A novel visible light mediated catalytic system based on low cost iron complex, that is, Fe(bpy)3(PF)6 photocatalyst that initiates and control the free radical polymerization of methacrylates using ethyl α‐bromoisobutyrate (EBriB) as an initiator and 20 watt LED as light source is developed. The polymerization is initiated with turning the light on and immediately terminated by turning the light off. In addition, the molecular weight of polymer can be varied by changing the ratio of monomer and initiator. The merits of the present methodology lie in the use of low cost less precious, highly abundant iron‐based photocatalyst, avoidance of sacrificial donor and need of lower catalyst amount under visible light. The optimum amount of catalyst and initiator were established and successful polymerization of various methacrylates was achieved under the optimized polymerization conditions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2739–2746

Demand for fatty acids is increasing at an annual rate of 17%, due to their increased use in the oleochemical and transport industries. Presently, vegetable oils are the major source of fatty acids, whereas lipids with fatty acids similar to those of some vegetable oils have been reported to be synthesized by oleaginous microorganisms. In the present study, the culturing conditions for the oleaginous yeast Rhodotorula minuta IIP-33 have been optimized. In contrast to the lipid accumulation characteristics of most oleaginous yeasts, a carbonto-nitrogen ratio of 30 was favorable for maximal accumulation of lipids (48%) with 22.5% conversion of glucose as carbon substrate. The lipids contained fatty acids in the C 7 -C 18 range, the relative composition of which varied with culture temperature. JAOCS 75, 501-505 (1998).Natural fatty oils are the major source of fatty acids used as feedstock in the oleochemical industries. With the growing demand, at 17% per annum, for fatty acids in the oleochemical industries and the recent application of fatty acid esters as biodiesel and biodegradable lube oils (1,2), the feasibility of using microorganisms as the alternate source of fats and oils would be an attractive proposition. Biosynthesis of lipids, such as triglycerides, phospholipids and glycolipids, by some oleaginous yeasts has been well documented (3,4). Synthesis of fatty acids in oleaginous yeasts is facilitated by a decrease in the activity of the isocitrate dehydrogenase enzyme under diminished nitrogen levels in the culture (5).Temperature-induced changes are reported in the fatty acid composition of the accumulated lipids of various oleaginous yeasts (6). Thus, synthesis of lipids with varying fatty acid composition should be feasible by culturing oleaginous microorganism under different conditions.We report here the growth and lipid accumulation characteristics of a rarely explored yeast strain of Rhodotorula minuta. The effect of growth temperature on the regulation of fatty acid synthesis by the strain has also been investigated and reported. EXPERIMENTAL PROCEDURESYeast strain and culture media. The yeast strain was isolated from mineral oil-contaminated local soil and was identified as R. minuta. The strain grows in red-pigmented colonies on YPD agar plates or in YPD aqueous medium within a temperature range of 28-36°C. The strain was preserved on YPD agar slants and stored at 5°C. Preparation of inocula and growth studies of the strain were conducted in a synthetic medium (OP24) that contained the following major constituents (w/w %): D-Glucose, 2; MgSO 4 ·7H 2 O, 0.07; (NH 4 ) 2 SO 4 , 0.2; Na 2 HPO 4 ·2H 2 O, 0.07; KH 2 PO 4 ·2H 2 O, 0.12; and ZnSO 4 , CuSO 4 , and FeSO 4 in traces. Carbon-to-nitrogen (C/N) ratio was increased by adding excess glucose in the medium at the end of the growth phase.Preparation of inocula. The yeast strain R. minuta IIP33 was grown to the exponential growth phase (o.d. 0.8) in 250-mL Erlenmeyer flasks that each contained 50 mL of growth medium (OP24), incubated at a temperat...

Asphaltenes and insoluble fractions of vacuum residues (VRs) of two Indian crude oils (viz. Heera and Jodhpur) of different specific gravity were obtained by precipitation of VRs in n-hexane, n-heptane, and ethyl acetate, and also by subsequent reprecipitation of n-heptane and ethyl acetate soluble fractions by n-pentane. The effect of various solvents on average molecular structure of asphaltenes and insolubles was studied using nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), and size exclusion chromatography (SEC). The asphaltenes and insolubles of Jodhpur VR have higher amounts of high molecular weight species with a high concentration of condensed and substituted aromatic rings, branched and/or short alkyl side chains, oxygen and nitrogen functionalities, compared to that of Heera VR. Ethyl acetate insolubles comprise a higher number of substituted aromatic structures, branched aliphatic structures, complex average unit structures, nitrogen and oxygen functionalities, and high molecular weight (MW) species as compared to hexane and heptane asphaltenes. Heptane insolubles consist of more naphthenic rings condensed with aromatic rings than C6A and EAI.

Petroleum heavy distillates find wide application as feedstocks for upgradation through secondary conversion processes. Compositional data on such feedstocks provide useful information to the refiners for selecting processing parameters to achieve product selectivity, quality, and yield. A HPLC method has been optimized to estimate hydrocarbon group types in five lubricating oil base stocks using refractive index (RI) and UV detectors. Data generated at two wavelengths (210 and 254 nm) indicated best results for monoaromatics at 210 nm due to enhanced response and compared well with mass spectrometry data. RI data revealed that saturate content decreases from spindle oil (56%) to heavy oil (42%) which is corroborated by MS data measured for three samples. NMR data exhibited that light oil is more paraffinic (63%) in nature as indicated by branchiness index (0.478). UV data revealed an increasing trend of monoaromatics from spindle (16%) to deasphalted oil (DAO) (20%) and this is supported by MS data, while DAO and heavy oil indicated higher values of diaromatics.

n-Dodecyl acrylate (DA) and dodecyl-4-vinyl benzoate (DVB) were copolymerized by conventional free-radical polymerization (CFRP); atom transfer radical polymerization (ATRP), and nitroxide-mediated living free-radical polymerization (NMLFRP) with benzoyl peroxide, 1-phenyl ethyl chloride/cuprous chloride/2,2Ј-bipyridine, and benzoyl peroxide/2,2,6,6-tetramethylpiperidinyl-1-oxy initiator systems, respectively. In CFRP and NMLFRP, toluene and xylene were used as solvents, whereas ATRP was performed in bulk. Mayo-Lewis, Kelen-Tü dös, and Fineman-Ross methods were used for the determination of the monomer reactivity ratios (r 1 and r 2 ). They all gave nearly the same values of r 1 and r 2 . The reactivity ratios of the two monomers in CFRP, ATRP, and NMLFRP were 0.17 Յ r 1 Յ 0.4 (DA) and 1.0 Յ r 2 Յ 1.24 (DVB). The side-chain crystallinity of the copolymers decreased with an increasing DVB molar fraction.