Polyetherimide with improved color, and methods of manufacture thereof
A method of preparing a polyetherimide and an improved polyetherimide are disclosed. Low color polyetherimides are disclosed along with process improvements which produce the reduced color of the final product polymers.
1. A method for the manufacture of a polyetherimide, the method comprising
reacting a halophthalic anhydride having the formula
with an organic diamine having the formula
H 2 N—R—NH 2
at a temperature of 130 to 160° C. to form a bis(halophthalimide) having the formula
and
contacting the bis(halophthalimide) with an alkali metal salt of a dihydroxy aromatic compound having the formula
MO-Z-OM
to form the polyetherimide comprising structural units having the formula
wherein in the foregoing formulae
X is fluoro, chloro, bromo, iodo, or a combination thereof;
wherein each R is independently the same or different, and is a substituted or unsubstituted C 6-20 aromatic hydrocarbon group, a substituted or unsubstituted straight or branched chain C 2-20 alkylene group, a substituted or unsubstituted C 3-8 cycloalkylene group, or a combination thereof;
M is an alkali metal;
Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof; and
n is an integer greater than 1;
wherein the polyetherimide has a Yellowness Index of less than 85, wherein the halophthalic anhydride contains less than 0.02% of residual halophthalide.
2. The method of claim 1 , wherein the composition comprising the bis(halophthalimide) comprises less than 0.02% of halophthalide.
3. The method of claim 1 , further comprising combining the halophthalic anhydride with the organic diamine at a temperature of 18° C. to 25° C. to provide a reaction mixture;
degassing the solution with an inert gas; and
heating the solution to a temperature of 130 to 160° C.
4. The method of claim 1 , wherein less than 0.75% of hexaethyl guanidinium chloride is added to the bis(halopthalimide) after it is formed.
5. The method of claim 4 , wherein hexaethylguanidinium chloride is in contact with the bis(halophthalimide) for less than 60 minutes at 180° C., before the polymerization starts; or
less than 180 minutes when reacting the halophthalic anhydride with the diorganic amine at temperature of less than 170° C.; or
less than 20 hours when reacting the halophthalic anhydride with the diorganic amine at temperature of 130° C. to 160° C.
6. The method of claim 1 , wherein the molar ratio of the halophthalic anhydride to the organic diamine is 2:1 to 2.04:1.
7. A method for the manufacture of a polyetherimide, the method comprising
contacting a halophthalic anhydride having the formula
and which contains less than 0.02% of residual halophthalide; with an organic diamine having the formula
H 2 N—R—NH 2
to provide an imidization composition comprising the halophthalic anhydride and the organic diamine, the imidization composition comprising less than 0.75% of hexaethyl guanidinium chloride and less than 0.02% of residual halophthalide;
reacting the imidization composition to form a bis(halophthalimide) having the formula
and
contacting the bis(halophthalimide) with an alkali metal salt of a dihydroxy aromatic compound having the formula
MO-Z-OM
to form the polyetherimide comprising the structural units having the formula
wherein in the foregoing formulae
X is fluoro, chloro, bromo, iodo, or a combination thereof;
each R is independently the same or different, and is a substituted or unsubstituted C 6-20 aromatic hydrocarbon group, a substituted or unsubstituted straight or branched chain C 2-20 alkylene group, a substituted or unsubstituted C 3-8 cycloalkylene group, or a combination thereof;
M is an alkali metal;
Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof; and
n is an integer greater than 1;
wherein the polyetherimide has a Yellowness Index of less than 85.
8. The method of claim 7 , comprising reacting the halophthalic anhydride with the organic diamine at a temperature of less than 170° C.
9. The method of claim 7 , wherein the molar ratio of the halophthalic anhydride to the organic diamine is 2:1 to 2.04:1.
10. The method of claim 7 , wherein less than 0.75% of hexaethyl guanidinium chloride is added to the bis(halopthalimide) after it is formed.
11. The method of claim 10 , wherein hexaethylguanidinium chloride is in contact with the bis(halophthalimide) for less than 60 minutes at 180° C., before the polymerization starts; or
less than 180 minutes when reacting the halophthalic anhydride with the diorganic amine at temperature of less than 170° C.; or
less than 20 hours when reacting the halophthalic anhydride with the diorganic amine at temperature of 130° C. to 160° C.
12. A method for the manufacture of a polyetherimide composition, the method comprising
contacting a halophthalic anhydride having the formula
with an organic diamine having the formula
H 2 N—R—NH 2
at a temperature of 130 to 160° C. to form a bis(halophthalimide) having the formula
wherein the molar ratio of the halophthalic anhydride relative to the organic diamine is 2:1 to 2.02:1; and
contacting the bis(halophthalimide) with an alkali metal salt of a dihydroxy aromatic compound having the formula
MO-Z-OM
to form the polyetherimide comprising the structural units having the formula
wherein in the foregoing formulae
X is fluoro, chloro, bromo, iodo, or a combination thereof;
each R is independently the same or different, and is a substituted or unsubstituted C 6 -20 aromatic hydrocarbon group, a substituted or unsubstituted straight or branched chain C 2-20 alkylene group, a substituted or unsubstituted C 3-8 cycloalkylene group, or a combination thereof;
M is an alkali metal;
Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof; and
n is an integer greater than 1;
wherein the polyetherimide has a Yellowness Index of less than 85, wherein the halophthalic anhydride contains less than 0.02% of residual halophthalide.