摘要:
Polyether polymers, such as polyetherimides, are prepared by the reaction of a dihydroxy-substituted aromatic hydrocarbon alkali metal salt, such as bisphenol A disodium salt, with a bis(N-(chlorophthalimido))aromatic compound, such as 1,3- and/or l,4-bis(N-(4-chlorophthalimido))benzene, in a solvent such as o-dichlorobenzene and in the presence of a phase transfer catalyst such as a hexaalkylguanidinium chloride. Several embodiments may be employed to improve the method. They comprise employing substantially dry reagents, employing a high solids level in solvent, beginning with an excess of bis(N-(chlorophthalimido))- aromatic compound and incrementally adding alkali metal salt, employing alkali metal salt of small particle size, and using reagents of high purity.
摘要:
A coated glass fiber for reinforcing a rubber includes a glass fiber, a first coating layer covering the glass fiber, and a second coating layer covering the first coating layer. The first coating layer is prepared by a process including (a) dispersing a resorcinol-formaldehyde resin and a rubber latex in water to prepare a first coating solution; (b) applying the first coating solution to the glass fiber to form a first precursory layer; and (c) drying the first precursory layer into the first coating layer. The second coating layer is prepared by a second process including (d) dispersing bisallylnadiimide, a rubber elastomer, a vulcanizing agent, and an inorganic filler in an organic solvent to prepare a second coating solution; (e) applying the second coating solution to the first coating layer to form a second precursory layer; and (f) drying the second precursory layer into the second coating layer.
摘要:
A blend comprises a polyaryletherketone and a polysiloxane. The blend has improved properties, for example toughness compared to the polyaryletherketone alone. A method of preparing the blend and its uses are described.
摘要:
These prepolymers containing maleimid functions (f) consist in reaction products of at least one maleic anhydride (I), of at least one compound (II) having at least one -NH2 function and at least one other function F: -OH, -NH2, -NH-, -COOH or -COOR or -OCOR (R = C1-C5 alkyl) and at least one chain forming compound (III) by polycondensation and/or polyaddition; (II) having been first reacted with (I) to open the maleic anhydride cycles, with formation of maleamic acid functions (f) which have then been at least partially re-closed by heat to produce N-substituted maleimids by the groups functionalised by F; the chain having been formed by polycondensation and/or polyaddition of the N-substituted maleimid bearing function F of compound(s) (III), of non aromatised products bearing a function F or not formed at the same time as said N-substituted maleimids, and of the maleic anhydride(s) (I) which could have been in excess after being opened by the compound(s) (II); the functionalities and proportions of (II) and (III) having been selected so as to preclude a gelation of the reaction medium. In (f), (I), and (f'), R , R = H, C11-C12 alkyl or halogen.
摘要:
Thermosetting polymers with high temperature capability for composite and adhesive applications are disclosed. Inhibitors for improving pot life, gel time and storage stability are disclosed. These polymers are ideally suited for adhesives and RTM, resin film infusion, and prepreg methods to make polymer matrix, fiber reinforced composite parts.
摘要:
These compositions comprise at least one compound (A) containing double olefinic bonds depleted of electrons and at least one compound (B) containing double olefinic bonds enriched with electrons. The compound(s) (A) are selected among prepolymers comprising maleimid functions (f) consisting in the reaction products of at least one maleic anhydride (I), of at least one compound (II) having at least one -NH2 function and at least one other function F: -OH, -NH2, -NH-, -COOH, or -COOR3 or -OCOR?3 (R3 = C¿1-C5 alkyl) and at least one chain forming compound (III) by polycondensation and/or polyaddition; (II) having been first reacted with (I) to open the maleic anhydride cycles, with formation of maleamic acid functions (f) which have then been at least partially re-closed by heat to produce N-substituted maleimids by groups functionalised by F; the chain having been formed by polycondensation and/or polyaddition of the N-substituted maleimid bearing the function F of compound(s) (III), of non aromatised products bearing a function F or not formed at the same time as said N-substituted maleimids, and of the maleic anhydride(s) (I) which could have been in excess after being. opened by the compound(s) (II); the functionalities and proportions of (II) and (III) having been selected so as to preclude a gelation of the reaction medium. In (a) (f), (I), and (f'), R1, R2 = H, C¿1?-C12 alkyl or halogen.
摘要:
An aligning agent for liquid crystals which is for use in a method in which a thin polymer film formed on a substrate is irradiated with polarized ultraviolet or electron beams from a given direction based on the plane of the substrate and this substrate is used to align a liquid crystal without rubbing the substrate, characterized by comprising a polymer containing photochemically reactive groups in the polymer backbone and having a glass transition point of 200 DEG C or higher.
摘要:
A process for producing a polyimide composition by reacting at least one polyamic acid or at least one polyamic ester or a mixture of at least one polyamic acid and at least one polyamic ester with a selected phosphoramide in the presence of at least one base catalyst to form a polyimide composition.
摘要:
A process for making polyimide composition comprising reacting at least one diamine, at least one tetracarboxylic diacid diester, selected phosphoramide and at least one base catalyst to form at least one polyimide compound, said reaction carried out at a temperature from about 20 °C to about 60 °C and wherein the molar ratio of diamine:tetracarboxylic diacid diester:phosphoramide:base catalyst is in the range of 0.8-1.2:1:2.5-4.0:2.5-4.0.
摘要:
A process for making polyimide-polyamic ester copolymer composition comprising reacting at least one diamine, a pyromellitic diacid diester compound; at least one other tetracarboxylic diacid diester compound and a selected phosphoramide in the presence of a base catalyst to form a polyimide-polyamic acid ester copolymer.