Functionalized liquid natural rubber and liquid epoxidized natural rubber: A promising green toughening agent for polyester

Toughened unsaturated polyester resins (UPRs) were prepared using two different reactive rubbers, namely, liquid natural rubber (LNR) and liquid epoxidized natural rubber (LENR). The effect of varying amounts of LNR and LENR on the morphology, thermal, and mechanical properties of UPR were evaluated. Fourier Transform Infrared spectroscopy was used to investigate the probable crosslinking reaction and changes in the functional groups on crosslinking. Field emission scanning electron microscopy and infinite focus microscopy were used to study the morphology of fracture surfaces. Tensile test showed that both the rubber‐modified resins (1.5 wt %) improved tensile strength. The viscoelastic properties and thermal stability of the toughened polyesters were evaluated using dynamic mechanical thermal analysis and thermogravimetric analysis, respectively. A slight reduction in the glass transition temperature (T_g) of the polyester was reported on the addition of both the rubbers. An increment in impact strength and fracture toughness was observed at 1.5 wt % for LNR and 4.5 wt % for LENR‐modified UPR. The results showed that both the liquid rubbers improved the mechanical properties of UPR. However, LENR‐modified UPR exhibited a more significant improvement in the mechanical properties compared to LNR‐modified UPR. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41292.     

Study on strength and gelation time of polyacrylamide/polyethyleneimine composite gels reinforced with coal fly ash for water shut‐off treatment

This study investigates the influence of coal fly ash (CFA) as a reinforcing material on the strength and the gelation of polyacrylamide (PAM)/polyethyleneimine (PEI) composite gels. Pure PAM/PEI gel and PAM/PEI gels containing CFA up to 2 wt % were synthesized via the cross‐linking reaction between PAM and PEI solutions at room temperature (25°C) in distilled water dispersed with CFA. The strength of each composite gel was measured at temperature of 80°C, while the gelation was determined from 80°C to 95°C. Rheological measurements indicated that the strength of PAM/PEI composite gels filled with CFA contents was significantly rigid and stronger than that of pure PAM/PEI gel as a result of the enhanced interfacial interaction of well‐dispersed CFA contents in PAM/PEI gel matrix. The gelation times of PAM/PEI gels containing CFA up to 2 wt % deviated from the gelation time of pure PAM/PEI gel. It was further observed that an increase in temperature resulted in a decrease in gelation time of PAM/PEI gel containing 2 wt % CFA. The scanning electron microscopy revealed the surface micrographs of PAM/PEI gels filled with CFA to be very dense without any noticeable micropores. The micropores were absent as scanning was performed on the dried composite gels. It also establishes the strong interaction between CFA and PAM/PEI gel matrix. Experimental findings showed that PAM/PEI composite gels reinforced with CFA are potential candidates for total water shut‐off treatment in oilfields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41392.     

Solubilization of graphene flakes through covalent modification with well‐defined azido‐terminated poly(ε‐caprolactone)

A well‐defined poly(ε‐caprolactone) (PCL) with terminal azido group was prepared. Grafting‐on reaction between the azido‐terminated PCL (N₃? PCL) and ultrasonication‐assisted exfoliated graphene flakes (GF) was carried out to obtain PCL‐grafted‐GF (PCL‐g‐GF) which showed good dispersibility in a wide variety of organic solvents. Gel permeation chromatography, ¹H NMR, IR, Raman, UV‐vis, and TEM measurements indicated that PCL macromolecules were covalently introduced on the surface of GF without disrupting the structure of GF. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41569.     

Preparation and Properties of Novel Quaternized Metal–Polymer Matrix Nanocomposites

A new class of PANI/Sn(II)SiO₃/FCNTs nanocomposite was synthesized by mixing polyaniline into the gel of Sn(II)SiO₃ followed by FCNTs (Polyaniline/Sn(II)SiO₃/Functionalized Carbon nanotubes). The physico-chemical characterization was carried out by scanning electron microscope, XRD (X-ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), ultraviolet–visible spectroscopy, and simultaneous thermogravimetric analysis studies. The ion-exchange capacity (1.2 meq/g) and distribution studies were also determined to understand the ion-exchange capabilities. The DC electrical conductivity studies revile it in the range of 3–5 × 10^?3 S/cm. On the basis of distribution studies, ion-selective membrane electrode was designed for Hg(II). The analytical utility of this membrane was established by using it as an indicator electrode in electrometric titrations.     

Investigation of resole, novalac and coal tar pitch blended binder for the production of metallurgical quality formed coke briquettes from coke breeze and anthracite

In order to reduce the cost and also enlarge the solid carbon source suitable for the formed coke production further investigations were conducted to produce formed coke using anthracite which can provide a new and relatively economic abundant raw material suitable for this purpose. The results indicated that, anthracite can also be used for the production of metallurgical quality formed coke, but the tensile strength of the anthracite formed coke were found to be comparatively lower than that of the coke breeze formed coke, 64.6 MPa, 73.2 MPa, respectively, when carbonized at 950 °C for 1 h, due to the decomposition of the volatiles that causes fissures, cracks and new pores. To produce anthracite briquettes of higher tensile strength, either anthracite of lower volatile matter should be used or it should be blended with coke breeze.     

Bioactive Compounds and Biological Activities of Jatropha curcas L. Kernel Meal Extract

Defatted Jatropha curcas L. (J. curcas) seed kernels contained a high percentage of crude protein (61.8%) and relatively little acid detergent fiber (4.8%) and neutral detergent fiber (9.7%). Spectrophotometric analysis of the methanolic extract showed the presence of phenolics, flavonoids and saponins with values of 3.9, 0.4 and 19.0 mg/g DM, respectively. High performance liquid chromatography (HPLC) analyses showed the presence of gallic acid and pyrogallol (phenolics), rutin and myricetin (flavonoids) and daidzein (isoflavonoid). The amount of phorbol esters in the methanolic extract estimated by HPLC was 3.0 ± 0.1 mg/g DM. Other metabolites detected by GC-MS include: 2-(hydroxymethyl)-2 nitro-1,3-propanediol, β-sitosterol, 2-furancarboxaldehyde, 5-(hydroxymethy) and acetic acid in the methanolic extract; 2-furancarboxaldehyde, 5-(hydroxymethy), acetic acid and furfural (2-furancarboxaldehyde) in the hot water extract. Methanolic and hot water extracts of kernel meal showed antimicrobial activity against both Gram positive and Gram negative pathogenic bacteria (inhibition range: 0-1.63 cm) at the concentrations of 1 and 1.5 mg/disc. Methanolic extract exhibited antioxidant activities that are higher than hot water extract and comparable to β-carotene. The extracts tended to scavenge the free radicals in the reduction of ferric ion (Fe(3+)) to ferrous ion (Fe(2+)). Cytotoxicity assay results indicated the potential of methanolic extract as a source of anticancer therapeutic agents toward breast cancer cells.     

A Facile and Convenient Synthesis of some Novel Hydrazones, Schiff's Base and Pyrazoles Incorporating Thieno[2,3-b]thiophenes

A facile and convenient synthesis of some novel hydrazones, schiff's base and pyrazoles from thieno[2,3-b]thiophene derivatives 1 have been achieved in high yields assisted by microwave and classical methods. The structures of all the title compounds have been elucidated by elemental analysis, IR, MS, (1)H-NMR and (13)C-NMR. Generally, these findings represent a new class of sulfur and nitrogen moieties that should also be of interest as new materials.     

Ozonation In Direct Filtration

The effects of pre-ozonation on the effluent quality and the head losses through a deep filter were investigated using two identical deep bed filters receiving the same raw water. One of the influents to the filters was pre-ozonated and the other was aerated using identical contact chambers and diffusers. It was observed that the pre-ozonated filter resulted in significantly better effluent quality. It was found that the delay time after the pre-ozonation process has an important effect in direct filtration. The shorter the delay time, the less is the head loss and the better is the effluent quality. Indices that calculate Specific Energy (cm of head required per gram of solids captured) in deep bed filters were developed. The Filterability Index given in the literature and the Specific Energy values were used to compare the performance of the two identical filters receiving the same raw water. It was shown that the pre-ozonated water required on average 1.1 times more specific energy compared to the same aerated water and the experiments with short ozone delay times had on average 4.9 times less specific energy compared to the long delay experiments.     

Thorium (IV) phosphate‐polyaniline composite‐based hydrophilic membranes for bending actuator application

In the present study, ionic polymer metal composite (IPMC) membrane actuator based on triple‐layered thorium(IV) phosphate/polyaniline/Pt (ThP‐PANI‐Pt) was prepared via consecutive solution recasting and electroless plating methods. The triple‐layered membrane is composed of thorium(IV) phosphate (ThP) inorganic cation exchanger layer in the middle section, two layers of polyaniline deposited through in situ polymerization and finally Pt electrode layers on both the surfaces on the outer section. The water uptake capacity of the ThP‐PANI composite polymer membrane was found to be 95.40% at 45ºC for 10 h of immersion time. The ion exchange capacity and proton conductivity was found to be 1.6 meq g^?1of dry membrane and 1.12 × 10^?3 S cm^?1, respectively. Maximum water loss from IPMC was 38% at 4 V for a time period of 12 min. Scanning electron micrographs shows the smooth and uniform coating of Pt on both side of composite polymer membrane surfaces. Cyclic voltammetry, linear sweep voltammetry, transmission electron microscopy, Fourier transforms infrared spectroscopy, thermal gravimetric analysis, X‐ray diffraction, and tip displacement of ThP‐PANI‐Pt IPMC membrane actuator was also examined. POLYM. ENG. SCI., 57:258–267, 2017. © 2016 Society of Plastics Engineers     

Cauliflower-like poly(3,4-ethylenedioxythipohene)/nanocrystalline cellulose/manganese oxide ternary nanocomposite for supercapacitor

A cauliflower-like ternary nanocomposite of poly(3,4-ethylenedioxythipohene)/nanocrystalline cellulose/manganese oxide (PEDOT/NCC/MnO₂) was synthesized using one-step electropolymerization technique. The effect of manganese (Mn) concentration on the supercapacitive performance was investigated. The structural and morphology studies were conducted using field emission scanning electron microscope, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction. The morphology of ternary nanocomposite at an optimized concentration of Mn resembles the cauliflower-like structure. The two-electrode electrochemical analysis of a ternary nanocomposite PEDOT/NCC/MnO₂ exhibited a higher specific capacitance of 144.69 F/g at 25 mV/s in 1.0 M potassium chloride compared to PEDOT/NCC(63.57 F/g). PEDOT/NCC/MnO₂ ternary nanocomposite was able to deliver a specific power of 494.9 W/kg and 10.3 Wh/kg of specific energy at 1 A g⁻¹ and retained 83% of initial capacitance after 2,000 cycles. These promising results from the incorporation of Mn displayed great prospective in developing PEDOT/NCC/MnO₂ as an electrode material for supercapacitor.