CS242532B1 - Preparation method of hydrate miperseabille membranes on the base of polyvinilchloride - Google Patents

Abstract

The invention provides for the preparation of hydrate semipermeabilous membranes casting from solution polyvinyl chloride in the solvent mixer with water so that this solution is poured! let it become airborne and then, n is immersed in water where it gelatinizes and forming a semipermeable membrane. These membranes can be used for roiciltration, ultrrafiltration, dialysis, csmiosis and reverse osmosis. They excel excellent fuincial properties - selectivity and permeability - and, above all, considerable durability chemical-physical effects, high temperature, acids, alkalis and oxidizing agents. Therefore, it is advantageous used in whey membrane separation, milk, iroiztokov enzymes, horanonu, fruit juices, different types of waste leader, egg white and melange, gelatin and similar

Description

It is an object of the present invention to provide hydrated semipermeable membranes from polyvinyl chloride suitable for the practical implementation of multiple membrane processors such as microfiltration, ultrafiltration, dialysis, osmosis reverse osmosis. In this way it is possible to produce sernipermeable membranes with excellent fumigation properties, i.e. selectivity and permeability with high physicochemical resistance. The main advantage of their use in practice is the ability to clean them vigorously with solutions of acids, bases, and oxidizing agents, even at higher temperatures in practice without changing their functional properties.

Membrane separation processes have been used in the wider period of time in wider measuring instruments in practically all branches of industry. Their advantage is the course of separation without changing the temperature of the separated solution and energy saving. The most widespread of the membrane process micro-filtration, ultrafiltration, reverse oisimosis, electrodialysis and dialysis have been achieved. A semipermeable membrane is an essential part of any membrane device. This semipermeable membrane must have good functional properties, i.e. selectivity and permeability, mechanical properties as well as high chemical and physical resistance. Initially, mainly cell-ester ester membranes have been used which, although they have excellent functional and mechanical properties, but cannot be operated at temperatures above 35 ° C, and also their low chemical resistance, especially in alkaline environments, is relatively low. Therefore, in the subsequent reaction, increased attention is paid to membranes prepared from different polymers, which also have high chemical and physical resistance with excellent functional properties. The cross-linked, water-soluble polymers, hydrophilic-hydrophobic copolymers, polar monamers homopolymers, aromatic and heiterocyclic condensation polymers have been tested.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydrated semipermeable membrane from polyvinyl chloride. This membrane has a wide application mainly in ulfrafiltration and dialysis, the advantage being that it can be used at temperatures up to 60 ° C, at pH values of 1 to 13 even in the presence of oxidizing agents.

Polyvinyl chloride is a polymer readily available, manufactured in types suitable for use in the food industry.

These membranes are prepared by casting from a solution of polyvinyl chloride in dimethylformamide, N-methylpyrrolidone, or another water-soluble solvent. This solution is prepared by dissolving poly (vinyl chloride) at an elevated temperature under reflux. During casting, it is sandwiched to a height of 0.1 to 0.5 mm, allowed to stand for 3 to 5 minutes in air, and immersed in water to form a semi-permeable hydrated membrane. The entire casting can advantageously be carried out on the surface of a rotating stainless steel cylinder partially immersed in water.

The membranes produced by the method described are widely applicable in the ultrafiltration of milk and whey, blood of slaughter animals, fruit juices, enzyme solutions, sugar extracts, gelatin solution, egg white and melange. Outside the food industry, they can advantageously be used in the recovery of latex from waste lines in the regeneration of rinse water from electrophoretic coating of lacquers, regeneration of abrasive emulsions, desiccation waste water and the like.

Example 1 parts of polyvinyl chloride are dissolved in 9 parts of N-methylpyrrolidone while boiling under constant stirring under reflux. This solution is cooled to 35 ° C and layered to a height of 0.5 mm, allowed to stand in air for 3 seconds and immersed in 15 ° C water for 3 minutes. In water, the solution gels and a membrane is formed from which N-methylpyrrolidone escapes into the water. This membrane in the hydrated state is preferably used for ultrafiltration and dialysis.

EXAMPLE 2 parts of polyvinyl chloride are dissolved in 6 parts of dimethylformamide, at ambient temperature with continuous stirring. This solution with a height of 0.5 mm is immersed in 5 ° C water for 15 minutes. In water, the solution gelatinizes and forms a membrane from which dimethylformamide escapes into the water. This membrane is useful for ultrafiltration, microfiltration, dialysis and reverse osmosis.

Claims (2)

SUBJECT Process for preparing hydrated semipermeable membranes from polyvinyl chloride, characterized in that 1 to 4 parts by weight of polyvinyl chloride are dissolved in 5 to 10 parts by weight of a water-miscible solvent, preferably dimeitylformamide, N-methylpyrrolidine, N-methylcaprolactam, optionally in combination solvent at 20 to 180 ° C, then the mixture is cooled to ambient temperature and stacked to a height of 0.1 to 0.5 mm, allowed to stand in air for 3 to 5 minutes, and immersed in water at 5 to 50 ° C warm for 1 to 20 minutes. 2. A method according to claim 1, characterized in that the layer of the mixture, standing in air and extending into water is carried out on the surface of a rotating cylinder partially immersed in water, from which a hydrated semipermeable membrane is continuously unwound.