Introduction

Abstract

Polymeric (high-molecular-weight organic) materials such as polyolefin, polyester and polyamide, and organic (relatively low-molecular-weight) materials, like liquid crystals, are very significant in the life of contemporary humans because of their very wide usage. The amount of product of plastics in the world increases as 115 x 10⁶ t (in 1994), 121 x 10⁶ t (1995) and 129 x 10⁶ t (1996) compared to the almost constant amount of production of iron and steel (approximately 730x10⁶ t). These values also suggest that the volume of produced plastics is greater than iron and steel because the density is approximately 1.0 g•cm^-3 for plastics and approximately 7.8 g•cm^-3 for iron and steel. This is one of the most important reasons why we must take into account recycling and environment-protection for polymeric materials. Polymeric materials are very safe from the point of view of chemical safety and the application areas of polymeric materials are extending more and more via the establishment of systems of recycling including materials recycle, chemical recycle and thermal recycle, which must take into account the safety of the outputs during burning.