Dilute Solution of Bisphenol A Polycarbonate

Abstract

ABSTRACT:Narrow-distribution fractions of bisphenol A polycarbonate in tetrahydrofuran (THF) and chloroform were studied by light-scattering, sedimentation velocity, and viscosity measurements over the range of molecular weights from 4x 103 to 5x 10 5 • The asymptotic values of a dimensionless quantity A2Mwl[r;] and the interpenetration function lJf where significantly lower than those usually expected for flexible polymers, suggesting a certain stiffness of the polycarbonate chain. Here A2 is the second virial coefficient, Mw is the weight-average molecular weight, and [r;] is the intrinsic viscosity. Data for statistical radii <S 2 ) 1 / 2 , sedimentation coefficients so, and [r;] in THF were analyzed in terms of the wormlike chain model. First, the three parameters q, ML, and d characterizing the wormlike cylinder were estimated by using a recent theory of so by Yamakawa and Fujii and assuming that the hydrodynamic volume per gram is equal to the partial specific volume of the polymer. Here q is the persistence length, ML is the shift factor defined as the molar weight per contour length, and d is the diameter of the cylinder. The results were q= 18 A, ML=26 daltonsiA, and d=6.6 A. It was then shown that these molecular parameters and small expansion factors for the excluded volume allowed a consistent interpretation of the experimental data for so, <S 2 ), and [r;]. The consistency between the intra-and inter-molecular excluded-volume effects were also examined by use of the perturbation theories for a 8 (expansion factor for <S2)) and for A2 of the wormlike beads. An important finding from the present study is that, while as of the polycarbonate in THF is rather small, the binary cluster integral between a pair of monomers is quite large (about 170 x 10-24 cm3).

Stiff Chain Behavior of Poly(phthaloyl-trans-2,5-dimethyIpiperazine) in Dilute Solution

“…In this case, the value of -(2qML}1 12 g(d/2q) also may be determined from the initial slope of the plot together with the <Poo value so obtained. As a necessary fourth relation, we propose, in accordance with Tsuji,et al,5 Polymer J., Vol. 9, No.…”

“…The data points for each fraction follow a linear relation represented by 12 ( 5) It is to be observed that two sets of plotted points, one from the peak method and the other from the Baldwin method, fall on a single line, as should be expected. Table V summarizes the values of s0 and ks for all the fractions that were subjected to sedimentation velocity experiments.…”

“…The procedures of measurement used were the same as described elsewhere. 5 The absolute Rayleigh ratio for benzene at 25°C and 436 nm was taken to be 46.5 x 10-6 cm-1 for the calibration of the apparatus. 6 The depolarization, Pu, of benzene was found at be 0.429 at 436 nm, in good agreement with the reported values.…”

Stiff and hierarchical chain nature of atactic and stereoregular poly(substituted methylene)s

“…The high l p (6.0 nm) relative to the contour length (16.9 nm) of atactic PPMO also indicates the abnormal linearity of its main chain. The l p value of PPMO is much larger than that of various ordinary synthetic polymers such as polystyrene ( ca 0.9 nm), poly(α‐methylene‐γ‐butyrolactone) ( ca 0.9 nm), bisphenol A polycarbonate ( ca 1.8 nm) and poly(1‐phenyl‐1‐propyne) ( ca 3.8 nm) . Furthermore, the l p of PPMO is comparable to that of polysaccharides such as alginate ( ca 9 nm) and single‐stranded deoxyribonucleic acid ( ca 2.5 nm) despite the chemical structure of PPMO without any functional moieties such as polar substituents.…”

“…Here, E was estimated from the slope of the tangent (red lines). The black dots are derived from the form factor for the Gaussian coil model (0.02 − 0.1 nm −1 ), fuzzy spheres model (0.1 − 1.1 nm −1 ) and wormlike chain model (1.1 − 3.0 nm −1 ) in the relevant regions. The peak at 4.5 nm −1 corresponds to the helical pitch of stereoregular PPMO (and discussed in detail in the main text).…”