New polymer syntheses: II. Preparation of aromatic poly(ether ketone)s from silylated bisphenols

Bulk condensations of 4,4′-difluorobenzophenone and various silylated bisphenols were carried out at 220°–320°C, with caesium fluoride as catalyst. Silylated bisphenol-A, tetramethylbisphenol-A, 1,1-bis(4-hydroxyphenyl)cyclohexane or 4,4′-dihydroxydiphenylsulphone as monomers and glassy polymers were soluble in several organic solvents. Their glass transitions were determined by differential scanning calorimetry (d.s.c.) and their number molecular weights ($\text{M}\text{?}{}_{\mathrm{<mtext>n</mtext>}}$) determined by means of vapour pressure osmometry. M_n's up to 10 000 were obtained. When silylated hydroquinone, 4,4′-dihydroxydiphenyl, 2,7-dihydroxynaphthalene or 4,4′-dihydroxydiphenylsulphide undergo polycondensation the resulting poly (ether ketone)s form crystals. It is demonstrated that transesterification does not take place and that block copoly(ether ketone-ether sulphone)s are synthesized. Furthermore, the thermostability of the poly(ether ketone)s in air was investigated.