Poly-α-olefin(PAO) synthetic oil is the base oil of high-quality lubricants, and has a huge market potential.We illustrate PAO synthesis by catalytic polymerization of 1-decene with a boron trifluoride(BF_3)/alcohol ...Poly-α-olefin(PAO) synthetic oil is the base oil of high-quality lubricants, and has a huge market potential.We illustrate PAO synthesis by catalytic polymerization of 1-decene with a boron trifluoride(BF_3)/alcohol system. Gas chromatography–mass spectrometry, proton nuclear magnetic resonance and ^(13) C nuclear magnetic resonance analysis confirmed dimer, trimer and tetramer structures of PAO. Each component contained branched chains with a 1,2 insertion of a head-to-tail link; a 2,1 insertion of a tail-to-tail link and a methyl-containing linked structure. At a low conversion rate, the reaction rate was related directly with the reaction temperature and the catalyst/1-decene concentration. An apparent kinetic equation for PAO formation was determined during 1-decene polymerization.展开更多
In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concent...In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concentration of BF_3 is less than 0.1 mol/L.Two ionic equilibrium models were proposed to simulate the hydrolysis equilibrium of BF_3 and tested by special acid-base titration technique.The most accurate ion equilibrium constants were determined.The model,which was assumed to have no HF,was proved to be more representative for the real system and used to simulate the hydrolysis equilibrium of BF_3.The simulation suggested that H^+,BF_4^-,BF_3OH^- and H_3BO_3 were the main species in the dilute hydrolysis solution,while BF_2(OH)_2^- and F^- were insignificant species whose concentrations were both in the order of 10^(-4) mol/L magnitude,and BF(OH)_3^- could be omitted because its concentration almost equaled zero.Meanwhile,the equilibrium constant of the overall ionic reaction at 25℃ was obtained as 161.6.展开更多
The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of ap...The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of applied polymerization potential and the monomer concentration ratios on the copolymerization were investigated by linear sweep voltammetry and cyclic voltammetry(CV).The structure of copolymer films were investigated by UV-Vis,infrared spectroscopy,thermal analysis.As-formed novel copolymers ...展开更多
Fatty acid methyl ester (FAME) preparation is an important step to determine fatty acid composition of oils and fats. Transesterification with boron trifluoride (BF3) in methanol has been widely used;however, the tran...Fatty acid methyl ester (FAME) preparation is an important step to determine fatty acid composition of oils and fats. Transesterification with boron trifluoride (BF3) in methanol has been widely used;however, the transesterification of triacylglycerols usually involves a long heating time, whereas much shorter reaction times may be sufficient when microwave irradiation is used. The purpose of this paper was to optimize FAME preparation with BF3 by microwave irradiation. A three-factor central composite routable (CCRD) design was used to study the effect of the heating time (A), irradiation power (B), and volume of sodium hydroxide (C) on FAME concentration. A second-order polynomial model was employed to generate a surface response. Optimum conditions obtained for FAME preparation were time of 60 s, irradiation power of 220 W, and base volume of 1.5 mL. Compared to conventional methods, the advantages of this method are the quick result and the accuracy.展开更多
For developing coating materials, the fluorides of scandium, lanthanum, strontium, barium, magnesium and aluminum were produced from their oxides and chlorides by means of exposure to chlorine trifluoride gas at tempe...For developing coating materials, the fluorides of scandium, lanthanum, strontium, barium, magnesium and aluminum were produced from their oxides and chlorides by means of exposure to chlorine trifluoride gas at temperatures between room temperature and 700°C. The metal chlorides could be easily fluorinated even at room temperature, while the metal oxides required temperatures higher than 300?C. After the heating in ambient hydrogen at 1100°C, the fluorides of lanthanum and barium showed very low weight losses at 1100°C, although the weights of the other fluorides significantly decreased. These materials may work as protective films against corrosive and high temperature environments, particularly when using the chlorine trifluoride gas.展开更多
An annealing process was developed for the practical recover of a purified py-rolytic carbon (PPyC) surface from damage, such as color change and peeling, due to fluorination during exposure to chlorine trifluoride ga...An annealing process was developed for the practical recover of a purified py-rolytic carbon (PPyC) surface from damage, such as color change and peeling, due to fluorination during exposure to chlorine trifluoride gas at high tempera-tures for the cleaning of a silicon carbide chemical vapor deposition reactor. The PPyC surface was annealed at 900</span><span style="color:#4F4F4F;font-family:Verdana;">°</span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">C for 10 min in ambient nitrogen con-taining oxygen at the concentrations of 0.01% - 20%. The rainbow-like colored surface returned to the dark gray color of the original PPyC. Simultaneously, the thin peeled films disappeared. The Raman spectra showed that the PPyC surface chemical bonding returned to that of the original one. The oxygen concentration as low as 0.01% could recover the PPyC surface along with re-ducing the surface pit formation, when the combination of the exposure to chlorine trifluoride gas and the recovery was repeated.展开更多
The commercial hydroxyl group terminated polytetramethylene glycol （PTMG）is prepared by the cationic ring-opening polymerization of tetrahydrofuran （THF）by using a strong protonic acid initiator system such as fum...The commercial hydroxyl group terminated polytetramethylene glycol （PTMG）is prepared by the cationic ring-opening polymerization of tetrahydrofuran （THF）by using a strong protonic acid initiator system such as fuming sulfuric acid and others. There has been considerable interest in the low-corrosive BF<sub>3</sub> initiator system. However, the展开更多
The active catalysts of the BF_(3)/n-C_(4)H_(9)OH-catalyzed 1-decene oligomerization reaction,as well as the distribution of the reaction products,was investigated by molecular simulation.The calculation results show ...The active catalysts of the BF_(3)/n-C_(4)H_(9)OH-catalyzed 1-decene oligomerization reaction,as well as the distribution of the reaction products,was investigated by molecular simulation.The calculation results show that(BF_(3))_(2)·n-C_(4)H_(9)OH catalyzes the 1-decene oligomerization reaction with higher activity compared to BF_(3)·n-C_(4)H_(9)OH,which is the most catalytically active substance in the BF_(3)/n-C_(4)H_(9)OH catalyst system.The reaction energy barriers and heats of reaction of chain initiation,chain growth,and chain termination in BF_(3)/n-C_(4)H_(9)OH-catalyzed 1-decene oligomerization are calculated to reveal the product distribution.The calculation results show that the contents of the oligomerization reaction products in descending order are trimer,tetramer,pentamer,and dimer.The calculated results were consistent with the experimentally obtained product distribution.展开更多
An economic and effective method of preparing enriched 10B boric acid was established by chemical reactionof enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certainc...An economic and effective method of preparing enriched 10B boric acid was established by chemical reactionof enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certainconditions. Calcium carbonate was selected to counteract hydrofluoric acid followed on. Some key operation factorswere investigated, such as temperature, reaction time and the ratio of CaCO3 to 10BF3. The results showed that the yieldof enriched 10B boric acid could reach 97. 2% and the purity was up to 94. 1% under the following conditions： the temperaturewas 50-60,℃, the reaction time was 28 h and the ratio of CaCO3 to 10BF3 was 4. In addition, after recrystallizationand titration analysis, the purity of the product could reach over 99. 2% from 94.1%.展开更多
Because of the superior features of boron-10 isotope in absorbing hot neutrons, boric-10 acid(H310BO3)has been used widely in nuclear industry. Boric-10 acid is obtained from boron-10 trifluoride(10BF3) by esterificat...Because of the superior features of boron-10 isotope in absorbing hot neutrons, boric-10 acid(H310BO3)has been used widely in nuclear industry. Boric-10 acid is obtained from boron-10 trifluoride(10BF3) by esterification and hydrolyzation. In this study, trimethyl borate-10 [(CH3O)310B] was prepared from boron-10 trifluoride(10BF3)through chemical exchange rectification. In addition, the hydrolyzation of trimethyl borate-10 was investigated with different p H values, temperatures and molar ratios of water to trimethyl borate-10. Under the optimum process conditions, high yield of boric-10 acid with nuclear industrial purity grade was realized.展开更多
The BF3/n-BuOH complexes were investigated as active species in catalyzing n-decene polymerization reaction.The structures of BF3/n-BuOH complexes were characterized not only by modern spectrum but also by calculation...The BF3/n-BuOH complexes were investigated as active species in catalyzing n-decene polymerization reaction.The structures of BF3/n-BuOH complexes were characterized not only by modern spectrum but also by calculation at theoretical level. The results confirmed that BF3/n-BuOH complexes changed from BF3·(n-BuOH)2 complexes to BF3·n-BuOH complexes with the mass fraction of BF3 increasing. These two complexes have different catalytic activity, but BF3·n-BuOH was superior. The highest n-decene conversion could reach 99% and the most excellent selectivity of n-decene trimer and tetramer could reach up to 80% yield by a series of controlled conditions. This work can help to understand the catalytic active species of n-decene polymerization and provide support for industrialization of poly-alpha-olefins(PAOs).展开更多
?-Phenyl－4－aroylfuran－3－carboxylic acids were reduced in aqueous alkaline solutions ofNaBH4 to afford hydroxy acids in excellent yields． Under the catalysis of boron trifluoride etherate，the hydroxy acids were c...?-Phenyl－4－aroylfuran－3－carboxylic acids were reduced in aqueous alkaline solutions ofNaBH4 to afford hydroxy acids in excellent yields． Under the catalysis of boron trifluoride etherate，the hydroxy acids were converted to lactones smoothly．展开更多
基金supported by the Natural Science Foundation of China(21576048)the PetroChina Innovation Foundation(2014D-5006-0503)
文摘Poly-α-olefin(PAO) synthetic oil is the base oil of high-quality lubricants, and has a huge market potential.We illustrate PAO synthesis by catalytic polymerization of 1-decene with a boron trifluoride(BF_3)/alcohol system. Gas chromatography–mass spectrometry, proton nuclear magnetic resonance and ^(13) C nuclear magnetic resonance analysis confirmed dimer, trimer and tetramer structures of PAO. Each component contained branched chains with a 1,2 insertion of a head-to-tail link; a 2,1 insertion of a tail-to-tail link and a methyl-containing linked structure. At a low conversion rate, the reaction rate was related directly with the reaction temperature and the catalyst/1-decene concentration. An apparent kinetic equation for PAO formation was determined during 1-decene polymerization.
基金Supported by the Independent Innovation Fund of Tianjin University(No.1307)
文摘In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concentration of BF_3 is less than 0.1 mol/L.Two ionic equilibrium models were proposed to simulate the hydrolysis equilibrium of BF_3 and tested by special acid-base titration technique.The most accurate ion equilibrium constants were determined.The model,which was assumed to have no HF,was proved to be more representative for the real system and used to simulate the hydrolysis equilibrium of BF_3.The simulation suggested that H^+,BF_4^-,BF_3OH^- and H_3BO_3 were the main species in the dilute hydrolysis solution,while BF_2(OH)_2^- and F^- were insignificant species whose concentrations were both in the order of 10^(-4) mol/L magnitude,and BF(OH)_3^- could be omitted because its concentration almost equaled zero.Meanwhile,the equilibrium constant of the overall ionic reaction at 25℃ was obtained as 161.6.
基金This work was financially supported by the Natural Science Foundation of China(Nos.50663001,20564001)Ministry of Education(No.2007-207058).
文摘The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of applied polymerization potential and the monomer concentration ratios on the copolymerization were investigated by linear sweep voltammetry and cyclic voltammetry(CV).The structure of copolymer films were investigated by UV-Vis,infrared spectroscopy,thermal analysis.As-formed novel copolymers ...
文摘Fatty acid methyl ester (FAME) preparation is an important step to determine fatty acid composition of oils and fats. Transesterification with boron trifluoride (BF3) in methanol has been widely used;however, the transesterification of triacylglycerols usually involves a long heating time, whereas much shorter reaction times may be sufficient when microwave irradiation is used. The purpose of this paper was to optimize FAME preparation with BF3 by microwave irradiation. A three-factor central composite routable (CCRD) design was used to study the effect of the heating time (A), irradiation power (B), and volume of sodium hydroxide (C) on FAME concentration. A second-order polynomial model was employed to generate a surface response. Optimum conditions obtained for FAME preparation were time of 60 s, irradiation power of 220 W, and base volume of 1.5 mL. Compared to conventional methods, the advantages of this method are the quick result and the accuracy.
文摘For developing coating materials, the fluorides of scandium, lanthanum, strontium, barium, magnesium and aluminum were produced from their oxides and chlorides by means of exposure to chlorine trifluoride gas at temperatures between room temperature and 700°C. The metal chlorides could be easily fluorinated even at room temperature, while the metal oxides required temperatures higher than 300?C. After the heating in ambient hydrogen at 1100°C, the fluorides of lanthanum and barium showed very low weight losses at 1100°C, although the weights of the other fluorides significantly decreased. These materials may work as protective films against corrosive and high temperature environments, particularly when using the chlorine trifluoride gas.
文摘An annealing process was developed for the practical recover of a purified py-rolytic carbon (PPyC) surface from damage, such as color change and peeling, due to fluorination during exposure to chlorine trifluoride gas at high tempera-tures for the cleaning of a silicon carbide chemical vapor deposition reactor. The PPyC surface was annealed at 900</span><span style="color:#4F4F4F;font-family:Verdana;">°</span><span style="font-family:Verdana;"></span><span style="font-family:Verdana;">C for 10 min in ambient nitrogen con-taining oxygen at the concentrations of 0.01% - 20%. The rainbow-like colored surface returned to the dark gray color of the original PPyC. Simultaneously, the thin peeled films disappeared. The Raman spectra showed that the PPyC surface chemical bonding returned to that of the original one. The oxygen concentration as low as 0.01% could recover the PPyC surface along with re-ducing the surface pit formation, when the combination of the exposure to chlorine trifluoride gas and the recovery was repeated.
文摘The commercial hydroxyl group terminated polytetramethylene glycol （PTMG）is prepared by the cationic ring-opening polymerization of tetrahydrofuran （THF）by using a strong protonic acid initiator system such as fuming sulfuric acid and others. There has been considerable interest in the low-corrosive BF<sub>3</sub> initiator system. However, the
基金This work was financially supported by China Petrochemical Corporation Project(120055).
文摘The active catalysts of the BF_(3)/n-C_(4)H_(9)OH-catalyzed 1-decene oligomerization reaction,as well as the distribution of the reaction products,was investigated by molecular simulation.The calculation results show that(BF_(3))_(2)·n-C_(4)H_(9)OH catalyzes the 1-decene oligomerization reaction with higher activity compared to BF_(3)·n-C_(4)H_(9)OH,which is the most catalytically active substance in the BF_(3)/n-C_(4)H_(9)OH catalyst system.The reaction energy barriers and heats of reaction of chain initiation,chain growth,and chain termination in BF_(3)/n-C_(4)H_(9)OH-catalyzed 1-decene oligomerization are calculated to reveal the product distribution.The calculation results show that the contents of the oligomerization reaction products in descending order are trimer,tetramer,pentamer,and dimer.The calculated results were consistent with the experimentally obtained product distribution.
基金Supported by the Independent Innovation Fund of Tianjin University(No.1307)
文摘An economic and effective method of preparing enriched 10B boric acid was established by chemical reactionof enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certainconditions. Calcium carbonate was selected to counteract hydrofluoric acid followed on. Some key operation factorswere investigated, such as temperature, reaction time and the ratio of CaCO3 to 10BF3. The results showed that the yieldof enriched 10B boric acid could reach 97. 2% and the purity was up to 94. 1% under the following conditions： the temperaturewas 50-60,℃, the reaction time was 28 h and the ratio of CaCO3 to 10BF3 was 4. In addition, after recrystallizationand titration analysis, the purity of the product could reach over 99. 2% from 94.1%.
基金Supported by the Independent Innovation Fund of Tianjin University(No.1307)
文摘Because of the superior features of boron-10 isotope in absorbing hot neutrons, boric-10 acid(H310BO3)has been used widely in nuclear industry. Boric-10 acid is obtained from boron-10 trifluoride(10BF3) by esterification and hydrolyzation. In this study, trimethyl borate-10 [(CH3O)310B] was prepared from boron-10 trifluoride(10BF3)through chemical exchange rectification. In addition, the hydrolyzation of trimethyl borate-10 was investigated with different p H values, temperatures and molar ratios of water to trimethyl borate-10. Under the optimum process conditions, high yield of boric-10 acid with nuclear industrial purity grade was realized.
基金Support by National Key Research and Development Program of China(2017YFB0306701)State Key Laboratory Opening Project Foundation of Jilin University(2018-16).
文摘The BF3/n-BuOH complexes were investigated as active species in catalyzing n-decene polymerization reaction.The structures of BF3/n-BuOH complexes were characterized not only by modern spectrum but also by calculation at theoretical level. The results confirmed that BF3/n-BuOH complexes changed from BF3·(n-BuOH)2 complexes to BF3·n-BuOH complexes with the mass fraction of BF3 increasing. These two complexes have different catalytic activity, but BF3·n-BuOH was superior. The highest n-decene conversion could reach 99% and the most excellent selectivity of n-decene trimer and tetramer could reach up to 80% yield by a series of controlled conditions. This work can help to understand the catalytic active species of n-decene polymerization and provide support for industrialization of poly-alpha-olefins(PAOs).
文摘?-Phenyl－4－aroylfuran－3－carboxylic acids were reduced in aqueous alkaline solutions ofNaBH4 to afford hydroxy acids in excellent yields． Under the catalysis of boron trifluoride etherate，the hydroxy acids were converted to lactones smoothly．
