Film making liquid for polyvinyl chloride hydrophilicity alloy separating film and preparing method thereof

Abstract

The invention discloses a membrane casting solution for PVC hydrophilic alloy separation membrane and a preparation method thereof. PVC, PVB and maleic anhydride are blended, a pore-forming agent is added dissolved and form pores. The PVC hydrophilic alloy separation membrane prepared by the membrane casting solution of the invention has the advantages of good hydrophilic property, good compatibility, high mechanical property, large water flux, strong contamination resistant ability, long service life and low application cost.

Description

technical field [0001] The invention relates to a membrane-making solution for a polyvinyl chloride hydrophilic alloy separation membrane and a preparation method thereof. Background technique [0002] Due to the characteristics of energy saving, environmental protection and simple operation of membrane separation technology, this industry has developed rapidly, and its application scope has been extended to biology, medicine, environmental protection, energy, municipal water treatment, wastewater treatment and other fields. Due to the large filtration area per unit volume of the separation membrane, the equipment manufacturing cost is low, and cross-flow filtration can be realized, which greatly prolongs the service life of the filter element. However, the currently commercialized ultrafiltration membrane products generally use polysulfone (PS), polybias Materials such as ethylene dichloride (PVDF), polyaldehyde sulfone (PES), and polyacrylonitrile (PAN) cannot be widely us...

AI Technical Summary

Problems solved by technology

Due to the large filtration area per unit volume of the separation membrane, the equipment manufacturing cost is low, and cross-flow filtration can be realized, which greatly prolongs the service life of the filter element. However, the currently commercialized ultrafiltration membrane products generally use polysulfone (PS), polybias Materials such as ethylene dichloride (PVDF), polyaldehyde sulfone (PES), and polyacrylonitrile (PAN) cannot be widely used due to their low cost performance

[0003] Polyvinyl chloride has high physical properties, and is resistant to microbial erosion, acid and alkali resistance, good chemical stability, and has a wide range of sources, complete varieties, and low prices, so it has been valued by research units. However, due to the hydrophilicity of polyvinyl chloride itself Not good, it makes the permeability of the PVC hydrophilic alloy separation membrane poor, and it is easier to be polluted, so that the filtration capacity drops rapidly

In order to manufacture a liquid separation membrane of polyvinyl chloride with excellent performance, efforts must be made to improve its hydrophilic property after film formation. The methods that can be adopted are: ① Copolymerization modification, that is, introducing other polyvinyl chloride into the vinyl chloride chain segment by copolymerization. Chemical substances with hydrophilic groups; ②Plasma surface modification, which is to treat polyvinyl chloride powder or polyvinyl chloride film with plasma, so that chlorine-containing hydrophilic groups are generated on the surface of polyvinyl chloride powder or polyethylene film; ③surface Grafting modification, surface grafting is a kind of chemical modification of the filter membrane. Through high-energy radiation methods such as Y-rays and electron beams, the polyvinyl chloride molecular chain generates free radicals, and then introduces them on the membrane surface through graft polymerization. The required hydrophilic groups, the above three methods can improve the hydrophilicity of the polyvinyl chloride hydrophilic alloy separation membrane, but industrial production is difficult and the cost is high