摘要:
The present invention also relates to a process for preparing a diamine/dicarboxylic acid salt wherein the dicarboxylic acid comprises an aromatic dicarboxylic acid and is provided in a powder form; the diamine is provided in a liquid form gradually dosed to the dicarboxylic acid powder, while keeping the dicarboxylic acid powder in constant movement; the processing temperature is above 0° C. and below the boiling temperature of the diamine and the melting temperature of the acid and the salt, and the reaction mixture comprises at most 5 wt. % of water. The present invention also relates to an anhydrous diamine/dicarboxylic acid salt obtainable by the process according to invention, or any embodiment thereof as described above.
摘要:
The invention relates to a branched polyamide prepolymer obtained or obtainable by polymerization of a polyamide forming monomer mixture, comprising AA-BB repeat units and branching units derived from diamines (monomer A) dicarboxylic acids (monomer B), and/or a salt of A and B, and a higher functional monomer (monomer C) present in a molar amounts defined by formula I and formula II: MC=(Q/FC)*(MA+MB) (Formula I) and R=((MA*2)+(MC*FCA))/((MB*2)+(MC*FCB)) (Formula II) wherein—MA, MB and MC represent the molar amounts of repeat units derived from the monomers A, B and C, respectively;—FC represent the functionality of monomer C, and is equal to FC-A+FC-B;—FC-A is the number of the amino functional groups comprised by monomer C;—FC-B is the number of carboxyl functional groups or precursor groups thereof comprised by monomer C;—Q is a number in the range of 0.06-1.00; and—R is a number in the range of 0.7-1.3, which polyamide prepolymer has a viscosity number (VN), measured according to ISO 307, in the range of 7-30 mL/g. The invention also relates to a process for preparing a branched polyamide polymer, comprising (1) a melt-mixing step wherein an essentially linear polyamide (pre)polymer and a branched polyamide prepolymer are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture; and (2) a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer.
摘要:
The invention relates to a process for increasing the molecular weight of a polyamide via solid-state post-condensation by exposing the polyamide in the solid-state at elevated temperature to an inert gas atmosphere, that comprises a step (a) wherein the gas atmosphere to which the polyamide is exposed has a dew temperature Tdew-1, followed by a step (b) wherein the gas atmosphere to which the polyamide is exposed has a dew temperature Tdew-2, whereby Tdew-1 is higher than Tdew-2. The effect is that a high molecular weight polyamide can be obtained in a shorter production time.
摘要:
The invention relates to a semi-aromatic polyamide containing at least tetramethylene terephthalamide units and also hexamethylene terephthalamide units. The copolyamide has a melting point higher than approximately 290° C., a high crystallinity and a good stability. Preferably the copolyamide according to the invention contains approximately 30-75 mol % hexamethylene terephthalamide units and also approximately 0.01-20 mol % other units. The invention also relates to a process for the preparation of a semi-aromatic copolyamide containing at least tetramethylene terephthalamide units and hexamethylene terephthalamide units, characterized in that, successively, a first polymerization is effected in the melt phase, followed by an post-polymerization of the low molar mass polymer thus obtained in the solid phase; and to compositions and products that contain said copolyamide.
摘要:
The invention relates to a semi-aromatic polyamide, and a polyamide composition comprising the semi-aromatic polyamide, comprising a diamine component (a) comprising, based on the total number of moles of the diamine component (a): between 5 and 30 mole % of at least one C2-C5 diamine, between 5 and 30 mole % of at least one C7+ diamine, and between 45 and 90 mole % of a C6 diamine; and a dicaboxylic acid component (b) comprising, based on the total number of moles of the dicaboxylic acid component (b): at least 50 mole % of terephthalic acid and at most 50 mole % of another dicarboxylic acid.
摘要:
The invention relates to a semi-crystalline semi-aromatic polyamide comprising A-A-B-B units derived from (a) dicarboxylic acids consisting of a mixture of aromatic dicarboxylic acid and aliphatic dicarboxylic acid and (b) diamines consisting of a mixture of long chain aliphatic diamine and short chain aliphatic diamine, wherein (a-i) the aromatic dicarboxylic acid consists for at least 80 mole % of terephthalic acid, and (a-ii) the aliphatic dicarboxylic acid constitutes at least 5 mole % of the dicarboxylic acids, (b-i) the short chain aliphatic diamine constitutes at least 10 mole % of the diamines, and (c) the aromatic dicarboxylic acid and the long chain aliphatic diamine constitute 60-90 mole % of the total molar amount of dicarboxylic acids and diamines.
摘要:
The invention relates to a high molecular weight branched polyamide polymer comprising (a) blocks predominantly consisting of AA-BB repeat units, (b) blocks predominantly consisting of AB repeat units, and (c) branching units. The invention also relates to a process for the preparation of the high molecular weight branched polyamide polymer, comprising (1) a melt-mixing step wherein an essentially linear polyamide prepolymer (X-1), predominantly consisting of AA-BB repeat units, an essentially linear polyamide (pre)polymer (X-2), predominantly consisting of AB repeat units, and a branching agent are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture; and (2) a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer.
摘要:
This invention relates to a flame retardant polyamide composition comprising a semi-aromatic polyamide, a flame retardant system and a reinforcing agent, wherein the semi-aromatic polyamide comprises units derived from dicarboxylic acids comprising terephthalic acid and aliphatic dicarboxylic acids, and aliphatic diamines. In the semi-aromatic polyamide the aliphatic diamines consist of 10-70 mole % of a short chain aliphatic diamine with 2-5 C atoms and 30-90 mole % of a long chain aliphatic diamine with at least 6 C atoms; the dicarboxylic acids consist of 5-65 mole % aliphatic dicarboxylic acid and optionally aromatic dicarboxylic acid other than terephthalic acid and 35-95 mole % terephthalic acid; and the combined molar amount of terephthalic acid and the long chain aliphatic diamine is at least 60 mole %, relative to the total molar amount of the dicarboxylic acids and diamines. The invention also relates to a housing for an electrical/electronic (E/E) connector and use therein of the flame retardant polyamide composition, to a surface mounting process wherein the E/E connector is used and to a surface mounted device comprising the E/E connector.
摘要:
The invention relates to a semi-aromatic polyamide, and a polyamide composition comprising the semi-aromatic polyamide, comprising a diamine component (a) comprising, based on the total number of moles of the diamine component (a): between 5 and 30 mole % of at least one C2-C5 diamine, between 5 and 30 mole % of at least one C7+ diamine, and between 45 and 90 mole % of a C6 diamine; and a dicaboxylic acid component (b) comprising, based on the total number of moles of the dicaboxylic acid component (b): at least 50 mole % of terephthalic acid and at most 50 mole % of another dicarboxylic acid.
摘要:
The invention relates to a process for the preparation of polyamide nanofibers by electrospinning, wherein the process is a multi-nozzle electrospinning process with the use of a multi-nozzle device or a nozzle-free electrospinning with the use of nozzle free device, comprising steps wherein a high voltage is applied, a polymer solution comprising a polymer and a solvent is fed to the multi-nozzle device or the nozzle free device and transformed under the influence of the high voltage into charged jet streams the jet streams are deposited on a substrate or taken up by a collector, and the polymer in the jet streams solidifies thereby forming nanofibres, and wherein the polymer comprises a semi-crystalline polyamide having a C/N ratio of at most 5.5 and a weight average molecular weight (Mw) of at most 35,000. The invention also relates polyamide nanofibers made by the electrospinning process, as well as to products made thereof and use thereof.