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 invention relates to styrene polymer beads, characterized in that the styrene polymer beads contain 0.5 to 5 wt % of one or more high-temperature peroxides, wherein the high-temperature peroxides have a half-value period of one hour in the range of 110 to 160⁰C, measured in cumene.
Abstract:
Method for producing polymers by means of controlled radical polymerisation, wherein the polymerisation of one or several radically polymerisable monomers of general formula (I), where R 1 , R 2 , R 3 are H, C 1 -C 4 alkyl, R 4 is C(=O)OR 5 , C(=O)NHR 15 , C(=O)NR 5 R 6 , OC(=O)CH 3 , C(=O)OH, CN, aryl, hetaryl, C(=O)OR 5 OH, C(=O)OR 5 Si(OR 5 ) 3 , halogen, NHC(O)H, P(=O)(OR 7 ) 2 , R 5 is C 1 -C 20 alkyl, R 15 is C 1 -C 20 -alkyl, R 6 is C 1 -C 20 alkyl, and R 7 is H, C 1 -C 20 alkyl, occurs in the presence of a. one or several catalysts containing Cu in the form of Cu(0), Cu(l), Cu (II) or mixtures thereof, b. one or several initiators selected from the group of organic halogenides or pseudohalogenides, c. one or several ligands, d. optionally one or several solvents, and e. optionally one or several inorganic halogenide salts, said method consisting of the following steps i) addition of the catalyst a., ii) optional addition of monomers of general formula (I), iii) optional addition of solvent d., iv) addition of ligand c., v) addition of initiator b., vi) addition of monomers of general formula (I), and vii) optional addition of inorganic halogenide salts e., on the proviso that the addition of at least some of the monomers of general formula (I) occurs immediately before or shortly after the last of the steps i), iv) and v).
Abstract:
A reverse-phase suspension polymerisation process for the manufacture of polymer beads comprising forming aqueous monomer beads comprising an aqueous solution of water-soluble ethylenically unsaturated monomer or monomer blend and polymerising the monomer or monomer blend to form polymer beads while suspended in a non-aqueous liquid, and recovering polymer beads, in which the process comprises, providing in a vessel (1) a volume (2) of non-aqueous liquid wherein the volume of non-aqueous liquid extends between at least one polymer bead discharge point (3) and at least one monomer feed point (4), feeding the aqueous monomer or monomer blend through orifices (5) into, or onto, the non-aqueous liquid to form aqueous monomer beads, allowing the aqueous monomer beads to flow towards the polymer bead discharge point subjecting the aqueous monomer beads to polymerisation conditions to initiate polymerisation to form polymerising beads, wherein the polymerising beads have formed polymer beads when they reach the polymer bead discharge point, removing a suspension of the polymer beads in non-aqueous liquid from the vessel at the polymer bead discharge point and recovering water soluble or water swellable polymer beads from the suspension. The invention also relates to the apparatus suitable for carrying out a reverse-phase suspension polymerisation and polymer beads obtainable by the process or employing the apparatus.
Abstract:
A reverse-phase suspension polymerisation process for the manufacture of polymer beads comprising forming aqueous monomer beads comprising an aqueous solution of water-soluble ethylenically unsaturated monomer or monomer blend and polymerising the monomer or monomer blend, to form polymer beads while suspended in a non-aqueous liquid, and recovering polymer beads, in which the process comprises providing in a vessel (1) a volume (2) of non-aqueous liquid wherein the volume of non-aqueous liquid extends between at least one polymer bead discharge point (3) and at least one monomer feed point (4), feeding the aqueous monomer or monomer blend through orifices (5) into, or onto, the non-aqueous liquid to form aqueous monomer beads, allowing the aqueous monomer beads to flow towards the polymer bead discharge point initiating polymerisation of the aqueous monomer beads to form polymerising beads, wherein the polymerising beads form polymer beads when they reach the polymer bead discharge point, removing a suspension of the polymer beads in non-aqueous liquid from the vessel at the polymer bead discharge point and recovering, water soluble or water swellable polymer beads from the suspension, in which the aqueous monomer or monomer blend and/or the orifices is/are vibrated such that the frequency multiplied by the weight average droplet diameter is between 150 and 800 mm/s. The invention also relates to the apparatus suitable for carrying out a reverse-phase suspension polymerisation and polymer beads obtainable by the process or employing the apparatus. Furthermore, the invention also relates to polymer beads having a weight mean particle size in the range of 0.05 to 5 mm which are held in a container in an amount of at least 300 kg having a standard deviation of particle size less than 20%. In addition, the invention also provides polymer beads having a weight mean particle size in the range 0.05 to 5 mm having a standard deviation of particle size less than 20% and having an amount of residual acrylamide of less than 500 ppm.
Abstract:
The invention relates to a composition containing at least one expandable styrene polymer component and at least one cyclohexane carboxylic acid ester, and optionally other components. Said composition can be processed to form mechanically loadable foams.
Abstract:
A reverse-phase suspension polymerisation process for the manufacture of polymer beads comprising forming aqueous monomer beads of an aqueous solution comprising water-soluble ethylenically unsaturated monomer or monomer blend and polymerising the monomer or monomer blend to form polymer beads while suspended in a non-aqueous liquid, recovering polymer beads, and then cleaning the non-aqueous liquid in which the process comprises providing the non-aqueous liquid in a vessel (1), forming a suspension of monomer beads from the aqueous monomer or monomer blend in the non-aqueous liquid, initiating polymerisation to form polymerising beads, removing a suspension of the polymer beads in non-aqueous liquid from the vessel and recovering, water soluble or water swellable polymer beads from the suspension, in which the non-aqueous liquid contains impurities which comprise particles, and then transferring the non-aqueous liquid from the suspension to a cleaning stage, in which the cleaning stage provides a cleaned non-aqueous liquid suitable for use in a reverse-phase suspension polymerisation process, which cleaning stage comprises removing particles from the non-aqueous liquid in at least one filtration step. The invention also relates to the apparatus suitable for carrying out a reverse-phase suspension polymerisation and polymer beads obtainable by the process or employing the apparatus. The invention further relates to a cleaned non-aqueous liquid obtainable by the process.
Abstract:
The invention relates to a method for producing expandable styrene polymers containing particulate additives, said method comprising the following steps: a) producing prepolymer pellets by means of a first suspension polymerization of an aqueous suspension containing styrene monomers and particulate additives; b) separating the prepolymer pellets; c) optionally dividing the prepolymer pellets into fractions of different particle size and selecting one or more fractions for subsequent steps; d) producing an aqueous suspension of the prepolymer pellets and performing at least one second suspension polymerization in the presence of blowing agent and while metering additional monomers.