Graft polymerization of methacrylic and acrylic acids on preirradiated polyethylene film and evaluation of strength characteristics of graft copolymers

Membranes on the basis of synthetic and modified natural polymeric substrates are widely used in separation and filtration processes and as conductive or isolating media. Grafting acrylic monomers onto polymeric substrates is an effective method of their production. Polyethylene, a synthetic polymer, has high strength properties, thermal and chemical resistance, which makes it a good substrate for various products. The objective of this work was producing ion exchange grafted films on the basis of preirradiated polyethylene grafted with methacrylic and acrylic acids, and regulation of their properties during synthesis. Methacrylic and acrylic acids have been grafted onto preirradiated polyethylene film (thickness 30±5 μm) in concentrated solutions with a monomer content up to 45 wt.% in the presence of iron (II) ions at temperatures within 90–97 °C. The concentration of the monomers, initiators, additives of modifiers and the reaction temperature have been varied. The kinetics of grafting polymerization, grafting degree and the degree of swelling in an electrolyte have been studied by a gravimetric method. The influence of the nature of grafted monomers, the concentration of components and modifiers on the above quantities and mechanical properties of the grafted films have been established. Our modified films have been characterized by FTIR spectroscopy, chemical elemental analysis, scanning electron microscopy (the relief and surface morphology), and their mechanical properties have been assessed by the uniaxial tensile method. The study of the resulting ion exchange composites for the purpose of further application in the technology of treating waste and industrial waters from polyvalent metals and as ion conducting media will be carried out in the future.