4,4'-Diaminodicyclohexyl Methane CAS 1761-71-3 PACM

Disperse 1 g of titanium dioxide powder in a mixed solution of 40 mL of water and methanol (the volume ratio of water and methanol is 9:1), stir evenly and add 60 μmol/ml of RuCl3 x H2O dark brown aqueous solution, and control the amount so that the amount of ruthenium on the titanium dioxide The loading was 5 wt%. Seal and stir at room temperature for 3 hours, then dropwise add 1M sodium hydroxide solution to pH 10.5, continue to seal and stir for 20 hours, centrifuge and wash with a mixture of water and ethanol for 3-5 times, then vacuum dry at 60°C overnight to obtain a light green powder. catalyst.

The freshly prepared catalyst is placed in a reactor, a certain volume of solvent is added, and an appropriate amount of 4,4′-diaminodiphenylmethane (MDA) is added to control the molar ratio of ruthenium in MDA and catalyst 4 to be 10000. Close the reaction kettle and flush the reaction kettle with hydrogen for 10 times, then raise the temperature to 150°C to start the reaction, control the molar ratio of hydrogen to MDA not less than 80, and the hydrogen pressure at 1-5 MPa, and take real-time samples to detect the reaction product and conversion rate. The benzene ring in MDA can be rapidly hydrogenated to produce a single benzene ring hydrogenation product (+6H) and a double benzene ring hydrogenation product 4,4′-diaminodicyclohexylmethane (+12H) without deamination products It is worth mentioning that 4,4′-diaminodicyclohexylmethane is a raw material compound for special nylon.

In a 2L autoclave with a built-in filter, add 5gRh/Al2O3catalyst, add 500gMDA raw material and 500gTHF and 15gMDA oligomer at the same time, use 1MPa (absolute pressure) after N2 Replace three times, and then use 1MPa (absolute pressure) Pressure) H2 replacement three times, then H2 supplement pressure to 4.5-5.0MPa (absolute pressure). The CO concentration in the H2 cylinder used is 10ppm. Raise the temperature to 190°C, and continuously feed H2 into the reactor through the hydrogen flow controller during the reaction to ensure that the reaction pressure is maintained at 6MPa (absolute pressure). Stop feeding H2, when the pressure drop of the reactor is less than 0.01MPa/min, stop the reaction, and lower the temperature and release the pressure of the reactor. When the temperature of the reactor drops to 50°C, use N2 not exceeding 0.6MPa (absolute pressure) to filter and separate the product liquid from the catalyst through the built-in filter, and conduct gas chromatography analysis on the product liquid. After the product liquid is filtered clean, continue to add 500g of MDA raw materials, 500g of tetrahydrofuran and 15g of MDA oligomers, repeat the above steps, and carry out recycling of the catalyst.

Add 15kgMDA and 45kg dioxane to an autoclave with a volume of 200L, then add 450g5%Ru/Al2O3 catalyst and 300g potassium metaaluminate, replace the air in the autoclave with hydrogen after sealing, and then feed 8MPa hydrogen into the autoclave. The temperature was raised to 160° C., the hydrogen valve was adjusted to maintain the pressure in the autoclave at 10 MPa, and the reaction was vigorously stirred for 4 hours. Sampling after cooling is detected by gas chromatography-mass spectrometry, and the detection result is that the conversion rate of MDA is 100%, and the PACM yield is 98.8%, and the content sum of by-product 4-amino-dicyclohexylmethane and dicyclohexylmethane is 0.26%.