New polymeric additives for allowing photoelectric sensing of plastics during manufacturing

Metallic mercaptides are inert organic compounds (i.e., Mex(SR)y) that can be used to make thermoplastic polymers high luminescent to UV-light. Luminescence is strictly required in polymer manufacturing since this characteristic allows detection of polymer pieces by photoelectric sensors. Luminescent Au, CdS, and ZnS nanoparticles can be generated into thermoplastics like: polystyrene, polycarbonate, poly(vinyl acetate), etc. by thermolysis of the corresponding mercaptides. PL spectra of polymeric films embedding these nanoparticles show intensive visible ligh emission in different spectral regions. The formation of nanoparticles was probably related to the viscous nature of reaction medium which significantly limit the growth stage.