Investigation of irradiated biodegradable blends by FTIR and wide-angle X-ray diffraction

Abstract

In the present work, twin screw extruded films of PLLA and PCL biodegradable homopolymers and 50:50 (w:w) blend were irradiated with gamma rays from Co-60 and electron beam at doses in the range of 50 to 500 kGy in order to evaluate the effect of irradiations on homopolymers and blend. The FTIR results have shown that this technique was neither sensitive enough to observe the degradation promoted by ionizing radiation of studied homopolymers and blends and, nor on the miscibility of the blends. Wide-angle X-ray diffraction (WAXD) of PCL samples, non-irradiated and irradiated showed two strongest reflections at angles 2Θ = 21.4° and 2Θ = 23.7° that have been attributed in the literature to the (110) and (200) reflections, respectively. As for extruded non-irradiated and irradiated PLLA, it was observed broad diffusion peaks corresponding to an amorphous polymer. PLLA annealed samples showed reflections at angles 2Θ =16.4° and 2Θ =18.7° previously attributed in the literature to distorted 103 (α-form) helices. It was possible to observe slight alteration of the crystallite size of all irradiated samples of PCL in the dose range studied.