These free-radicals are capable of reacting with other molecules in the same area . They usually combine with oxygen , and in the presence of air react with oxygen to for aldehydes and ketones , as shown in figure below : Fig 6 (Greenwald , Bauer Rice 2003 ) This leads to the oxidative degeneration of the polymer . Ketones are found to the extent of 75 of the degradation . It was also seen that the growth concentration ketone itself increased up to eight years . This suggests...











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