Conformations of hydrogenated ring-opened poly(norbornene)s in dilute solution

The characteristic ratios C ∞ of syndiotactic, isotactic, and atactic hydrogenated ring-opened poly(norbornene)s, H-poly(NB)s, were determined in 1,2,4-trichlorobenzene (TCB) at 140 °C with molecular dynamics simulations and size exclusion chromatography with a multiangle light-scattering online detector (SEC-MALS). The C ∞ results were 11, 14 and 12 for syndiotactic, isotactic and atactic H-poly(NB), respectively, all of which were consistent with the rotational isomeric state model. These C ∞ values for H-poly(NB)s were definitely larger than those for polyethylene and syndiotactic and isotactic polypropylenes. The stiffness of the H-poly(NB) chains was induced by the internal rotations of two main-chain bonds included in the cyclopentane ring in each H-poly(NB) repeat unit, which were restricted near the trans conformation. The characteristic ratios C ∞ of syndiotactic, isotactic, and atactic hydrogenated ring-opened poly(norbornene)s, H-poly(NB)s, were determined in 1,2,4-trichlorobenzene at 140 °C with molecular dynamics simulations and size exclusion chromatography with a multiangle light-scattering online detector (SEC-MALS). The C ∞ results were 11, 14 and 12 for syndiotactic, isotactic and atactic H-poly(NB), respectively, all of which were consistent with the rotational isomeric state model, and definitely larger than those for polyethylene and polypropylenes. The stiffness of the H-poly(NB) chains was induced by the cyclopentane ring in the chains.