Poly(p-methylstyrene) with broad molecular weight distribution and process for preparation
AssigneeMobil Oil Corporation
InventorAristotle G. Prapas
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Abstract
Poly(p-methylstyrene) with a broad molecular weight distribution and having a melt index suitable for injection molding is prepared by polymerizing p-methylstyrene monomer with a low temperature initiator and a high temperature initiator added with all the monomer at the start of the reaction.
Claims8
Poly(methylstyrene) having a molecular weight distribution (MWD) of at least about 4.0 and a melt index of at least 5.0, said polymethylstyrene comprising the polymerization product of methylstyrene isomers in the following proportions:
- p-methylstyrene at least 90 weight percent;
- m-methylstyrene 0 to 10 weight percent;
- o-methylstyrene less than 0.1 weight percent.
A process for polymerizing a methylstyrene isomer mixture which is predominantly the para-isomer comprising the steps of mixing substantially all of the methylstyrene isomer mixture to be polymerized with polymerization initiators including a high temperature initiator and a low temperature initiator and reacting the mixture at a temperature sufficient to effect polymerization to obtain a product having a MWD of at least 4.0 and a melt index of at least 5.0.
Dependencies are inferred from the claim text.