1107-00-2Relevant articles and documents
A new synthetic route of 4,4′-hexafluoroisopropylidene-2, 2-bis-(phthalic acid anhydride) and characterization of 4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic acid anhydride)-containing polyimides
Zhu, Shi-Zheng,Zhao, Jing-Wei,Zhang, Yun-Xiang
, p. 221 - 225 (2003)
The title product 4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic acid anhydride) was prepared from hexafluoroacetone and o-xylene as the starting materials by condensation, oxidation and dehydration three-step reaction sequence. It reacted with diamines in DMF or xylene to give polyimides by condensation polymerization. Thermal and viscosity analyses show that these polyimides have lower molecular weight but excellent thermal stability.
Method for preparing polyimide monomer having low yellow index
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Paragraph 0041; 0080-0081, (2021/11/02)
The present invention chemically synthesizes a polyimide monomer. 10. The synthesized polyimide monomer is introduced into the loading area of the sublimation purification apparatus. - 3 TTTorr under vacuum above sublimation temperature of the synthesized polyimide monomer, followed by recrystallization. Provided is a method for preparing a polyimide monomer having improved yellowness index.
Synthesis method of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride
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Paragraph 0009; 0011; 0013-0014, (2020/09/09)
The invention belongs to the technical field of synthesis of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride, in particular to a synthesis method of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride. The synthesis method has the advantages of easy separation of intermediate products, high yield, less waste and good economic benefit, and a mixed solvent of isobutanol and butyl acetate is adoptedto reduce the solubility of the product, facilitate the separation of the product and increase the yield. Besides, the Pd/C catalyst is pretreated, a proper amount of sulfide is added for pretreatment, the sulfur poisoning resistance of the catalyst is improved, the service life of the catalyst is prolonged, and the application frequency of the catalyst is increased; because nitro compounds contain trace amount of sulfides such as sulfuric acid and like, catalyst is easily poisoned. In the step 2, an alumina-silica gel catalyst is added so that 2, 2-bis (3-amino-4-hydroxyphenyl) molecules canbe adsorbed on the surface of the catalyst in a flat shape, hydroxyl is closer to the surface of the catalyst, and the amination reaction of hydroxyl is facilitated; in the step 4, a small amount of urea is added in the cyanolysis reaction to prevent diazonium salt from being oxidized, becoming tar and other side reactions.