Size reduction and polymer encapsulation of carbon black in gas-expanded solvents

[摘要] (cont.) Adsorption of 85/15 and 75/25 BzMA/MAA polymers onto carbon black from CO₂-expanded acetone was measured at 35°C and pressures between 0 psig and 300 psig over a range of mixture compositions relevant to particle coating operations. Pressurization with CO₂ to pressures up to 200 psig caused a decrease in the amount of polymer adsorbed on particle surfaces, but further increases in pressure resulted in higher polymer loadings. In the case of 75/25 BzMA/MAA polymer, the polymer loading increased significantly between 200 psig and 300 psig as the solubility limit was approached or exceeded. Our results are valuable not only in providing quantitative data to facilitate process optimization, but also in offering a more fundamental understanding of interactions among the pigment particles, the dispersant resin, and the gas-expanded liquid media. Such information is important to both process and product design.

[发布机构] Massachusetts Institute of Technology