Synthesis and Properties of Poly(1,6-Heptadiyne) Derivatives Containing Hydroxy Functional Group

Abstract

Abstract 1,6-Heptadiyne derivatives containing hydroxy and aromatic substituents, 4-hydroxy-4-phenyl-l,6-heptadiyne (HPHD), 4-hydroxy-4-(4′-methylphenyl)-l,6-heptadiyne (HMHD), and 4-hydroxy-4-(4′-methoxy-phenyl)-l,6-heptadiyne (HMOHD), were prepared and polymerized by various transition metal catalyst systems. A molybdenum complex was found to be the most effective catalyst for the cyclopolymerization of 4-hydroxy-l,6-heptadiyne derivatives. Polymerization of 4-hydroxy-l,6-heptadiyne derivatives by MoCl5-based catalysts gave soluble and highly colored polymers. HMOHD containing the methoxy functional group showed the highest reactivity in cyclopolymerization. The structures of the resulting polymers were elucidated with IR, 1H- and 13C-NMR, and UV-visible spectroscopies. The present polymers were thermally and oxidatively more stable and had higher number-average molecular weights (Mn) of 2 × 104 to 3 ×104 than the corresponding 4-hydroxy-1,6-heptadiyne derivatives containing aliphatic substituents.