Method for preparing modified polyvinylidene fluoride one-step grafted sulfobetaine (SBMA) proton exchange membrane
The invention relates to a method for preparing a modified polyvinylidene fluoride one-step grafted sulfobetaine (SBMA) proton exchange membrane, which belongs to the field of fuel cell electrolyte membrane materials. The method provided by the invention comprises the following steps: firstly dissolving polyvinylidene fluoride in dimethyl sulfoxide in a nitrogen atmosphere, heating and stirring to fully dissolve the polyvinylidene fluoride, adding a quaternary ammonium base alcohol solution, reacting for a period of time, and heating to volatilize the unreacted quaternary ammonium base and related fluoride products to obtain a modified polyvinylidene fluoride solution; meanwhile, adding a certain amount of sulfobetaine (SBMA) monomers and an initiator in the solution, heating and reacting in the nitrogen atmosphere, cooling and paving the solution on a glass plate, and vacuum drying the solution to a membrane to obtain the modified polyvinylidene fluoride grafted sulfobetaine proton exchange membrane. The modified polyvinylidene fluoride grafted sulfobetaine proton exchange membrane prepared by the method provided by the invention has good size stability and small methanol permeability, and the synthesis steps are simplified, so that the modified polyvinylidene fluoride grafted sulfobetaine proton exchange membrane is convenient for industrial production. 1. A modified polyvinylidene fluoride one-step grafting sulfonic acid betaine proton exchange membrane preparation method, characterized in that the specific preparation method is as follows : (1) measure a quality pvdf for in dimethyl sulfoxide, wherein each gram of pvdf need to dimethyl sulfoxide 15-20mL, in the oil bath boiler and is heated 60-80 the stirring under [...] 0.5-1h, A get transparent solution ; (2) according to the solution with A 2.77mol/L the quaternary ammonium alkali is mellow solution volume ratio of 50 : 0.3-1.2 the quaternary ammonium alkali is mellow a certain amount of volume of the solution in the solution is slowly added A, B make the solution, in an atmosphere of nitrogen at the same time the 30-40 magnetic stirring [...] 1-2h, to obtain solution C ; (3) according to the PVDF powder, sulfonic acid betaine (SBMA), benzoyl peroxide each ingredient parts by mass proportion is 88-68 parts, 10-30 parts, 2 parts, weighing sulfonic acid betaine (SBMA) in C dissolved in solution, the heating and stirring to dissolve the same, then adding initiator benzoyl peroxide, in the nitrogen atmosphere heating oil bath the 80-90 [...] , reaction 24h the rear, the spreading the solution on the glass plate, 90-100 the vacuum drying [...] 8h, to obtain the modified polyvinylidene fluoride one-step grafting sulfonic acid betaine proton exchange membrane. 2. A modified polyvinylidene fluoride one-step grafting sulfonic acid betaine proton exchange membrane preparation method according to Claim 1, characterized in that the step (1) comprising a quaternary ammonium hydroxide, tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide. 3. A modified polyvinylidene fluoride one-step grafting sulfonic acid betaine proton exchange membrane preparation method according to Claim 1, characterized in that the step (2) of the quaternary ammonium hydroxide in solution in the concentration of the B 0.016-0.065mol/L.