3. Main thermosetting materials

Thermoset materials may have been victims of the formidable privilege of being among the first macromolecular compounds to be manufactured industrially, with all the imperfections associated with faulty development, lack of experience, low tonnages and incorrect applications. They may also have suffered from the widespread and unfounded belief that a new material is superior to its predecessors.

Indeed, formophenolics and aminoplasts were the only plastics manufactured between 1900 and 1930, along with cellulosics and PMMA [poly(methyl methacrylate)]. These products are still widely used today.

Thermorigid materials, whose cohesion is ensured by covalent bonds, have mechanical properties that are little affected by temperature: they do not melt, nor do they possess a rubbery state; they are insoluble in solvents; their coefficients of linear...