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測量應(yīng)用案例-131-90Plus
閱讀:194 發(fā)布時間:2018-4-8提 供 商 | 美國布魯克海文儀器公司 | 資料大小 | 5MB |
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摘要:This investigation is aimed to the development of vinyl-acrylic polymer emulsions by an experimental design 23, whose factors were: total concentration of emulsifiers -CET-; VeoVa10 monomer concentration -CV10- and concentration of vinyl sodium sulfonate -CSVS-. The final properties to be followed were: percentage of water absorption, average particle size (APS) and potential Z. The lowest absorption percentages were obtained at higher CV10 and CET, while the smaller APS were obtained by increasing CET and decreasing CSVS. This variable was also dependent of CV10, which also cause a decrease in APS, as it was 143,40 ± 1,84 nm. On the other hand, the absolute values of potential Z increased if CV10 decreased and CSVS increased. Likewise, this absolute value increased with increasing CET, as they were -37.76 ± 1.56 mV, and -38.09 ± 0.70 mV. With these results, it was verified that when CET is increased this caused a smaller APS. This might be a consequence of surface tension in the reacting mixture that favors the formation of smaller and homogeneous particles. Also when higher CSVS are used the highest absolute values of potential Z are obtained; probably due to the formation of a hydrophilic layer of polyelectrolytes on the latex particles, that provides electrostatic and steric stability. Finally, an increase in CV10 shows the best results of hydrophobicity with lower percentages of water absorption, probably due to the voluminous nature of the hydrophobic branches of VeoVa10, which might avoid the hydrolysis of vinyl acetate segments.