In-situ Polymerization of a Ring Opening or Condensation Polymer in the Presence of Syndiotactic Polystyrene

In-situ Polymerization of a Ring Opening or Condensation Polymer in the Presence of Syndiotactic Polystyrene

This publication describes the invention of a polymer blend prepared by the polymerization of a ring opening or condensation polymer in the presence of a syndiotactic polystyrene (SPS) polymer.� Polymer blends are commonly formed by melt mixing two polymeric components in a processing device such as an extruder.� This invention eliminates that extra step since the two components are mixed during the condensation or ring opening polymerization step.� In addition to economic advantages, this invention would offer blends with improved properties due to superior mixing.� This invention is quite broad and there are many variations, including some listed below:

Syndiotactic polystyrene:� The syndiotactic polystyrene can be a homopolymer, copolymer, terpolymer, etc.� The comonomers or termonomers are typically substituted styrenes, such as p-methylstyrene.� The homopolymer SPS has a melting point of 270 deg C.� By replacing some of the styrene with p-methylstyrene, the melting point of the syndiotactic copolymer is decreased.� For example, a syndiotactic copolymer containing 7 mole % p-methylstyrene has a melting point of about 250 deg C.

Form of the syndiotactic polystyrene:� The syndiotactic polystyrene may be fed to the condensation or ring opening polymerization reactor as a solid (pellets, chips, granules, powder, etc.); as a melt; as an emulsion, suspension or dispersion; or as a solution in a solvent.� Depending on the temperature of the condensation or ring opening polymerization and melting point of the syndiotactic polystyrene polymer, the syndiotactic polystyrene polymer may remain as a solid or become melted at some stage of the reaction.

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