Novel pH- and Temperature-Sensitive Behavior of Binary Graft DMAEMA/PEGMEMA onto LDPE Membranes

Low-density polyethylene membranes (LDPEs) were modified by the mutual grafting of 2-(dimethylamino) ethyl methacrylate (DMAEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) using a direct method with gamma-rays. The effects of absorbed dose and monomer concentration were determined. The grafted samples were confirmed by Fourier transform infrared spectroscopy, thermal properties were analyzed by differential scanning calorimetry and thermogravimetric analysis, and the stimuli-responsive behavior and critical pH point were studied by swelling determination and measurement of the contact angle in water. pH- and thermo-responsive membranes of LDPE-g-DMAEMA/PEGMEMA exhibited a low critical solution temperature of 40 degrees C and critical pH point around 7.5. (C) Koninklijke Brill NV, Leiden, 2009