Preparation and properties of SBS-g-DMAEMA copolymer membrane by ultraviolet radiation

A styrene-butadiene-styrene triblock copolymer (SBS) membrane was prepared by solvent casting. Grafting of dimethyl amino ethyl methacrylate (DMAEMA) to this SBS membrane was subsequently conducted by ultraviolet radiation-induced graft copolymerization without degassing to obtain a SBS-g-DMAEMA copolymer membrane. The graft copolymer was characterized by infrared spectroscopy and scanning electron microscopy. The degree of grafting and the mechanical properties of SBS and SBS-g-DMAEMA were measured. Contact angle, water content, and protein absorption of fibrinogen and albumin experiments were also performed to evaluate the biocompatibility of SBS-g-DMAEMA graft copolymer membranes. It was found that the degree of grafting was related to the irradiation time, DMAEMA concentration, and temperature. The tensile strength of the SBS-g-DMAEMA membrane increased with an increase in the degree of grafting. By using Kaelble's equation and the contact angle data, the surface tension of SBS-g-DMAEMA was determined. It was found that with an increase in the degree of grafting, the surface tension and water content of SBS-g-DMAEMA membrane increased, whereas the contact angle decreased. The amount of absorption of albumin and fibrinogen decreased with an increase in amount of grafting. However, there was a minimum for the adsorption of proteins in the SBS-g-DMAEMA membrane.