Table of Contents
What is cationic polymerization example?
Several classes of molecules can undergo polymerization initiated by an acid species (cationic polymerization). Examples of these molecules include epoxies, vinyl ethers, oxetanes, etc.
What is polymerization isobutylene?
Isobutylene is generally polymerized via carbocationic polymerization processes to form products with very broad molecular weight distributions and exhibiting consistencies which vary from liquids, for oligomers, to solids, for high-molecular-weight polymers.
What is the initiator in the polymerization of isobutylene?
The protected phenol 24 was used as initiator for the polymerization of isobutene yielding 25.
Which is best for cationic polymerization?
Correct Option c AlCl3 Explanation: Electron-deficient specie Lewis acid is used as an initiator for cationic polymerization.
What type of alkenes prefer under cationic polymerization?
q Cationic polymerization of simple alkenes is especially efficient for alkenes which form relatively stable carbocations (note the tertiary carbocation intermediate) and which have one double bond terminus of the alkene unsubstituted, so as to minimize steric effects in the TS for the addition reaction.
Why is isobutylene not good for anionic polymerization?
Anionic polymerization of isobutylene can’t be observed, due to the low reactivity of isobutylene with anionic species/initiator.
How do you make isobutylene?
Essentially pure isobutylene is obtained by the controlled dehydration of a feed stream containing tertiary butyl alcohol and only traces of butenes. Dehydration takes place over an aluminum oxide catalyst wherein the reaction zone is maintained between 400* and 800* F.
Which polymerisation method S can be used for making poly isobutylene isobutylene 2-methylpropene?
Cationic polymerization: Polyisobutylene is formed by cationic polymerization of 2-methylpropene.
Which monomer will undergo cationic polymerization?
Monomers. Monomer scope for cationic polymerization is limited to two main types: alkene and heterocyclic monomers. Cationic polymerization of both types of monomers occurs only if the overall reaction is thermally favorable.
What types of monomers undergo cationic polymerization?
The types of monomers necessary for cationic polymerization are limited to alkenes with electron-donating substituents and heterocycles. Similar to anionic polymerization reactions, cationic polymerization reactions are very sensitive to the type of solvent used.
Which of the following can undergo cationic addition polymerisation?
Cationic addition polymerisation is applicable to vinyl monomers having e− rich double bond and is an important technique for the preparation of butyl rubbers, for eg:- polyisobutylene (PIB).
What is the difference between anionic and cationic polymerization?
The broad difference between the two (2) polymers is that one (1) polymer has a net positive charge (cationic) and the other has a net negative charge (anionic).
What happens when isobutylene is treated with acidified potassium permanganate?
1 Answer. Isobutylene is treated with acidified KMnO4 to give acetone.
Which polymer is formed by free radical polymerization of propene?
Polypropylene
Propene undergoes addition polymerization to produce poly(propene), often known as polypropylene, which is one of the most versatile thermoplastic polymers available commercially. Mixtures of propene and other monomers form a wide range of important co-polymers.
Which one of the following polymers is prepared by condensation polymerization?
Condensation polymerization is used to make Dacron, Nylon-6.6, and Bakelite.
Can ethene undergo cationic polymerization?
Ethene does not polymerize by the cationic mechanism because it does not have sufficiently electron-donating groups to permit easy formation of the intermediate growing-chain cation.
What is the difference between cationic polymerization and anionic polymerization?
Is isobutylene cationic polymerization possible?
These and other approaches demonstrate that the cationic polymerization of isobutylene is still not fully explored, and new innovative catalyst systems can lead to surprising results of high commercial interest. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
What results in the formation of polyisobutylene?
Polymerization of isobutene (or) isobutylene results in the formation of Polyisobutylene. It is a vinyl polymer that is synthesized from the monomer named isobutylene. Polyisobutylene is formed by the cationic polymerization of the monomer isobutylene.
What is the IUPAC name of polyisobutylene?
Polyisobutylene (or) polyisobutene is an organic polymer that is formed by the polymerization of isobutylene/isobutene. The IUPAC name of isobutylene is 2-methylpropene. It is an alkene and it undergoes addition polymerization to form the polymer isobutylene.
What are the steps involved in polymerization of isobutylene?
The polymerization reaction of isobutylene takes place in three steps: The tertiary butyl cation which is formed by addition of proton to isobutylene monomer follows the Markovnikov’s rule. The propagation step of polymerization of isobutylene is written as,