Synthesis, characterization and enzymatic degradation of copolymers of ε-caprolactone and hydroxy-fatty acids

2016 ◽  
Vol 88 (12) ◽  
pp. 1191-1201 ◽  
Author(s):  
Diana Aparaschivei ◽  
Anamaria Todea ◽  
Iulia Păuşescu ◽  
Valentin Badea ◽  
Mihai Medeleanu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Degradation Products ◽  
Hydroxy Fatty Acids ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Chemical Structures ◽  
Buffer Solutions ◽  
Different Temperatures ◽  
Ft Ir ◽  
Candida Antarctica B

AbstractNew copolymers of ε-caprolactone with three hydroxy-fatty acids, 12-hydroxy stearic acid, 16-hydroxyhexadecanoic acid and ricinoleic acid, were synthesized by catalytic polyesterification. The reactions were carried out in solvent-free systems and in organic solvents as well, using tin(II) 2-ethylhexanoate as catalyst, at different temperatures and molar ratios of the comonomers. Cyclic and linear polymeric products with medium molar weight of about 2000 Da have been synthesized and their chemical structures were confirmed by FT-IR, NMR and MALDI-TOF MS analysis. The synthesis parameters were optimized and the ε-caprolactone/hydroxy acid molar ratio was set as 5:1, according to mass spectrometry results. The biodegradability of the newly synthesized polymers was studied in the presence of Candida antarctica B lipase in phosphate buffer solutions (pH=7.4), at 37°C. The weight-loss profile emphasized the degradation of the 16-hydroxyhexadecanoic acid based polymer samples at more than 50% of their initial weight in 18 days of incubation in the presence of the lipase. The composition of the degradation products was assessed using the GC-MS technique and displayed residues of the comonomers moieties.

scholarly journals Optimization of the Lipase Catalyzed Production of Structured Acylglycerols With Polyunsaturated Fatty Acids Isolated From Sardine Oil

2013 ◽  
Vol 2 (6) ◽  
pp. 97 ◽  
Author(s):  
Juan Antonio Noriega-Rodriguez ◽  
Esther Carrillo-Perez ◽  
Nohemi Gamez-Meza ◽  
Luis A. Medina-Juarez ◽  
Ramiro Baeza-Jimenez ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Immobilized Lipase ◽  
Reaction Times ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Sardine Oil ◽  
Different Temperatures ◽  
Urea Crystallization

<p>In the present work, direct enzyme-catalyzed esterification of n-3 polyunsaturated fatty acids (n-3 PUFA) isolated from sardine oil was optimized to obtain structured acyglycerols. A n-3 PUFA concentrate was prepared by urea crystallization of refined sardine oil and esterification was carried out mixing free fatty acids and glycerol at different molar ratios (<em>M</em> = 0.48, 1.5, 3.0, 4.5 and 5.52 mol/mol), using an immobilized lipase preparation from <em>Candida antarctica</em> (NV-435) at different temperatures (<em>T</em> = 38, 45, 55, 65 and 72 °C) and reaction times (<em>t</em> = 0.7, 2.75, 5.75, 8.75 and 10.8 h) in a rotatable central composition design. The degree of esterification was determined by analysis of the acylglycerides produced, using liquid chromatography (HPLC-ELSD). Optimization by response surface methodology (RSM) showed that in order to obtain higher esterification levels of n-3 PUFA to glycerol (99.5%), a molar ratio of 1.3 mol n-3 PUFA/mol glycerol, time 8.3 h and temperature 38 °C, are required. However, results of this work show that it is possible to drive the reaction to any determined product (MAG, DAG or TAG) by modifying the reaction conditions.</p>

Empirical and Theoretical Calculations for Corrosion Inhibition of Carbon Steel C1018 in Acidic Solutions Using Some Selected Fatty Acid Surfactants

2016 ◽  
Vol 230 (8) ◽  
Author(s):  
Hany M. Abd El-Lateef ◽  
Mohamed Ismael ◽  
Ahmed H. Tantawy
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Theoretical Calculations ◽  
Acidic Solutions ◽  
Chemical Structures ◽  
Ft Ir

AbstractThree different surfactants based on fatty acids (octanoic, tridecanoic and oleic) and ethylenediamine were synthesized and their chemical structures were confirmed by FT-IR,

Synthesis and Characterisation of P-perfluoro{-1-[2-(2-fluorosulfonylethoxy) Propoxy]}Ethylated Polystyrene

2005 ◽  
Vol 2005 (8) ◽  
pp. 546-548
Author(s):  
Ji-Cheng Yang ◽  
Hong-Bo Ni ◽  
Jin Li ◽  
Cheng-Xue Zhao ◽  
Yong-Ming Zhang
Keyword(s):  
Thermogravimetric Analysis ◽  
Contact Angles ◽  
Molar Ratio ◽  
Ethyl Group ◽  
Molar Ratios ◽  
Modified Polymer ◽  
Ft Ir

A new kind of fluorinated polystyrene bearing a p-perfluoro{-1-[2-(2-fluorosulfonyl)propoxy]}ethyl group has been synthesised by one-electron oxidation of polystyrene by perfluoro{2-[2-(2-fluorosulfonyl) propoxy]}propionyl peroxide at different peroxide to polystyrene molar ratios. The yield of ω–fluorosulfonyl perfluoroalkylation decreases with increase in the reactant molar ratio. The modified polymer was characterised by various techniques: the ring perfluoro{-1-[2-(2-fluorosulfonyl)propoxy]}ethylation was proved by FT-IR, 19F NMR and DSC; desulfonylation of the fluorinated polystyrene appearing at 126° has been found by thermogravimetric analysis (TGA). The contact angles of water on the surface of ω–fluorosulfonyl perfluoroalkylated polystyrene were determined.

scholarly journals The Influence of Interesterification of Structured Fats on the Properties of the Fat Blends

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S293-S296
Author(s):  
M. Tesařová ◽  
M. Zárubová ◽  
V. Filip ◽  
V. Spěváčková ◽  
J. Šmidrkal
Keyword(s):  
Fatty Acids ◽  
Saturated Fatty Acids ◽  
Point Of View ◽  
Molar Ratio ◽  
Medium Chain ◽  
Molar Ratios ◽  
Lower Molar ◽  
Long Chain ◽  
Soft Margarines

Consistency, rheology and melting/solidification characteristics of model fat blends (FB) on the basis of interesterified structured fats (SF) are discussed. SF were prepared by an alkaline catalysed random interesterification of fully hydrogenated coconut (FHCO) and high-erucic rapeseed (FHHERO) oils with variable molar ratio (2:1; 1.4:1; 1:1; 1:1.4 and 1:2) of the medium chain (M; C8:0–C14:0) and long chain (L; C16:0–C22:0) saturated fatty acids (FA) to find out, if stearic/arachic/behenic acids can substitute palmitic/stearic acids in SF. This substitution in SF is possible at molar ratios M:L 2:1 and 1.4:1 from the point of view of melting and solidifications characteristics as well as consistency and rheology for soft margarines. Lower molar ratios of M:L are suitable for FB of shortenings. The final ratio of saturated:unsaturated FA in FB for soft-margarines is 33:67 w/w.

scholarly journals Characteristics and Antioxidant Potential of Cold-Pressed Oils—Possible Strategies to Improve Oil Stability

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1630
Author(s):  
Magdalena Grajzer ◽  
Karolina Szmalcel ◽  
Łukasz Kuźmiński ◽  
Mateusz Witkowski ◽  
Anna Kulma ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Molar Ratio ◽  
Seed Oils ◽  
Stability Parameters ◽  
Molar Ratios ◽  
Naturally Occurring ◽  
Phytosterol Content ◽  
Cold Pressed ◽  
Lipophilic Fraction

The relations of the antiradical capacity to oxidative stability parameters and the contents of fatty acids, sterols, tocopherols, phenols, flavonoids, chlorophyll, Cu, and Fe were assessed in 33 cold-pressed seed oils: Walnut (7 brands of oils), rosehip (3), camelina (6), milk thistle (5), flax (6), and pumpkin (6). The antiradical capacity of oils depended strongly on tocopherol contents with a synergistic effect with polyphenols. The efficacy of tocopherols in cold-pressed oils was accompanied by a negative correlation of their antioxidant capacity with the peroxide value increase after 3 months of shelf life. This study also showed a positive correlation between the content of phytosterols and the antiradical capacity in the lipophilic fraction of cold-pressed oils rich in n-3 polyunsaturated fatty acids (PUFAs). Multiple regression analysis identified groups of antioxidants naturally occurring in cold-pressed oils in relation to their fatty acid composition, which added to the cold-pressed oils could provide possible strategies to improve their stability. Achieving high stability is primarily a result of high phytosterol content exceeding the molar ratio of 1:100 for total phytosterols to α-linolenic acid. However, the molar ratios of tocopherols to linoleic acid below 1:2000 and polyphenols to linoleic acid below 1:3000 does not prevent oxidation in oils with the predominance of linoleic acid.

SYNTHESIS, AND SURFACE-ACTIVE PROPERTIES OF PALM FATTY ACID AND 1(2-HYDROXYETHYL PIPERAZINE)-BASED ESTERAMIDE QUAT

2007 ◽  
Vol 14 (06) ◽  
pp. 1129-1133 ◽  
Author(s):  
SHILPI MISHRA ◽  
V. K. TYAGI
Keyword(s):  
Fatty Acids ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
H Nmr ◽  
Surface Active Properties ◽  
Optimum Reaction ◽  
Ft Ir ◽  
Surface Active ◽  
And Performance ◽  
Hydroxyethyl Piperazine

In this study, an attempt has been made to synthesize esteramide quat by esterification of palm fatty acids with 1(2-hydroxyethyl piperazine) followed by quaternization with dimethyl sulphate (DMS). The optimum reaction conditions for esterification of palm fatty acids and 1(2-hydroxyethyl piperazine) were found to be 170°C reaction temperature and 150 mmHg pressure. The obtained esteramide was subjected to quaternization with different molar ratios of DMS. The consequences revealed that esteramide to DMS ratio of 1 : 0.95 and duration of quaternization for 2 h yielded esteramide quat of maximum cationic content, i.e., 64.9%. The instrumental analysis, viz. FT-IR, 1 H NMR, 13 C NMR verified the esterification and subsequent quaternization of the obtained esteramide quat. Furthermore, the surface-active and performance properties of synthesized esteramide quat were also evaluated.

scholarly journals Short-chain fatty acids produced in vitro from fibre residues obtained from mixed diets containing different breads and in human faeces during the ingestion of the diets

2000 ◽  
Vol 84 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Elisabeth Wisker ◽  
Martina Daniel ◽  
Gerhard Rave ◽  
Walter Feldheim
Keyword(s):  
Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Fibre Diet ◽  
The Difference ◽  
Wholemeal Bread ◽  
Chain Fatty Acids

It was studied whether the type of bread (i.e. a low-fibre wheat–rye mixed bread and coarse or fine wholemeal rye bread) either as part of a diet or alone, had an influence on the short-chain fatty acids (SCFA) produced during in vitro fermentation. Fermentation substrates were dietary fibre residues obtained from diets and breads. In addition, it was investigated whether the faecal SCFA pattern in the inoculum donors, who ingested the experimental diets, could be predicted by in vitro fermentation. Yields of SCFA in vitro were 0·51–0·62 g/g fermented polysaccharide. In vitro, the molar ratios of butyrate were higher for the two high-fibre diets containing coarse or fine wholemeal bread than for the low fibre diet containing wheat–rye mixed bread; the difference was significant for the coarse (P < 0·01), but not for the fine bread diet (P = 0·0678). The coarse wholemeal bread alone produced a higher molar ratio of butyrate than the fine wholemeal bread (P < 0·05) and the wheat–rye mixed bread (P < 0·01). Ingestion by the inoculum donors of the diets containing wholemeal bread led to higher faecal butyrate ratios (molar ratios: coarse bread diet 19·6, fine bread diet 17·7) compared with the wheat–rye mixed bread-containing diet (14·9), but the differences between the diets were not significant. For the diets investigated, there were no significant differences between faecal and in vitro SCFA patterns.

Some Features of Cycloalkylation Reactions of Phenol with 1-Methylcyclopentene

2021 ◽  
Vol 899 ◽  
pp. 726-732
Author(s):  
Fatma I. Gasimova ◽  
Zaur Z. Aghamali̇yev ◽  
Gulshan J. Gasanova ◽  
Chingiz K. Rasulov
Keyword(s):  
Reaction Time ◽  
Nmr Spectroscopy ◽  
Physicochemical Parameters ◽  
Molar Ratio ◽  
High Yield ◽  
Target Product ◽  
Molar Ratios ◽  
Chemical Structures ◽  
Effective Conditions ◽  
Yield Of Target Product

The present study deals with the investigation of catalytic cycloalkylation reactions of phenol with 1-methylcyclopentene. KU-23 and aluminum phenolate were used as catalysts for the process. The effect of kinetic parameters (temperature, duration, molar ratios of the initial components and the amount of catalyst) on the yield and selectivity of methylcyclopentyl phenols obtained as a result of scientific research was investigated. As a result, effective conditions were found for the production of para- and ortho-, ortho- (1-methylcyclopentyl) phenols with high yield and selectivity. It was determined that high yield of target product in the presence of phenol, 1-methylcyclopentene and catalyst KU-23, was 71.2% for phenol and selectivity for target product - 92.8% is obtained under the following conditions of cycloalkylation reaction: temperature 110°C, reaction time-5 hours, molar ratio phenol to methylcyclopentene-1 : 1, the amount of catalyst-10% according to the phenol taken. The cycloalkylation reaction of phenol with 1-methylcyclopentene in the presence of aluminum phenolate catalyst was carried out in an autoclave in a nitrogen environment and effective conditions were found: temperature 260°C, reaction time - 5 hours, molar ratio of phenol to 1-methylcyclopentene 1: 2, amount of catalyst 20% according to the phenol taken. Under these conditions, the yield of the target product is 44.3% for the phenol taken, and the selectivity is 87.6% for the target product. The chemical structures of the synthesized para- and ortho-, ortho- (1-methylcyclopentyl) phenols were confirmed by IR-, 1H and NMR spectroscopy, and physicochemical parameters were determined.

Biodiesel Production from Pongamia Pinnata and its Characterization using GC-MS, NMR and FT-IR Spectral Studies

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
J. Fernandez ◽  
V. Hariram ◽  
S. Seralathan ◽  
S.A. Harikrishnan ◽  
T. Micha Premkumar
Keyword(s):  
Fatty Acids ◽  
Methyl Esters ◽  
Cetane Number ◽  
Calorific Value ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Major Constituent ◽  
Spectral Studies ◽  
Biodiesel Synthesis ◽  
Ft Ir

Biodiesel synthesis from the pongamia oil seed and its characterization is elaborated in this paper. A double stage transesterification i.e. acid catalysed transesterification and base catalysed esterification are adopted to reduce the free fatty acids content and conversion of triglycerides into methyl esters. In this process, H2SO4, NaOH and methanol are used at the methanol/oil molar ratio of 7:1. By this process, 95% of pongamia biodiesel is obtained. The physiochemical properties like calorific value, Cetane number, density, kinematic viscosity, flash point, fire point etc. are analysed and it is found to be within the ASTM standards. GC-MS analysis indicated the existence of 14 prominent fatty acids with oleic acid as the major constituent. 13C and 1H NMR results supported the GC-MS data and it also confirmed the conversion efficiency of converting the vegetable oil into PBD as 87.23%. The shifting and appearance of major peaks in the FT-IR spectrum confirmed the formation of FAMEs from the triglycerides.

Effects of Bi3+ Doping Amounts on the Magnetic Properties of FeSmO3 Nanopowders

2014 ◽  
Vol 680 ◽  
pp. 61-65
Author(s):  
Xuan Wen Liu ◽  
He Liu ◽  
Yu Zhang ◽  
Xi Wei Qi
Keyword(s):  
Magnetic Properties ◽  
High Purity ◽  
Remanent Polarization ◽  
Raw Materials ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Coprecipitation Process ◽  
Different Temperatures ◽  
Series Of Experiments ◽  
Almost All

The samples of FeSmO3 nanopowders were synthesized from the main raw materials of FeCl3 and SmCl3 by coprecipitation process. The samples were prepared by different precipitating agents including Na2CO3,NaOH and triethylamine (C6H15N). When the precipitating agent was NaOH, almost all of the Sm3+ and Fe3+ were precipitated. In this series of experiments, the molar ratios of Sm3+ to Fe3+ were 0.95:1, 1:1, 1.05:1, 1.1:1, 1.15:1 and 1.2:1. And when the molar ratio was 1.2:1, there was the least impurities in the obtained samples. The samples were sintered in the oven at different temperatures including 600°C,700°C, 800°C and 900°C. And only at 900°C, were the FeSmO3 nanopowders made without impurities. The Sm3+ in FeSmO3 was substituted by the Bi3+ in different doping amounts, which urged the preparation of BixFeSm(1-x)O3 nanopowders. And these nanopowders were characterized by XRD, VSM, SEM and fluorescent property technologies. The results showed that the obtained nanopowders were in high purity when x was 5% and it had the highest remanent polarization when x was 15%.

Sign in / Sign up

Export Citation Format

Share Document