Ethynyl-terminated sulfone

Ethynyl-terminated sulfone oligomers (ETS) were prepared by end-capping hydroxy-terminated sulfone oligomers with 4-ethynyl benzoyl chloride as indicated in Eq. 8 (20). The... 

Table III. Properties of Cured Ethynyl-Terminated Sulfones...

The reaction sequence used to synthesize these flexible systems involved four steps which are outlined in Figure 1. The first of these was an aromatic nucleophilic substitution, a polymer forming reaction in which 4,4 -dichlorodiphenyl sulfone reacts with various diols. The second step, an Ullmann ether reaction, gives bromine terminated products in which the bromines can be replaced by ethynyl end groups in the final stages. 

The most successful class of thermally reactive oligomers consists of the functional polymers containing either pendant or terminal triple bonds, especially ethynyl groups. This area of research was recently reviewed (2), and the more recent developments in the field of a,w-bis(ethynylpheny1) aromatic polyether sulfones were summarized in two recent papers (5,6). 

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