Monoglyceride(MAG)is a widely used nonionic surfactant.In this work,an economic and green solid superbase HND-63 was utilized to synthesize monoglyceride,and the independent variables were examined to achieve the high...Monoglyceride(MAG)is a widely used nonionic surfactant.In this work,an economic and green solid superbase HND-63 was utilized to synthesize monoglyceride,and the independent variables were examined to achieve the highest MAG content.HND-63 was characterized in order to explore the potential reasons for its high MAG selectivity.At the same time,the catalytic mechanism of HND-63 in glycerolysis reaction was also focused on in this paper.A maximum of 72.50%MAG content was obtained under the optimal reaction parameters(reaction temperature of 110.5◦C,reaction time of 209 min,molar ratio of glycerol to oil of 9.2:1,and catalyst dosage of 10.1%).The activation energy Ea and the pre-exponential factor A of the reaction were 61.37 kJ/mol and 6.33×10^(6) mol·L^(-1)·min^(-1),respectively.The basic site of HND-63 is O^(2-),which is loaded on molecular sieve analogs in the form of Na_(2)O,thus providing great convenience for recovery.The findings offer a novel solid superbase that could be potentially applied to glycerolysis reactions,providing the foundation for further development of plantbased surfactants.展开更多
This work gives a comparison on the microstructural characteristics,textural discrepancies,and twinning behaviors of lamellar and equiaxed nearβ-Ti alloys during multi-pass cross rolling with a rolling reduction of 2...This work gives a comparison on the microstructural characteristics,textural discrepancies,and twinning behaviors of lamellar and equiaxed nearβ-Ti alloys during multi-pass cross rolling with a rolling reduction of 20%,50%and 80%.The results showed that the restoration mechanism of the alloy inβphase is strongly dependent on theαmorphologies,and in comparison,strain path has weaker influences on the grain refinement of theβmatrix.Therefore,the texture intensities of bothαandβphases were weakened owing to the dynamic recrystallization(DRX)of the two phases in the equiaxed microstructure.While,with regard to the lamellar microstructure,dynamic recovery(DRV)of theβphase predominated,forming elongatedβsubgrains.Besides,theαandβmatrix in lamellar microstructures obeyed the Burgers orientation relationship,which was gradually broken down until the final reduction.Lastly,the{1101}twinning exhibits a strong size effect.With the continuous DRX ofαphases,theα-twinning is suppressed owing to progressive grain refinement.The activation ofβ-twinning,namely{332}?113?and{112}?111?,in nearβ-Ti alloys is heavily dependent on the deficientβ-stabilizing elements and the local stress concentration.These findings provide an effective way to obtain ultra-fine grain microstructures of this alloy.展开更多
基金financially sponsored by Natural Science Foundation of Henan(252300421033).
文摘Monoglyceride(MAG)is a widely used nonionic surfactant.In this work,an economic and green solid superbase HND-63 was utilized to synthesize monoglyceride,and the independent variables were examined to achieve the highest MAG content.HND-63 was characterized in order to explore the potential reasons for its high MAG selectivity.At the same time,the catalytic mechanism of HND-63 in glycerolysis reaction was also focused on in this paper.A maximum of 72.50%MAG content was obtained under the optimal reaction parameters(reaction temperature of 110.5◦C,reaction time of 209 min,molar ratio of glycerol to oil of 9.2:1,and catalyst dosage of 10.1%).The activation energy Ea and the pre-exponential factor A of the reaction were 61.37 kJ/mol and 6.33×10^(6) mol·L^(-1)·min^(-1),respectively.The basic site of HND-63 is O^(2-),which is loaded on molecular sieve analogs in the form of Na_(2)O,thus providing great convenience for recovery.The findings offer a novel solid superbase that could be potentially applied to glycerolysis reactions,providing the foundation for further development of plantbased surfactants.
基金financial supports from the National Natural Science Foundation of China(No.51871242)Scientific and technological innovation projects of Hunan Province,China(No.2017GK2292)the National Key R&D Program of China(2018YFB0704100)。
文摘This work gives a comparison on the microstructural characteristics,textural discrepancies,and twinning behaviors of lamellar and equiaxed nearβ-Ti alloys during multi-pass cross rolling with a rolling reduction of 20%,50%and 80%.The results showed that the restoration mechanism of the alloy inβphase is strongly dependent on theαmorphologies,and in comparison,strain path has weaker influences on the grain refinement of theβmatrix.Therefore,the texture intensities of bothαandβphases were weakened owing to the dynamic recrystallization(DRX)of the two phases in the equiaxed microstructure.While,with regard to the lamellar microstructure,dynamic recovery(DRV)of theβphase predominated,forming elongatedβsubgrains.Besides,theαandβmatrix in lamellar microstructures obeyed the Burgers orientation relationship,which was gradually broken down until the final reduction.Lastly,the{1101}twinning exhibits a strong size effect.With the continuous DRX ofαphases,theα-twinning is suppressed owing to progressive grain refinement.The activation ofβ-twinning,namely{332}?113?and{112}?111?,in nearβ-Ti alloys is heavily dependent on the deficientβ-stabilizing elements and the local stress concentration.These findings provide an effective way to obtain ultra-fine grain microstructures of this alloy.
