Problems of Plastics

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]. 

The best-known renewable resources able to create biopolymer and biodegradable plastics are starch and cellulose [10,12]. Weber et at believed that the only biobased food packaging materials in use commercially on a major scale are based on cellulose [13]. 

Since starch is a source of energy and has an important role in human food, research should be focused on other subjects that are not food but can be used by people. Therefore, cellulose is a good subject to be used in the packaging industry. 

According to regulations of the European Union (EU), cellulose is available in the list of allowed monomers and other starting substances, which shall be used for the manufacture of plastic materials, intended to be exposed to foodstuffs. In addition, according to Great Britain, cellulose is certified without time limit for use in the production of polymeric materials in contact with food or drinks or intended for such contact [14]. 

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An application of fire retardants in plastics solves the problem of plastics flammability efficiently but usually creates problems with plastics processing and with plastics properties. In this paper we intend to evaluate various solutions to these problems. 

This article highlights the growing problem of plastics waste disposal and then investigates modes of polymer degradation - thermal, chemical, mechanical, photodegradation, bio-degradation, solvolysis andglycerolysis. 4 refs. 

Only few polymers can be recycled by pyrolysis under economically favourable conditions. Nevertheless, important amounts are collected with the aim of realizing recycling quota that were introduced under environmental pressure. The logistical problems of plastics waste collection are huge even collecting astronomical numbers of films or bottles generates only rather modest amounts of materials, sufficient only to feed a pilot plant. 

The research and development carried out so far in has shown that, even though microwave pyrolysis will not be the solution to the whole problem of plastic disposal, it certainly has the potential to help reducing the number of resources currently committed to landfill. Evidence of this potential is the number of companies interested in the development of the process and that are currently active, trying to commercialize proprietary microwave pyrolysis processes. However, this chapter has shown that in order to accomplish a more widespread utilization of this kind of processes a better communication between the commercial and scientific communities is needed. The companies with their patents would be able provide many innovative ideas that may help to increase processes efficiency and the scientific community would provide explanations for the improvements, that would in turn generate even more ideas in a self-sustaining cycle of improvement. 

The ecological situation will depend on rates of the decision of a problem of plastic waste products in the world, so both intensity and directions of development of manufacture of synthetic plastic in the come century substantially. Otherwise people will bury themselves plastic dust. 

Responding to the toxicity problem of plastics in greenhouse applications, the Dutch horticultural industry developed a test for screening. Plastics that pass the test qualify as safe horticultural plastics and... 

The concept of biodegradable synthetic polymers was first proposed in the 1960s as a potential solution to the problem of plastics litter. This was initially welcomed by environmentally aware public, particularly in the USA, since it was perceived to be a possible solution to the landfill problem. Packaging producers in collaboration with corn growers were quick to respond to the public mood by adding corn starch to polyethylene. Carrier bags made from this material were claimed, without experimental evidence, to be biodegradable but the... 

P. Groenewegen and F. den Hond, Technological Innovation in the Plastics Industry and its Influence on the Environmental Problems of Plastics Waste (SAST Project N° 7) ... 

Naturally, the increasing proportion of plastics incorporated in vehicles has widened the interest in the flammability problems of plastics. Flammability tests and specifications have been much less clarified in the car industry than in the previously discussed architecture, electrotechnics and textile industries. Although some countries have introduced regulations for flammability testing of plastics employed... 

The consummatory act is relatively simple, at its most complex, it is a chain of reactions, each of which may be a simultaneous combination of a taxis and a fixed pattern. But appetitive behavior is a true purposive activity, offering all the problems of plasticity, adaptiveness, and of complex integration that baffle the scientist in his study of behavior as a whole. Appetitive behavior is a conglomerate of many elements of very different order, of reflexes, of simple patterns like locomotion, of conditioned reactions, of insight behavior, and so on. (Tinbergen, 1951, pp. 105-106)... 

There are four ways of tackling the problems of plastic waste. In ascending order of perceived environmental benefit these are ... 

A combination of efforts from different sectors of film producers, farmers, and municipalities will be needed to resolve this problem [60, 61]. The various solutions to curtail the problems of plastic film waste disposal include ... 

The problem of plastic debris in the oceans will continue to grow in the future with more plastics being added each year into the ecosystem. Also, demographic patterns show preferential migration of human population to coastal regions. Already about half of the world s population live within 200 km of a coastline and that number will double by 2025 (Creel, 2003). The recreational use of beaches and the ocean (especially boating) is on the increase making it even more likely that plastics and other wastes will end up in the oceans. Once in water, plastics are dispersed in oceans worldwide plastic debris has even been detected in waters in Antarctica (Barnes et al., 2010). 

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