Polymers oxo-biodegradable

Chiellini E, Corti A, Del Sarto G, D Antone S (2006) Oxo-biodegradable polymers - effect of hydrolysis degree o biodegradation behaviour of poly(vinyl alcohol). Polym Degrad Stab 91 3397-3406... 

Lignocellulose is strong and tough, and provides physical, chemical and biological protection to the plant. Lignin is resistant to peroxidation (see oxo-biodegradable polymers), as a result of the presence of many antioxidant-active phenolic groups, which act as... 

It is not possible to provide a specific timescale in a general standard for oxo-biodegradable polymers, (as distinct from a standard for industrial composting) because the conditions found in industrial composting are specific and the conditions foimd in the open environment are variable. Also, the time taken for oxo-biodegradable plastic to commence and complete the processes of degradation and biodegradation can be varied. 

This directive requires that carbonaceous biomass should be retained in the soil for the benefit of growing plants in the same way as natural lignocellulosic materials. Oxo-biodegradable polymers contribute to soil fertility in the same way as lignocellulosic materials. 

It is now accepted by CEN (TC 249/WG9) that, in the case of oxo-biodegradable polymers, biometric tests should be preceded by weathering tests (UV exposure in a weatherometer) before mineralisation. This together with the eco-tests, shown in simplified form in Fig. 7, provides a basis for ensuring that not only is the carbon of the plastic ultimately converted to useful fertiliser but also that no non-biodegradable toxic products are produced in the process. 

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