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ABSTRACT Poor flame retardancy of polyurethanes (PU) is a global issue as it limits their applications particularly in construction, automobile, and household appliances industries. The global challenge of high flammability of PU can be addressed by incorporating flame-retardant materials. However, additive flame-retardants are non-compatible and depreciate the properties of PU. Hence, reactive flame-retardants (RFR) based on aliphatic (Ali-1 and Ali-2) and aromatic (Ar-1 and Ar-2) structured bromine compounds were synthesized and used to prepare bio-based PU using limonene dimercaptan. The aromatic bromine containing foams showed higher close cell content (average 97 and 100%) and compressive strength (230 and 325 kPa) to that of aliphatic bromine containing foams. Similar behavior was observed for a horizontal burning test where with a low concentration of bromine (5 wt %) in the foams for Ar-1 and Ar-2 displayed a burning time of 12.5 and 11.8 s while, Ali-1 and Ali-2 displayed burning time of 25.7 and 37 s, respectively. Neat foam showed a burning time of 74 s. The percentage weight loss for neat PU foam was 26.5%, while foams containing 5 wt % bromine in Ali-1, Ali-2, Ar-1, and Ar-2 foams displayed weight loss of 11.3, 14, 7.9, and 14%, respectively. Our results suggest that flame retardant PU foams could be prepared effectively by using RFR materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46027. [ABSTRACT FROM AUTHOR]

ABSTRACT Polyaniline/cobalt oxide (PANI/Co3O4) nanocomposites have been investigated for their sensitivity towards carbon monoxide (CO) gas at room temperature. The Co3O4 nanoparticles were prepared by ultrasound assisted coprecipitation method and then incorporated into the PANI matrix. Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy, powder X-ray diffraction, and field emission scanning electron microscopy have been used to characterize the nanomaterials. The PANI/Co3O4 nanocomposite sensors were found to be highly selective to CO gas at room temperature. A significantly high response of 0.81 has been obtained for 75 ppm CO concentration with a response time of 40 s. Based on the observations of the sensing study, a mechanism for CO sensing by the nanocomposite has been proposed. Influence of humidity on the sensor response towards CO has also been studied and the results presented. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44115. [ABSTRACT FROM AUTHOR]

In this study, ethylene vinyl acetate-fly ash (EVA-FA) composites were prepared by the melt mixing technique using a rheomixer for the purpose of removing 2,4,6-trichlorophenol (TCP) and p-nitrophenol (PNP) from water. The fly ash was characterized by X-ray fluorescence spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD); the composites were characterized using SEM and XRD. Brunauer, Emmett, and Teller (BET) measurements revealed a surface area ( SBET) of 0.07110 m2/g for the fly ash. The adsorption of TCP and PNP were monitored by UV-Vis spectrophotometer. The maximum adsorption of PNP was obtained at pH 5 after a contact period of 12 h, whereas that of the TCP was obtained at pH 4 after a period of 10 h has elapsed. The equilibrium adsorption data were evaluated using Langmuir and Freundlich adsorption isotherm models. The Langmuir adsorption model gave the better correlation coefficients for the equilibrium adsorption data. The kinetics data followed the pseudo-second-order model for both TCP and PNP. The theoretical maximum adsorption capacity ( qmax) of the adsorbent used in the study was found to be 3.424 mg/g and 2.544 mg/g for TCP and PNP, respectively. The desorption of the phenols from the composites was performed using 0.2 M NaOH. About 82.6% and 76.3% of TCP and PNP were recovered, respectively. The study showed that the pH of the solution and contact time play a significant role in the adsorption process. Furthermore, we have demonstrated that EVA-FA composites have the potential to adsorb phenols from acidic water solutions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Surface modification of montomorillonite for improvement in d-spacing was done by column chromatography with quaternary long chain ammonium salt having cation exchange capacity of 110 meq/100 g. Organically modified montomorillonite (OMMT)/poly(vinyl chloride) (PVC) nanocomposites were prepared through direct melt compounding on a conventional twin screw extruder. Because of improved d-spacing of OMMT, the polymer chains get exfoliated in between the plates of clay and dispersed uniformly. The mechanical properties of the nanocomposites were found to be appreciable at 12 wt % loading of OMMT. Moreover, rheological data, such as torque, fusion time, viscosity, and shear rate were also recorded on Brabender Plasticorder. The improvement in mechanical properties with increase in amount of OMMT loading is evidenced from reduction in shear viscosity and torque. Also nanoclay is acting as a lubricating agent with packing effect, which reduces the torque with decrease in viscosity along with increment in elongation at break. Because of soft nature of OMMT and improvement in d-spacing the processing of PVC becomes easier, and hence, OMMT is playing a dual role as a (i) good processing aid and (ii) filler. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

The article presents a study on the preparation, phosphorescent behavior and material properties of the polymer-phosphor composites. These composites were prepared by melt mixing or extrusion methods. Scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy were used in determining the morphology of the polymer and the composites. The study concludes that the ethyl vinyl acetate-phosphor composites are more crystalline.

The article presents a study on the effect of organic peroxides in the morphology and magnetic properties of ethylene vinyl acetate copolymer (EVA)/Cloisite 15A nanocomposites. It states that both the dicumyl peroxide (DCP) and dibenzoyl peroxide (DBP) had initiated de-acetylation and chain scission of EVA chains. It also says that the clay presence inhibits the of EVA degradation initiation through DCP free radicals. It adds that the DBP contributes to the polymer degradation.