摘要 |
Macrocyclic polyetherimide oligomer compositions are prepared by the reaction of an alkali metal salt of a dihydroxyaromatic compound, preferably of bisphenol A, with a substituted bis-phthalimide, typically a chloro-, fluoro- or nitro-substituted o- or m-phenylene bis-phthalimide. The reaction takes place in a substantially non-polar solvent such as o-dichlorobenzene and at temperatures in the range of about 180 DEG -225 DEG C. in the presence of a phase transfer catalyst which is stable at such temperatures, such as a guanidinium salt. The concentration of phase transfer catalyst is such as to maintain the alkali metal salt at high dilution in the solvent, and the substituted bis-phthalimide is preferably also maintained at high dilution by portionwise addition.
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