Formation of monomer residues in PS,PC,PA-6 and PVC upon gamma-irradiation

摘要

Food packaging polymers,polystyrene (PS),polycarbonate (PC),polyamide-6 (PA-6),and polyvinylchloride (PVC),were irradiated with dose in the range 5-200 kGy.The quantities of corresponding monomer residues (styrene monomer,bisphenol-A,epsilon-caprolactam,vinyl chloride)released from target materials were analyzed using a SIM mode of GC/MSD.Styrene monomer in PS showed a slight increase from 740 to 777 ppm at 5-30 kGy and then decreased as the dose increased from 30 to 200 kGy.Bisphenol-A in PC was dose independent at the low doses,5,10 and 30 kGy,but its level increased from 173 to 473 ppm at 30 kGy and thereafter remained unchanged through 200 kGy.epsilon-Caprolactam in PA-6 was also dose independent,in the range of 5-200 kGy,but its level (122-164 ppm)was found to be higher than those (71 ppm)of non-irradiated sample.As for PVC,the quantity of vinyl chloride tended to increase from 8 to 18 ppm at 5-200 kGy.