Process for the preparation of polymer particles
AssigneeNOVA Chemicals (International) S.A.
InventorsJeroen Joost Crevecoeur, Eric Wilhelmus Johannes Frederik Neijman, Laurentius Nicolaas Ida Hubertus Nelissen, Johannes Maria Zijderveld
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Abstract
It is desirable to reduce the amount of volatile organic blowing agent in expandable polystyrene. This may be accomplished by partially polymerizing a mass of styrene and incorporating therein water together with an emulsifier. The partially polymerized mass is then polymerized to a high conversion using conventional suspension techniques. The polymer beads containing water which acts as a blowing agent are recovered.
Claims10
Process for the preparation of polymer particles containing a vinylarene polymer by suspension polymerization, which process comprises:
- a) pre-polymerising vinylarene monomers to a conversion degree of 20 to 70%, based on the vinylarene monomer, to yield a pre-polymerised mass, which pre-polymerised mass further contains water emulsified therein and an emulsifier, which pre-polymerisation is carried out with water already present or before water is added;
- b) suspending the pre-polymerised mass in an aqueous medium to yield suspended droplets;
- and
- c) polymerising the vinylarene monomer in the suspended droplets to complete monomer conversion to yield suspended polymer particles.
Dependencies are inferred from the claim text.