Bonding and Response to Temperature

Bond Type Interatomic Distance, r, nm Dissociation Energy, e, kcal/mol 

There are some exceptions to these generalizations. It is occasionally possible for secondary bonds to make up for in quantity what they lack in the quality (or strength) of a 

three —OH groups in the basic repeat unit for cellulose, glucose or C6H12O6, are converted to acetate esters. Since cellulose is already a polymer, the acetate esters simply modify side groups, making the structure of these cellulose derivatives more workable. They are commonly used in pharmaceutical coatings and a number of foodstuffs, even being a component in some soft-serve ice creams. 

Polytetrafluoroethylene (Teflon, TFE) with the repeat unit —(CF2—CF2)— is another example of a thermosetting material, as the close packing and extensive secondary bonding of the main chains prevents flow when the polymer is heated. 

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