Prediction of the Properties of Polymers from Their Structures

Ionic transport processes in polymer mixture solutions based on quaternized polysulfones

“…Theoretical determination of the molar conductivity of salt-free quaternized polysulfone solutions requires knowledge of the average distance between the charged groups in the fully extended conformation. Accordingly, this parameter was calculated considering the approach of Robinson and Stokes [63,64] applied to some linear polyelectrolytes with structures kindred to that of quaternized polysulfone, considering that each monomer unit presents charged groups (tetra-substituted ammonium ions), as well as the following structural parameters: the NAC internuclear distance of 0.347 nm, the CANAC valence bond angle of 109.5°, the CAC bond length of 0.154 nm, the length of 0.491 nm for the polymeric repeating unit in its fully extended conformation and the average distance between the charged groups belonging to consecutive units equal to 0.745 nm. Applied to the quaternized polysulfone chain, this model gave b ¼ 0:24 nm and the charge density parameter, calculated according to Eq.…”

Natural-Based Polyurethane Biomaterials for Medical Applications

“…Herein the effects of the chemical structure of polyurethanes-cellulose on their surface properties are discussed. Investigations are based on the geometric mean approach of Kälble, Owens and Wendt, Rabel (Kälble, 1969;Owens & Wendt, 1969;Rabel, 1977), on the Lifshitz-van der Waals acid/base approach of Van Oss and co-workers (Van Oss et al, 1988a;Van Oss et al, 1988b;Van Oss, 1994) and on the theoretical methods involving quantitative structure-property relationship (Bicerano, 1996). By scanning electron microscopy surface morphology was investigated.…”

“…2. Calculation of cohesive energy, by two methods, by applying the group contributions of Fedors, (Bicerano, 1996;Van Krevelen, 1990) and those of Van Krevelen and Hoftyzer, (Bicerano, 1996;Van Krevelen, 1990), (Table 7). 3.…”

“…(3)- (5)), (Van Oss et al, 1988a;Van Oss et al, 1988b;Van Oss, 1994), and theoretical method based on the structure-property relationship considering the group contribution techniques (Eqn. (6)), (Bicerano, 1996) , were used. …”

“…(6) in the following steps, (Bicerano, 1996): 1. Calculation of the zeroth-order connectivity indices o χ and o χ v and of the first-order connectivity indices 1 χ and 1 χ v , according the values of the atomic simple connectivity indices and of the valence connectivity indices (Table 6).…”