"Front Matter". In: Modern Polyesters: Chemistry and Technology of ...

6 J. E. McINTYRE
(a) (b)
Reactivity (2, 2) chain
formation
Reactivity (2, 3) or greater
intertwining formation
Figure 1.1 Kienle’s illustration of polymer formation from (a) two bifunctional
reactants and (b) one bifunctional and one trifunctional reactant [1]
investigated and, to some extent, clarified by Bradley and co-workers [15] and
Vincent [16] during this period, and their ‘convertibility’ to insoluble, infusible
structures was identified as being due to the double bonds, whose concentration
in the precursors had to exceed a certain limit.
During World War II, polyesters containing unsaturated groups, particularly
those based on maleic and fumaric esters with various diols, grew greatly in
importance as constituents of shaped composite structures, notably in combination
with glass fibres to make glass-reinforced polyesters (GRPs). The polyester was
dissolved in an unsaturated monomer, commonly styrene, and copolymerisation
was brought about by any of the various forms of initiation appropriate to doublebond
polymerisation.
3 FIBRES FROM PARTIALLY AROMATIC POLYESTERS
3.1 EARLY WORK LEADING TO POLY(ETHYLENE TEREPHTHALATE)
In February 1928, Wallace H. Carothers (Figure 1.2), then an Instructor at Harvard,
joined du Pont at Wilmington to set up a fundamental research group in
organic chemistry. One of the first topics he chose was the nature of polymers,
which he proposed to study by using synthetic methods. He intended to build up
some very large molecules by simple and definite reactions in such a way that