scholarly journals Esterification of Cellulose with Long Fatty Acid Chain through Mechanochemical Method

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4397
Author(s):  
Jacqueline Lease ◽  
Tessei Kawano ◽  
Yoshito Andou
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Fourier Transforms ◽  
Mechanochemical Reaction ◽  
Esterification Reaction ◽  
Aliphatic Chain ◽  
Cellulose Esters ◽  
Fatty Acid Chain ◽  
Absorbance Peak

Mechanochemical reaction, a green synthetic esterification route was utilized to prepare long-chain cellulose esters from microcrystalline cellulose. The influence of reaction conditions such as reaction temperature and time were elucidated. Only low dosage of oleic acid, 1-butyl-3-metylimidazolium acetate, and p-toluenesulfonyl chloride were required. The success of modification reaction was confirmed by Fourier transforms infrared spectroscopy as a new absorbance peak at 1731 cm−1 was observed, which indicated the formation of carbonyl group (C=O). Solid-state nuclear magnetic resonance was also performed to determine the structural property and degree of substitution (DS) of the cellulose oleate. Based on the results, increasing reaction temperature and reaction time promoted the esterification reaction and DS. DS values of cellulose oleates slightly decreased after 12 h reaction time. Besides, X-ray diffraction analysis showed the broadening of the diffraction peaks and thermal stability decreased after esterification. Hence, the findings suggested that grafting of oleic acid’s aliphatic chain onto the cellulose backbone lowered the crystallinity and thermal stability.

scholarly journals A Long-Chain Alkylation of Dialdehyde Starch to Improve Its Thermal Stability and Hydrophobicity

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jiang Zhu ◽  
Zhaodong Wang ◽  
Haitao Ni ◽  
Xiang Liu ◽  
Jian Ma ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Orthogonal Experiment ◽  
Raw Material ◽  
Molar Ratio ◽  
Dialdehyde Starch ◽  
Hydrophobic Properties ◽  
Feed Composition ◽  
Long Chain

Hydrophobic dialdehyde starch (HDAS) was synthesized by dialdehyde starch (DAS) and eighteen-alkyl primary amine as the raw material in DMSO. The effect of the reaction conditions on the yield of HDAS was investigated such as catalyst content, reaction temperature, reaction time, and the in-feed molar ratio of -CHO/-NH2. Moreover, the optimized test parameters were obtained by conducting orthogonal experiment. The molecular structure and the morphology of HDAS were characterized via Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). And the thermal stability and the hydrophobic properties of HDAS were investigated by thermal gravimetric analyzer (TG) and the hydrophobic testing. The results indicate that the yield of HDAS is the highest up to 44.21%, with feed composition 1 : 0.9, reaction temperature 40°C, reaction time 8 h, and acetic acid content 3%. And the introduction of the long-chain alkyl groups into the DAS backbones will ameliorate efficaciously the thermal stability and the hydrophobic properties of DAS, which almost has no effect on the DAS particle size.

Optimization of Synthesis Process for Sodium Ascorbate

2012 ◽  
Vol 550-553 ◽  
pp. 10-15 ◽  
Author(s):  
Jing Chen Wang ◽  
Feng Xia Cui ◽  
Tao Li
Keyword(s):  
Reaction Time ◽  
Sodium Carbonate ◽  
Reaction Temperature ◽  
Conversion Rate ◽  
Sodium Ascorbate ◽  
Synthesis Process ◽  
Esterification Reaction ◽  
Reaction Yield ◽  
Process Conditions ◽  
Reactant Ratio

With 2-keto-L-gulonic acid(2KLG) and methanol as raw materials, 98% concentrated sulfuric acid as catalyst, the methyl esterification reaction is occurred. Then with sodium carbonate as a transforming agent, a conversion reaction sodium carbonate is obtained. In this experiment, the effects of reaction time, reaction temperature and reactant ratio on conversion rate of sodium ascorbate were studied. The results showed that sodium carbonate as the reactant of lactonization reaction can effectively shorten the reaction time and improve reaction yield. By experiment under the optimum process conditions: the reaction temperature is 65 °C, reaction time is 150 minutes and the molar ratio of 2-keto-L-gu methyl to sodium carbonate is 1:0.6, the conversion rate reaches 98 % and the effect is better than with sodium bicarbonate as transforming agent.

Properties of Polyaniline with the Doping of Different Acid

2012 ◽  
Vol 502 ◽  
pp. 31-35 ◽  
Author(s):  
Xiao Hua Wang
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Content ◽  
In Situ Polymerization ◽  
Ammonium Persulfate ◽  
Dodecylbenzenesulfonic Acid ◽  
Thermal Stability Of

Polyaniline(PANI) with the doping of hydrochloride(HC1), aminosulfonic acid (NH2SO3H) or dodecylbenzenesulfonic acid(DBSA) was prepared by in-situ polymerization. Effects of acid content, reaction time, oxidant ammonium persulfate (APS) dosage and reaction temperature on the conductivity of PANI were studied. The resistance and thermal stability of them were compared. Results show that the largest conductivity of HC1-PANI is 1.98 s.cm-1 among them in case the C(HC1)=0.5mol/L, reaction time is 6.0h, n(APS/aniline)=1.0; The conductivity of NH2SO3H-PANI is 0.2s.cm-1 in case the C(NH2SO3H)=1.0mol/L, reaction time is 6.0h, n(APS/aniline)=2.0; The conductivity of DBSA-PANI is 0.98s.cm-1 in case the C(DBSA)=1.0 mol/L, reaction time is 8.0h, n(APS/aniline) = 2.0. The the least resistance of HC1-PANI is 10Ω, and that of NH2SO3H- PANI is the largest of 120Ω. The order of their thermal stability is DBSA-PANI > NH2SO3H-PANI > HC1-PANI before 350°C, that of their thermal stability is inverse when it reaches 350°C.

Study on Bio-Fuels Drop Acid by [BSPy]HSO4 Catalytic Esterification

2013 ◽  
Vol 781-784 ◽  
pp. 2433-2437 ◽  
Author(s):  
Ai Hua Zhang ◽  
Zhi Hong Xiao ◽  
Liang Bo Zhang ◽  
Ru Kuan Liu ◽  
Wu Hong Zhong ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Value ◽  
Esterification Reaction ◽  
Process Conditions ◽  
High Catalytic Activity ◽  
Brønsted Acidic Ionic Liquid ◽  
The Stability ◽  
Acid Esterification

Research on the synthesis of BrOnsted acidic ionic liquid by the method of solvent, the pyrolysis bio-fuel with cornus wisoniana oil drop acid esterification reaction, the catalyst dosage, reaction time and reaction temperature on the effects of the acid dropping and in the best optimization under the condition of the stability of the catalyst were investigated. The experimental results show that [BSPHSO4 with high catalytic activity, optimization of process conditions as follows: 1.2% of catalyst, reaction temperature 75 °C, reaction time of 70 min, acid value reduced to 2.0 mg KOH/g. By optimizing the cycle experiment, the stability of the catalyst performance is good, the catalytic activity is relatively stable.

scholarly journals Optimisation of Free Fatty Acid Removal in Nyamplung Seed Oil (Callophyllum inophylum L.) using Response Surface Methodology Analysis

2021 ◽  
Vol 29 (4) ◽  
Author(s):  
Ratna Dewi Kusumaningtyas ◽  
Haniif Prasetiawan ◽  
Radenrara Dewi Artanti Putri ◽  
Bayu Triwibowo ◽  
Siti Choirunisa Furi Kurnita ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Fatty Acid ◽  
Reaction Time ◽  
Free Fatty Acid ◽  
Response Surface ◽  
Reaction Temperature ◽  
Seed Oil ◽  
Catalyst Concentration ◽  
Molar Ratio ◽  
Esterification Reaction

Nyamplung seed (Calophyllum inophyllum L.) oil is a prospective non-edible vegetable oil as biodiesel feedstock. However, it cannot be directly used in the alkaline catalysed transesterification reaction since it contains high free fatty acid (FFA) of 19.17%. The FFA content above 2% will cause saponification reaction, reducing the biodiesel yield. In this work, FFA removal was performed using sulfuric acid catalysed esterification to meet the maximum FFA amount of 2%. Experimental work and response surface methodology (RSM) analysis were conducted. The reaction was conducted at the fixed molar ratio of nyamplung seed oil and methanol of 1:30 and the reaction times of 120 minutes. The catalyst concentration and the reaction temperature were varied. The highest reaction conversion was 78.18%, and the FFA concentration was decreased to 4.01% at the temperature of 60℃ and reaction time of 120 minutes. The polynomial model analysis on RSM demonstrated that the quadratic model was the most suitable FFA conversion optimisation. The RSM analysis exhibited the optimum FFA conversion of 78.27% and the FFA content of 4%, attained at the reaction temperature, catalyst concentration, and reaction time of 59.09℃, 1.98% g/g nyamplung seed oil, and 119.95 minutes, respectively. Extrapolation using RSM predicted that the targeted FFA content of 2% could be obtained at the temperature, catalyst concentration, and reaction time of 58.97℃, 3%, and 194.9 minutes, respectively, with a fixed molar ratio of oil to methanol of 1:30. The results disclosed that RSM is an appropriate statistical method for optimising the process variable in the esterification reaction to obtain the targeted value of FFA.

Optimization and Kinetic Study of Biodiesel Production from Diseased Swine Carcasses

2019 ◽  
Vol 13 (4) ◽  
pp. 464-474 ◽  
Author(s):  
Youzhou Jiao ◽  
Yahe Mei ◽  
Le Wang ◽  
Jiaao Liu ◽  
Zhiping Zhang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Kinetic Analysis ◽  
Reaction Temperature ◽  
Catalyst Concentration ◽  
3D Ultrasound ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Control Group ◽  
Ultrasound Group

The innocuous utilization of diseased swine carcasses is a key issue in reducing environmental pollution and ensuring safety in animal husbandry. In this study, by using fat from diseased swine carcasses as raw materials, response surface experiments were conducted to investigate the influences of reaction time, catalyst concentration, reaction temperature, and methanol/oil molar ratio on the biodiesel purity and the optimum conditions for biodiesel production were determined. Furthermore, three-dimensional (3D) ultrasound assistance was adopted and kinetic analysis was performed. The results show that the influencing factors on biodiesel purity, in descending order, were determined to be reaction temperature > catalyst concentration > reaction time > methanol/oil molar ratio. Moreover, the maximum biodiesel purity was 93.7% under the following optimal conditions: catalyst concentration of 5.0 wt%; reaction temperature of 68 °C; methanol/oil molar ratio of 10:1; reaction time of 37 h. When 3D ultrasound assistance was adopted, the maximum biodiesel purity of 98.1% was obtained for the reaction process of 8 h under the ultrasound power and frequency of 500 W and 20 kHz, respectively. And the esterification reaction time was significantly reduced, compared to without ultrasound assistance. The results of kinetic analysis demonstrate that the reaction rate constants of the ultrasound group were 4.45–5.52 times greater than that of the control group. And the activation energy for the ultrasound group was 25.58 kJ/mol, which is 22.81% lower than that of the control group. This study will help to conduct large-batch biodiesel production from diseased swine carcasses in the future.

scholarly journals Synthesis, Optimization, Property, Characterization, and Application of Dialdehyde Cross-Linking Guar Gum

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Tang Hongbo ◽  
Li Yanping ◽  
Zhang Wen ◽  
Dong Siqing
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Guar Gum ◽  
Sodium Periodate ◽  
Decomposition Temperature ◽  
Melting Enthalpy ◽  
Cross Linking ◽  
The Cross ◽  
Thermal Stability Of

Dialdehyde cross-linking guar gum (DCLGG), as a novel material, was synthesized using phosphorus oxychloride as a cross-linking reagent, sodium periodate as an oxidant, and ethanol as a solvent through keeping the original particle form of guar gum. The process parameters such as the reaction temperature, reaction time, pH, amount of sodium periodate, and amount of ethanol were optimized by the response surface methodology in order to obtain the regression model of the oxidization. The covalent binding of L-asparagine onto the surfaces of DCLGG was further investigated. The results showed that the best technological conditions for preparing DCLGG were as follows: reaction temperature = 40°C, reaction time = 3.0 h, pH = 4.0, and amount of ethanol = 74.5%. The swelling power of DCLGG was intermediate between cross-linking guar gum and dialdehyde guar gum. The cross-linking and dialdehyde oxidization reduced the viscosity of GG. The cross-liking reduced the melting enthalpy of GG. However, the oxidization increased melting enthalpy of ACLGG. The thermal stability of GG was increased by cross-linking or oxidization. The variation of the onset decomposition temperature and end decomposition temperature of GG was not consistent with thermal stability of GG. L-asparagine could be chemically bound well by DCLGG through forming Schiff base under the weak acidity. The maximum adsorption capacity of L-asparagine on DCLGG with aldehyde content of 56.2% reached 21.9 mg/g.

scholarly journals Optimization of lipase-catalyzed synthesis of flavour esters in solvent free system

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Syamsul Kamar Muhamad ◽  
Salina Mat Radzi ◽  
Siti Salhah Othman ◽  
Mohd Basyaruddin Abdul Rahman ◽  
Hanina Mohd Noor
Keyword(s):  
Reaction Time ◽  
Chain Length ◽  
Reaction Temperature ◽  
Immobilized Lipase ◽  
Solvent Free ◽  
Esterification Reaction ◽  
Reaction Parameters ◽  
Free System ◽  
Solvent Free System ◽  
Flavour Esters

The effects of important reaction parameters for enhancing flavour esters formation through lipase-catalyzed reaction were investigated in this study.Various commercial immobilized lipases were used to catalyze the esterification reaction between short-chain fatty acids and alcohols to produce flavour esters which are nonyl caprylate and ethyl valerate which differ in chain length of esters. These synthetic flavour esters with fruity notes are widely used in food, cosmetic and pharmaceutical industries. The effect of various reaction parameters was optimized to obtain a high yield of flavour esters. A maximum percentage for nonyl caprylate with conversion of flavour esters more than 90 % in a solvent-free system was successfully obtained under the following conditions: reaction time (RT), 5 hours; reaction temperature, 40 °C; amount of immobilized lipase, 25 % w/w of total substrate and shaking speed 200 rpm. Compared to ethyl valerate, a maximum percentage conversion of flavour ester more than 80 % in solvent free system was successfully obtained under following conditions: reaction time (RT), 45 minutes; reaction temperature, 40 °C; amount of immobilized lipase, 15 % w/w of total substrate and shaking speed 200 rpm. Comparison between these two ester showed that the chain length give an effect to optimize the reaction condition in esterification reaction.

scholarly journals Optimization and kinetic study of methyl laurate synthesis using ionic liquid [Hnmp]HSO 4 as a catalyst

2018 ◽  
Vol 5 (9) ◽  
pp. 180672 ◽  
Author(s):  
Benyong Han ◽  
Wudi Zhang ◽  
Fang Yin ◽  
Shiqing Liu ◽  
Xingling Zhao ◽  
...  
Keyword(s):  
Reaction Time ◽  
Kinetic Study ◽  
Reaction Temperature ◽  
Frequency Factor ◽  
Methyl Laurate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Hydrogen Sulfate ◽  
Single Factor ◽  
Esterification Rate

Methyl laurate was synthesized from lauric acid (LA) and methanol via an esterification reaction using ionic liquids (ILs) as catalysts. The efficiencies of three different catalysts, 1-methylimidazole hydrogen sulfate ([Hmim]HSO 4 ), 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSO 4 ) and H 2 SO 4 , were compared. The effect of the methanol/LA molar ratio, reaction temperature, reaction time and catalyst dosage on the esterification rate of LA was investigated by single-factor experiments. Based on the single-factor experiments, the esterification of LA and methanol was optimized using response surface methodology. The results showed that the most effective catalyst was the IL [Hnmp]HSO 4 . The optimal conditions were as follows: [Hnmp]HSO 4 dosage of 5.23%, methanol/LA molar ratio of 7.68 : 1, reaction time of 2.27 h and reaction temperature of 70°C. Under these conditions, the LA conversion of the esterification reached 98.58%. A kinetic study indicated that the esterification was a second-order reaction with an activation energy and a frequency factor of 68.45 kJ mol −1 and 1.9189 × 10 9 min −1 , respectively. The catalytic activity of [Hnmp]HSO 4 remained high after five cycles.

Synthesis and Optimization of Methyl Laurate Using Sulfonated Pyrrolidonium Ionic Liquid as a Catalyst

2018 ◽  
Vol 17 (3) ◽  
Author(s):  
Benyong Han ◽  
Fang Yin ◽  
Shiqing Liu ◽  
Xingling Zhao ◽  
Jing Liu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Lauric Acid ◽  
Methyl Laurate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Hydrogen Sulfate ◽  
Single Factor ◽  
Central Composite

Abstract Methyl laurate was synthesized from lauric acid and methanol using Brønsted acid ionic liquids as catalysts, by an esterification reaction. The efficiencies of four different catalysts, 1-methylimidazolium hydrogen sulfate ([Hmim]HSO4), 2-pyrrolidonium hydrogen sulfate ([Hnhp]HSO4), 1-(3-sulfonic acid) propyl-2-pyrrolidonium hydrogen sulfate ([C3SO3Hnhp]HSO4) and H2SO4 were compared. The effect of the methanol/lauric acid molar ratio, reaction temperature, reaction time, and catalyst dosage on the lauric acid conversion was investigated by single-factor experiments. On the basis of single-factor experiments, the esterification of lauric acid and methanol was optimized using response surface methodology (RSM) based on central composite design (CCD). The results showed that the most effective catalyst was the ionic liquid [C3SO3Hnhp]HSO4. The optimal conditions were as follows: [C3SO3Hnhp]HSO4 dosage of 10 % (based on the mass of lauric acid), methanol/lauric acid molar ratio of 9:1, reaction time of 1 h and reaction temperature of 70 °C. Under these conditions, the lauric acid conversion reached 95.33 %. The catalytic activity of [C3SO3Hnhp]HSO4 still remained high after 5 cycles.

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