| Abstract: | Polystyrene is with a present day sales volume of 8,5 million tons a year one of the most important thermoplastics worldwide. Its unique property profile makes polystyrene an ideal material for housings, refrigerator inliners and demanding packaging applications, when transparency and/or surface quality as well as stiffness are important. Its economic success is due to its favourable price/performance ratio and also not least to its excellent processability as an amorphous material. In this contribution the versatility and potential for innovation of polystyrene and its copolymers are discussed. Using standard and impact modified polystyrene, it is shown how the maturity of the polymerisation process, the broad spectrum of product modifications as well as processing know how of this class of materials have helped to promote the breakthrough of this product to an acknowledged plastic material. Modern polystyrene variations are increasingly meeting the special property requirements of other materials, like for example high heat resistant PPE/PS-I blends, weather resistant ASA and AES plastics, tough and crystal clear star polymers or hydrogenated and unhydrogenated elastomers. A special feature of polystyrene is that it is one of the few monomers which can be polymerised using all the known methods for vinyl monomers to produce high molecular weight products. Thus the newest polymerisation techniques using metallocene catalysed and anionic polymerisation methods lead to products with the property profile of engineering plastics. Polystyrene will continue to grow in the future and thus increase in importance, especially while it can be easily depolymerised and in the form of styrene monomer recycled. |
