Dilute Solution Properties of Acrylonitrile/Vinylidene Chloride Copolymer

Kamide, Kenji; Miyazaki, Y.; Yamazaki, Hitoshi

doi:10.1295/polymj.18.645

Cited by 12 publications

(10 citation statements)

References 13 publications

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“…Assumptions (2) and (3) can be proved by the facts that 1) them part both in y-PAN and R-PAN in DMF solution preferentially interacts with cupric ion, 16 2) solubility of y-PAN, which is rich in them diad, 6 in DMF is poorer than that of R-PAN under the same conditions, and 3) the short range interaction parameter A for y-PAN in DMSO is larger than that for R-PAN. 17 Fact 1) shows that the m part is more anionic than the r part and facts 2) and 3) show that the m part is more rigid than the r part. For y-PAN, it is reasonable to consider the existence of the ladder-like part in them sequence.…”

Section: Cnmrmentioning

confidence: 98%

Stereoregiilarity of Polyacrylonitrile by High Resolution 13C NMR Analysis

Kamide

Yamazaki

Okajima

et al. 1985

Polym J

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ABSTRACT:A method for evaluating the pentad tacticity of polyacrylonitrile (PAN) was proposed by analyzing the splittings of the CN carbon NMR peak with high magnetic field 13 C NMR. The method was applied to PAN prepared by polymerization with a redox catalyst (R-PAN). The results showed that R-PAN is completely random in stereoregularity and the peak assignment for CN and CH carbons of R-PAN, formerly carried out for evaluating the triad tacticity, was confirmed as correct.KEY WORDS Polyacrylonitrile / 13 C NMR / Triad Tacticity / Pentad Tacticity / Bernoulli Statistics / So far numerous studies on the stereoregularity of polyacrylonitrile (PAN) have been carried out by 1 H NMR analysis. 1 -12 By analyzing CH 2 proton signals of partially deuterated PAN in solvents which make the CH 2 proton magnetically equivalent or nonequivalent, Yoshino et al. 6 concluded that PAN prepared by y-ray irradiation on the ure<,1-acrylonitrile canal complex (y-PAN) is rich in the meso (m) configuration in diad tacticity, compared with that of PAN prepared by a redox catalyst (R-PAN). Schaefer 13 and Inoue et al. 14 have recently proposed methods for determining the triad tacticity of PAN by using 13 C NMR technique at 25.14MHz. They observed three peaks in both CN and CH carbon peak regions and assigned these three peaks from a lower magnetic field to isotactic (I), heterotactic (H), and syndiotactic (S) triads for CN carbon peaks and the reverse for CH carbon peaks, assuming that the largest peak in y-PAN is attributable to I triad. Obviously, their assignment cannot be unconditionally accepted because an abundance of m diads in y-PAN increases the intensity of the NMR peaks not only for the I triad but also the H triad and if the randomness of the R-PAN can be confirmed by other methods than NMR methods, the assignment can be rigorously performed.Recently, we have found, by using a higher magnetic field (l 00. 7 MHz) 13 C NMR spectrometer, that each peak attributable to I, H, and S triads in CN carbon region is moreover constituted of three or four peak components.

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Section: Cnmrmentioning

confidence: 98%

Stereoregiilarity of Polyacrylonitrile by High Resolution 13C NMR Analysis

Kamide

Yamazaki

Okajima

et al. 1985

Polym J

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“…[2][3][4][5] 2D-heteronuclear NMR spectroscopy is being frequently used for the study of many homopolymers 6 -9 and copolymers. 10 -12 Kamide et al 13 studied the sequence distribution of acrylonitrile-vinylidene chloride copolymers by 13 C-NMR spectroscopy. Bailey and Henrichus 14 reported the relationship of sequence distribution determined by 13 C-NMR to both the copolymer property, T g , and copolymerization theory for acrylonitrile-vinylidene chloride copolymers.…”

Section: Introductionmentioning

confidence: 99%

“…10 -12 Kamide et al 13 studied the sequence distribution of acrylonitrile-vinylidene chloride copolymers by 13 C-NMR spectroscopy. Bailey and Henrichus 14 reported the relationship of sequence distribution determined by 13 C-NMR to both the copolymer property, T g , and copolymerization theory for acrylonitrile-vinylidene chloride copolymers. Fischer et al 15 and Johnson 16 reported the assignments for methylene proton resonance for vinylidene chloride-isobutylene and vinyl chloride copolymers.…”

Section: Introductionmentioning

confidence: 99%

Microstructure analysis of poly(styrene‐co‐vinylidene chloride) copolymers by NMR spectroscopy

Brar

Hekmatyar

2001

J. Appl. Polym. Sci.

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Poly(styrene-co-vinylidene chloride) (S/V) copolymers were prepared by free-radical photopolymerization using uranyl nitrate as an initiator. The microstructure of the copolymer S/V was investigated by 1 H-and 13 C{ 1 H}-NMR, 1 H-13 C-heteronuclear shift quantum correlation (HSQC) NMR, and homonuclear total correlated spectroscopy (TOCSY). The 1 H-NMR spectra of the copolymers is complex due to overlapping resonance signals of the various triad configurations. Assignments were made up to the triad and tetrad levels for the methylene and methine regions using two-dimensional HSQC experiments. A 13 C-distortionless enhancement by polarization transfer (DEPT) spectrum was used to differentiate between the carbon resonance signals of methine and the methylene units. The geminal couplings in the methylene protons and vicinal coupling between the methine and methylene protons were detected from the TOCSY spectra. Monte Carlo simulations were used to investigate the effect of the degree of polymerization on the triad fractions.

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“…This note, as an extension of the previous study,1 intends (1) to evaluate the pentad tacticity of PAN, prepared by y-ray irradiation on the urea-acrylonitrile canal complex at -78°C (hereafter, referred to as y-PAN) and (2) to assign correctly the peaks for mmrr and mrmr sequences.…”

mentioning

confidence: 99%

“…The molecular characteristics of y-PAN samples having almost the same stereoregularity in solution will be described elsewhere. 2 A whole R-PAN sample used without fractionation was the same as employed in the previous work (Mw= 16.8 x 10 4 ). 1 13 C NMR measurements were made on an FT-NMR (JEOL, FX-400) spectrometer under the following operating conditions: Polymer concentration, 5 wt%; temperature, 80°C; pulse repetition, 5 s; pulse width, 10 µs (45°); number of pulse, 64 x 50.…”

mentioning

confidence: 99%