Thermoplastic (co)polyimides and synthesis methods
A salt composition includes at least one ammonium carboxylate salt obtained from: (a) at least one aromatic compound comprising 2 anhydride functional groups and/or its carboxylic acid and/or ester derivatives; and (b) one or more aliphatic diamines in which said aliphatic diamine or diamines are chosen from the diamines of formula (I) NH 2 —R—NH 2 with R being a saturated aliphatic divalent hydrocarbon radical, the two amine functional groups of which are separated by 4 to 6 carbon atoms and 1 or 2 hydrogen atoms of the divalent radical of which are replaced by 1 or 2 methyl and/or ethyl groups; and optionally the diamines of formula (II) NH 2 —R′—NH 2 with R′ being a saturated or unsaturated and aliphatic, cycloaliphatic or arylaliphatic divalent hydrocarbon radical, which optionally comprises heteroatoms; and at least one chain-limiting compound chosen from monoamines, monoacids or diacids in the α,β positions.
1. A salt composition, comprising:
at least one ammonium carboxylate salt obtained from:
(a) at least one aromatic compound comprising 2 anhydride functional groups and/or its carboxylic acid and/or ester derivatives selected from the group consisting of: pyromellitic anhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, pyromellitic acid, 3,3′,4,4′-biphenyltetracarboxylic acid and their mixtures; and
(b) one or more aliphatic diamines, the amine functional groups of which are not covalently bonded to a carbon atom of an aromatic ring, in which said one or more aliphatic diamines are of formula (I) NH 2 —R—NH 2 with R being a saturated aliphatic divalent hydrocarbon radical, the two amine functional groups of which are separated by 4 to 6 carbon atoms and 1 or 2 hydrogen atoms of the divalent radical of which are replaced by 1 or 2 methyl and/or ethyl groups; and wherein the one or more aliphatic diamines optionally further comprises at least one diamine of formula (II) NH 2 —R′—NH 2 with R′ being a saturated or unsaturated and aliphatic, cycloaliphatic or arylaliphatic divalent hydrocarbon radical, which optionally comprises heteroatoms; and
at least one chain-limiting compound chosen from monoamines, monoacids or diacids in the α,β positions such that they can form an anhydride functional group by a dehydration reaction, wherein the at least one chain-limiting compound is added to a preformed ammonium carboxylate salt.
2. The salt composition as claimed in claim 1 , characterized in that the diamine of formula (I) is selected from the group consisting of: 2-ethyltetramethylene-1,4-diamine, 2-methylpentamethylene-1,5-diamine or a mixture of these.
3. The salt composition as claimed in claim 1 , characterized in that the diamine of formula (I) is 2-methylpentamethylene-1,5-diamine.
4. The salt composition as claimed in claim 1 , characterized in that the chain-limiting compound is chosen from: 1-aminopentane, 1-aminohexane, 1-aminoheptane, 1-aminooctane, 1-aminononane, 1-aminodecane, 1-aminoundecane, 1-aminododecane, benzylamine, ortho-phthalic acid, acetic acid, propionic acid, benzoic acid, stearic acid or their mixtures.
5. A process for the manufacture of semi-aromatic thermoplastic (co)polyimide by polymerization of the salt composition as claimed in claim 1 .
6. A method of manufacturing a semi-aromatic thermoplastic (co)polyimide, comprising:
subjecting a salt composition as claimed in claim 1 to a melt polymerization or a solid-state polymerization.
7. A salt composition, comprising:
at least one ammonium carboxylate salt obtained from:
(a) at least one aromatic compound comprising 2 anhydride functional groups and/or its carboxylic acid and/or ester derivatives; and
(b) one or more aliphatic diamines in which said one or more aliphatic diamines are of formula (I) NH 2 —R—NH 2 with R being a saturated aliphatic divalent hydrocarbon radical, the two amine functional groups of which are separated by 4 to 6 carbon atoms and 1 or 2 hydrogen atoms of the divalent radical of which are replaced by 1 or 2 methyl and/or ethyl groups; and wherein the one or more aliphatic diamines optionally further comprises at least one diamine of formula (II) NH 2 —R′—NH 2 with R′ being a saturated or unsaturated and aliphatic, cycloaliphatic or arylaliphatic divalent hydrocarbon radical, which optionally comprises heteroatoms; and
at least one chain-limiting compound chosen from a salt of monoamines, monoacids or diacids in the α,β positions such that they can form an anhydride functional group by a dehydration reaction, wherein the at least one chain-limiting compound is added during the formation of the at least one ammonium carboxylate salt.