Dilute solution properties of poly(vinyl acetate). I. Molecular weight dependence of the limiting viscosity number in a few solvents

Ueda, Minoru; Kajitani, Koichi

doi:10.1002/macp.1967.021080110

Cited by 38 publications

(3 citation statements)

References 33 publications

(3 reference statements)

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“…In figure 1 we give the log [TI] ] versus log M representation for three polymer-solvent systems : polyethyleneglycol (POE)-dimethylformamide (DMF) [7], poly[2-(triphenylmethoxy) ethyl methacrylate] (PTEMA)-toluene [8] and polyvinylacetate (PVAc)-chloroforme [9]. The deviation of [q from the linearity of log [77 ] versus log M representation is appeared in a very different molecular weight for each polymer.…”

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confidence: 99%

Characteristic numbers of polymers in dilute solution : a universal description of the cross-over effects

Dondos

1987

J. Phys. France

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The viscosimetric behaviour of eleven polymer-solvent systems is analysed in order to determine the characteristic numbers in the beginning and in the end of the cross-over region. In the beginning we have a cross-over between Gaussian and excluded volume behaviour and in the end a cross-over between partial excluded-volume and complete excluded-volume behaviour (in the second cross-over the chain exhibits an excluded volume statistics on a macroscopic scale and starts the linearity between log [η ] and log M). We show that in the beginning and in the end of the cross-over region the characteristic molecular weight or the characteristic number of monomers is different for different polymers and the second is related to the stiffness of the chain. In the contrary, the characteristic number of statistical segments in the beginning and in the end of the cross-over region are about the same for all the polymers, and this result confirms the validity of a universal description of polymer solutions

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confidence: 99%

Characteristic numbers of polymers in dilute solution : a universal description of the cross-over effects

Dondos

1987

J. Phys. France

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“…The region where the asymptotic behavior is attained depends on the values of A′ η and K 0 and, therefore, on the structure of the polymer. The shape of plots of log [η] vs log M predicted for chains with positive ξ has indeed been observed with polystyrene, 9 polyisobutylene, 10 poly(methyl methacrylate), 11 and poly-(vinyl acetate) 12 (code numbers 10, 5, 25, and 17). We content ourselves with this qualitative conclusion and do not pursue the discussion in quantitative terms because, as has been shown recently, [9][10][11]13 other factors not accounted for in the theory of the wormlike cylinder (e.g., loose helical conformations) may take the hydrodynamic behavior more involved at low molecular weights.…”

Section: Discussionmentioning

confidence: 55%

Mark−Houwink−Kuhn−Sakurada Exponent at the ϑ Condition. Its Invariancy with Respect to the Cross-Sectional Dimensions of Polymer Chains

Bohdanecký

1996

Macromolecules

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The question raised by Fujita has been examined, namely why the intrinsic viscosity of many polymers at the ϑ condition [η]0 is proportional to M 1/2 over a broad range of molecular weights. An explanation is proposed, based on a combination of the theory of the wormlike cylinder model with reported data on cross-sectional dimensions of 30 polymers with the carbon backbone differing in both the size and type of side groups (vinyl polymers, polyacrylates, polymethacrylates). The behaviors of poly(dimethylsiloxane) and poly(ethylene oxide), which are not in line with this explanation, are briefly discussed.

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“…Thus, HMW PVAc with high conversion is rarely obtained at the same time 17. To reduce the polymerization heat and the viscosity of the medium, solution polymerization of VAc was tried 25, 26. This solution polymerization method has advantages of easy control of polymerization exotherm and of higher conversion than those of bulk polymerization.…”

Section: Introductionmentioning

confidence: 99%

Preparation of high molecular weight poly(vinyl alcohol) with high yield using low‐temperature solution polymerization of vinyl acetate

Lyoo¹,

Han²,

Choi³

et al. 2001

J of Applied Polymer Sci

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Vinyl acetate (VAc) was solution-polymerized in tertiary butyl alcohol (TBA) and in dimethyl sulfoxide (DMSO) having low chain transfer constant at 30, 40, and 50°C, using a low temperature initiator, 2,2Ј-azobis(2,4-dimethylvaleronitrile) (ADMVN). The effects of polymerization temperature and initiator concentration were investigated in terms of polymerization behavior and molecular structures of poly(vinyl acetate) (PVAc) and corresponding poly(vinyl alcohol) (PVA) obtained by saponification with sodium hydroxide. The polymerization rates of VAc in TBA and in DMSO were proportional to the 0.49 and 0.72 powers of ADMVN concentration, respectively. For the same polymerization conditions, TBA was absolutely superior to DMSO in increasing the molecular weight of PVA. In contrast, TBA was inferior to DMSO in causing conversion to polymer, indicating that the initiation rate of VAc in TBA was lower than that in DMSO. These effects could be explained by a kinetic order of ADMVN concentration calculated using initial rate method and by an activation energy difference of polymerization obtained from the Arrhenius plot. Low-temperature solution polymerization of VAc in TBA or DMSO by adopting ADMVN proved successful in obtaining PVA of high molecular weight (number-average degree of polymerization (P n ): 4100 -6100) and of high yield (ultimate conversion of VAc into PVAc: 55-80%) with diminishing heat generated during polymerization. In the case of bulk polymerization of VAc at the same conditions, maximum P n and conversion of 5200 -6200 and 20 -30% was obtained, respectively. The P n and lightness were higher, and the degree of branching was lower with PVA prepared from PVAc polymerized at lower temperatures in TBA.

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Dilute solution properties of poly(vinyl acetate). I. Molecular weight dependence of the limiting viscosity number in a few solvents

Cited by 38 publications

References 33 publications

Characteristic numbers of polymers in dilute solution : a universal description of the cross-over effects

Characteristic numbers of polymers in dilute solution : a universal description of the cross-over effects

Mark−Houwink−Kuhn−Sakurada Exponent at the ϑ Condition. Its Invariancy with Respect to the Cross-Sectional Dimensions of Polymer Chains

Preparation of high molecular weight poly(vinyl alcohol) with high yield using low‐temperature solution polymerization of vinyl acetate

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