Polymer00018 - hydrogen atoms in the polymer chains...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
7 fragments with unpaired electrons, which are in unstable state and tend to react with other materials to make the electron to pair with another. The process of rubber peroxide crosslinking consists of three basic steps as follows (Moore 2005). (a) Homolytic cleavage When a peroxide is heated to above its decomposition temperature, the oxygen- oxygen bond ruptures. The resulting molecular fragments are called free radicals, which are reactive species with high energy. (b) Hydrogen abstraction Those radicals that are generated from the peroxide decomposition are reactive to
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: hydrogen atoms in the polymer chains. Hydrogen abstraction is a process that the radical removes a hydrogen atom from another nearby atom, through which radicals are transferred from the peroxide molecular fragments to the rubber backbone. (c) Radical coupling Rubber radicals are highly reactive species and when the two of these radicals come in contact, the unpaired electrons will couple and form a covalent bond or crosslink between the rubber chains. ROOR RO* + *OR RO* + P-H ROH + P*...
View Full Document

This note was uploaded on 08/18/2011 for the course MATSE 447 taught by Professor Colby,r during the Spring '08 term at Penn State.

Ask a homework question - tutors are online