The production of environmental friendly emulsion paint is of great significance. Vacuum steam stripping of methyl isobutyl ketone (MIBK) and methyl ethyl ketone (MEK) from cathodic electrophoretic emulsion was st...The production of environmental friendly emulsion paint is of great significance. Vacuum steam stripping of methyl isobutyl ketone (MIBK) and methyl ethyl ketone (MEK) from cathodic electrophoretic emulsion was studied. The effects of mass ratio of vapor to feed (V/F), vacuum degree and feed temperature on removal rate of MIBK and MEK, emulsion size and solid volume fraction of the emulsion were investigated, and the removal of MIBK and MEK from cathodic electrophoretic emulsion by vacuum desorption was also studied. The results show that removal rates of both MIBK and MEK increase with the increase of V/F, vacuum degree and feed temperature. Removal rates of MIBK and MEK are 98.3% and 93.6%, respectively, at the operating condition V/F of 0.7, feed temperature of 27℃ and vacuum degree of 90 kPa. The emulsion size of cathodic electrophoretic emulsion increases slightly with feed temperature when temperature is below 42 ℃, and increases rapidly with feed temperature when temperature is above 42℃. Solid volume fraction increases by 10% as vacuum degree increases from 0 to 90 kPa at V/F of 0.7 and feed temperature of 27 ℃. Compared with vacuum desorption, vacuum steam stripping can get a higher removal rate of MIBK and MEK under the same feed flow, vacuum degree and feed temperature.展开更多
The rheological properties of two specific waterborne polyurethane (PU) paints were studied by both macrorheological and microrheological methods. During the macrorheological measurement on a rotary rheometer, evapo...The rheological properties of two specific waterborne polyurethane (PU) paints were studied by both macrorheological and microrheological methods. During the macrorheological measurement on a rotary rheometer, evaporation of solvent cannot be totally excluded, which has an influence on the reliability of rheological results. So, the linear oscillatory frequency sweep results (storage and loss modulus versus frequency) and steady shear results (viscosity versus shear rate) got from the rotary rheometer measurement are only used for qualitative analysis. As the evaporation of solvent can be neglected during microrheological measurements on a diffusing wave spectroscope (DWS), the results of storage modulus (G3 and loss modulus (G'~) versus frequency are more credible than the results obtained from the rotary rheometer measurement. Thus, the results of G' and G" versus frequency from DWS measurements are used for quantitative analysis in this work. The G' for both of the waterborne PU paints are larger than G" at low frequency and that is opposite at high frequency in the experimental angular frequency range. The values of modulus at same frequency and viscosity at low shear rate for the two PU paints have apparent difference, which determines the difference of their application.展开更多
基金Project(21176264)supported by the National Natural Science Foundation of ChinaProject(ZL110414)supported by the Undergraduate Free Exploration Innovation Foundation of Central South University,China
文摘The production of environmental friendly emulsion paint is of great significance. Vacuum steam stripping of methyl isobutyl ketone (MIBK) and methyl ethyl ketone (MEK) from cathodic electrophoretic emulsion was studied. The effects of mass ratio of vapor to feed (V/F), vacuum degree and feed temperature on removal rate of MIBK and MEK, emulsion size and solid volume fraction of the emulsion were investigated, and the removal of MIBK and MEK from cathodic electrophoretic emulsion by vacuum desorption was also studied. The results show that removal rates of both MIBK and MEK increase with the increase of V/F, vacuum degree and feed temperature. Removal rates of MIBK and MEK are 98.3% and 93.6%, respectively, at the operating condition V/F of 0.7, feed temperature of 27℃ and vacuum degree of 90 kPa. The emulsion size of cathodic electrophoretic emulsion increases slightly with feed temperature when temperature is below 42 ℃, and increases rapidly with feed temperature when temperature is above 42℃. Solid volume fraction increases by 10% as vacuum degree increases from 0 to 90 kPa at V/F of 0.7 and feed temperature of 27 ℃. Compared with vacuum desorption, vacuum steam stripping can get a higher removal rate of MIBK and MEK under the same feed flow, vacuum degree and feed temperature.
基金financially supported by the National Natural Science Foundation of China(Nos.2127415251473168 an21234007)
文摘The rheological properties of two specific waterborne polyurethane (PU) paints were studied by both macrorheological and microrheological methods. During the macrorheological measurement on a rotary rheometer, evaporation of solvent cannot be totally excluded, which has an influence on the reliability of rheological results. So, the linear oscillatory frequency sweep results (storage and loss modulus versus frequency) and steady shear results (viscosity versus shear rate) got from the rotary rheometer measurement are only used for qualitative analysis. As the evaporation of solvent can be neglected during microrheological measurements on a diffusing wave spectroscope (DWS), the results of storage modulus (G3 and loss modulus (G'~) versus frequency are more credible than the results obtained from the rotary rheometer measurement. Thus, the results of G' and G" versus frequency from DWS measurements are used for quantitative analysis in this work. The G' for both of the waterborne PU paints are larger than G" at low frequency and that is opposite at high frequency in the experimental angular frequency range. The values of modulus at same frequency and viscosity at low shear rate for the two PU paints have apparent difference, which determines the difference of their application.
文摘为了提高丙烯酸树脂的耐水性、附着力以及耐溶剂性,以桐油酸和环氧树脂E-44为原料制备环氧酯,采用溶液聚合和自乳化工艺合成了环氧酯改性水性丙烯酸树脂,并引入氰特CY325氨基树脂制备双组分环氧酯改性水性丙烯酸树脂漆膜。利用FT-IR、1 H NMR、粒径测试等对环氧酯单体、环氧酯改性水性丙烯酸树脂的结构和性能进行表征和分析,并测试了单组分和双组分环氧酯改性水性丙烯酸树脂漆膜的硬度、光泽、吸水率、水接触角、耐溶剂性等性能。结果表明:当环氧酯用量为35%时,单/双组分漆膜综合性能达到最佳,双组分漆膜光泽(60°)达102.3,耐溶剂擦拭次数为500次,耐水性可达480 h,附着力为0级,铅笔硬度为4H,耐冲击性为50 cm。