High-throughput polyamide reverse osmosis composite membrane

[0041] Examples 1-8

[0042] Dissolved in N,N-dimethylformamide with 13.5wt% Udel PS3500 polysulfone, 0.2wt% water and 0.1wt% nonylphenol polyoxyethyl ester phosphate, applied to polyester nonwoven , and then immersed in water to remove the solvent to obtain a porous support membrane with a molecular weight cut-off of 100,000-120,000, which is stored in a wet state for later use.

[0043] The wet polysulfone porous support membrane is immersed on one side into an aromatic polyamine (m-phenylenediamine, or 4-chloro-m-phenylenediamine, or 4-nitro-m-phenylenediamine, or 2,4-diphenylene diamine, respectively). Aminotoluene) and aliphatic macromolecular polyamine polyvinylamine (molecular weight = 30,000; degree of aminolysis a = 0.52) in an aqueous solution with a total content of 2.0 wt% for 4 minutes, use a rubber roller to roll the support film surface, and drain the aqueous solution After drying the surface of the support film with nitrogen, it is unilaterally contacted with a 0.08 wt% solution of trimesoyl chloride (TMC) in n-heptane to perform interfacial polymerization for 30 to 40 seconds. The obtained ecological composite film was dried in the air for 2 minutes, and then subjected to two-step heat treatment: the first step was to treat at 50-60°C for 5 minutes, and the second step was to treat at 80-100°C for 8 minutes. Then two-step rinsing is performed: the first step is rinsing in 15wt% methanol aqueous solution at 40-50°C for 40 minutes, and the second step is rinsing in water at 40-50°C for 30 minutes. The prepared reverse osmosis composite membrane was tested with a 1000 mg/l sodium chloride aqueous solution under the conditions of an operating pressure of 225 psi, a temperature of 20 °C, and a pH of 6.8. These examples are to investigate the effect of adding aliphatic macromolecular polyamine polyvinylamine on the properties of films formed from different aromatic polyamines.

[0044] Example

[0045] The above examples show that: adding aliphatic macromolecular polyamine polyvinylamine to the aqueous solution containing different aromatic polyamines can significantly improve the performance of polyamines made from different aromatic polyamines on the premise of keeping the membrane rejection rate almost unchanged. The flux of the reverse osmosis composite membrane.

[0046] Examples 9-14

[0047] As in the previous example, according to the above method, an aqueous solution with a total content of m-phenylenediamine and polyvinylamine (molecular weight = 30,000; degree of aminolysis a = 0.52) with a total content of 2.4 wt %, and 0.05 wt % of an aromatic polybasic acid chloride ( The n-heptane solution of trimesoyl chloride (TMC), or 5-isocyanate-isophthaloyl chloride (ICIC), or 5-oxocarbonyl chloride-isophthaloyl chloride (CFIC) was used to prepare reverse osmosis composite membrane. These examples are to investigate the effect of adding aliphatic macromolecular polyamine polyvinylamine on the film-forming properties of different polybasic acid chlorides.

[0048]

[0049] The above example shows that: adding aliphatic macromolecular polyamine polyvinylamine to the aqueous phase solution of aromatic polyamine can significantly improve the reverse osmosis composite formed by different polybasic acid chlorides on the premise of keeping the membrane desalination rate almost unchanged. membrane flux.

[0050] Examples 15-21

[0051] As in the previous example, according to the above method, the total content of m-phenylenediamine and polyvinylamine (molecular weight = 30,000; degree of aminolysis a = 0.52) is 1.2 wt%, and different weight ratios of m-phenylenediamine and polyvinylamine are used. Aqueous solution, and 0.12wt% trimesoyl chloride (TMC) in n-heptane to prepare reverse osmosis composite membrane. These examples are to investigate the influence of the weight ratio of aromatic polyamines and aliphatic macromolecular polyamines in the aqueous solution on the film-forming properties.

[0052] Example

[0053] The above example shows that high-flux reverse osmosis composite membrane can be obtained by adding aliphatic macromolecular polyamine polyvinylamine to the aqueous phase solution of aromatic polyamine, but the excessive content of polyvinylamine will lead to the decrease of membrane desalination rate.