In this paper, four kinds of polymethacrylates(PMAs) used as multifunctional additives were synthesized from quaternary C1—C14 methacrylate, among which sample 4 exhibited relatively better performance. According to ...In this paper, four kinds of polymethacrylates(PMAs) used as multifunctional additives were synthesized from quaternary C1—C14 methacrylate, among which sample 4 exhibited relatively better performance. According to the methacrylate ratio of sample 4, the optimized reaction conditions of PMA were explored by orthogonal experiments comprising 4 factors and 3 levels, and the optimized reaction conditions covered an initiator dosage of 0.8 %, a molecular weight regulator dosage of 0.4%, a reaction temperature of 95 ℃ and a reaction time of 8.5 h. When the optimized PMA samples were used to formulate the 75W/90 automotive gear base oil, they exhibited improved shear stability and good low temperature property. In comparison with foreign commercial polymethacrylate GP, the optimized PMA samples exhibited better thickening ability, similar shear stability and slightly weak low temperature property, with their performance being the same as GP's on the whole. The slight difference in the performance between the optimized PMA and GP was attributed to the difference of chain length of copolymers and the distribution of relative molecular mass between them.展开更多
The conditions for synthesis of overbased lithium sulfonate were investigated in this paper.Various performances of lithium sulfonate,such as its corrosiveness,high temperature detergency,oxidization stability,wear re...The conditions for synthesis of overbased lithium sulfonate were investigated in this paper.Various performances of lithium sulfonate,such as its corrosiveness,high temperature detergency,oxidization stability,wear resistance,dispersity, bubble ability and acid neutralization capability were evaluated in a 15W/40 thickened oil.On companson with other sulfonates, the overbased lithium sulfonate exhibited a lowest sulphate ash,a best detergency and a moderate corrosiveness in 15w/40CD and 15w/40SD oil formulations.However,the weak wear resistance was its only disadvantage.展开更多
Six kinds of alkylbenzene sulfonic acids were selected to prepare the sulfonates S1—S6. Among them, the sulfonates S3, S4, and S6 could be incorporated into lubricating grease with good performance in comparison with...Six kinds of alkylbenzene sulfonic acids were selected to prepare the sulfonates S1—S6. Among them, the sulfonates S3, S4, and S6 could be incorporated into lubricating grease with good performance in comparison with the grease produced from commercial sulfonates T106-1 and T106-2. The optimized conditions for synthesis of the sulfonates S3, S4, and S6 were explored by using different mass ratios of methanol, water and the type of copromoters. It was found out that the appropriate conditions for synthesis of the sulfonate S3 included a methanol to M(M is the total mass of alkylbenzene sulfonic acid and base oil) mass ratio of 16%, a water to M mass ratio of 4%, and a copromoter A to M mass ratio of 2%; the appropriate conditions for synthesis of the sulfonate S4 included a methanol to M mass ratio of 24%, a water to M mass ratio of 2%, a copromoter B to M mass ratio of 2%; and the optimized conditions for synthesis of the sulfonate S6 included a methanol/ M mass ratio of 8%, a water/M mass ratio of 4% and a copromoter B/M mass ratio of 2%. The new sulfonates S3, S4, and S6 produced under the optimized conditions exhibited higher TBN and better antiwear property in camparison with the previous products. Grease samples G9, G10, and G11 were prepared with new sulfonates S3, S4, and S6 successfully and exhibited improved water stability and high temperature performance.展开更多
In this paper,the propene oligomerization reaction catalyzed by phosphotungstic acid supported on two kinds of silica gel was studied,it had been found out that the conversion of propene catalyzed by the type A silica...In this paper,the propene oligomerization reaction catalyzed by phosphotungstic acid supported on two kinds of silica gel was studied,it had been found out that the conversion of propene catalyzed by the type A silica gel-phosphotungstic acid catalyst was 3.38m%,while the conversion of propene catalyzed by the type B silica gel-phosphotungstic acid catalyst was 90.1m% with a nonene selectivity of 42.33m%,and a dodecene selectivity of 31.79m%.The influence of reaction temperature,pressure and liquid hourly space velocity(LHSV) on the reaction catalyzed by the type B silica gelphosphotungstic acid catalyst was investigated.It had been verified that when the reaction temperature increased from 170℃ to 190℃,the conversion of propene increased while the selectivity of nonene and dodecene decreased;when the reaction pressure increased from 3.5 MPa to 4.5 MPa,the conversion of propene increased also,and the selectivity of nonene and dodecene changed very little.The conversion of propene at a space velocity of between 0.5h-1 and 1.0h-1 was higher than that achieved at 2.0h-1,but the selectivity of nonene and dodecene did not show regular fluctuations.An optimum conversion of propene(91.05m%) and an optimum selectivity of nonene and dodecene(89.51m%) could be achieved at a reaction temperature of 170℃,a reaction pressure of 4.5MPa,and a LHSV of 1.0h-1.The experiments on catalyst life showed that the activity of the type B silica gel-phosphotungstic acid catalyst could be only maintained in 25 hours,and the reason was explained also.展开更多
The single-photon absorption induced single event transient in the silicon-germanium heterojunction bipolar transistor is investigated.The laser wavelength and bias condition have been proven to have significant impac...The single-photon absorption induced single event transient in the silicon-germanium heterojunction bipolar transistor is investigated.The laser wavelength and bias condition have been proven to have significant impacts on the characterization of the single event transient(SET) response of the device by two-dimensional(2-D) raster scanning.After optical analytical calculation,the laser-induced charge distribution is well-embedded in the 3-D TCAD process simulation conducted to explore the underlying physical mechanism.In addition to the ion shunt effect,the excess electron injection from the emitter to the base could play a vital role in the SET peak amplitude and charge collection.The impact of the metal layer on the SPA experimental results is also determined by establishing a figure of merit that will help researchers estimate the laser-induced transient sensitivity of devices with metal layer blocking.展开更多
文摘In this paper, four kinds of polymethacrylates(PMAs) used as multifunctional additives were synthesized from quaternary C1—C14 methacrylate, among which sample 4 exhibited relatively better performance. According to the methacrylate ratio of sample 4, the optimized reaction conditions of PMA were explored by orthogonal experiments comprising 4 factors and 3 levels, and the optimized reaction conditions covered an initiator dosage of 0.8 %, a molecular weight regulator dosage of 0.4%, a reaction temperature of 95 ℃ and a reaction time of 8.5 h. When the optimized PMA samples were used to formulate the 75W/90 automotive gear base oil, they exhibited improved shear stability and good low temperature property. In comparison with foreign commercial polymethacrylate GP, the optimized PMA samples exhibited better thickening ability, similar shear stability and slightly weak low temperature property, with their performance being the same as GP's on the whole. The slight difference in the performance between the optimized PMA and GP was attributed to the difference of chain length of copolymers and the distribution of relative molecular mass between them.
文摘The conditions for synthesis of overbased lithium sulfonate were investigated in this paper.Various performances of lithium sulfonate,such as its corrosiveness,high temperature detergency,oxidization stability,wear resistance,dispersity, bubble ability and acid neutralization capability were evaluated in a 15W/40 thickened oil.On companson with other sulfonates, the overbased lithium sulfonate exhibited a lowest sulphate ash,a best detergency and a moderate corrosiveness in 15w/40CD and 15w/40SD oil formulations.However,the weak wear resistance was its only disadvantage.
文摘Six kinds of alkylbenzene sulfonic acids were selected to prepare the sulfonates S1—S6. Among them, the sulfonates S3, S4, and S6 could be incorporated into lubricating grease with good performance in comparison with the grease produced from commercial sulfonates T106-1 and T106-2. The optimized conditions for synthesis of the sulfonates S3, S4, and S6 were explored by using different mass ratios of methanol, water and the type of copromoters. It was found out that the appropriate conditions for synthesis of the sulfonate S3 included a methanol to M(M is the total mass of alkylbenzene sulfonic acid and base oil) mass ratio of 16%, a water to M mass ratio of 4%, and a copromoter A to M mass ratio of 2%; the appropriate conditions for synthesis of the sulfonate S4 included a methanol to M mass ratio of 24%, a water to M mass ratio of 2%, a copromoter B to M mass ratio of 2%; and the optimized conditions for synthesis of the sulfonate S6 included a methanol/ M mass ratio of 8%, a water/M mass ratio of 4% and a copromoter B/M mass ratio of 2%. The new sulfonates S3, S4, and S6 produced under the optimized conditions exhibited higher TBN and better antiwear property in camparison with the previous products. Grease samples G9, G10, and G11 were prepared with new sulfonates S3, S4, and S6 successfully and exhibited improved water stability and high temperature performance.
文摘In this paper,the propene oligomerization reaction catalyzed by phosphotungstic acid supported on two kinds of silica gel was studied,it had been found out that the conversion of propene catalyzed by the type A silica gel-phosphotungstic acid catalyst was 3.38m%,while the conversion of propene catalyzed by the type B silica gel-phosphotungstic acid catalyst was 90.1m% with a nonene selectivity of 42.33m%,and a dodecene selectivity of 31.79m%.The influence of reaction temperature,pressure and liquid hourly space velocity(LHSV) on the reaction catalyzed by the type B silica gelphosphotungstic acid catalyst was investigated.It had been verified that when the reaction temperature increased from 170℃ to 190℃,the conversion of propene increased while the selectivity of nonene and dodecene decreased;when the reaction pressure increased from 3.5 MPa to 4.5 MPa,the conversion of propene increased also,and the selectivity of nonene and dodecene changed very little.The conversion of propene at a space velocity of between 0.5h-1 and 1.0h-1 was higher than that achieved at 2.0h-1,but the selectivity of nonene and dodecene did not show regular fluctuations.An optimum conversion of propene(91.05m%) and an optimum selectivity of nonene and dodecene(89.51m%) could be achieved at a reaction temperature of 170℃,a reaction pressure of 4.5MPa,and a LHSV of 1.0h-1.The experiments on catalyst life showed that the activity of the type B silica gel-phosphotungstic acid catalyst could be only maintained in 25 hours,and the reason was explained also.
文摘The single-photon absorption induced single event transient in the silicon-germanium heterojunction bipolar transistor is investigated.The laser wavelength and bias condition have been proven to have significant impacts on the characterization of the single event transient(SET) response of the device by two-dimensional(2-D) raster scanning.After optical analytical calculation,the laser-induced charge distribution is well-embedded in the 3-D TCAD process simulation conducted to explore the underlying physical mechanism.In addition to the ion shunt effect,the excess electron injection from the emitter to the base could play a vital role in the SET peak amplitude and charge collection.The impact of the metal layer on the SPA experimental results is also determined by establishing a figure of merit that will help researchers estimate the laser-induced transient sensitivity of devices with metal layer blocking.
