A new sesquiterpene polyol ester was isolated from the leaves of Celastrus angulatus. Its structure was determined as 1 (beta), 2 (beta), 9 (a) -triacetoxy-8 (a) -((a) -hydroxyl-isobutyryloxy)-15-benzoyloxy-4 (a) -hyd...A new sesquiterpene polyol ester was isolated from the leaves of Celastrus angulatus. Its structure was determined as 1 (beta), 2 (beta), 9 (a) -triacetoxy-8 (a) -((a) -hydroxyl-isobutyryloxy)-15-benzoyloxy-4 (a) -hydroxy-dihydroagarofuran by means of NMR, MS and IR spectral analysis. Preliminary biological study on antitumor activity revealed that this compound showed strong nonselective cytotoxicity against four of the NCI panel cell lines.展开更多
In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(PO...In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(POE)which is a representative component of the lubricating oil,using molecular dynamics simulations.The research focuses on pentaerythritol ester(PEC)with medium to long chain lengths,specifically PEC9.Relevant parameters such as solubility parameters,diffusion coefficients,binding energies,and radial distribution functions were calculated to elucidate the interaction dynamics.The variation in solubility parameters suggests that the miscibility of PEC9 and R1336mzz(Z)diminishes as the number of PEC9 chains increases.Additionally,the compatibility between these two components deteriorates with rising temperature,which is accompanied by a reduction in their binding energy.The simulation results presented in this study offer theoretical insights into the behavior of refrigerant R1336mzz(Z)upon contact with lubricating oil during actual operation,as well as implications for the operational efficiency of the equipment.展开更多
By evaluating the SEM images,specific surface area,and the catalytic synthesis reaction conditions of an activated carbon-supported p-toluenesulfonic acid catalyst,and comparing the physical and chemical properties,in...By evaluating the SEM images,specific surface area,and the catalytic synthesis reaction conditions of an activated carbon-supported p-toluenesulfonic acid catalyst,and comparing the physical and chemical properties,infrared spectra,nuclear magnetic resonance spectra,oxidation stability,thermal stability,hydrolytic stability,and extreme pressure anti-wear performance of the synthesized trihydroxymethylpropyl trioleate with imported reference esters,the feasibility of its application as a substitute was investigated.The results indicated that the activated carbon-supported p-toluenesulfonic acid catalyst exhibited loose porosity,high specific surface area,and high esterification efficiency.When synthesized under optimal conditions,the yield rate of trihydroxymethylpropyl trioleate reached 99.3%,with a simple separation process that did not require additional steps such as neutralization and washing and generated minimal wastewater.The physical and chemical properties of the synthesized trihydroxymethylpropyl trioleate were comparable to those of the reference ester in terms of color,viscosity,viscosity index,flash point,and pour point.Moreover,the peak position and peak height in the infrared and nuclear magnetic carbon spectra were essentially the same.Through comprehensive evaluations and comparisons of various properties,it was determined that the performance of trihydroxymethylpropyl trioleate was comparable to that of the imported reference esters.展开更多
Polyol esters of lubricating oil were synthesized by dipentaerythritol（di-PE）with n-Valeric acid,n-Hexanoic acid,n-Heptanoic acid and n-Caprylic acid（C5 to C8 carboxylic acids）under microwave radiation.The best sy...Polyol esters of lubricating oil were synthesized by dipentaerythritol（di-PE）with n-Valeric acid,n-Hexanoic acid,n-Heptanoic acid and n-Caprylic acid（C5 to C8 carboxylic acids）under microwave radiation.The best synthetical conditions of di-PE with C5 to C8 carboxylic acids were investigated under microwave radiation.The best molar ratio of C5 to C8 carboxylic acids vs di-PE was 8∶1.The best microwave power was between 300W and 320W.The best composite catalyst was selected,and the ratio of composite catalyst（vitriol oil vs P-Toluene Sulphonic acid）was from 1∶2.5 to 1∶3.0.The esterifiable temperatures of dipentaerythritol hexa-valerianate,dipentaerythritol hexa-caproate,dipentaerythritol hexa-heptylate,dipentaerythritol hexa-caprylate were respectively 114℃～116℃、126℃～128℃、134℃～136℃、140℃～142℃.The yields were at least 93% within 9～10min.The viscosity coefficients were determined by Ubbelohde viscosimeter at 31℃±0.05℃ and were respectively 66.4mm2/s,70.8mm2/s,75.3mm2/s,78.1mm2/s.With the increase of carbon atom number of carboxylic acids,the esterifiable temperatures and viscosities of 3a-3d gradually went up.The structures of 3a-3d were identified by 1H NMR,13C NMR and IR spectra.The refractive indexs of 3a-3d were determined with ZWA-J refractometer.This method is fast,efficient and high-yielding,and may provide a new researchful orientation for traditional technology improvement of esters lubricating oil.展开更多
文摘A new sesquiterpene polyol ester was isolated from the leaves of Celastrus angulatus. Its structure was determined as 1 (beta), 2 (beta), 9 (a) -triacetoxy-8 (a) -((a) -hydroxyl-isobutyryloxy)-15-benzoyloxy-4 (a) -hydroxy-dihydroagarofuran by means of NMR, MS and IR spectral analysis. Preliminary biological study on antitumor activity revealed that this compound showed strong nonselective cytotoxicity against four of the NCI panel cell lines.
基金supported by Hainan Provincial Natural Science Foundation of China(No.422CXTD509).
文摘In the organic Rankine cycle,the refrigerant inevitably interacts with the lubricating oil.This study investigates the interaction mechanism between the fourth-generation refrigerant R1336mzz(Z)and the polyol ester(POE)which is a representative component of the lubricating oil,using molecular dynamics simulations.The research focuses on pentaerythritol ester(PEC)with medium to long chain lengths,specifically PEC9.Relevant parameters such as solubility parameters,diffusion coefficients,binding energies,and radial distribution functions were calculated to elucidate the interaction dynamics.The variation in solubility parameters suggests that the miscibility of PEC9 and R1336mzz(Z)diminishes as the number of PEC9 chains increases.Additionally,the compatibility between these two components deteriorates with rising temperature,which is accompanied by a reduction in their binding energy.The simulation results presented in this study offer theoretical insights into the behavior of refrigerant R1336mzz(Z)upon contact with lubricating oil during actual operation,as well as implications for the operational efficiency of the equipment.
文摘By evaluating the SEM images,specific surface area,and the catalytic synthesis reaction conditions of an activated carbon-supported p-toluenesulfonic acid catalyst,and comparing the physical and chemical properties,infrared spectra,nuclear magnetic resonance spectra,oxidation stability,thermal stability,hydrolytic stability,and extreme pressure anti-wear performance of the synthesized trihydroxymethylpropyl trioleate with imported reference esters,the feasibility of its application as a substitute was investigated.The results indicated that the activated carbon-supported p-toluenesulfonic acid catalyst exhibited loose porosity,high specific surface area,and high esterification efficiency.When synthesized under optimal conditions,the yield rate of trihydroxymethylpropyl trioleate reached 99.3%,with a simple separation process that did not require additional steps such as neutralization and washing and generated minimal wastewater.The physical and chemical properties of the synthesized trihydroxymethylpropyl trioleate were comparable to those of the reference ester in terms of color,viscosity,viscosity index,flash point,and pour point.Moreover,the peak position and peak height in the infrared and nuclear magnetic carbon spectra were essentially the same.Through comprehensive evaluations and comparisons of various properties,it was determined that the performance of trihydroxymethylpropyl trioleate was comparable to that of the imported reference esters.
文摘Polyol esters of lubricating oil were synthesized by dipentaerythritol（di-PE）with n-Valeric acid,n-Hexanoic acid,n-Heptanoic acid and n-Caprylic acid（C5 to C8 carboxylic acids）under microwave radiation.The best synthetical conditions of di-PE with C5 to C8 carboxylic acids were investigated under microwave radiation.The best molar ratio of C5 to C8 carboxylic acids vs di-PE was 8∶1.The best microwave power was between 300W and 320W.The best composite catalyst was selected,and the ratio of composite catalyst（vitriol oil vs P-Toluene Sulphonic acid）was from 1∶2.5 to 1∶3.0.The esterifiable temperatures of dipentaerythritol hexa-valerianate,dipentaerythritol hexa-caproate,dipentaerythritol hexa-heptylate,dipentaerythritol hexa-caprylate were respectively 114℃～116℃、126℃～128℃、134℃～136℃、140℃～142℃.The yields were at least 93% within 9～10min.The viscosity coefficients were determined by Ubbelohde viscosimeter at 31℃±0.05℃ and were respectively 66.4mm2/s,70.8mm2/s,75.3mm2/s,78.1mm2/s.With the increase of carbon atom number of carboxylic acids,the esterifiable temperatures and viscosities of 3a-3d gradually went up.The structures of 3a-3d were identified by 1H NMR,13C NMR and IR spectra.The refractive indexs of 3a-3d were determined with ZWA-J refractometer.This method is fast,efficient and high-yielding,and may provide a new researchful orientation for traditional technology improvement of esters lubricating oil.
