Which catalyst is used for olefin polymerization?
Which catalyst is used for olefin polymerization?
Ziegler-Natta catalyst
We know that olefin polymerization is one of the most important polymerization reactions and the catalyst used in this polymerization is the Ziegler-Natta catalyst. The name Ziegler-Natta catalyst was named after two scientists, Karl Ziegler and Giulio Natta.
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 do you mean by mechanism of polymerization?
The mechanism of polymerization involves addition of a proton acid to aziridine to produce the corresponding aziridinium ion (6; equation 1). If an alkylating agent is used as initiator, the alkylated monomer will transfer a proton to a monomer thus producing the same initiating species (equation 2).
What occurs during polymerization?
polymerization, any process in which relatively small molecules, called monomers, combine chemically to produce a very large chainlike or network molecule, called a polymer. The monomer molecules may be all alike, or they may represent two, three, or more different compounds.
How is Ziegler-Natta catalyst used in process of polymerization?
Ziegler-Natta catalyst, any of an important class of mixtures of chemical compounds remarkable for their ability to effect the polymerization of olefins (hydrocarbons containing a double carbon–carbon bond) to polymers of high molecular weights and highly ordered (stereoregular) structures.
What is the mechanism of olefin polymerization?
With regard the mechanism of olefin polymerization, it is well-established that the active metal center, in addition to being ligated by atoms of the ligand, should be cationic, attached to the growing polymer chain and must have a vacant coordination site to accommodate the incoming olefin.
Can late transition metal complexes catalyze α-olefin polymerization?
Olefin polymerization catalyzed by late transition metal complexes has received great prominence over the past decade especially since Brookhart’s report on Pd (II) and nickel (II) diimine catalyst systems which showed notable catalytic activity for both ethylene and α-olefin polymerization [1].
What is the effect of 1-hexene on crystallinity in catalytic olefin polymerization?
In catalytic olefin polymerization processes, the polymer crystallinity decreases with the percentage of the incorporated comonomer (i.e., 1-hexene) in the polymer chains. As the 1-hexene incorporation in the polymer increases, crystallinity decreases. Thus, the comonomer content is strongly related with polymer density.
How much catalyst is required to produce α-olefins?
Usually, only very small quantities of catalyst is required. The most important α-olefin is propylene; it is the second most widely used commercial polymer today and almost exclusively produced via stereospecific polymerization.
