Solid wastes packaging applications

World demand for polypropylene is expected to be 30 billion pounds by 2002. This is the strongest growth forecast for any of the major thermoplastics (5.9%). Many of the resins new applications particularly in packaging come at the expense of PS and PVC, the two resins that have been the subject of regulatory restrictions related to solid waste issues and potential toxicity. 

Other Plastics. A relatively small amount of poly(vinyl chloride) goes into packaging applications and appears in municipal solid waste (25). 

Because of their low density, plastics comprise approximately 20% by volume of landfilled solid waste, although they contribute only about 7% of the total weight. Public opposition limits the disposal of plastics via incineration, despite their comparatively high energy content. These factors have stimulated considerable interest in the development of biodegradable plastics as replacements for conventional plastics, particularly in packaging and disposable applications. 

The qualities of plastics can also be disadvantageous. Their high durability, often used as a sales argument, becomes a problem in applications where the service life is short, such as packaging. Plastics packaging waste makes up a considerable and very visible share of municipal solid waste (MSW) and litter. 

With increased use of plastics in consumer applications environmental concerns relating to these materials are beginning to be raised. For instance, a particularly visible plastics-related environmental problem is that of municipal solid waste disposal. With about 30% of the plastics production used in packaging, it is not surprising to find a significant and growing fraction of plastics in the municipal solid waste and in urban litter streams. Consumer awareness and sensitivity to the environmental impact of solid waste has never been at a higher... 

Consumption of virgin polyethylene terephthalate (PET) resin in the United States and Canada totaled 5110 million pounds in 2000 [3]. Bottles were by far the largest application (Fig. 4.8). Soft drink bottles continue to be the largest use for PET bottles, but other applications (custom bottles) have been growing at a much faster rate for the past several years. According to EPA estimates, soft drink bottles accounted for 49.4% of all PET packaging in U.S. municipal solid waste in 1998, and 53.2% of all PET containers in municipal solid waste [1]. 

Therefore, there is a considerable interest in replacing some or all of the synthetic plastics by natural or biodegradable materials in many applications. Since the food industry uses many plastics, even a small reduction in the amount of materials used for each package would result in a significant polymer reduction, and may improve solid waste problems [10]. It is clear that the use of biodegradable polymers for packaging offers an alternative and partial solution to the problem of gathering of solid waste composed of synthetic inert polymers [11]. 

Most significant environmental issues with respect to block copolymer S5m-thesis relate to manufacturing process, taste and odor issues in end use, and solid waste in final disposal of these pol5uners. Manufacturing process issues relate to industrial hygiene, exposure, and volatile organic emissions. In end use, block copolymer/polystyrene blends tend to have taste and odor issues, especially for sensitive food packaging applications. 

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