PREPARATION OF IMIDE OLIGOMERS VIA CONCURRENT REACTIVE EXTRUSION

摘要

Reactive extrusion can be used in a continuous, solvent-less preparation of imide oligomers involving two competing reactions among three ingredients, the first reaction between a dianhydride and a diamine and the second reaction between an endcap and the same diamine. The imide oligomer can form a composite via conventional production methods or via formation of a film from imide oligomer re-melted in an extruder before being impregnated into tape or fabric.

主权项

1. A process for preparing low-melt viscosity imide oligomers derived from a solvent-free reaction of stoichiometric effective amounts of at least one asymmetric dianhydride having the formula: wherein X is selected from the group consisting of nil, C═O, —CH2 and oxygen, and at least one aromatic diamine having the formula selected from the group consisting of: wherein the Y radicals are either the same or different and are selected from the group consisting of nil, CH2, C2H4, C═O, and oxygen, and an endcap selected from the group consisting of 4-phenylethynylphthalic anhydride and cis-5-norbornene-endo-2,3-dicarboxylic anhydride, wherein the process comprises the steps of: (a) introducing the asymmetric dianhydride, the aromatic diamine, and the endcap into an extruder at its throat; (b) melt mixing the asymmetric dianhydride, the aromatic diamine, and the endcap for a sufficient period of time in at least one mixing zone having at least one temperature to thoroughly blend them together and to permit concurrent reaction of both the asymmetric dianhydride and the endcap with the diamine to form the imide oligomer; and (c) extruding the imide oligomer from the extruder.