What happens in step growth polymerization?

What happens in step growth polymerization?

Step-growth polymerization refers to a type of polymerization mechanism in which bi-functional or multifunctional monomers react to form first dimers, then trimers, longer oligomers and eventually long chain polymers.

What is the difference between step growth polymerization and addition polymerization?

The main difference is this: In a step growth reaction, the growing chains may react with each other to form even longer chains. But in an addition polymerization, only monomers react with growing chains. Two growing chains can’t join together the way they can in a step growth polymerization.

What are the three main stages of chain growth polymerisation?

Usually an initiator compound reacts with the monomer to start the reaction, and the mechanism of chain polymerization consists of three phases, called initiation, propagation, and termination.

Which is the step growth polymer?

The polyester Dacron and the polyamide Nylon 66, shown here, are two examples of synthetic condensation polymers, also known as step-growth polymers. Although polymers of this kind might be considered to be alternating copolymers, the repeating monomeric unit is usually defined as a combined moiety.

Which of the following is step growth polymer?

Polyester is a step growth polymer and others are chain growth polymers.

Which of the following shows step-growth polymerization?

Nylon-66, Bakelite, Nylon-6 are step growth Condensation polymers.

How are step growth polymers formed?

A step-growth polymerization is a stepwise reaction between bi-functional or mult-ifunctional monomers in which high-molecular-weight polymers are formed after a large number of steps. If some of the monomers have more than two reactive sites, branched or cross-linked polymers (thermosets) are formed.

What is step growth and chain growth polymerization?

In chain growth, the polymer chain always grows one monomer at a time. In step growth, the polymer chain doubles with each step. As a result, the rate of growth of the polymer chain is very different in these two cases. Chain growth results in a steady increase in chain length with every coupling step.

Which of the following shows step growth polymerization?

Which step will grow the polymer chain in an addition reaction?

In chain-growth polymerization, the only chain-extension reaction step is the addition of a monomer to a growing chain that possesses an active center such as a free radical or ion (cation or anion).

Which of the following is a step-growth polymer?

Bakelite is an example of step growth polymer.

What is step growth polymerization?

Step growth polymerization refers to a type of polymerization mechanism in which bifunctional or multifunctional monomers react to form first dimers, then trimers, longer oligomers, and eventually long-chain polymers [5,18–22]. Hari Madhav, Gautam Jaiswar, in Materials for Biomedical Engineering, 2019

What is the polymerization of acrylonitrile and isoprene?

Polyacrylonitrile, Polyisoprene and Polythene polymerize by chain-growth polymerization of acrylonitrile, isoprene ( 2 -methyl- 1, 3 -butadiene) and ethene, respectively. Chain-growth polymerization (or addition polymerization) involves the linking together of molecules incorporating double or triple carbon-carbon bonds.

What is the kinetics of polymerization of isoprene with N-butyuithium initiator?

(December 13, 1964) The kinetics of polymerization of isoprene with n-butyUithium initiator was investigated in n-hexane solution over an extended concentration range of poly-organolithium. The propagation reaction was found to be first-order with regard to monomer and half-order with respect to chain anion concentration.

What is chain growth polymerization of Terylene?

Chain-growth polymerization (or addition polymerization) involves the linking together of molecules incorporating double or triple carbon-carbon bonds. Terylene polymerizes by step-growth polymerization, in which bi-functional or multifunctional monomers react to form first dimers, then trimers, longer oligomers and eventually long-chain polymers.