Monomer‐isomerization polymerization. XIII. Monomer‐isomerization polymerization of 1,4‐cyclohexadiene with Ziegler‐Natta catalyst

Abstract

Abstract1,4‐Cyclohexadiene underwent monomer‐isomerization polymerization to yield poly(1,3‐cyclohexadiene) with a Ziegler‐Natta catalyst comprising TiCl4–Al(C2H5)3 catalyst with Al/Ti molar ratios of 0.5–3.0 at 60°C for 96 hr. Good yields of polymer were obtained (49.5% yield at Al/Ti = 3.0; [η] = 0.04 dl/g). The infrared and NMR spectra of the polymer were identical to those of poly‐(1,3‐cyclohexadiene), confirming that 1,4‐cyclohexadiene first isomerizes to 1,3‐cyclohexadiene and then homopolymerizes to give poly‐1,3‐cyclohexadiene. 1,3‐Cyclohexadiene polymerized without isomerization easily in the presence of TiCl3–Al(C2H5)3 catalyst at Al/Ti molar ratios of 0.5–3.0 at 60°C for 3 hr (76.3% yield at Al/Ti = 3.0; [η] = 0.06 dl/g).

Synthesis of Polymers with an Alicyclic Structure in the Main Chain. Living Anionic Polymerization of 1,3-Cyclohexadiene with the n-Butyllithium/N,N,N‘,N‘-Tetramethyl- ethylenediamine System

“…Although the synthesis of the above-mentioned polymers by the polymerization of cycloolefins, bicyclic olefins, and cyclodiolefins , has been reported, examples of polymers with directly connected alicyclic structures have been limited to those of cycloolefins or cyclodiolefins by addition polymerization. However, in all of these cases, polymers with narrow molecular weight distribution and controlled molecular weight have not yet been obtained.…”

The Most Well-Known Rearrangements in Organic Chemistry at Hand

“…Polymers were found to consist almost entirely of 1-olefin units. 1,4-Cylohexadiene also underwent monomer isomerization polymerization to yield poly(1,3-cyclohexadiene) [59]. CH…”

Scandium-Catalyzed Regio- and Stereospecific cis-1,4-Polymerization of 1,3-Cyclohexadiene and Copolymerization with Ethylene

“…1,3-Cyclohexadiene (CHD)-based polymers are of much interest from both scientific and practical perspective, because the presence of six-membered rings in the main polymer chain is expected to bring high mechanical strength and thermal stability, and moreover, chemical modification or functionalization of the residual C−C double bonds in the cyclic structure could lead to formation of a new family of high-performance polymer materials. − A variety of initiators/catalysts were reported to effect the polymerization of CHD, but few were regio- and stereospecific, because CHD can be polymerized in several different patterns in terms of 1,2- and 1,4-regioselectivity and cis - and trans -stereoselectivity. The polymerization of CHD by radicals, anions, , cations, or Ziegler−Natta catalysts usually gave amorphous poly(CHD)s containing a mixture of 1,2- and 1,4-CHD units without stereoregularity. Nickel-based catalysts were reported to show high regio- and stereoselectivity, but the resulting polymers are insoluble in common organic solvents and show melting points close to their decomposition temperatures (>300 °C), which thus makes them difficult to process and characterize by NMR and GPC analyses …”