SYNTHESIS AND CHARACTERIZATION OF POLY(DIOXYNAPHTHYLENE-1,4-DICARBONYLNAPHTHYLENE)S WITH VARIOUS ISOMERIC NAPHTHYLENE LINKS

Six all-naphthylene polyesters were prepared by the condensation of 1, 4-naphthalenedicarboxylic acid (NA) chloride with 1,4-, 1,5-, 1,6-, 2, 3-, 2,6- and 2,7-naphthalenediol (ND) isomers and effects of the isome rism of NDs on structure and properties of the polyesters were investi gated. The polymers-1,4, -1,5 and -2,6 with more or less linear ND lin k were insoluble and the others with bent ND link were soluble in the mixed solvent from nol/p-chlorophenol/1,1,2,2-tetrachloroethane(TCE). The polymer-2,6 with the most linear ND link did not show a T-g and th e highest decomposition initiation temperature(T-D) and T-g's and T-D' s of the other polymers were only marginally dependent on their struct ures. The polymer-2,3 is believed to have a macrocyclic structure cons isting of four to six monomer units and the polymer-1,6 is amorphous i n its stable chain conformation, while all the other polymers are semi crystalline. The polymers-1,4 and -1,5 exhibited an irreversible cryst al-to-crystal transition at 380 and 320 degrees C respectively, wherea s the polymer-2,6 a reversible one at 240 degrees C. The polymer-2,7 e xhibited an irreversible crystal-to-amorphous transition at 360 degree s C.