Published: December 2001
This report evaluates recent developments in technologies for polystyrene production. We provide preliminary designs and economics for both general purpose polystyrene (GPPS) and high impact polystyrene (HIPS) by current commercial processes and by the emerging technology using anionic polymerization.
In the past, the almost explosive polymerization rate and tendency to form gels have hindered the commercialization of anionic technology. New technology is now available which eliminates these two stumbling blocks and allows production of superior products with superior economics.
For GPPS production, the total capital investment of the anionic process is about 85% of that for a comparable free radical process, and has the potential to be further improved. The product produced anionically is a cleaner resin, having none of the usual dimer and trimer content and a very low residual styrene content (10 ppm or lower, compared to several hundred ppm for conventional processes). In addition, the anionic product has better strength and processability, as well as considerable capability for more improvements in the future.
For HIPS production, new emulsion techniques are used to produce a rubber concentrate that can be incorporated into the anionic GPPS to produce anionic HIPS. This combined technology has similar total capital to conventional HIPS, but about 10% less raw material costs. The emulsion technology allows superior control of rubber particle size and microstructure. The use of anionic GPPS as a base adds its improvements in processability, strength, and "cleanliness".
Recent innovations are also incorporated into our conceptual designs for GPPS and HIPS processes by free radical polymerization. These innovations provide for improved heat management techniques, improved recycle handling and better rubber particle size control.
The Report also discusses the current status of the polystyrene industry. We provide data on historical and projected world polystyrene capacity, production and consumption by region, end uses, and producing companies worldwide.