This chapter evaluates step-growth polymers. In the case of step-growth (condensation) polymers, the mechanism is simply an extension of the normal organic condensation reactions in which a small molecule is expelled as the link is built. This is a different situation to the chain polymerizations described in the previous chapter. It is assumed that most step polymerizations involve bimolecular reactions as key mechanistic processes. The chapter then looks at the kinetics of step polymerization. It also considers the commercial preparations of step-growth polymers. The industrial preparation of polyethylene terephthalate (PET) exploits the reversibility of esterification. A key feature in polymer technology is the manipulation of polymer properties by post-polymerization processing. PET behaviour is affected by its crystallinity.
Chapter
Step-growth polymers
Chapter
Aldehydes and Ketones
This chapter describes aldehydes and ketones. Aldehydes have one alkyl group and one hydrogen atom attached to the carbonyl carbon. Ketones have two alkyl groups and resist oxidation. Both aldehydes and ketones contain the carbonyl group which has a carbon atom doubly bonded to an oxygen atom. Fehling's solution and Tollens' reagent can also help determine the differences between aldehydes and ketones. Oxidation can also help the reduction of aldehydes and ketones to primary and secondary alcohols respectively. The chapter also explains nucleophilic addition, condensation reactions, and alpha carbon reaction of aldehydes and ketones.
