Conformation and dynamic aspects of poly(.gamma.-n-octadecyl L-glutamate) in the solid state and liquid-crystalline state as studied by variable-temperature carbon-13 CP/MAS NMR spectroscopy

A study of diffusional behavior of polymer having semiflexible main-chain with long n-alkyl side-chains as associated with structural behavior of the side-chains

“…1). This spectral behavior is similar to that of polypeptides [3][4][5] and polymers [16,17] with n-alkyl sidechains. On the other hand, the intensity for peaks in the observed 13 C DD-MAS spectrum of PODMA is increased with an increase in temperature from 30 to 80°C as shown in Figs.…”

“…2 together with the chemical structure, of which all of the carbons are numbered. The peak assignments are made by using reference data for poly(L-glutamate) with n-octadecyl side-chains as reported previously [2][3][4][5]17] and for rodlike aromatic B-Cn polyester as reported by Sone, et al [16] The CH 3 and CH 2 carbons of the n-alkyl side-chain and main-chain appear in the range of 0-40 ppm and the carbonyl carbon appears in the vicinity of 175-177 ppm. These peaks are straightforwardly assigned to the n-alkyl side-chain CH 3 , CH 3 attached to the main-chain, a-CH 2 , b-CH 2 , internal CH 2 , c-CH 2 , OCH 2 and C@O carbons from upfield, respectively, which are numbered to C9, C1, C8, C7, C6, C3, C2, C5 and C4 carbons on corresponding peaks by using reference data reported previously [2][3][4][5]16,17].…”

“…often form the LC phase at temperatures above the T m of the crystallized side-chains. For example, poly(c-glutamate)s with n-alkyl side-chains longer than n = 10 (n: the number of carbon atoms in the n-alkyl side-chain) form thermotropic cholesteric LC phase by the melting of the sidechain crystallite as studied by Watanabe et al [1] Structural and dynamic characterizations of the main-chain and the n-alkyl sidechains of poly(c-glutamate)s having n-alkyl side-chains with various chain-lengths have been systematically made to understand the formation of thermotropic LC phase by means of solid-state 13 C NMR method as studied by Yamanobe, Ando et al [2][3][4][5] Further, it has been reported that poly(c-glutamate) with n-oleyl side-chains forms the thermotropic LC phase in a wide range of temperatures [6,7], but poly(b-aspartate) with n-octadecyl side-chains does not form the thermotropic LC phase because a change of the helical sense of the main-chain occurs at higher temperatures above the T m of the side-chain crystallite [8]. Recently, structure and dynamics of poly(b-aspartate) with n-octadecyl side-chains in the solid-state have been studied in details [9,10].…”

Diffusional Behavior of Polypeptides in the Isotropic, Biphasic, and Liquid Crystalline Phases As Studied by the Pulse Field-Gradient Spin−Echo1H NMR Method

“…[3][4][5][6][7][8] From these experimental results, it has been shown that the diffusion of the rodlike polypeptide chain is anisotropic and follows the Kirkwood theory of rodlike polymers 9,10 and that high field-gradient NMR is a very powerful means for determining very small diffusion coefficient for polypeptide systems.…”

Effect of nonconjugated polymers on the conjugation length and structure of poly(3‐octylthiophene) in ternary polymer blend

“…The rest methylenes (numbered [5][6][7][8][9][10] show split peaks at 31.2 ppm from amorphous (gauche-) region and 33.2 ppm from crystalline (trans-) region. [28][29] The rest carbons of thiophene ring contribute to the peaks of 126 (numbered 2), 131 (numbered 3), 133 (numbered 1), and 136.5 (numbered 4), respectively.…”