摘要:
A process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer in an indirect heat exchanger, wherein a quaternary ammonium salt, a tertiary amine or a salt thereof with a Brønsted acid is added to the liquid mixture to reduce fouling.
摘要:
A process for preparing and/or working up mixtures by (meth)acrylic acid and/or (meth)acrylic ester in the presence of at least one polymerization inhibitor and at least one oxygenous gas, which comprises metering in at least part of the oxygenous gas at an exit rate of at least 50 mm/s.
摘要:
A process for rectificatively separating an acrylic acid-containing liquid, by withdrawing an acrylic acid-rich stream from the rectification column above the feed point and polymerization-inhibiting the upper section of the rectification column by means of diacrylic acid.
摘要:
A process for preparing N-alkenyl compounds by reacting the corresponding NH compounds with alkynes in the liquid phase in the presence of a catalyst, wherein the reaction is carried out in the presence of at least one stabilizer, and the use of stabilizers for increasing the selectivity in a process for preparing N-alkenyl compounds by reacting the corresponding NH compounds with alkynes in the liquid phase in the presence of a catalyst.
摘要:
Method for stabilizing polyvinylpyrrolidones, which comprises treating the polyvinylpyrrolidones with sulfur dioxide, sulfurous acid or alkali metal sulfites and then with free-radical scavenger, and converting the solutions treated in this way into the powdered polyvinylpyrrolidones by drying.