Properties of polymer track membranes modified by grafting with poly(2-methyl-5-vinylpyridine) and poly(N-isopropylacrylamide)

The properties of track membranes (TM) based on poly(ethylene terephthalate ) (PETP) and polypropylene (PP) and modified by radiation-induced graft pol ymerization of 2-methyl-5-vinylpyridine (MVP) and N-isopropylacrylamide (NI PAA) were studied. The rate of grafting and the limiting degree of grafting increase linearly as the pore diameter of TM increases. The gasdynamic and hydrodynamic pore diameters of modified TM were determined. The dependence of water permeability of TM modified by grafting with poly(2-methyl-5-viny lpyridine) (PMVP) on the degree of grafting passes through a maximum, which , according to the data of wetting angle measurements, corresponds to the m aximum hydrophilicity. The negative zeta-potential of TM changes sign after modification by grafting with PMVP. Thermosensitive TM based on PETP and P P were prepared by radiation-induced graft polymerization of NIPAA. The str ucture of modified TM was studied by electron microscopy and atomic force m icroscopy.