Life cycle assessment other polymers

Recent researches in life cycle assessments (LCA) have also focused to enable PLA to find its place among traditional commodity polymers for many applications in the agricultural sector as well as in the packaging field (the food and nonfood sector). It was found that PLA can be processed like all other thermoplastic polymers with extrusion, injection molding, blow molding, thermoforming or fiber spinning processes into various products. 

Life cycle assessment reveals that no petroleum-derived polymer can rival the greenhouse gas sink effect of the improved PLA process. Although disposal of PLA products - whether by combustion, composting or other conventional means - results in a return of carbon dioxide to the atmosphere, this advantage survives. 

Other factors also need to be assessed in comparing the ecological impact and sustainability of natural and man-made products, these have been discussed elsewhere. ° Since life cycle assessment (LCA) has not yet played a significant role in the thinking of Standards committees, they will not be discussed in detail here. It can be concluded, however that natural polymers have not so far demonstrated superiority over synthetic polymers in sustainability. ... 

The question of how to systematically assess material alternatives in specific application cases, has not been answered so far. The next chapter will help with this and provides an introduction on how to assess the overall effects on the environment in such cases. The life cycle based methods and tools that will be presented are already in use by a number of leading companies to support realizeation of the possibilities of polymers (and many other materials) while minimizing the risks involved. 

A decision matrix was used to create two single value metrics for each polymer, one evaluating each polymer for life cycle environmental impacts and the other evaluating each polymer for adherence to green design principles. Results from both assessments were normalized to the average across aU polymers, shown in Eq. (15.3), where N- is the normalized value for polymer i in metric/impactj, V- is the... 

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