Isoprene rubber without antioxidant was carried out in 150℃ for the thermal oxygen aging. Molecular weight

molecular weight distribution and changes of chemical structure have been investigated by GPC and

1

H-NMR. It is shows that degradation reaction of isoprene rubber happened but no significant chemical structure changed at the beginning of ageing

but molecular weight decreased gradually

molecular weight distribution becomes wider. However

in later stage

crosslinking reaction happened

but the extent of the crosslinking reaction is lower than the degradation reaction

and aldehydes

carboxylic acid

olefin and alchole were generated. Thermogravimetric kinetics to isoprene rubbers without antioxidant has been investigated by TG under N2. It suggested that with the increase of proportion of weightlessness

the activation energy increased.