Back to results
US 7,935,779 B2Granted
Synthesis of polyimides (PI) from poly-carbodiimides and dianhydrides by sequential self-repetitive reaction (SSRR)
AssigneeGreat Eastern Resins Industrial Co., Ltd.
InventorsShenghong A. Dai, Jiang-Jen Lin, Kuan-Liang Wei
Life of this patent
Estimating the term…
Abstract
Disclosed are processes for synthesizing polyimides by a sequential self-repetitive reaction between poly (aryl carbodiimide) (p-CDI) or aryl diisocyanates with dianhydrides.
Claims18
A process for synthesizing a polyimide having the formula
- comprising:
- a) reacting a dianhydride having the formula
- with R2—OH in a molar ratio of about 1:1 to form an acid-ester functionalized anhydride having the formula
- b) reacting a poly (aryl carbodiimide) (p-CDI) and said acid-ester functionalized anhydride to form a poly-acylurea-functionalized ester-anhydride (p-AEA) having the formula
- c) reacting said p-AEA with R2—OH in a molar ratio of about 1:1 to form a poly-acylurea-functionalized ester-acid-ester (p-AEAE) having the formula
- d) heating said p-AEAE in the presence of a CDI catalyst to a temperature from about 120° C. to about 280° C. to form an aryl isocyanate and a poly(acid-ester-amide) having the following formula
- and simultaneously conducting a sequential self-repetitive reaction to form said polyimide, wherein said sequential self-repetitive reaction involves repetitions of three sequential steps comprising:
- 1) catalytically converting said aryl isocyanate into said p-CDI in the presence of said CDI catalyst;
- 2) reacting said p-CDI and said poly(acid-ester-amide) to form a poly-acylurea-functionalized amide-ester (p-AAE) having the formula
- 3) thermolyzing said p-AAE obtained in step 2) into said aryl isocyanate and a poly-di(ester-amide) having the formula
- said poly-di(ester-amide) further being subject to a ring-closure reaction to release R2OHs and form said polyimide as a product
- wherein, in the formulas above:
- n is an integer in the range of 1 to 100;
- R is a tetravalent aromatic organic radical containing at least one benzene ring or a tetravalent aliphatic organic radical containing at least two carbon atoms;
- and,
- R2 is C1-8 alkyl.
13 more elements
A process for synthesizing a polyimide having the structural formula
- comprising:
- a) reacting a dianhydride having the formula
- with R2—OH in a molar ratio of about 1:2 to form a di(ester-acid) having the formula
- b) heating said di(ester-acid) and a p-CDI (poly (aryl carbodiimide)) to a temperature from about 120° C. to about 280° C. to form an aryl isocyanate and a poly(acid-ester-amide) and simultaneously to conduct a sequential self-repetitive reaction, wherein said sequential self-repetitive reaction involves repetitions of three sequential steps comprising:
- 1) catalytically converting said aryl isocyanate into said p-CDI in the presence of a CDI catalyst;
- 2) reacting said p-CDI and said poly(acid-ester-amide) to form a poly-acylurea-functionalized amide-ester (p-AAE) having the formula
- 3) thermolyzing said p-AAE obtained in step 2) into said aryl isocyanate and a poly-di (ester-amide) having the formula
- said poly-di(ester-amide) further being subject to a ring-closure reaction to release R2OHs and form said polyimide as a product
- wherein, in the formulas above:
- n is an integer in the range of 1 to 100;
- R is a tetravalent aromatic organic radical containing at least one benzene ring or a tetravalent aliphatic organic radical containing at least two carbon atoms;
- and, R2 is C1-8 alkyl.
9 more elements
Dependencies are inferred from the claim text.