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NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2014, 5 (6), P. 829–835

NEW ROUTE TO POLY (2,6-DIIMIDAAZO(4,5-b: 4’,5’-e) PYRIDINELENE-1,4(2,5-DIHYDROXY)-PHENYLENE) (PIPD) AND HIGH MODULUS FIBER ON IT BASIS

Jun Li – School of Chemical Engineering and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001 Harbin, China
Zhen Hu – School of Chemical Engineering and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001 Harbin, China
Yuanjun Song – School of Chemical Engineering and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001 Harbin, China
Yudong Huang – School of Chemical Engineering and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001 Harbin, China; yudonghuang@163.com
V.V. Zuev – ITMO University; Institute of Macromolecular Compounds of the Russian Academy of Sciences, Saint Petersburg, Russia; zuev@hq.macro.ru

A novel entry toward poly( 2,6-diimidazo(4,5-b: 4’,5’-e) pyridinylene-1,4(2,5-dihydroxy)-phenylene) (PIPD) has been elaborated. A strategy based on a new route to monomers: a sequential nitration of 2,6-diaminopyridine with KNO3/H2SO4 gives 2,6- diamino- 3,5-dinitro pyridine (DNDAP) in moderate yield and its hydrogenation with Raney nickel as catalyst leads to 2,3,5,6-tetraaminopyridine (TAP) in high yield. The second monomer 2,5-dihydroxyterephthalate (DHTA) was synthesized in high yield as product of sulfurmediated aromatization of dimethyl succinoyl succinate with subsequent base hydrolysis. PIPD was synthesized by step-by-step heating in polyphosphoric acid with molecular weights of 19 – 25 kilodaltons. The macromolecule of PIPD can be seen as lap-join chain form nanosized rigid fragment. The as-polymerized liquid crystalline PIPD solution was used for fiber spinning. The tensile strength of PIPD fibers were 1.28 – 1.99 GPa and depended on the molecular weight of the polymer used for spinning.

Keywords: Nano-sized rigid polymer, synthesis, fiber spinning, mechanical properties, liquid crystallinity.

PACS 81.07.Lb

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