Aluminoxanes containing both ethyl and iso-butyl groups were synthesized by thehydrolysis of Al(C2H3)3 (TEA)/Al(i-C4H9)3 (TIBA) mixtures. The aluminoxane made from theTEA/TIBA mixture of molar ratio 7:3 showed cocatal...Aluminoxanes containing both ethyl and iso-butyl groups were synthesized by thehydrolysis of Al(C2H3)3 (TEA)/Al(i-C4H9)3 (TIBA) mixtures. The aluminoxane made from theTEA/TIBA mixture of molar ratio 7:3 showed cocatalyst activity of about five times as those ofethylaluminoxane or isobutylaluminoxane for ethylene polymerization catalyzed by Cp2ZrCl2. Thealuminoxane was characterized and the possible reasons for its high activity were discussed.展开更多
The flocculating properties of polymer-colloid complexes (PCCs) formed via noncovalent interactions of positively charged aluminoxane particles (APs) with macromolecules of weakly charged cationic acrylamide copolymer...The flocculating properties of polymer-colloid complexes (PCCs) formed via noncovalent interactions of positively charged aluminoxane particles (APs) with macromolecules of weakly charged cationic acrylamide copolymers from the Praestol and Organopol series have been studied. The PCCs that spontaneously formed during mixing of sols of a high-basicity aluminum polyhydroxochloride (APHC) with aqueous solutions of the copolymers exhibit high flocculating ability under the conditions of gravity sedimentation of the model kaolin dispersion with Сd = 8 g/dm3, and their efficiency exceeds both that of the copolymers and the earlier obtained PCCs with nonionogenic polyacrylamide (PAA). In contrast to weakly charged polycationites, the fully charged KF-99 polyelectrolyte does not form PCCs and the products of its mixing with APHC do not reveal an increased flocculating effect.展开更多
文摘Aluminoxanes containing both ethyl and iso-butyl groups were synthesized by thehydrolysis of Al(C2H3)3 (TEA)/Al(i-C4H9)3 (TIBA) mixtures. The aluminoxane made from theTEA/TIBA mixture of molar ratio 7:3 showed cocatalyst activity of about five times as those ofethylaluminoxane or isobutylaluminoxane for ethylene polymerization catalyzed by Cp2ZrCl2. Thealuminoxane was characterized and the possible reasons for its high activity were discussed.
文摘The flocculating properties of polymer-colloid complexes (PCCs) formed via noncovalent interactions of positively charged aluminoxane particles (APs) with macromolecules of weakly charged cationic acrylamide copolymers from the Praestol and Organopol series have been studied. The PCCs that spontaneously formed during mixing of sols of a high-basicity aluminum polyhydroxochloride (APHC) with aqueous solutions of the copolymers exhibit high flocculating ability under the conditions of gravity sedimentation of the model kaolin dispersion with Сd = 8 g/dm3, and their efficiency exceeds both that of the copolymers and the earlier obtained PCCs with nonionogenic polyacrylamide (PAA). In contrast to weakly charged polycationites, the fully charged KF-99 polyelectrolyte does not form PCCs and the products of its mixing with APHC do not reveal an increased flocculating effect.
