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Hydroxyl terminated polybutadiene based polyurethanes with various crosslinker compounds have been prepared to investigate the effect of crosslinker content and structure on polyurethanes mechanical properties. Three various crosslinkers have been used in this study, including trimethylolpropane, triethanolamine, and boron trifluoride triethanolamine complex. The results established that increasing crosslinker content increased the polyurethane strength. Moreover, boron trifluoride triethanolamine complex showed better ability in making network polyurethanes. The tensile test revealed that using boron trifluoride triethanolamine complex as crosslinker led to increasing chemical crosslinking bonds in comparison to two other crosslinkers via catalyzing side reaction like chain coupling. Swelling test and dynamical‐mechanical analysis confirmed this result, too.

Highlighting mixed matrix membrane (MMM) susceptibility in improving the membrane performance along with established p-tert-butylcalix[4]arene (CA) ability in CO 2 sorption, Pebax-1657-based MMMs have been prepared using various contents of CA. In this regard, well-distributed particles in the polymeric matrix without agglomeration has been achieved because of the organic nature of both Pebax-1657 and CA. Additionally, their miscibility was intensified by noncovalent interactions between functional groups on the backbone of two materials. Furthermore, permeability of CO 2 gas was significantly increased by introducing CA into the polymeric matrix, as well as selectivity of CO 2 /N 2 and CO 2 / CH 4 . This result was more remarkable in the sample containing 0.75 wt % CA that improved the permeation of CO 2 from 140.78 Barrer to 265.18 (about 88%) in comparison to the pure Pebax-1657 membrane. Accordingly, the selectivity of CO 2 /CH 4 and CO 2 /N 2 was enhanced from 25.35 to 51.51 (almost 103%) and from 43.18 to 109.16 (almost 152%), respectively, compared with the pure membrane. As a consequence, physical interactions between functional groups of CA and CO 2 gas were considered to be the key parameter affecting the remarkable permeation results. It is noteworthy that the MMM containing 0.75 wt % of CA overpassed the 2008 Robeson upper-bound limit.

4-Aminophenyl disulfide and bis(4-aminophenyl)methane chain extenders containing hydroxyl-terminated polybutadienebased polyurethane-ureas are prepared one-shot to explore the effect of the chain extender structure on the elastomers mechanical properties. However, the results revealed that the participation of the disulfide chain extender in side reactions like thiol-ene and proton abstraction prevented disulfide metathesis reaction due to decomposing chain extender in the polyurethane-urea matrix. Also, these side reactions improved the phase mixing via chemical crosslinking between polyurethane-ureas soft and hard segments, too. Tensile test results showed higher stress strength of the elastomers in the presence of the disulfide chain extender in comparison with the nondisulfide bond containing elastomers. This result was in agreement with the observed result in dynamical mechanical analysis. Dynamic mechanical analysis results established that the absence of the disulfide bond in the polyurethane-urea matrix led to the higher viscous modulus. The swelling test revealed chemical crosslinking increased in the presence of the disulfide bond. V C 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46309.

2014) A convenient and efficient one-pot method for the synthesis of novel acridine-calix[4]arene derivatives as new DNA binding agents via multicomponent reaction, Supramolecular Chemistry, 26:5-6, 442-449, A new approach is applied for the synthesis of novel acridine-calix[4]arene derivatives via a multicomponent reaction. These compounds have been characterised by 1 H NMR, 13 C NMR and HR-MS. Our binding studies between acridinefunctionalised calix[4]arenes and calf thymus DNA (CT-DNA) via fluorescence titration show that these compounds have a good affinity to CT-DNA.

Extra-high-performance low-level filler-loaded mixed-matrix membranes (MMMs) were fabricated by embedding a flexible cyclo­oligomer, calix[4]­arene (CA), as a macrocyclic porous filler in two blends of a commercial polyether block amide polymer, Pebax MH 1657. Two kinds of liquid phases, PEG550 (PEG) and [OMIM]­[PF6] (IL), were separately introduced into the Pebax MH 1657 matrix to prepare blended membranes for enhancing the CO2 permeability and comparing their performance. Afterward, CA as the third generation of supra­molecular hosts with high inherent affinity to CO2 was synthesized and incorporated in the polymer blends to fabricate high-performance MMMs. The organic nature, the high compatibility of other applied additives with Pebax MH 1657 polymer, and the tiny size of CA particles were responsible for the desirable particle distribution in ternary MMMs. In the case of the Pebax/PEG550 (30 wt%)/CA (0.5 wt%) MMM, the results revealed the CO2 permeability to be about 632.60 Barrer, with CO2/CH4 and CO2/N2 selectivities about 59.83 and 139.88, respectively. For Pebax/IL (6.5 wt%)/CA (0.5 wt%), the CO2 permeability was about 263.82 Barrer, with CO2/CH4 and CO2/N2 selectivities about 64.39 and 152.45, respectively. Therefore, the fabricated ternary MMMs present a promising outlook for CO2 separation, which surpasses the Robeson upper limits.

The effect of the mixture of two antioxidants has been evaluated on the thermal‐oxidant degradation of the hydroxyl‐terminated polybutadiene (HTPB) because of its importance in the coatings and adhesives industries. 2,2‐Methylene bis(4‐methyl‐6‐tertiarybutylphenol) or A.O.2246 and 3‐hydroxy pyridine have been considered as antioxidants in this study as a common HTPB antioxidant and an active antioxidant, respectively. The thermal‐oxidant degradation behavior of the HTPB has been investigated in the presence of a mixture of two antioxidants by TGA and DTG tests, and, subsequently, the results of these tests have been interpreted by two model‐free methods, e.g., Kissinger–Akahira–Sunose and Friedman methods. The results revealed that the mixture of two antioxidants affected the activation energy of the thermal‐oxidant degradation reaction of the HTPB. The calculated activation energy value obtained from the Kissinger–Akahira–Sunose method was about 199 ± 1 kJ⋅mol−1. In addition, the Ea value at various conversion rates has also been calculated by using the Friedman method. This method showed that the highest Ea value in the thermal‐oxidant degradation reaction belonged to the initiation step of the reaction (about 299 kJ⋅mol−1). Moreover, the lowest activation energy value was correlated to the second step of the degradation reaction at a conversion rate of 0.6 (about 184 kJ⋅mol−1).