CHEMILUMINESCENCE STUDY ON THE OXIDATION OF SEVERAL POLYOLEFINS - I -THERMAL-INDUCED DEGRADATION OF ADDITIVE-FREE POLYOLEFINS

Chemiluminescence (CL) has been applied to evaluate the oxidation susc eptibility of various polyolefins: low-density polyethylene (LDPE), li near low-density polyethylene (LLDPE), high-density polyethylene (HDPE ) and isotactic polypropylene (i-PP). The intensity of CL emission in inert atmosphere could be related to the previous oxidation level. The thermal stability at 170 degrees C of the hydroperoxides in LDPE seem s to be lower than that in LLDPE or HDPE. The kinetic parameters of th e oxidation at 170 degrees C in oxygen, calculated from CL data, sugge st the following stability order: HDPE > LLDPE > LDPE>>i-PP. The inten sity of CL emission was related to the CH3 content as evaluated by Fou rier transform infra-red spectroscopy. (C) 1998 Elsevier Science Limit ed. All rights reserved.