摘要:
Disclosed herein is a method comprising: (a) adding an aqueous solution comprising a quaternary ammonium salt to an organic solvent in a vessel under an inert atmosphere, thereby forming a first mixture comprising the quaternary ammonium salt and the solvent; and (b) mixing the first mixture at a temperature and for a time sufficient to remove water and a portion of the solvent from the first mixture, wherein the mixing is performed in an inert atmosphere and the temperature is less than the decomposition temperature of the quaternary ammonium salt.
摘要:
Disclosed herein is a method comprising: (a) adding an aqueous solution comprising a quaternary ammonium salt to an organic solvent in a vessel under an inert atmosphere, thereby forming a first mixture comprising the quaternary ammonium salt and the solvent; and (b) mixing the first mixture at a temperature and for a time sufficient to remove water and a portion of the solvent from the first mixture, wherein the mixing is performed in an inert atmosphere and the temperature is less than the decomposition temperature of the quaternary ammonium salt.
摘要:
Methods of reducing the amount of undesirable by-products in the production of polymers are disclosed. The resulting polyetherimides have lower polydispersivity and enhanced thermomechanical properties. In some embodiments, cyclic and low molecular weight linear oligomers are also obtained.
摘要:
Bis(halophthalimides) such as, 3-bis[N-(4-chlorophthalimido)]benzene are prepared in slurry in an organic liquid such as o-dichlorobenzene or anisole, by a reaction at a temperature of at least 150° C. between at least one diamino compound, preferably an aromatic diamine such as m- or p-phenylenediamine, and at least one halophthalic anhydride such as 4-chlorophthalic anhydride, in the presence of an imidization catalyst such as sodium phenylphosphinate. The solids content of the reaction mixture is at least about 5% and preferably at least about 12% by weight. The product slurry may be employed directly in the preparation of polyetherimides, and similar slurries may be employed to prepare other polyether polymers.
摘要:
A method for preparing a polyimide includes introducing a mixture of an oligomer and a solvent to an extruder, removing solvent via at least one extruder vent, and melt kneading the oligomer to form a polyimide. The polyimide has a low residual solvent content. The method is faster than solution polymerization of polyimides, and it avoids the stoichiometric inaccuracies associated with reactive extrusion processes that use monomers as starting materials.
摘要:
A method for the manufacture of a polyetherimide composition includes catalyzing the reaction of a dianhydride and an organic diamine with a catalyst selected from guanadinium salts, pyridinium salts, imidazolium salts, tetra(C6-24)aryl ammonium salts, tetra(C7-24 arylalkylene) ammonium salts, dialkyl heterocycloaliphatic ammonium salts, bis-alkyl quaternary ammonium salts, (C7-24arylalkylene)(C1-16alkyl) phosphonium salts, (C6-24aryl)(C1-16alkyl)phosphonium salts, phosphazenium salts and combinations thereof, optionally in the presence of a solvent.
摘要:
A polyetherimide having an OH content that is greater than 0 and equal or less than 100 ppm; a Relative Thermal Index that is greater than or equal to 170° C.; and a chlorine content that is greater than 0 ppm is disclosed herein. A method for preparing the polyetherimide is also disclosed.
摘要:
A cyanoresin polymer is described, wherein about 10 percent to about 60 percent of the side chains on the polymer include a cyano group; and substantially all of the remaining polymer side chains include a hydroxyl group. A method of forming such a cyanoresin polymer is described. A capacitor having a dielectric film including such a cyanoresin polymer is also presented.
摘要:
Novel silicate minerals that have undergone a cation exhange with at least one heteroaromatic cation comprising a positively charged organo-substituted heteroatom and/or at least one positively charged heteroatom not part of an aromatic ring with at least one bond having a bond order greater than one and compositions comprising the same are described.
摘要:
Bis(halophthalimides) are prepared in mixture in an organic liquid such as ortho-dichlorobenzene or anisole, by a reaction at a temperature of at least 150° C. between at least one diamine compound and at least one halophthalic anhydride in the presence of imidization catalyst. The reaction mixture is maintained at about 15% by weight solids content and rich in the halophthalic anhydride by constantly monitoring the reaction mixture using analytical methods such as high performance liquid chromatography. The product mixture may be directly employed in the direct preparation of polyetherimides, and similar slurries may be employed to prepare other polyether polymers.