General Chemical Reactions of Polymers

A polymer possessing a number of diverse properties may be required to perform a particular task. The available, simple homopolymers may not possess the required properties, and hence it becomes necessary to transform them into new polymers by carrying out chemical reactions on them. 

Those affecting degree of polymerization (DP). These involve further polymerization (including cross-linking) of already formed polymers and the synthesis of a graft or a block copolymer, as well as degradation reactions. Such reactions have been classified as macromolecular.  

Those not affecting DP. These involve reactions of functional groups already contained in the polymer molecules Some of these reactions are reversible and are referred to as polymer-analogous transformations. These reactions have been used in polymer-mediated organic syntheses and will be the subject of the bulk of this book. 

Some overlap between categories can occur. For example, the sequential synthesis of a polypeptide on a polymer support is equivalent to grafting the polypeptide onto the original polymer support, whereas each step of the solid-phase peptide synthesis can be regarded as a polymer-analogous transformation. 

Polymer-analogous reactions can be carried out to modify the properties of commercial polymers. A well-known sequence of polymer-analogous reactions is the conversion of poly(vinyl acetate) to poly(vinyl acetal) via poly (vinyl alcohol). 

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