Effect of Copper Sulfide Nanoparticles in Poly(vinyl chloride) Exposed to Gamma Irradiation

Hybrid organic-inorganic materials combine both typical inorganic and organic material properties, allowing them to be applied in a wide range of areas, including radiation-resistant polymers. In this study, Copper sulfide (CuS) is presented as an unprecedented inorganic radiolytic stabilizer for Poly(vinyl chloride). CuS nanoparticles were synthesized from copper (II) chloride (CuCl2) and thioacetamide (CH3CSNH2) by sonochemical route. TEM image showed the size of CuS nanoparticle ranging around 50 nm in diameter. Commercial PVC containing CuS nanoparticles in concentrations of 0.10; 0.30; 0.50 and 0.70 wt% were irradiated with gamma radiation (Co-60) at room temperature in air. Samples containing 0.5 wt% of CuS nanoparticles showed no detectable decrease in viscosity-average molar mass (M-v), while appreciable degradation was seen in the remaining samples. These results suggest that the addition of CuS nanoparticles imparted molecular protection to the polymer matrix. The observed FTIR band shifts indicate the intermolecular interactions between the CuS and the PVC matrix. These interactions favored the action of nanoparticles as a plasticizer in PVC matrix. In addition, the CuS act as thermal stabilizer because an increase in PVC thermal degradation onset temperature was evidenced. Our findings pave the way to the use of CuS as a nanostructured multifunctional stabilizer for PVC.