Polish version
Drukuj

Syndiotactic polystyrene (sPS)

Structural thermo-resistant polymer, with melting point 250–275 °C (depending on the catalyst used in the production process) and perfect processing properties, not requiring drying before processing, easily able to be painted and metalized.

Main applications:

  • photographic films, magnetic films of „high density” type;
  • insulation films for electric and electronic products;
  • heat-resistant dishes, especially for microwave ovens;
  • car parts exposed to chemicals and high temperature: e.g. radiators, reflectors, battery covers, car body elements;
  • machine parts working at high temperature and in contact with steam;
  • food packaging films;
  • machine construction materials, machine housings;
  • pipes to transport fluids and gases (except for aromatic compounds) at temperature > 100 °C (for overheated steam – standard: 140 °C);
  • office furniture;
  • appliances and equipment used in medicine and dentistry, resistant to sterilization with overheated steam, ethylene oxide and UV.


A brief description of the technology

The process of syndiotactic styrene polymerization in the presence of catalysts [P-318774 and P-318775 (1997)], proceeds under waterless and oxygen-free conditions, in an organic solvent – hexane. The raw product is purified by extraction with organic solvents and distillation with steam, and then dried at temperature up to 90 °C in inert gas atmosphere. The process proceeds under normal pressure and at temperature up to 70 °C. Properties of the resulting product and the process yield do not diverge from those described in literature and patents.


Advantages of the technology offered

The process is similar to suspension propylene polymerization, what enables to use its redundant installations to produce sPS.

The process, proceeding in a solvent, directly provides granulation favorable to modification with improvers increasing mechanical strength of the product.

High melting point of the product (about 260 °C) enables a wide range of high--temperature processing.

Easy control of the process, proceeding in solvents.

It is possible to use both installations and catalytic system to conduct reactions of styrene and ethylene copolymerization (INSITE DOW CHEMICAL process) and butadiene polymerization (90 % of 1,4-cis-polybutadiene), which can be used to obtain high impact strength polystyrene (HIPS).


Equipment

  • Typical reactor equipped with a stirrer, dephlegmator, drain valve, heating / cooling jacket. The reactor is coupled with a column to purify technical styrene and a filter separating the polymer from the solvent and possibly the unreacted monomer;
  • metering pumps dosing hexane, styrene and MAO;
  • continuous distillation columns to purify hexane and styrene;
  • catalyst dosing device;
  • pressure filter or centrifuge;
  • apparatus for distillation with steam;
  • centrifuge for aqueous suspensions;
  • shelf dryer;
  • nitrogen heater;
  • sensors and elements metering temperature, flow and power consumption by the stirrer.


Patents

Patent No P-186 001 (2003) „Method to produce catalysts for syndiotactic styrene polymerization”.

Patent No P-186 002 (2003) „Method to obtain syndiotactic polystyrene”.


Market competitiveness

At present only IDEMITSU company (Japan) is a producer of syndiotactic polystyrene.


References

Process verified in an experimental installation with a 250 l reactor (acid resistant steel and enamel), capable of obtaining about 20 kg of polymer.


Information

Prof. Wincenty Skupiński, D.Sc., Chem. Eng.

phone: + 48 22 568 21 83

fax: + 48 22 568 22 33