Cationic polymerization of bromoalkenyl aromatic compounds with aromatic chain transfer agent, and products
AssigneeGeneral Electric Company
InventorDavid F. Aycock
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Abstract
Flame retardant poly(alkenyl aromatic) oligomers and lower molecular weight polymers having bromine substituents on the aromatic nucleus are prepared by cationic polymerization from the corresponding brominated monomers, for example, bromostyrene, in an organic solvent, using a Lewis acid catalyst and an aromatic chain transfer agent. The lower molecular weights enable greater tolerance with other thermoplastic polymers, and as a result compatible flame retardant blends with good ductile impact properties are possible.
Claims21
A process for preparing a poly(bromoalkenyl aromatic) polymer of controlled molecular weight, comprising
- (a) cationically polymerizing a nuclear bromine-substituted alkenyl aromatic monomer or a mixture of nuclear bromine-substituted monomers in solution in an organic solvent, in the presence of a Lewis acid catalyst and an aromatic chain transfer agent for the cationic polymerization reaction, until the desired molecular weight has been achieved;
- and
- (b) separating and isolating the resulting poly(bromoalkenyl aromatic) polymer from the reaction mixture.
A process for preparing a poly(bromoalkenyl aromatic) polymer having a number average molecular weight of less than about 1100 and a bromine content of from about 45 to about 60 percent by weight, based on 100 percent by weight of the polymer, comprising:
- (a) cationically polymerizing a nuclear bromine-substituted alkenyl aromatic monomer or a mixture of nuclear bromine-substituted monomers in solution in an organic solvent, in the presence of a Lewis acid catalyst and an aromatic chain transfer agent for the cationic polymerization reaction, until the desired molecular weight has been achieved;
- and
- (b) separating and isolating the resulting poly(bromoalkenyl aromatic) polymer from the reaction mixture.
Dependencies are inferred from the claim text.