What are plastics? Plastics are polymers that are either synthetic or semi-synthetic. Plastics derive their name from the fact they are malleable (and also ductile) and hence they have “plasticity”. They come in many forms and the commonly used ones are Polyvinyl chloride, Polyethylene, Polystyrene, Polyethylene terephthalate etc. They are generally classified by their polymer backbone and also include silicones, acrylics and polyurethanes. While all plastics can be polymers, the reverse is not true. Plastics can be divided into two types: 1) Thermoplastics; that can be reused and recycled and 2) Thermosets; once set cannot be reused (Bakelite). Rubber, the elastic material, which we use in our day-to-day lives is an “elastomer” and has all the properties to qualify to be a polymer (while vulcanization deprives rubber of its thermoplastic property and makes it a thermoset). Although everyone can distinguish between rubber and plastic, sometimes the difference becomes vague; since there are a lot of plastics that are also elastic. These groups of plastics differ in their molecular structure and this determines the very nature of thermal behaviour of plastics (Appendix 1). Commonly plastics are named and identified after their acronyms. Manufacture of plastics In the olden days, plastics were manufactured from vegetable matter. The most commonly used raw materials were furfural, various starch derivates, vegetable oils and cellulose. Ever since the use of plastics has burgeoned and the supply of natural raw materials has dwindled, people have turned to synthetic manufacture of plastics from petrochemicals. Petrochemicals are now being used widely since they are relatively cheap compared to other raw materials. The only hitch in this is that the supply is dwindling fast and researchers are trying for other raw materials. The first step in the manufacture of plastics is polymerization which is done by either by addition or condensation. This is done either in the gaseous or liquid phase of the ingredients and very rarely in the solid phase. During the process of manufacture of plastic chemical additives are added to achieve certain characteristics. These additives are used according to the nature of use; for e.g. for the plastic not to disintegrate in the sun, ultraviolet stabilizers are used. Plasticizers are used to increase flexibility, anti-oxidants to protect from the effects of ozone or oxygen etc. Similarly lubricants, coloring pigments are also added. The way plastics are given “shape” or how is it “moulded” is not mentioned here and is beyond the scope of this paper. How and why do plastics degrade? Contrary to popular belief all plastics are degradable and they do deteriorate with age. All plastics are organic in nature and are by products of either petroleum or natural gas hence they have to degrade over time. Plastic starts to deteriorate no sooner than the polymer is produced and it is amplified by the “residual stresses” left by the process of moulding. This is further exacerbated by exposure to sunlight, ultraviolet radiation, heat, stress, oxygen and other bacterial agents. They can also get contaminated by other plastic materials. For ex