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Polymer Polyaddition

Polymer Polyaddition

Last update 

Items (7)

  • PA What happens if isocyanate reacts faster with water than with polyol?

    Water and isocyanate create urea groups.

  • PA Which tertiary amines are suitable for PU.

    Triethylamine (90°C) or Diethylaminoethanol (161°C)

  • PA Why are tertiary amines with low boiling temp not used as catalysts?

    PA has an activation energy so at low temperatures the reaction rate decreases.

  • PA How do urea groups react?

    They react with isocyanate and create biuret groups.

  • PA Why are no primary and secondary amines used as cat. to make PU?

    They are too reactive. They react with isocyanate groups and form urea groups.

  • PA What happens if isocyanate reacts faster with polyol than with isocyanate?

    Isocyanate and polyol react to form the polymer.

  • PA Which side reactions can happen if moisture is present in PU?

    Water reacts with the end group of the isocyanate under elimination of CO2 which create urea groups.