Study On Preparation And Performance Of PVC/PVA Blend Ultrafiltration Membrane

Polyvinyl chloride(PVC) has a wealth of production, relatively inexpensive, good physical and chemical properties, it is widely used in areas such as ultrafiltration; but because of its poor hydrophilicity and film- forming, therefore in the application is greatly restricted. In this paper, against the problem of PVC membrane in the application process, use hydrophilic polymer- polyvinyl alcohol(PVA) to improve the hydrophilic membrane of material PVC, and study the PVC / PVA common mix compatibility, preparation and properties of the blend ultrafiltration membrane system.In this paper, polyvinyl chloride(PVC) as membrane material, polyethylene glycol(PEG) and polyvinylpyrrolidone(PVP) as additive, N, N- Dimethylacetamide( DMAC) as solvent, With phase catalysis of PVC/PVA blend was prepared by ultrafiltration membrane, mainly study the compatibility of polymer, polymer concentration, blending ratio and the influence of types of additive on the membrane performance. Experiment firstly using the theory of solubility parameter prediction and cosolvent method, viscosity method to investigate the compatibility of PVC /PVA and its change rule, and then through the different polymer blending ratio, polymer concentration, additives PVC/PVA blend was discussed the structure and properties of ultrafiltration membrane. Finally the best process conditions were determined as follows: polymer concentration was 12%, the optimum blending ratio of PVC/PVA at 9/1, additive content is 3%.The experimental results show that the suitable blending ratio, polymer concentration, join the right amount of additives, can be prepared with good performance of PVC/PVA blend ultrafiltration membrane. First determine through the experiment of PVC and PVA for part of compatible system, the higher temperature, the more homogeneous casting solution, namely the compatibility, the better, and do with 10-channel DMAC solvent blend membranes performance better than DMF; Then determined in the preparation of PVC/PVA blend membrane concentration of casting solution with 12%, polymer blending ratio of 9:1, can be made into good porous membrane water flux and entrapment rate, water flux is 247.1L/m2·h, withholding rate is 82.5%; With the PVA content increased from 0 to 40%, water contact Angle from 76° fall to 41°, account obviously improve the hydrophilic membranes; under SEM see add PVA membrane structure changed, membrane layer thickness increases, the pore size is bigger; Join different additives found that the PVP-k90 and PEG-3500 with better water flux, found that using the additive PVP do intercept rate is better than do additives with PEG; Join the PVA to improve the comprehensive mechanical properties of the membrane.