- Highly hydrophobic metal-organic framework for self-protecting gate dielectrics
-
A hydrophobic metal-organic framework (MOF) showing high-κ behaviour was synthesized by the reaction of copper ions with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (HFDPA). The unique, highly hydrophobic nature of the material protects it from re-adsorbing water, even in a high humidity environment. The dielectric constant of the MOF showed an unprecedented increasing trend, reaching up to κ ≈ 99 at 300 K and 1 kHz after the complete removal of guest and coordinated water molecules. The unusual dielectric behaviour of the compound along with its water resistant properties is the first report of such behaviour and it paves the way for the development of moisture-stable microelectronic devices.
- Chen, Jenq-Wei,Chiang, Ming-Hsi,Chiou, Kuan-Ru,Inamdar, Arif I.,Kamal, Saqib,Liu, Yen-Hsiang,Lu, Kuang-Lieh,Mendiratta, Shruti,Pathak, Abhishek,Tsai, Pei-Hsien,Usman, Muhammad
-
-
Read Online
- Method for synthesizing 4, 4'-(perfluoropropane-2, 2-diyl) diphthalic acid
-
The invention provides a method for synthesizing 4, 4'-(perfluoropropane-2, 2-diyl) diphthalic acid, which is characterized in that 4, 4'-(perfluoropropane-2, 2-diyl) bis(1, 2-dimethylbenzene) is used as a raw material, oxygen is used as an oxidant, a catalytic amount of bromide is used as an initiator, and the 4, 4'-(perfluoropropane-2, 2-diyl) diphthalic acid is synthesized by adopting a photocatalytic oxygen oxidation method through reaction at normal temperature and normal pressure. According to the method for synthesizing the 4, 4'-(perfluoropropane-2, 2-diyl)diphthalic acid, no transition metal participates in the method, the reaction condition is mild, the reaction yield is high and is larger than 90%, the purity of the obtained product is high and is larger than 99.0%, and potential commercial value is achieved.
- -
-
Paragraph 0023-0030
(2021/06/23)
-
- Preparation method of hexafluorodianhydride
-
The invention relates to the field of preparation of fluorine-containing monomers, and particularly discloses a preparation method of hexafluorodianhydride. The preparation method comprises the following steps: S1, preparation of hexafluorotetracid according to the following reaction process flow: step (1), with o-dichlorobenzyl and hexafluoroacetone used as raw materials, adding a catalyst, and performing stirring reflux at 130-150 DEG C for 20-40 h to obtain a product a; step (2), hydrolyzing the product a into a product b under an alkaline condition; step (3), oxidizing a hydroxyl group into an aldehyde group to obtain a product c; and step (4), oxidizing the aldehyde group into a carboxyl group to obtain hexafluorotetracid; and S2, preparation of hexafluorodianhydride according to the reaction process flow that hexafluorotetracid is dehydrated and anhydridized to prepare hexafluorodianhydride. Compared with the prior art, the preparation method provided by the invention has the advantages that reaction conditions in the whole process are mild, the use of a potassium permanganate strong oxidant is avoided in a route, requirements on a reaction container are lower, and reaction safety is higher.
- -
-
-
- Preparation method of 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride
-
The invention discloses a preparation method of 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride. The method comprises the following steps of (a) accurately weighing N-alkyl phthalimide and a catalyst, stirring and raising the temperature to 90-110 DEG C, and dissolving; slowly dropwise adding hexafluoroacetone hydrate, raising the temperature to 100 to 130 DEG C, reacting for 22 to 80 hourswhile stirring, and discharging to obtain 4, 4-(hexafluoroisopropyl) bis (N-alkyl phthalimide); (b) adding alkali to hydrolyze, and acidifying to obtain hexafluorotetracid; and (c) dehydrating to obtain the 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride. According to the preparation method, the hexafluoroacetone and specific N-alkyl phthalimide directly react under the action of a specific catalyst to prepare hexafluorodianhydride, the step of oxidizing methyl in a traditional method is omitted, the use of metal oxides is avoided, the environmental pollution is small, a normal-pressure reaction is adopted, a high-pressure reaction is not needed, the reaction risk is reduced, the purity of the prepared 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride is high, and the yield reaches 87% or above.
- -
-
Paragraph 0022
(2020/04/17)
-
- Synthesis method of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride
-
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.
- -
-
-
- Synthesis process of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride
-
The invention belongs to the technical field of synthesis of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride, in particular to a synthesis process of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride. The synthesis process has the advantages of easy separation of intermediate products, high yield, less waste and good economic benefit, adopts a mixed solvent of long-chain alcohol and ester, reduces the solubility of the product, is beneficial to product separation, and has higher yield. Besides, the Pd/C catalyst is pretreated, a proper amount of sulfide is added for pretreatment, the sulfurpoisoning 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 can be 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 addedin the cyanolysis reaction to prevent diazonium salt from being oxidized, becoming tar and other side reactions.
- -
-
-
- Preparation process of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride
-
The invention belongs to the technical field of synthesis of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride, in particular to a preparation process of 4, 4-(hexafluoroisopropenyl) diphthalic anhydride. The preparation process has the advantages of easy separation of intermediate products, high yield, fewer wastes and favorable economic benefit, and adopts a mixed solvent of amyl alcohol and butyl acetate to lower the solubility of the product, thereby being beneficial to product separation and higher 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 can be 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.
- -
-
Paragraph 0013-0014
(2020/09/09)
-
- Method for preparing hexafluorodianhydride under mild condition
-
The invention discloses a method for preparing hexafluorodianhydride under a mild condition. The method comprises the steps of: a) preparing hexafluoro-orthophenyl tetranitrile: dissolving phthalic nitrile in hexafluoroacetone trihydrate, adding a catalyst, introducing nitrogen for shielding, and performing reflux for 50-70 h under a stirring condition at 150-160 DEG C, b) hydrolyzing hexafluoro-orthophenyl tetranitrile to generate hexafluoro-tetracid: adding alkali, water and methanol into pure hexafluoro-orthophenyl tetranitrile obtained in the step a), and performing reflux for 30-50 h at 100-120 DEG C, and c) adding methylbenzene and acetic anhydride into hexafluoro-tetracid obtained in the step b) and performing reflux for 8-12 h at 110-130 DEG C. According to the method, liquid hexafluoroacetone trihydrate is used in the step a); the toxicity and operation difficulty are reduced; in addition, strong corrosion and high risk anhydrous hydrofluoric acid is not used; requirements onequipment and recovery are low; the method is more environmentally friendly; hydrolysis and acidification treatment are used in the step b); a strong oxidation compound is not used; and the productionoperation requirements are low.
- -
-
-
- PROCESS FOR MAKING 2,2-BIS (3,4-DICARBOXYPHENYL) HEXAFLUOROPROPANE
-
There is provided a continuous process for making 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane. The process has the following steps: a) continuously feeding 2,2-bis(3,4-dimethylphenyl)hexafluoropropane and aqueous nitric acid into a reactor cell and b) heating the mixture to a temperature sufficient to effect reaction between the 2,2-bis(3,4-dimethylphenyl)hexafluoropropane and the nitric acid.
- -
-
Page/Page column 2
(2009/07/03)
-
- 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
-
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.
- Zhu, Shi-Zheng,Zhao, Jing-Wei,Zhang, Yun-Xiang
-
p. 221 - 225
(2007/10/03)
-