Melt polymerization of low melt viscosity liquid crystalline polymers

摘要

A method for forming a high molecular weight liquid crystalline polymer is provided. The method include melt polymerizing two or more precursor monomers (e.g., acetylated or non-acetylated) in the presence of an aromatic amide oligomer. The present inventors have discovered that such an oligomer can lower the melt viscosity of the viscous polymer as it is formed. The ability to lower melt viscosity in situ during melt polymerization enables the formation of high molecular weight polymers that display low melt viscosity and can still be removed from the reactor vessel without solidifying therein. This not only improves the ease of processing, but also allows molecular weights to be reached that are even higher than conventionally practical.

主权项

1. A method for forming a liquid crystalline polymer composition comprising a liquid crystalline polymer, the method comprising forming a liquid crystalline polymer by melt polymerizing at least two monomers in the presence of an aromatic amide oligomer, wherein the monomers are precursors for the liquid crystalline polymer, and further wherein the aromatic amide oligomer has the following formula (I): wherein, ring B is a 6-membered aromatic ring wherein 1 to 2 ring positions are optionally a nitrogen and wherein ring B may be optionally fused or linked to a 5- or 6-membered aryl, heteroaryl, cycloalkyl, or heterocyclyl; R5 is halo, haloalkyl, alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, or heterocyclyl; m is from 0 to 4; X1 and X2 are independently C(O)HN or NHC(O); and R1 and R2 are independently aryl, heteroaryl, cycloalkyl, or heterocyclyl, and wherein the liquid crystalline polymer composition has a melting temperature of from about 270° C. to about 400° C.