gels based on acrylic acid and allyl tetrasodium thiacalix[4]arene tetrasulfonate

“…For instance, recently immobilized calixarenes on polymeric beds have been used as adsorbent for removal of toxic metal cations from water [14][15][16]. In continuation of our ongoing work on calixarenebased high performance polymers, more recently various attempts have been undertaken to incorporate thiacalixarenes into polyurethanes [17].…”

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 .…”

“…Yadav et al have studied the mechanical and structural properties of calix[4]arene‐segmented polyurethane and its nanocomposites with single‐walled carbon nanotubes . Mohammadi et a. have investigated the synthesis and properties of thiacalix[4]arene‐based polyurethane elastomers …”