Y. Sasada, Y. Shibasaki, Masato Suzuki
2003
Citations
0
Influential Citations
38
Citations
Journal
Polymer
Abstract
Abstract A convenient synthesis of regiocontrolled poly(2,6-dihydroxy-1,5-naphthylene) (PDHN) with high molecular weights by oxidative coupling polymerization of 2,6-dihydroxynaphthalene (2,6-DHN) has been developed. Polymerizations were conducted in 2-methoxyethanol in the presence of di-μ-hydroxo-bis[( N , N , N ′, N ′-tetramethylethylenediamine)copper (II)] chloride (CuCl(OH)TMEDA) as the catalyst under air at 25 °C. To determine the optimum conditions, the effects of the amounts of the catalysts and the solvents were investigated. In the presence of 5 mol% of the catalyst to the monomer in 2-methoxyethanol, polymerization proceeded smoothly, giving PDHN with a number average molecular weight ( M n ) of 52,000. PDHN was converted to poly(2,6-dibutoxy-1,5-naphthylene) (PDBN) to improve the solubility. The structure of PDBN was characterized by 1 H and 13 C NMR spectroscopy and was estimated to consist completely of the 1,5-linkage. The average refractive indices ( n AV ) of the PDHN and PDBN films were 1.6003 and 1.5815, respectively, and the dielectric constants ( e ) estimated from the refractive indices were 2.82 and 2.75, respectively.