What is the thermal polymerization?
A purely thermal polymerization is one in which monomer is converted to polymer by thermal energy alone. Self-initiated or spontaneous homo- and co-polymerization has been reported for many monomers and monomer pairs.
Does styrene go off gas?
In addition to being an endocrine disruptor, prolonged exposure to styrene has been found to be toxic to the brain and nervous system. Children can be exposed to styrene in food containers, second-hand smoke, car exhaust fumes, contaminated drinking water, and “off-gassing of building materials”.
Is polystyrene highly flammable?
Polystyrene is highly flammable and ignites at relatively low temperatures. It has been linked with huge fires, often in commercial buildings and warehouses, where its use is more common.
What happens to polymer when heated?
When substances made of small molecules are heated, they simply melt and form a free-flowing liquid; however with polymers the process is more complex. When polymers are cooled, they will often become very brittle. When heated, the polymers will first become flexible before melting. This is due to their structure.
Is polymerization endothermic or exothermic?
exothermic reaction
Generally, polymerization is an exothermic reaction. The polymerisation is the reaction in which the monomers combine to form polymers.
Is styrene polymerization exothermic?
First of all, the styrene polymerization reaction is relatively highly exothermic with a heat generation at around 71 kJ·mol–1.
Are styrene fumes flammable?
Styrene Monomer is a FLAMMABLE LIQUID. Use dry chemical, CO2, water spray or foam as extinguishing agents. POISONOUS GASES ARE PRODUCED IN FIRE. CONTAINERS MAY EXPLODE IN FIRE.
How do you extinguish fire with styrene?
Styrene
- Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
- Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.
- Use water spray to cool unopened containers.
- Use water spray, dry chemical, foam, or carbon dioxide.
Is polystyrene a combustible material?
Like practically all organic building materials polystyrene foam is combustible. However, in practice, its burning behavior depends on the conditions under which it is used, as well as the inherent properties of the material. When installed correctly, expanded polystyrene products do not present an undue fire hazard.
Is combustion of liquid styrene monomer explosive?
Combustion of pools of liquid styrene monomer was unsteady, unpredictable and often explosive, therefore yields of cumulative PAH (totaling 55 mg/g of styrene burned at Tg = 1000 °C (1273 K) and ϕglobal = 1.67) were substantially higher than the aforementioned PAH yields from polystyrene powder combustion, see Fig. 4.
Why is styrene combustion unstable?
The unstable character of styrene combustion may be attributed to simultaneous polymerization of styrene and pyrolysis of styrene/PS. Emissions of organic pollutants and soot were higher in styrene combustion than in polystyrene combustion.
What are the problems with converting styrene to polystyrene?
This is energy intensive and is further complicated by the tendency of styrene to undergo thermally induced polymerisation into polystyrene, requiring the continuous addition of polymerization inhibitor to the system.
What is the pathophysiology of styrene toxicity?
Styrene is largely metabolized into styrene oxide in humans, resulting from oxidation by cytochrome P450. Styrene oxide is considered toxic, mutagenic, and possibly carcinogenic.