Backbone structure aromatic ring structures

Each of the above mentioned specialty polymers exhibits enhanced rigidity at high temperatures. Tltis is a consequence of their high glass-transition temperatures, presence of aromatic ring structures in the backbone chain and relatively strong hydrogen bonds. 

Fig. 9 Enzymatic mechanism involved in the formation of estrogens. A The sulfatase pathway. B,C Structure of the potent STS inhibitors EMATE and COUMATE. D New pharmacophore for the inhibition of estrone sulfatase R general carbon backbone (aromatic or aliphatic), X electron withdrawing groups (e.g. nitro), Y additional functionality including fused or adjacent/remote ring structures so as to meet the log requirement...

The aromatic sulfone polymers are a group of high performance plastics, many of which have relatively closely related structures and similar properties (see POLYMERS containing SULFUR, polysulfones). Chemically, all are polyethersulfones, ie, they have both aryl ether (ArOAr) and aryl sulfone (ArS02Ar) linkages in the polymer backbone. The simplest polyethersulfone (5) consists of aromatic rings linked alternately by ether and sulfone groups. 

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