Abstract
A kinetic study has been made of the preparation of poly(diphenylene ether sulphone) from monomers containing fluorine and phenoxide end groups. The rate of reaction depends on the structure of the compound containing the end groups, for example fluorine and phenoxide end groups on polymer react 40 times as fast as these groups in the potassium salt of 4-fluoro-4'-hydroxydiphenyl sulphone (monomer) under the same conditions. Phenoxide in a para position to sulphone reacts approximately 10 times as fast as phenoxide in the ortho position. The rate of reaction between poly(diphenylene ether sulphone) and fluoride ion was also studied as well as the equilibrium between this polymer and fluoride ion, which was found not to obey a simple theory. The rate of reaction between poly(diphenylene ether sulphone) and phenoxide end groups (ether exchange reaction) was measured. The rate of the polymerisation reaction, the fluoride cleavage reaction and the ether exchange reactions were shown to be similar at equilibrium. The preparation and properties of poly(diphenylene ether sulphone) containing ortho links, meta links, branching, 1,5 dioxynaphthalene units, 1-oxy-4-sulphonyl naphthalene units and 4,4'-dioxydiphenyl units are described. The polymers had similar glass transition temperatures (230°) with the exception of poly m,p' (diphenylene ether sulphone) which was lower (175°) The ortho and meta links decrease impact strength and increase modulus and density. Branching also decreases impact strength. The 1,5-dioxynaphthalene and 1-oxy-4-sulphonyl naphthalene units decrease the impact strength and increase the modulus, while 4,4'-dioxydiphenyl increases the impact strength and decreases the modulus and density. The results indicate that for aromatic polymers the best physical properties are to be expected with a linear, para polymer containing no bulky side groups.