Plastics

Recommendations

Info

6 Conclusions 30 biodegradable PLASTICs Can plastic designed to be ‘biodegradable’ have a significant role in reducing ocean litter? Photo: © Rob (www.bbmexplorer.com) / CReative common
CONclusions Plastic debris is ubiquitous in the marine environment, comes from a multitude of sources and is composed of a great variety of polymers and copolymers, which can be grouped into a relatively limited number of major classes. Polymers most commonly used for general applications, with the required chemical and mechanical properties (e.g. PE, PP, PVC) are not readily biodegradable, especially in the marine environment. Polymers which will biodegrade in the terrestrial environment, under favourable conditions (e.g. AcC, PBS, PCL, PES, PVA), also biodegrade in the marine environment, but much more slowly and their widespread use is likely to lead to continuing littering problems and undesirable impacts. Biodegradable polymers tend to be significantly more expensive. Their adoption, in place of lower-cost alternatives, for well-justified purposes (e.g. key components of a fishing trap) may 0.0004 millimeters require financial inducement. The inclusion of a pro-oxidant, such as manganese, in oxo-degradable polymers is claimed to promote fragmentation by UV irradiation and oxygen. The fate of these fragments (microplastics) is unclear, but it should be assumed that oxo-degradable polymers will add to the quantity of microplastics in the oceans, until overwhelming independent evidence suggests otherwise. The current usage of these polymers is very limited. Oxo-degradable polymers do not fragment rapidly in the marine environment (i.e. persist > 2-5 years) and so manufactured items will continue to cause littering problems and lead to undesirable impacts. Some of the claims and counter-claims about particular types of polymer, and their propensity to biodegrade in the environment, appear to be influenced by commercial interests. Some evidence albeit limited suggests that 1.002 millimeters public perceptions about whether an item is biodegradable can influence littering behaviour; i.e. if a bag is marked as biodegradable it is more likely to be discarded inappropriately. On the balance of the available evidence, biodegradable plastics will not play a significant role in reducing marine litter. 1.0542 millimeters 1.24 millimeters 31 BIODEGRADABLE PLASTICS AND MARINE LITTER 0.002 millimeters Misconceptions, concerns and impacts on marine environments
Page 1 and 2: Biodegradable Plastics & MARINE LIT
Page 3 and 4: Biodegradable Plastics & MARINE LIT
Page 5 and 6: Contents Abbreviations list 2 Execu
Page 7 and 8: Executive Summary The development a
Page 9 and 10: Background The objective of this br
Page 11 and 12: 1.002 millimeters Photo: Ludwig Tr
Page 13 and 14: Polymers and plastics - terminology
Page 15 and 16: Single-use plastic shopping bag mar
Page 17 and 18: Table 2.3 Common synthetic polymers
Page 19 and 20: Abbreviation Full name Common sourc
Page 21 and 22: 1.002 millimeters Photo: Doug Becke
Page 23 and 24: Fragmentation, degradation and biod
Page 25 and 26: The biodegradability of polymers is
Page 27 and 28: 1.002 millimeters Fig. 3.3 Examples
Page 29 and 30: The behaviour of ‘biodegradable
Page 31 and 32: were collected from the stomach, th
Page 33: Public perceptions, attitudes and b
Page 37 and 38: Moravek, S. J., M. K. Hassan, D. J.

Plastics

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?