Abstract:
The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-postcrosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180° C.
Abstract:
The invention relates to a method for the thermal surface post-crosslinking of water-absorbing polymer particles, wherein the polymer particles are coated with an aqueous solution, the coated polymer particles are disaggregated, and the disaggregated polymer particles are thermally surface post-crosslinked by means of a drum-type heat exchanger having an inverse screw flight.
Abstract:
Amphiphilic graft polymers based on water-soluble polyalkylene oxides (A) as a graft base and side chains formed by polymerization of a vinyl ester component (B), said polymers having an average of ≤1 graft site per 50 alkylene oxide units and mean molar masses Mw of from 3000 to 100 000.
Abstract:
The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-post-crosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180°C.
Abstract:
The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution comprising less than 0.3% by weight of persulfate and at least 0.05% by weight of azo initiator and thermal aftertreatment of the formed polymer particles at less than 100° C. in a fluidized bed for 60 to 300 minutes.
Abstract:
The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution comprising less than 0.3% by weight of persulfate and at least 0.05% by weight of azo initiator and thermal aftertreatment of the formed polymer particles at less than 100° C. in a fluidized bed for 60 to 300 minutes.
Abstract:
The invention relates to a method for producing expandable styrene polymers, which method comprises the following steps: (a) adding an aqueous phase containing a suspension stabilizer and an organic phase containing styrene and initiator to a reactor, (b) starting the addition of a blowing agent at a conversion rate of styrene in the range from 40 to 70% and addition of the blowing agent over a period of 30 to 60 minutes, (c) adding a stabilizer for stabilizing the bead size distribution of the expandable styrene polymer at a conversion rate of styrene in the range from 65 to 99%.
Abstract:
The present invention relates to processes for preparing copolymers A) containing A1) one or more vinylaromatic monomers, A2) one or more vinyl cyanides and A3) one or more dicarboxylic anhydrides by bulk or solution polymerization, it being essential to the invention that the polymerization be performed in the presence of 0.01 to 0.5% by weight of water, based on the total weight of the polymerization mixture. The present invention further relates to the copolymers A), to thermoplastic moulding compositions comprising the copolymers A), to the use of the copolymers A) and of the thermoplastic moulding compositions, and to the mouldings, films, fibres and foams obtainable from the copolymers A) and the thermoplastic moulding compositions.
Abstract:
The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-post-crosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180°C.