Intrinsic Viscosity-molecular Weight Relationship Research Articles

Synthesis and Intrinsic Viscosity-molecular Weight Relationship of Poly(ethylene adipate)

Synthesis and Intrinsic Viscosity-molecular Weight Relationship of Poly(ethylene adipate)

Determination of intrinsic viscosity-molecular weight relationship for cellulose in BmimAc/DMSO solutions

For simply and accurately determining molecular weight of cellulose, an ionic liquid mixed with a co-solvent, 1-butyl-3-methylimidazolium acetate/dimethyl sulfoxide (BmimAc/DMSO) (1:1, w/w) was used and dissolved cellulose well at ambient temperature. During the dissolution process no degradation of cellulose was observed, and all the resultant cellulose/BmimAc/DMSO solutions were transparent and stable. These advantages make it as an ideal solvent system to build a new characteristic method of cellulose’s molecular weight by the measurement of the intrinsic viscosity [η], which is significantly better than the currently used solvent systems. [η] of solutions of nine cellulose samples was measured by using rheometer with cylinder fixture and Ubbelohde viscometer, respectively. The [η] values obtained by these two methods were well consistent. The degree of polymerization (DP) of these cellulose samples was determined by Copper (II) ethylenediamine method. Then the molecular weight and its distribution of representative samples were cross-checked by gel permeation chromatography for soluble derivatives of cellulose. As a result, a relationship DP = 134 [η]1.2 was built, suitable for DPs in the range of 220–1400. The uncertainty of this relationship was estimated to be 5 %. This work provided a simple, accurate and reliable method for determining [η] and the molecular weight of cellulose.

Characteristics of Poly(3,5-Dimethylphenylacrylate) in Ethyl Acetate at 25 and 30°C

The flow times of ethyl acetate (EA) and poly(3,5-dimethylphenylacrylate) (35PDMPA) in EA were measured using a Cannon-Ubbelohde semi-micro-dilution capillary viscometer in a thermostated water bath at 25 and 30°C ± 0.02°C. The intrinsic viscosities [η] of 35PDMPA/EA solutions were evaluated by classical Huggins, and Kraemer's methods. The values of Huggins’ constant were related to the polymer–solvent interactions and the nature of the polymer solution. The intrinsic viscosity–molecular weight relationship was established with the two-parameter classical methods of Staudinger–Mark–Houwink–Sakurada and Stockmayer–Fixman. The conformational parameter C∞ and the rigidity factor σ indicated 35PDMPA was semiflexible. Also, the values of [η] and of 35PDMPA samples in EA fit well into the Yamakawa–Fujii worm-like touched-bead model of stiff chains theory modified by Bohdanecký. Comparing the molecular parameters of 35PDMPA in EA with that of 35PDMPA in toluene at the same temperature showed that this polymer was more flexible in EA.

Intrinsic viscosity–molecular weight relationship and hydrodynamic volume for pullulan

AbstractA numerical method for determination of Mark–Houwink–Sakurada (MHS) equation constants, a and K, was tested with success for two series of pullulan standard samples having narrow and broad molecular weight distributions (MWD) and taken into account their polydispersity. Different solvents, which were used to determine the intrinsic viscosities and the viscometric constants, a and K (published in the literature for pullulan), were compared. The various parameters affecting the constants are discussed. The procedure to determine the correct value of the hydrodynamic volume for pullulan was also described. This study resulted in the following MHS equations for narrow and broad MWD series of pullulan samples with Mw in the range of 5–1000 kDa: equation image equation image where qMHS is the polydispersity correction factor and [η] is the intrinsic viscosity in dL g−1. The plot of log K versus exponent a was linear and inversely related. This curve was used to estimate the constant K for pullulan with a known exponent a. Among various reported solvents, the diluted aqueous salt solutions have more advantages than other solvents. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4325–4332, 2006

Flow properties of sugar beet pulp cellulose and intrinsic viscosity–molecular weight relationship

Cellulose was extracted with 5, 10, 15% NaOH at 25, 35, 45 °C for 10, 16, 22 h from defatted, protein, pectin and hemicellulose free, delignified sugar beet pulp. Extraction with 10% NaOH at 35 °C for 22 h gave the highest yield of the removal of substances with the exception of cellulose. The effects of temperature and concentration on the viscosity of sugar beet pulp cellulose solutions were examined at different temperatures and concentration levels. Twenty-eight different model equations that describe the combined effects of temperature and concentration on the viscosity were derived. Theoretical models describing the temperature and concentration dependence of viscosity were fitted to the experimental data and the model parameters in equations were determined by multiple regression analysis of the experimental data in the temperature range 10–60 °C and in the concentration range 0.5–10 kg/m 3. The viscosity of cellulose from sugar beet pulp can be predicted by the single equation: ln η=−2.8C 0.0186+1031C 0.025/T+2654 exp(0.1896C)/T 2. The average molecular weight was measured by light scattering technique. Intrinsic viscosities and molecular weights of cellulose obtained at different extraction conditions ranged between 0.347–0.0836 m 3/kg and 303,200–893,500 kg/kg mol, respectively. The molecular weight dependence of the intrinsic viscosity of the sugar beet pulp cellulose solutions was expressed by Mark-Houwink-Sakurada equation. The intrinsic viscosity–molecular weight relationship was found as η i =2.313×10 −6( M w,ave) 0.7665.

Viscoelastic properties of dilute polymer solutions: The effect of varying the concentration

Dynamic viscoelastic behavior was investigated for solutions of polystyrene in tricresyl phosphate, a good solvent, at concentrations, c, less than the coil-overlapping concentration, c*. At the infinite dilution limit, the behavior was in accord with the theory of Doi and Edwards involving the excluded volume potential and hydrodynamic interaction (HDI). Thus, the viscoelastic functions were completely derived from the intrinsic viscosity–molecular weight relation. At finite c, the complex modulus was represented by the sum of two terms. One was a Rouse–Zimm (RZ) term conveniently represented by the Zimm theory with an arbitrarily chosen value of the HDI parameter. The other was a term with a single relaxation time, longer than the longest RZ relaxation time, and with a high-frequency modulus proportional to the square of c [the long-time (LT) term]. The behavior of the RZ term indicated the stronger screening of HDI with increasing c. Using the experimental c dependence of the longest RZ relaxation time to get the relevant parameter, we compared the RZ viscoelastic function with the Muthukumar–Freed theory. The agreement was good at low concentrations, c < c*. The contribution of the LT term, which was not included in the theory, was quite significant at low frequencies; about 60% of the Huggins coefficient was attributable to this term. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 211–217, 2001

Intrinsic viscosity-molecular weight relationship for chitosan

The intrinsic viscosity–molecular weight relationship for chitosan was determined in 0.25 M acetic acid/0.25M sodium acetate. Chitosan samples with a degree of acetylation (DA) between 20 and 26% were prepared from shrimp-shell chitosan by acid hydrolysis (HCl) and oxidative fragmentation (NaNO2). Absolute molecular weights were measured by light scattering and membrane osmometry. Size exclusion chromatography (SEC) was used to determine average molecular weights (Mn, Mv, and Mw) and polydispersity. The following Mark–Houwink–Sakurada equation (MHS) is proposed for chitosan of Mw in the range of 35–2220 kDa: The value of the MHS exponent a suggests that chitosan behaves as a flexible chain in this solvent. Examination of MHS constants obtained in this work and those available in the literature with other solvents indicates that a and K are inversely related and that they are influenced by DA, and pH and ionic strength of the solvent. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2591–2598, 2000

Effect of temperature and concentration on viscosity of orange peel pectin solutions and intrinsic viscosity–molecular weight relationship

The effects of temperature and concentration on the viscosity of orange peel pectin solutions were examined at five different temperatures between 20 and 60°C and five concentration levels between 2.5–20 kg/m 3. The effects of temperature was described by an Arrhenius-type equation. The activation energy for viscous flow was in the range 19.53–27.16 kJ/mol, depending on the concentration. The effect of concentration was described by two types of equation, power-law and exponential. Equations were derived which describes the combined effects of temperature and concentration on the viscosity for two different models in the range of temperatures and concentrations studied. Orange peel pectin was extracted by using HCl (pH 2.5, 90°C, 90 min) ammonium oxalate (0.25%, pH 3.5, 75°C, 90 min) and EDTA (0.5%, 90°C, 90 min) extraction procedures. The best result was obtained with ammonium oxalate extraction in which the pectin content of the final product was 30.12%, although the efficiency among the procedures varied.The average molecular weight was measured by light scattering technique. Magnitudes of intrinsic viscosity and molecular weight of pectins obtained by extraction with HCl, ammonium oxalate and EDTA were 0.262, 0.281, 0.309 m 3/kg and 84 500, 91 400, 102 800 kg/kgmol, respectively. The molecular weight dependence of the intrinsic viscosity of the orange peel pectin solutions was expressed by Mark–Houwink–Sakurada equation. The data were fitted to equation as η i=2.34×10 −5( M w,ave) 0.8224 which helps to evaluate the average molecular weight of pectin solutions from orange peel with a knowledge of their intrinsic viscosity.

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 6. Influence of counterions on the viscosity behavior of dilute aqueous suspensions of ionic polymer latices

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 6. Influence of counterions on the viscosity behavior of dilute aqueous suspensions of ionic polymer latices

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 5. Further studies on solution viscosity of sodium poly(styrenesulfonates)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRevisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 5. Further studies on solution viscosity of sodium poly(styrenesulfonates)Junpei Yamanaka, Hidemasa Araie, Hideki Matsuoka, Hiromi Kitano, Norio Ise, Takuji Yamaguchi, Susumu Saeki, and Masakazu TsubokawaCite this: Macromolecules 1991, 24, 23, 6156–6159Publication Date (Print):November 1, 1991Publication History Published online1 May 2002Published inissue 1 November 1991https://doi.org/10.1021/ma00023a015RIGHTS & PERMISSIONSArticle Views177Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (480 KB) Get e-Alerts Get e-Alerts

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 3. Viscosity behavior of ionic polymer latices in ethylene glycol/water mixtures

The reduced viscosity of aqueous and ethylene glycol/water suspensions of ionic latex particles was measured in the presence and absence of a simple salt. The viscosity showed substantial shear-thinning effects in both the water and binary systems.

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 4. Viscosity behavior of ethylene glycol/water solutions of sodium poly(styrenesulfonate)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRevisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 4. Viscosity behavior of ethylene glycol/water solutions of sodium poly(styrenesulfonate)Junpei Yamanaka, Hidemasa Araie, Hideki Matsuoka, Hiromi Kitano, Norio Ise, Takuji Yamaguchi, Susumu Saeki, and Masakazu TsubokawaCite this: Macromolecules 1991, 24, 11, 3206–3208Publication Date (Print):May 1, 1991Publication History Published online1 May 2002Published inissue 1 May 1991https://doi.org/10.1021/ma00011a025RIGHTS & PERMISSIONSArticle Views145Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (365 KB) Get e-Alerts Get e-Alerts

A general intrinsic viscosity-molecular weight relationship for linear polydisperse polymers—3. Applicability to the evaluation of the mark-houwink-sakurada k and a constants

An empirical equation relating the intrinsic viscosity of a polymer and its number-, weight- and z-average molecular weights has been used to evaluate the K and a constants of the Mark-Houwink-Sakurada relationship, in cases where data either from monodisperse samples or from samples with known molecular weight distribution are not available. It is shown that accurate K and a values are obtained, provided the ratio of z- to weight-average molecular weights is not too high.

A general intrinsic viscosity-molecular weight relationship for linear polydisperse polymers—2. Applicability to the evaluation of molecular weights

A previously derived general equation, correlating the intrinsic viscosity of a polymer with M ̄ a , M ̄ w and M ̄ z , is tested with experimental data. Its application for the calculation of average molecular weights is discussed. Good results have been obtained for the calculation of M ̄ z using experimental [η], M ̄ n , M ̄ w together with a and K values of the Mark-Houwink-Sakurada equation taken from the literature. On the other hand, the calculation of M ̄ a , M ̄ w and M ̄ z from experimental values of [η] in different solvents gives good results for M ̄ w , whereas M ̄ n , and particularly M ̄ z may be very inaccurate in some cases.

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers: I. Viscosity behavior of dilute suspensions of ionic polymer latices

The viscosity of aqueous suspensions of ionic polymer latices was measured by using a variable shear viscometer, Ubbelohde viscometer, and a rotational viscometer. At variance with previous data, the reduced viscosity showed a strong shear rate dependence in the range between 10 and 1350 s −1 when the concentration of coexisting salt was low. At high-salt conditions, the shear rate dependence became smaller and the Einstein behavior was approached. For low-charge density latices at low- and high-salt conditions, the reduced viscosity ( η sp φ ) increased with increasing latex concentration in the low-concentration range. On the other hand, the η sp φ of highly charged samples decreased with increasing concentration at low-salt concentrations while it monotonically increased at high-salt concentration. The effective charge number of the latices, which was determined in a direct manner (by electric conductivity), was found to be rather insensitive toward the latex concentration in the same concentration range as employed in the viscosity measurements. By using the charge number thus found, we evaluated the first-order electroviscous effect from the viscosity and compared it with Booth's theory. A satisfactory agreement was found at relatively high-salt concentrations. Implications of these findings for latex systems in the viscosity properties of linear polyelectrolyte solutions are briefly discussed. The interpretation in terms of the Debye screening length is critically discussed.

Revisit to the intrinsic viscosity-molecular weight relationship of ionic polymers. 2. Viscosity behavior of salt-free aqueous solutions of sodium poly(styrenesulfonates)

La viscosite reduite des solutions depend fortement de la vitesse de cisaillement. La viscosite reduite extrapolee a cisaillement nul augmente avec la concentration du polymere jusqu'a un maximum puis decroit. L'exposant α de la relation [η]=K•M α varie entre 1,6 et 1,2. La validite de la relation masse moleculaire-viscosite pour les polyelectrolytes flexibles est discutee

Wormlike Chain Parameters of Poly(hexyl isocyanate) in Dilute Solution

Intrinsic viscosity-molecular weight relationships were determined for poly(hexyl isocyanate) in toluene and dichloromethane using a number of narrow-distribution samples covering a wide molecular weight range. The data were analyzed according to the Yamakawa–Fujii–Yoshizaki theory of viscosity of wormlike cylinders, yielding the following values for the persistence length q and molar mass ML per unit contour length: q=41—34 nm and ML=730—760 nm−1 in toluene between 10 and 40°C and q=21 nm and ML=750 nm−1 in dichloromethane at 20°C. These parameter values are favorably compared with those reported for other solvent conditions for the same polymer.

Intrinsic Viscosity-Molecular Weight Relationships for Poly(N-isopropylacrylamide) Solutions

Poly(N-isopropylacrylamide) prepared by free radical polymerization was successfully fractionated into several fractions by using a carefully water-freed acetone as solvent and n-hexane as non-solvent. Based on the viscometric and osmometric studies of these fractions, the intrinsic viscosity-molecular weight relationships were determined as: [η]=9.59 ×10-3 Mn0.65 (in tetrahydrofuran at 27°C)and [η]=14.5 ×10-2 Mn0.50 (in aqueous solution at 20°C)These relationships imply that the statistical segment of poly(N-isopropylacrylamide) takes a considerably extended form in water than it does in tetrahydrofuran. It was also found that the aqueous solution exhibited an abnormal concentration dependence of viscosity at temperatures higher than 25°C and the phase separation at 30°C.

ゲルろ過によるポリりん酸カルシウムの分別と固有粘度‐分子量関係式

ゲルろ過によるポリりん酸カルシウムの分別と固有粘度‐分子量関係式

Intrinsic Viscosity–Molecular Weight Relationships in Copolyphosphates

A number of samples of sodium potassium (Na:K=9:1 to 3:7) and lithium potassium (Li:K=9:1 to 5:5) copolyphosphates were prepared and characterized. Their number-average molecular weights were determined by end-group titration and intrinsic viscosities were determined in 0.035 N NaBr solution. Intrinsic viscosity–molecular weight relationships according to the Mark–Houwink equation were established for each series of compounds. A highly interesting feature of the results obtained was a decrease in the value of the constant a with an increase in the mole fraction of potassium in the copolyphosphates. This is a remarkable demonstration of the dependence of a on the degree of solvation; the solubilities of both kinds of copolyphosphates were found to decrease with an increase in the proportion of potassium.