Free radicals can be formed by a number of different mechanisms usually involving separate initiator molecules.
Chain growth polymerization of vinyl chloride.
Chain reaction polymerization sometimes called addition polymerization requires an initiator to start the growth of the reaction.
The main problem is the amount of r vcm in the final pvc slurry which has to be less than 1.
The reactants are then heated in the closed system to about 50 c and the pressure rises to about 0 5 mpa.
In slurry polymerization chain growth occurs as monomers dissolved in a hydrocarbon solvent add to growing chains also dissolved in the solvent.
Ch 2 ch in which the c c double bond is present.
To make the polyvinyl chloride pvc as per the requirements of the consumer market many other additives are added into it.
Free radical polymerization frp is a method of polymerization by which a polymer forms by the successive addition of free radical building blocks.
To repeat the animation click on the drawing.
With chain polymerization what are termed vinyl polymers are obtained because the monomers from which it starts contain the vinyl group.
Radical chain growth polymerization of vinyl chloride.
The polymerization of vinyl monomers occurs by rupture of the double bond and creation of a simple covalent bond with the nearby monomer.
Polymerization of isobutylene 2 methylpropene by traces of strong acids is an example of cationic polymerization.
Following its generation the initiating free radical adds nonradical monomer units thereby growing the polymer chain.
The in species represents the initiating radical which might originate from a peroxide or azo initiator.
In practice larger numbers of moderately sized chains are formed indicating that chain terminating reactions must be.
The largest family of polymers 3 vinyl polymers are produced by chain polymerization reactions a good example is the free radical polymerization of styrene which is initiated by a free radical r that reacts with styrene.
The polyisobutylene product is a soft rubbery solid tg 70ยบ c which is used for inner tubes.
There are a limited number of these active sites at any moment during the polymerization which gives this method its key characteristics.
A typical polymerization includes 180 parts water and 100 parts vinyl chloride monomer chain transfer agent trichloro ethylene.
The polymerization reaction in the reactor takes place by means of chain growth polymerization of vinyl chloride monomer vcm.
The following animation illustrates the polymerization of vinyl chloride initiated by radicals.
Chain polymerization of vinyl monomers is a convenient technique for the preparation of a wide variety of functional polymers.
In principle once started a radical polymerization might be expected to continue unchecked producing a few extremely long chain polymers.
