GYPSUM

[:ru]Абойтес Дж.[:en]Aboytes, J.[:] [:ru]д-р наук, проф., Институт неметаллических материалов технического университета Клаусталя, Клаусталь-Целлерфельд, Германия[:en]Dr., Prof., TU Clausthal Institut für Nichtmetallische Werkstoffe, Germany[:]

[:ru]Волтер А.[:en]Wolter, A.[:] [:ru]д-р наук, проф., Институт неметаллических материалов технического университета Клаусталя, Клаусталь-Целлерфельд, Германия[:en]Dr., Prof., TU Clausthal Institut für Nichtmetallische Werkstoffe, Germany[:]

[:ru]Хампель Ч.[:en]Hampel, Ch.[:] [:ru]д-р наук, компания Sika Technology AG, Цюрих, Швейцария[:en]Dr., Sika Technology AG, Zurich, Switzerland[:]

[:ru]Хюммель Г. -У.[:en]Hummel, H. -U.[:] [:ru]д-р наук, проф., Knauf Gips KG, отдел исследований и разработок, Ипхофен, Германия[:en]Dr., Prof., Knauf Gips KG, Forschung und Entwicklung, Iphofen, Germany[:]

Alitinform №1 (38) 2015 г. 90-100 p.

Abstract

PCEs are widely used as additives to decrease the water demand in the manufacture of wallboard without affecting the workability of gypsum systems. The main goal was to find a polycarboxylate-type admixture that will avoid the loss of its robustness while in contact with the impurities of natural hemihydrate, specially swelling clays.
In pure hemihydrate, a polycarboxylate possessing long side chains (2000 g/mol) with a methacrylic acid backbone and lower side chain density (C: E 9) is the ideal comb-polymer for the flowability required in the wallboard production. In the hemihydrate-bentonite system, experimental data was obtained for the decrease of the PCE performance due to adsorption and intercalation of the PCE into the bentonite-layered structure. The study showed the effect of the side chain lengths and backbone type of the copolymers on their undesired consumption by bentonite contaminants. The investigation revealed that the polymer consumption is dependent on the side chain length and backbone type.

Key words:

polymers; bentonite; gypsum; impurities; wallboard manufacture