Essential biotic degradation

Whether biotic or abiotic, degradation is essentially lydiolytic or (photo/thermo)-oxidative (other modes exist such as acid attacks by Thiobacillus). For example, for the hydrolysis of poly(lactic add) (PLA), the reaction is veiy slow at low temperatures (20-25°C), but very fast at temperatures around 60°C (Figure 14.2). We can also mention the abiotic degradation of poly(ethylene) by photo- and thermo-oxidation (Figure 14.3) which results in a drastic decrease in molar masses, a loss of mechanical properties of the material, an increase in the carbonyl index up to 1713 cm and the progressive appearance of degradation molecules, such as ketones, alcohols, acids and so on. 

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