Historical Overview and Commercialization of Syndiotactic Polystyrene

MICHAEL MALANGA, OSAMU ISOGAI, TAKESHI YAMADA,  

The discovery of isotactic polystyrene (IPS) gave a new dimension to this material since it now could crystallize and provide a melting point (Tm) of around 250 °C. Although it still has a Tg of 100 °C, the material will maintain its shape and may be used for many applications above this Tg and below the Tm. IPS has been the subject of several intense efforts for commercialization. Ultimately it has been unsuccessful for one primary reason that being the rate at which the polymer will crystallize is too slow under normal forming 

Syndiotactic Polystyrene, Edited by Jurgen Sehellenberg Copyright 2010 John Wiley Sons, Ine. 

With the publication of this report by IKC researchers on the discovery of SPS, a flurry of activity was set in motion in several laboratories around the world in an effort to find the catalysts used. In a coincidence of timing, researchers at The Dow Chemical Company (TDCC) had been investigating MAO counterions for polyethylene catalyst research. Researchers there also had a renewed interest in IPS based on the ability to produce very high purity styrene monomer for anionic polymerization at a large commercial scale. By December of 1986, Dow had been able to independently replicate the IKC discovery. At that time, Dow was the largest commercial manufacturer of both styrene monomer and atactic polystyrene in the world, and a decision was made to pursue research and development of this new polymer. At the same time, an intense research and development effort was in progress at Idemitsu and this had in fact already been ongoing for almost 2 years. 

At the same time, early work in film and fiber extrusion showed that SPS could undergo strain induced crystallization with good oriented strength and modulus. This opened up the prospects of applications in those markets as well. Clear films were possible if the crystalline phase was kept small enough not to scatter light. 

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