Chemiluminescence (CL) and imaging chemiluminescence (ICL) were used to stu
dy the thermo-oxidative stability of polyamide 6 in the temperature range o
f 100-140 degrees C. The CL intensity time curves (CL curves) for both unst
abilised and stabilised polyamide 6 film indicated an initial period at a h
igh intensity level of varying shape followed by a basically sigmoidal incr
ease and a subsequent maximum. This maximum was found to occur at a time co
rresponding to a drop in strain at break. Polyamide 6, stabilised with the
phenolic antioxidant Irganox 1098, showed a similar CL curve although shift
ed towards lower intensity levels and longer times. The ICL study revealed
essentially homogeneous oxidation. Both the ICL study and the CL studies cl
early indicated oxidation from the beginning of ageing, also in the presenc
e of the phenolic antioxidant. The CL intensity is not directly related to
the rate of oxygen uptake. Instead, the CL intensity in oxygen seems to be
related to the content of peroxides. However, other species causing lumines
cence cannot be excluded. (C) 2000 Elsevier Science Ltd. All rights reserve
d.