Why cationic polymerization is more Favoured than anionic?

Cationic Addition Polymerization : In the case of vinylic monomers containing electron donating groups, electron density on double bonded carbon will be more and it can easily be attacked by H+ so as to undergo cationic polymerization.

Why polymers are usually very slow to disappear in the environment?

3.6 Polymer degradation Degradation is often due to a change in the chemical and/or physical structure of the polymer chain, which in turn leads to a decrease in the molecular weight of the polymer. The susceptibility of a polymer to degradation depends on its structure.

What is the difference between anionic cationic and free radical polymerization?

Free-radical polymerizations require potent initiators (and coinitiators). Anionic polymerization reactions are rather insensitive to temperature and can be carried out at very low temperatures but are only suitable for monomers with strong electron withdrawing groups.

Why are polymers produced by the anionic polymerization of pure monomers called Living polymers?

Because living polymers have had their termination ability removed, this means that once your monomer has been consumed, the addition of more monomer will result in the polymer chains continuing to grow until all of the additional monomer is consumed.

What is the difference between cationic and anionic polymerization?

Anionic polymerization reactions are initiated by an active anionic species, whereas the cationic polymerization reactions are initiated by an active cationic species. This is the key difference between anionic and cationic polymerization. Both these polymerization reactions are sensitive to the solvent used.

Why does methyl methacrylate not undergo cationic polymerization?

the carbocation would be unstable. Thus the methyl methacrylate does not undergo cationic polymerization.

What are the limitations in using polymers in our environment?

Landfill Accumulation Even beyond their persistence in oceans and water pollution from their production, synthetic polymers are a significant challenge on land because they are often disposed of in landfills where they will remain for centuries into the future slowly leaking toxins into soil as time passes.

Why are Thermo polymers better for the environment?

Thermoplastic compounds are helping people live in a more environmentally friendly way. Because thermoplastics are lightweight materials, plastic packaging takes less energy to transport, and thermoplastics in vehicles increase fuel efficiency. Thermoplastic food packaging helps prevent food waste.

What are the differences between radical and cationic polymerization?

Summary – Free Radical vs Ionic Polymerization The key difference between free radical and ionic polymerization is that free radical polymerization occurs through radicals which contain an unpaired electron whereas ionic polymerization occurs via ionic species which has no unpaired electrons.

Why anionic polymerization is known as living polymerization?

The latter topic, living anionic ring-opening polymerization, is discussed in other section. Thus, since the propagating chain end maintains its reactivity and is still “living,” the resulting polymer and the polymerization system are called as “living polymer” and “living polymerization,” respectively.

Which monomer will undergo anionic polymerization?

The major monomers capable of anionic polymerization are (i) conjugated hydrocarbon monomers, such as styrene, 1,3-butadiene, and isoprene; (ii) electron-deficient polar monomers including 2- and 4-vinylpyridines, alkyl (meth)acrylates, N,N-dialkylacrylamides, (meth)acrylonitrile, and α-cyanoacrylate; and (iii) cyclic …

What is the difference between cationic and anionic polyelectrolyte?

A polyelectrolyte is characterized by its molecular weight, the nature of the functional group, and the charge density. Sensitivity to pH occurs with cationic polymers in which quaternary ammonium groups are dominant, and with anionic polymers containing sulfonic acid groups.