Is polystyrene a polymerization?

Polystyrene is an addition polymer that results when styrene monomers interconnect (polymerization). In the polymerization, the carbon-carbon π bond of the vinyl group is broken and a new carbon-carbon σ bond is formed, attaching to the carbon of another styrene monomer to the chain.

What is the degree of polymerization of polystyrene?

For example, polystyrene, with a degree of polymerization of n=7, is a viscous liquid. On the other hand, the commercial grade polystyrene is a solid with a degree of polymerization of n=1000. In addition, the degree of polymerization can be used to quantify the molecular length or size of a polymer.

What type of polymerization is polystyrene?

free radical vinyl polymerization
Polystyrene is a vinyl polymer. Structurally, it is a long hydrocarbon chain, with a phenyl group attached to every other carbon atom. Polystyrene is produced by free radical vinyl polymerization, from the monomer styrene.

How does polymerization reaction take place for polystyrene synthesis?

Polystyrene is created via the polymerization of styrene – a petroleum based, liquid hydrocarbon monomer. In this three-step synthesis, styrene is formed via the radical bromination of ethylbenzene and the elimination reaction of (1-bromo-ethyl)benzene.

How does styrene polymerize?

Styrene readily polymerizes to polystyrene by a relatively conventional free radical chain mechanism. Either heat or initiators will begin the polymerization. Initiators thermally decompose, thereby forming active free radicals that are effective in starting the polymerization process.

How is polystyrene foam made?

Styrofoam is made out of styrene which is a petroleum-based product. How is styrofoam made? Through polymerization, styrene is refined into polystyrene and then a hydrofluorocarbon agent is added. This combination is then extruded and allowed to expand under pressure until it forms a foam board.

What is average degree of polymerization?

The number-average degree of polymerization is a weighted mean of the degrees of polymerization of polymer species, weighted by the mole fractions (or the number of molecules) of the species. It is typically determined by measurements of the osmotic pressure of the polymer.

How is polystyrene polymer made?

Polystyrene (PS) is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum. At room temperature, PS is normally a solid thermoplastic but can be melted at higher temperature for moulding or extrusion, then resolidified.

What is the polymerization technique?

Polymerisation Techniques Solution Polymerization – In this industrial polymerization method, a monomer is to be dissolved in the non-reactive solvent having an initiator or catalyst, which increases the speed of reaction. The polymer formed in the process is also soluble in the same non-reactive solvent.

When styrene undergoes polymerization what is the product?

Styrene undergoes polymerization by all the common methods used in plastics technology to produce a wide variety of polymers and copolymers. Styrene is readily polymerized and copolymerized by both batch and continuous mass polymerization, emulsion, suspension and solution processes.

What is free radical polymerization?

Free radical polymerization is a type of chain-growth polymerization, where the polymer is formed by consecutive addition of unsaturated monomer molecules to an active, free radical center. Free radical polymerization can be iniitated by thermal, chemical or photolytic decomposition of initiator molecules.

What is the emulsifier used in radical polymerization of styrene?

Radical emulsion polymerization of styrene was successfully carried out at 80 °C by using sodium dodecylbenzenesulfonate as the emulsifier. The 2-bromopropane/CuSO4/sodium ascorbate-initiated emulsion polymerization shows the controlled free-radical polymerization features with linear growth of molecular weight.

What is polystyrene granulate foam?

Polystyrene granulate is prefoamed at temperatures above 90°C. This temperature causes the foaming agent to evaporate and hence inflating the thermoplastic base material to 20-50 times its original size.

What is the inhibitor of polystyrene propagation?

Oxygen is the common inhibitor. The growing chain will react with molecular oxygen, producing an oxygen radical, which is much less reactive (Figure 17). This significantly slows down the rate of propagation. Figure 17: Inhibition of polystyrene propagation due to reaction of polymer with molecular oxygen.