Why are solvents used in polymerization?

In general, the use of solvent in free radical polymerization is to increase the solubility formed polymer chain and 2) increase the heat transfer in the reaction system to make sure the polymerization is more “uniform” compared to the bulk polymerization regarding the molecular weight distribution.

Which catalyst is used in cationic polymerization?

Lewis acid catalyst
2.05. A Lewis acid catalyst is generally used to initiate the cationic polymerization reaction by activation of the oxetane ring oxygen, allowing nucleophilic attack from the ring oxygen atom of a second oxetane molecule and ring opening.

How is the solvent in solution polymerization?

The solution polymerization technique for monomers uses a solvent as a heat sink, which may affect the kinetics and the chemistry of the hydrogels. The traditional solvents used for solution polymerization of hydrogels include water, ethanol, and their mixtures, and benzyl alcohol [1,4].

How do cationic polymers work?

Cationic polymers produce a positive charge while anionic polymers produce a negative charge. These long chain molecules attract particles of an opposite charge while offering many sites for attachment. Polymer can be used in conjunction with metal salts as a coagulant aid, typically for phosphorous removal.

Which polymerization technique solvent is not necessary?

1.3. Bulk polymerization, which may also be referred to as mass polymerization, involves a monomer and an initiator as the main components, without a solvent. The polymerization conforms to the fixed shape of the reaction vessel when solidification occurs.

In which solvent will a cationic polymerization have a faster rate of reaction?

Since free ions are more reactive than ion pairs, the rate of propagation is faster in more polar solvents.

Which of the following monomer has highest reactivity towards cationic polymerization?

Explanation: Basic solvents or additives can inhibit the growth of polymer in cationic polymerization. 4. Which of the following monomer has highest reactivity towards cationic polymerization? Vinyl ethers>isobutylene>isoprene>styrene.

Why does the degree of polymerization of cationic polymerization increase as the temperature of the reaction is involved?

Explanation: The monomers with electron releasing substituent groups like alkoxy, phenyl, aryl-alkyl, etc. are readily susceptible to cationic polymerization as the it enables easy carbonium formation. So, the rate and degree of polymerization drops sharply with rise in the temperature.

What is polymer explain the free radical and cationic mechanism of polymerization?

Free-radical polymerization is a type of chain-growth polymerization, along with anionic, cationic and coordination polymerization. A chain polymerization in which the kinetic-chain carriers are radicals. Note: Usually, the growing chain end bears an unpaired electron.

What is the advantage of solution polymerization over emulsion polymerization?

If the polymer is soluble in the monomer, then the concentration of monomer decreases continuously and the viscosity changes. The advantage of solution polymerization over bulk polymerization is better heat control; the disadvantage solution polymerization is the removal of the diluent from the polymer.

What is the important difference of the initiators used in the suspension and emulsion polymerization?

The main difference between suspension and emulsion polymerization is that suspension polymerization requires a dispersing medium, monomer(s), stabilizing agents and initiators whereas emulsion polymerization requires water, monomer and a surfactant.