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In this study, a nanohybrid based on montmorillonite (oMMT2) was prepared through a two‐step method using Arquad MCB‐80 and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) as intercalation agents. The nanohybrid exhibited a basal spacing of 31.5 Å, which contained approximately 12.3% of Arquad MCB‐80 and 31.6% of DOPO. Various amount of oMMT2 nanohybrid was incorporated into a flame‐retardant polyethylene system containing aluminum trihydroxide and red phosphorus with a constant total additive content of 20 wt%. The dispersibility of oMMT2 in the composite matrix was evaluated by energy dispersive x‐ray mapping and x‐ray diffraction analyses. At a content of 3 wt% in the nanocomposite, oMMT2 showed a highly exfoliated state, while at a 5% content, a partially exfoliated and intercalated state was observed. A synergistic flame‐retardant effect between the nanohybrid and the mixture of aluminum trihydroxide and red phosphorus was found. The nanocomposite loading 3 wt% oMMT2 demonstrated the best flame retardancy, achieving a V‐0 rating of the vertical burning test with a limiting oxygen index of 27.6%. Moreover, the addition of the low oMMT2 contents (≤3 wt%) improved the mechanical properties of the flame‐retardant composite. [ABSTRACT FROM AUTHOR]

High fire‐resistance polypropylene (PP) composites were prepared by using environment‐friendly flame retardants including expandable graphite (EG), red phosphorus (RP), and magnesium hydroxide (MH). Synergism between EG, RP, and MH on the thermo‐oxidation behavior and flame resistance of PP was found. The incorporation of MH and RP formed highly thermally stable mixtures of magnesium phosphates consisting of Mg3(PO4)2, Mg(PO3)2, and α‐Mg2P2O7 at both amorphous and crystalline phases in the burning process. The mixture not only covered the surface of burning materials but also could reinforce the char structure of the PP/EG composites, thereby significantly enhancing the condensed phase flame retardant mechanism of the composites. Mass ratios of the flame retardants were also optimized to obtain the composite with the highest flame retardant efficiency. The result revealed that the combination of EG, RP, and MH in PP at MH/RP mass ratio of 3/2 with only a total additive content of 18 wt.% could make its limiting oxygen index (LOI) increase from 16.8% to 27.2% and the UL‐94 rating was improved from none to V‐0. In addition, the mechanical properties of the composites were improved via the surface treatment of MH and RP with calcium stearate and silicone oil, respectively. [ABSTRACT FROM AUTHOR]

A novel cyanine compound based on the conjugated perylene‐benzothiazole system (PBI) as a colorimetric and fluorometric dual‐channel sensor for cyanide (CN−) detection was synthesized and characterized via UV‐vis and fluorescence spectroscopy. PBI exhibited a high sensitivity and rapid optical response for CN− due to the intramolecular charge transfer (ICT) mechanism. The detection limit of PBI for CN− was 1.15×10−7 M in the mixture of DMSO/H2O (1 : 1, v/v). Moreover, probe PBI demonstrated high selectivity and sensitivity for CN− over other common anions, including Cl−, Br−, F−, I−, AcO−, ClO4−, HSO4−, SO42−, NO2−, NO3− and SCN−. This work provided a simple and effective approach to trace the toxic CN− ion with rapid response, high selectivity, and sensitivity that is possibly applied in environmental control and agricultural management. [ABSTRACT FROM AUTHOR]

The flame‐retardant low‐density polyethylene (LDPE) composites loading aluminum hydroxide (ATH), red phosphorus (RP), and expandable graphite (EG) were successfully prepared. The flame retardancy, the thermo‐oxidative stability, and the mechanical property of the composites were investigated. The synergistic effect of ATH, RP, and EG on the flame‐retardant property and thermal behavior of LDPE were observed. The limiting oxygen index value of LDPE significantly increased from 17.1% to 25.4% upon the incorporation of 15 wt.% of the mixture of three fillers with ATH:RP:EG mass ratio of 1:1:1; and this composite achieved the V‐0 classification of the UL94 vertical burning test. The thermogravimetric analysis of this composite under air atmosphere revealed that its residue weight remained 27.89% at 900°C. Furthermore, the results of tension tests indicated that the surface modification of ATH by magnesium stearate and RP by poly(methylhydrosiloxane) noticeably improved the tensile strength and the elongation of the composite. [ABSTRACT FROM AUTHOR]

In this research, new donor–acceptor (D‐A) photovoltaic polymers were synthesized from dithieno[3,2‐b:2′,3′‐d]pyrrole electron donor derivatives, including N‐benzoyldithieno[3,2‐b:2′,3′‐d]pyrrole and N‐(4‐hexylbenzoyl)dithieno[3,2‐b:2′,3′‐d]pyrrole, in combination with the electron deficient unit 2,5‐bis(2‐ethylhexyl)‐3,6‐di(thiophen‐2‐yl)‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione via direct (hetero)arylation polymerization. The D‐A conjugated polymers obtained were characterized via 1H NMR, gel permeation chromatography, Fourier transform infrared spectroscopy, DSC, XRD, photoluminescence and UV–visible methods. In addition, these D‐A polymers were used as activated layers in bilayer and bulk heterojunction structures for the fabrication of organic photovoltaic cells. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

ABSTRACT: A study of the reactions between various furan and maleimide model compounds and the effects of reaction conditions was performed, allowing for a proper design and preparation of a thermo‐reversible polyurethane (PU) material crosslinked via Diels–Alder (DA) bonds. Thus, a linear polyurethane containing furan groups along the main chain was synthesized and crosslinked with a bismaleimide by means of DA reaction. The obtained thermoset exhibited thermo‐reversibility as evidenced by DSC and FTIR microscopy, providing the material recyclability and scratch healability. Optical microscopy, SEM and tensile analysis of a scratched PU film revealed that efficient scratch healing was enabled by heating at 110 °C for 30 min and subsequently keeping at room temperature for 24 h, resulting in an approximately 80% recovery of the pristine mechanical strength. This material is a promising candidate for the development of self‐healing coatings. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1806–1814 [ABSTRACT FROM AUTHOR]

ABSTRACT A simple and facile strategy for the functionalization of commercial poly(ε-caprolactone) diols (PCLs) with pendant functionalities at the polymer chain termini is described. Well-defined allyl-functionalized PCLs with varying numbers of allyl end-block side-groups were synthesized by cationic ring-opening polymerization of allyl glycidyl ether using PCL diols as macroinitiators. Further functionalization of the allyl-functionalized PCLs was realized via the UV-initiated radical addition of a furan-functionalized thiol to the pendant allyl functional groups, showing the suitability for post-modification of the PCL materials. Changes in polymer structure as a result of varying the number of pendant functional units at the PCL chain termini were demonstrated. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 928-939 [ABSTRACT FROM AUTHOR]

Star-shaped molecules consisting of regioregular poly(3-hexylthiophene) ( P3HT) chains as the arms, attached to either a propeller-like triphenylamine or a planar triphenylbenzene core, have been synthesized via Suzuki coupling. The structures of the three-arm star-shaped poly(3-hexylthiophene) (s- P3HT) materials obtained were studied using Fourier transform infrared, 1H and 13C NMR, XRD, gel permeation chromatography and DSC. The s- P3HT polymers were soluble in common organic solvents and exhibited number-average molecular weights of 6000-7200 g mol−1. Their optical properties in solutions and in solid state films were investigated using the UV−visible absorption and photoluminescence techniques, and were compared with those of linear P3HT. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]