Method for prolonging antibacterial persistence of polyolefin microfiltration membrane

Abstract

The invention belongs to the technical field of antibacterial polyolefin microfiltration membranes and in particular relates to a method for prolonging the antibacterial persistence of a polyolefin microfiltration membrane. A cast membrane solution comprises the following raw materials in parts by weight: 36-42 parts of polyolefin material, 6-10 parts of 4,4'-biphenol p-phthalonitrile resin, 16-20parts of bisphenol A type phthalonitrile resin containing ether nitrile chain segments, 4-8 parts of silicon carbide powder, 1-2 parts of tribasic lead sulfate and 4-6 parts of nitrated chitosan antibacterial agent. Due to the preparation of the nitrated chitosan antibacterial agent, composite particles with stronger antibacterial property are obtained, the composite particles are uniformly dispersed in a membrane layer so as to have better antibacterial permanence, the permeability is kept not to be reduced on the basis that the strength is improved and the thickness of a film is reduced, the composite particles still have better hydrophility after being sufficiently dried for 96 h in a 50-DEG C drying oven, and meanwhile, the antibacterial effect can reach 90-100% of that before dryingtreatment, and therefore, the antibacterial property is persistent.

Description

Technical field [0001] The invention belongs to the technical field of antibacterial polyolefin microfiltration membranes, and specifically relates to a method for prolonging the antibacterial durability of a polyolefin microfiltration membrane. Background technique [0002] Ultrafiltration membranes and microfiltration membranes account for 50-60% of the entire membrane market in the United States, Japan, and Europe. They are widely used in the separation and refining of chemical processes, wastewater purification treatment and recovery of useful components, zero discharge of industrial wastewater, seawater desalination and other fields , The filter membrane mainly uses polysulfone (PS), polyacrylonitrile (PAN), polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC) and other polymer materials that can be dissolved in polar solvents Prepared by solution phase separation method. Currently, the most widely used materials in the field of polymer materials ...

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Problems solved by technology

[0002] Ultrafiltration membranes and microfiltration membranes account for 50-60% of the entire membrane market share in the United States, Japan, and Europe, and are widely used in the separation and refinement of chemical processes, wastewater purification and recovery of useful components, zero discharge of industrial wastewater, seawater desalination, etc. The filter membrane is mainly made of polysulfone (PS), polyacrylonitrile (PAN), polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC) and other polymer materials that can be dissolved in polar solvents Prepared by solution phase separation, the most widely used materials in the field of polymer materials are polyolefin materials such as polyethylene (PE) and polypropylene (PP). Compared with polysulfone and polyvinylidene fluoride materials, their material costs are lower. It is cheaper and the source is more extensive, but because there is no suitable solvent to dissolve these resins at room temperature, the application of polyolefin materials in membrane filtration is limited. Microfiltration membranes have large porosity, many micropores, and large surface area. It is adhered by microorganisms in water, then colonizes and multiplies, forms colonies and then develops into a microbial film, thereby blocking the membrane pores and affecting the separation performance of the membrane. Therefore, if the microorganisms can just adhere to the surface of the microfiltration membrane, the Microbial killing can effectively reduce the harm of microbial contamination to the membrane and maintain membrane performance. Since polyolefin materials themselves have no antibacterial effect, it is necessary to add antibacterial agents to ordinary polyolefin materials to inhibit the growth of microorganisms on the surface of polyolefin. Among them, Organic antibacterial agents have a good killing effect on bacteria, fungi, and algae, but most organic antibacterial agents are soluble in organic solvents, and some are also soluble in water. If the antibacterial agent is lost with water or solvent, it is difficult to maintain the antibacterial effect , since the polyolefin microfiltration membrane production method adopts the thermally induced phase separation method, the casting liquid needs to be prepared during the processing, which is very different from the preparation method of ordinary polyolefin material products, and the microfiltration membrane has been used for a long time during use. Water flow impact, so the antibacterial efficacy of the antibacterial component compounded in the microfiltration membrane, the compounding performance with the casting solution, the toxicity of the antibacterial agent, and the antibacterial persistence of the antibacterial membrane must be considered