C. Simionescu, S. Dumitrescu, V. Percec
Mar 1, 1976
Citations
0
Influential Citations
27
Citations
Journal
Polymer Journal
Abstract
The polymerization of β-ethynylnaphthalene with soluble and insoluble Ziegler—Natta catalysts, tertiary phosphine, stibine and arsine—transition metal complexes, as well as by cationic and thermal polymerization has been investigated. The following catalysts, MeII(dmg)2·2X/AlEt3 (where MeII=FeII, NiII; dmg=dimethylglyoxime; X=Pyridine (Py) or NH3), Me(acac)n/AlEt3 (where Me=VOII, FeIII, CoIII, CrIII; acac=acetylacetone; n=2, 3), TiCl4/AlEt3, specific to cis polymerization of acetylenic monomers and (ZY3)a· MeXb (where Me=Rh, Pd, Pt, Ni, Co; X=C1, Br, I, NO3, SCN; Z=As, P, Sb, and Y=butyl (Bu) or phenyl (Ph); a=2, 3; b=2, 1), Co(NO3)2·6H2O/NaBH4 and TiCl4 specific to trans polymerization, have been used. The polymers obtained have been analysed from the point of view of their structural and thermal properties. Evidence for three isomeric structures, i.e., cis-transoidal, cis-cisoidal, trans-cisoidal, and the cyclic trimer 1,3,5-tri(β-naphthyl)benzene has been found. Regarding the cis-cisoidal structure, an exothermal order—disorder transition was observed at 220°C indicating an isomerization from the insoluble cis-cisoidal high crystalline structure to the soluble trans-cisoidal amorphous structure.