Abstract:
The invention relates to process for the production of a PA-MXDT/ZT polyamide comprising the following steps: (i) providing a solid MXDT/ZT salt, wherein MXD is meta-xylylenediamine, T is terephthalic acid, Z is a linear aliphatic diamine having from 2 to 12 carbon atoms and wherein the amount of Z is from 0 to 40 mole % with respect to the total of the amount of MXD and Z units in the polymer, (ii) solid state polymerizing the MXDT/ZT salt to obtain the polyamide, wherein the solid state polymerization is carried out at least partly under a diamine atmosphere. The invention further relates to a PA-MXDT/ZT polyamide, wherein the polymer has a glass transition temperature fulfilling the following relation: Tg>226−475*Y, wherein Y is the weight ratio g/g of all CH2 groups in the polymer with respect to the total weight of the polyamide.
Abstract:
The present invention relates to a semi-crystalline semi-aromatic polyamide consisting of 95-100 mole % of monomeric units derived from diamine comprising aliphatic diamine comprising 5-40 mole % of a cycloaliphatic diamine, and dicarboxylic acid comprising at least 50 mole % of naphthalene dicarboxylic acid (N), or biphenyl dicarboxylic acid (B), or a combination thereof.
Abstract:
The invention relates to a flame-retardant polyamide composition comprising a polyamide with a melting temperature higher than 265° C. and ammeline and/or ammelide, in which the ammeline and/or ammelide is obtainable by a biocatalytic process from melamine in an aqueous reaction mixture comprising a biocatalyst, wherein melamine is converted into ammeline and optionally further into ammelide.
Abstract:
The invention relates to a process for the preparation of semi-crystalline semi-aromatic polyamide by direct solid-state polymerization of a diamine-dicarboxylic acid salt, comprising steps of (a) providing at least two salts of terephthalic acid and diamine, wherein each of these diamine/terephthalic acid salts is in solid state and has a melting temperature of at least Tx, wherein Tx is at least 260° C.; (b) preparing a mixture of the diamine/terephthalic acid salts, while retaining the salts in solid state; and (c) heating the mixture obtained from step (b) in the solid state to a temperature (T-c) in the range from 200° C. to 260° C., under a pressure below the saturation vapour pressure of water at said temperature, thereby condensing and polymerizing the salts and forming a semi-crystalline semi-aromatic polyamide in solid form.
Abstract:
The invention relates to a process for preparing a salt from diamine and dicarboxylic acid, the process comprising contacting a diamine gas, having a gas temperature T-gas, with a dicarboxylic acid, thereby forming a reaction mixture comprising diamine/dicarboxylic acid salt, wherein the dicarboxylic acid and the reaction mixture are kept at a temperature T-mixture of at least 10° C. below the lowest of the melting temperature of the dicarboxylic acid (Tm-acid) and the melting temperature of the resulting diamine/dicarboxylic acid salt (Tm-salt). The invention also relates to a process for preparing a polyamide comprising preparing a salt from diamine and dicarboxylic acid.
Abstract:
The present invention relates to a new process for the preparation of ammeline and/or ammelide from melamine by a solid-to-solid reaction in an aqueous reaction mixture comprising a biocatalyst, wherein the biocatalyst comprises at least one enzyme belonging to the amidohydrolase superfamily and having aminohydrolase activity towards 1,3,5-triazine compounds. The invention further relates a product obtainable by the process according to the invention, wherein the product comprises ammeline and/or ammelide.
Abstract:
The invention related to a process for the production of a PA-MXDT/ZT polyamide copolymer comprising the following steps: •i. providing a solid MXDT/ZT salt, wherein MXD is meta-xylylenediamine, T is terephthalic acid, Z is a linear aliphatic diamine having from 2 to 12 carbon atoms and wherein amount of Z is from 5 to 40 mole % with respect to the total amount of MXD and Z units in the copolymer and wherein the MXDT/ZT salt is provided by dosing of liquid diamines MXD and Z to a powder of terephthalic acid; •ii. heating the solid MXDT/ZT salt to a first condensation temperature (Tc1) thereby condensing the salt in solid state to produce a solid polyamide copolymer, wherein Tc1 is below the melting temperature (Tm-salt) of said salt. The invention further relates to a PA-MXDT/ZT polyamide copolymer, wherein MXD is meta-xylylenediamine, T is terephthalic acid, Z is a linear aliphatic diamine having from 2 to 12 carbon atom, Z is from 5 to 40 mole % with respect to the total of MXD and Z units in the copolymer.
Abstract:
The invention relates to a process for preparing a semi-aromatic polyamide from diamine and dicarboxylic acid, comprising steps of •(i) dosing a liquid diamine to an agitated powder comprising an aromatic dicarboxylic acid thereby forming a powder comprising a diamine/dicarboxylic acid salt (DD-salt), and •(ii) solid-state polymerizing the DD-salt to obtain the polyamide.