bluuebunny/crossref_metadata_2025_split huggingface dataset:
The conductivity of a cation‐exchange resin
Authors: Meares P. 
Published: April 2003

AbstractAn equation relating the equivalent conductance of ions in a cation‐exchange resin to their conductance in water and the volume fraction of polymer in the swollen resin has been tested using data for the conductance of potassium ions in crosslinked polymethacrylic acid. The equation is successful for degrees of ionization at which counterion binding is not large and for degrees of swelling sufficiently high for the network to exert no sieve action on the ions. The concentration dependence of conductivity in the resin is determined by a relaxation effect similar to that in free solution and an electrophoretic which has been treated using the Kozeny law for fluid flow in a porous medium. These effects tend to cancel one another so that the concentration dependence is small. When the mean pore diameter of the network approaches the diameter of the counterions the observed conductivity is less than the theoretical value.
An investigation of the dynamic mechanical properties of polymethyl methacrylate
Authors: Maxwell Bryce 
Published: April 2003

AbstractThe dynamic mechanical properties of polymethyl methacrylate have been studied over a frequency range of from 6 × 10−4 to 1.6 × 102 cycles per second and a temperature range of from −20° to +80°C. In order to cover this frequency range with a single piece of apparatus, a modified Kimball‐type testing machine was developed. The testing method is analyzed and the data taken on polymethyl methacrylate and other plastics interpreted in terms of molecular theory. The results on polymethyl methacrylate indicate that three mechanisms of relaxation are involved in the response of the material in this frequency and temperature range. The importance of dynamic mechanical properties to the practical engineering design of plastics components is discussed. It is suggested that three‐dimensional plots of modulus or loss factor vs. frequency and temperature is the best method of describing the mechanical behavior of plastics at their use conditions.
Studies on cation exchangers. I. Infrared spectrophotometric determination of ion exchange equilibrium constants and activity coefficients in resin phase
Authors: Sobue Hiroshi , Tabata Yoneho 
Published: April 2003

AbstractThe ion exchange equilibrium constants were obtained by measurements of infrared spectra of the ion exchange resin phase, using carboxymethylcellulose film (degree of etherification 0.66) as ion exchanger. The apparent constants are calculated by the following equation:

where A and B are the concentrations of the two exchangeable cations, respectively, rA is the valence of the A ion, γA is the activity coefficient of the A ion in the electrolyte solution, ϵA is absorption intensity of carbonyl band of the carboxy radical having the A ion in an exchanger, and k is a constant. The dependence of the apparent equilibrium constants on pH and the ionic concentration in the electrolyte was investigated in the Na‐H, K‐H, NH4‐H, Ca‐H, and Sr‐H exchange systems. Further, the activity coefficients of the exchangeable ions in the resin phase were evaluated in both the uniunivalent and unidivalent exchange systems. It is concluded that the abnormal behavior of the coefficients in the resin phase would be explained by the interaction energy between the ion pairs in the resin phase, independent of the concentration of the electrolyte solutions, in the range of comparatively dilute electrolyte solutions.
Molecular weight distribution of thermally polymerized triglyceride oils. I. Application of flory's polycondensation theory
Authors: Hoeve C. A. J. 
Published: April 2003

AbstractIt is shown that Flory's polycondensation theory can be applied to polymerized oils if in the original oils the different acids are esterified at random with the alcohol groups of glycerol. This is approximately the case. Departures from this random state are smoothed out by ester interchange when the oil is heated at 300°C. for long periods, as is the case in polymerized oils manufacture. The amount of monomeric triglycerides in polymerized oils is calculated and compared with the experimental result. The amounts of some other species are also calculated.
Component effects in phase separation of polymer‐polymer‐solvent systems
Authors: Kern R. J. 
Published: April 2003

AbstractThe nature of phase separation in polymer‐polymer‐solvent systems was investigated. Threshold concentrations necessary for the separation of polystyrene and poly(methyl methacrylate) in a variety of solvents were determined. Only a rough correlation between cohesive energy densities and solvent compatibilizing powers was found. Separation data for combinations of a number of substituted polystyrenes were determined in reference solvents. The general occurrence of phase separation in these systems is thought to stem from the unique array of functional groups presented by a polymer molecule to its environment. Phase separation in conjunction with available heats of mixing indicate the exothermic heat of mixing chlorobenzene and toluene is due to interaction of the chloro group with an aromatic ring. Changes in chain extension and solvation as a function of temperature were detected by means of phase separation.
Diffusion and gelation in polyadditions. I. Vindication of the classical network theory of gelation
Authors: Gordon Manfred , Roe Ryong‐Joon 
Published: April 2003

AbstractIn this, the first of a series of four papers, the theory of diffusion control of the gelation in polyfunctional polyadditions is rejected. It is shown experimentally, that the termination step in a model system is unaffected by diffusion control until after gelation. It is shown theoretically that diffusion control of the crosslinking step sets in even later. Investigations by Grün, and by Vaughan, are relevant to this demonstration. Quantitative application of the Stokes‐Einstein theory of diffusion confirms the conclusions reached. In the absence of diffusion‐controlled crosslinking, alternative causes are examined for observed delays in gelation. These causes are intramolecular cyclization and chain transfer effects. There are well‐known mass law effects of dilution in polyfunctional systems. However, progressive dilution with monovinyl monomer in polyaddition does not—in contrast to the effects of inert diluent in polycondensation—favor internal cyclization. The true mass law effects of such dilution can readily be allowed for.
Preparation and properties of fibers containing mixed polymers. III. Polyacrylonitrile‐silk fibers
Authors: Cates David M. , White Howard J. 
Published: April 2003

AbstractFibers containing both polyacrylonitrile and silk have been spun using an aqueous solution of ZnCl2(56% ZnCl2by weight) as solvent. The relative polymer proportions ranged from 100% polyacrylonitrile to 20% polyacrylonitrile. The conditions under which the fibers were spun are discussed, as are the results of various measurements on the fibers. The x‐ray diffraction patterns, optical appearance, absorptive capacity for water and an acid dye, electrical resistivity, and mechanical properties of the fibers were studied. A few measurements on the compatibility of the polymers in solution are also reported. The results suggest that the fibers contain small, discrete regions of each polymer which are neither highly crystalline nor strongly oriented.
Some isomorphous copolyamides
Authors: Cramer Francis B. , Beaman Ralph G. 
Published: April 2003

AbstractVarious copolyamides obtainable from heptamethylenediamine (7) and bis(3‐aminopropyl) ether (303) combined with adipic acid (6) and terephthalic acid (T) were prepared. They were characterized thoroughly as bulk polymer (visual appearance, viscosity number, polymer melt temperature, solubility), as melt‐pressed films (water absorption, glass transition temperature, crystallinity) and as melt‐spun, drawn monofils (tenacity, elongation, initial modulus, compliance ratio, tensile recovery, work recovery, orientation, crystallinity, fiber stick temperature, zero strength temperature, and crystalline melting point). The reality of isomorphism in polyamides was definitely established by the linear dependence on composition of all physical properties measured for the copolymer system 303‐6/7‐6. The copolymer systems 303‐T/7‐T, 303‐6/7‐T, and 7‐6/303‐T showed decreasing tendency toward ideal isomorphism, and the system 303‐6/303‐T showed deviation from perfect isomorphous behavior in all properties. It is concluded that in the aliphatic diamines used, and ether oxygen fits well as a substitute for a methylene group, but the benzene ring fits poorly as a substitute for the four‐carbon aliphatic chain of adipic acid.
Effect of some organic acids on the diffusion of orange II in nylon 66
Authors: Browne Colin L. , Steele Richard 
Published: April 2003

AbstractThe sorption of sixteen organic acids by nylon yarn has been studied at 30°C. and the isotherms were found to fit the empirical Freundlich equation. Heats of sorption indicated that the acids are probably sorbed by physical solution in the amorphous regions of the polymer. The effects of some of these acids on the diffusion coefficient, equilibrium sorption and activation energy of diffusion of orange II in nylon film have been determined. Benzoic acid and salicylic acid were found to act as “swelling agents” and increase the diffusion coefficient of the dye, while β‐naphthalenesulfonic acid and p‐toluenesulfonic acid had no marked effect on the diffusion constant. The effects of the acids in reducing requilibrium dye sorption were found to be dependent on the dye‐like character of the acid concerned. All of the acids increased the activation energy of diffusion for the dye, so that the increases in diffusion coefficient were attributed to increase in entropy of activation.
The x‐ray diffraction, birefringence, and infrared dichroism of stretched polyethylene
Authors: Stein Richard S. , Norris Forrest H. 
Published: April 2003

AbstractThe results of a study of x‐ray diffraction, birefringence, and infrared dichroism on a series of polyethylene samples elongated between 0 and 400% are presented. It is shown that, by using any two of the three methods together, one may determine individually the orientation of the amorphous and crystalline portions of the polymer. The results of the third method may then be predicted. Both amorphous and crystalline regions orient appreciably upon stretching. The amorphous orientation is somewhat lower than that of the crystallites. Many of the amorphous chains appear to become completely stretched out. The results indicate that the degree of crystallinity remains constant during stretching and that the oscillator strength of the CH2 rocking vibration is also constant.
The rotation of polar groups in high polymers
Authors: Lewis Charles W. , Hogle Donald H. 
Published: April 2003

AbstractThe dielectric constant and loss factor of cyanoethylcellulose have been studied as functions of frequency at four temperatures. The unusually high value of the dielectric constant (13.3 at 60 cycles and 25°C.) is attributed to rotation of the CH2CN group. Anomalous dispersion in the megacycle region also supports this interpretation. Similar properties are displayed by polyvinyl‐β‐cyanoethyl ether, but allyl cyanide polysulfone gives evidence of steric hindrance.
Poly‐n‐butyl methacrylate. III. Dilute solution properties by viscosity and light scattering
Authors: Chinai Suresh N. , Guzzi Rudolph A. 
Published: April 2003

AbstractPoly‐n‐butyl methacrylate prepared by the emulsion technique was fractionated three times by the fractional precipitation procedure to obtain eight fractions. Relationships between viscosity and weight‐average molecular weight were obtained in both an ideal solvent, isopropanol, and a nonideal solvent, methyl ethyl ketone. These relationships are represented by equations:

The effect of the size of the pendant groups (‐methyl, ‐ethyl, and n‐butyl ester) on the degree of extension of macromolecules in ideal solvents is discussed. It was found that the degree of flexibility of the macromolecule increases as the size of the pendant group increases. These results are believed to be due to the short‐range interference effect of the solvent molecule on the degree of free rotation of the macromolecule.
A comparison of the dielectric dispersion behavior of corn amylose and amylopectin acetates
Authors: Ferraro Charles F. , Maurer John J. , Zagar Walter T. 
Published: April 2003

AbstractThe dielectric constants and loss factors of disks of corn amylose and amylopectin triacetates, unplasticized and plasticized with 15% by weight of dioctyl phthalate, dimethyl phthalate, and diphenyl were measured at ten frequencies throughout the range 102 to 105 c.p.s. over the temperature interval of −78 to 80°C. A two‐terminal dielectric cell constructed from stainless steel and Teflon is described which may be thermostated by direct immersion into liquid baths. The values of ΔE*, ΔS*, and ΔF* for the dielectric relaxation processes occurring in each of the eight systems were calculated from the variation with frequency of the temperature at which the maximum values of the loss factors are found. The similarities and differences which are present in the dielectric dispersion data are discussed in terms of the molecular structures of amylose and amylopectin acetates, and possible mechanisms are suggested to explain the observed behavior.
Dielectric dispersion in solutions of copper‐cellulose nitrate complex
Authors: Pauley J. L. , Testerman M. K. 
Published: April 2003

AbstractThe dielectric dispersion of solutions of cellulose nitrate has been reaffirmed; however, the dispersion has been attributed to the formation of a copper‐cellulose nitrate complex. The phenomena can be explained in the light of present theories as a resonance phenomena and occurs in the unusual frequency region of 100 to 500 kc. The variation in the dispersion frequency can be explained in terms of a “lumped constant”, oscillating, polymer aggregate. The general properties of a stiffened random coil are experimentally confirmed.
Hydrodynamic properties of polyelectrolytes. Part IV. Viscosity of polyelectrolytes
Authors: Mathieson A. R. , Porter M. R. 
Published: April 2003

AbstractThe different types of viscosity behavior which have been observed for polyelectrolytes are discussed and classified. Data are presented for sodium deoxyribonucleate and for sodium polyacrylate of different molecular sizes, and give information on the influence on the viscosity of the degree of polymerization and the flexibility of the molecule. The influence of the shear gradient is also considered. A qualitative interpretation is given based on the size of the polyions and their mutual interactions.
A redox system utilizing N‐nitrosoacetanilide for the emulsion polymerization of styrene and of butadiene‐styrene
Authors: Kolthoff I. M. , Brackman D. S. , Meehan E. J. 
Published: April 2003

AbstractThe rate of reaction of N‐nitrosoacetanilide with ferrous versenate in slightly acid solution has been shown to be equal to its rate of rearrangement. One mole of ferrous versenate is oxidized per mole of benzenediazonium chloride at pH 5.0. In the two‐phase benzene‐water system 1.6 ± 0.1 mole of ferrous versenate are oxidized per mole of N‐nitrosoacetanilide, which ratio decreases to 1.1 ± 0.1 when ethanol is added to the system. N‐Nitrosoacetanilide in combination with ferrous versenate or citrate in slightly acid medium is a redox system for the initiation of the emulsion polymerization of styrene and butadiene‐styrene. The initiating efficiency of this combination for styrene emulsion polymerization decreases continuously up to about 20% conversion when a constant value of approximately 0.2 is found.
Light scattering properties of an isotactic polymer solution
Authors: Peaker F. W. 
Published: April 2003

AbstractA polystyrene of isotactic character having a melting point (221°C.) and a degree of crystallinity in the solid state of 40%, was found to be partially soluble in toluene at 100°C. Light scattering measurements on the soluble portion indicate that the material has the high weight‐average molecular weight of 8.93 × 106. The dimensions of the molecules in solution agree with those deduced from the theoretical treatment of the polydispersed random coil, and the second virial coefficient is of the expected order.
The structure of polysiloxanes: Molecular size and shape of highly crosslinked polymethylsiloxanes in solution
Authors: Price Fraser P. , Martin Sylvia G. , Bianchi Joseph P. 
Published: April 2003

AbstractMeasurements of solution light scattering and solution viscosity have been made in ideal solvents on polymethylsiloxanes containing large percentages of crosslinking units. For the 1.5 Me/Si and 1.8 Me/Si polymers [η] = 0.326 M0.21 and [η] = 0.240 M0.28, respectively. Densities of the polymer molecules within their spheres of action have been calculated from the viscosity relationship of Flory. They are 0.10 and 0.05 g./cc. for the 1.5 and 1.8 Me/Si resins, respectively. These are to be compared with 0.007 g./cc. for a linear polydimethylsiloxane (Me/Si = 2.0). The high densities, the low viscosities, and the low viscosity exponents lead to the conclusion that these molecules are, to good approximation, spheres of constant density, a sort of micromicrogel.
Copolymerization of vinyl siloxanes with organic vinyl monomers
Authors: Pike Ronald M. , Bailey Donald L. 
Published: April 2003

AbstractA series of simple vinyl siloxanes containing monofunctional, difunctional, and trifunctional silicon atoms has been copolymerized with various organic vinyl monomers. It is now possible to predict the behavior of vinyl siloxanes of complex structure in copolymerization reactions with these vinyl monomers. The structure of the vinyl siloxane does not appreciably affect the total rate of copolymerization or its reactivity toward a given organic vinyl monomer. Vinyl siloxane monomers have comparable reactivities to monomers such as vinyl acetate, vinyl chloride, and perfluorovinyl chloride but are less reactive than acrylonitrile, styrene, and N‐vinylpyrrolidone. In copolymerization reactions involving vinyl siloxanes the total polymerization rate and the molecular weight of the copolymers are markedly affected by the amount of vinyl siloxanes in the monomer mixture. An increase in the percentage of vinyl siloxane in the monomer mixture results in a decreased polymerization rate and copolymers having lower molecular weights.
Polymerization of methyl methacrylate in polyisoprene solutions
Authors: Allen P. W. , Merrett F. M. 
Published: April 2003

AbstractThe polymerization of methyl methacrylate in solutions of three polyisoprenes (rubber, gutta‐percha, and chicle gutta) results in a product which can be separated by fractional extraction and precipitation into free polyisoprene, free polymethyl methacrylate, and a compound of the two polymers. The molecular weight of the polymethyl methacrylate component in this compound is about the same as that of the free polymer. In solution this compound hinders the precipitation of polyisoprenes and this phenomenon is responsible for previous failures to separate free polyisoprene from reaction products by fractional precipitation. Polyisoprenes retard the polymerization, the effect increasing from chicle gutta (Mn ∼ 15,000) to rubber (Mn ∼ 500,000).
The oxidation of polybutadiene. II. Property changes during oxidation
Authors: Bauman Richard G. , Maron Samuel H. 
Published: April 2003

AbstractThe oxidation of emulsion polybutadiene has been followed by observation of changes in gel content, swelling index, intrinsic viscosity, and infrared spectra. The results show that, whereas simple heating of the polymer leads primarily to crosslinking, the presence of oxygen causes both scission and crosslinking, with the predominance of either of these processes being dependent on the amount of oxygen absorbed. Increase of temperature or degree of oxidation favors crosslinking. During oxidation acid, ester, aldehyde, ketone, ether, and alcohol groups appear, but their relative proportions remain essentially constant. Also, a large extent of the oxidation occurs without resultant decrease in unsaturation, indicating, in all probability, that the double bond is not the direct point of oxygen attack.
Nature of the end groups in polystyrene prepared using benzoyl peroxide as sensitizer
Authors: Bevington J. C. , Brooks C. S. 
Published: April 2003

AbstractSamples of polystyrene prepared using benzoyl peroxide labeled with carbon‐14 in the carboxyl group only have been used to establish the conditions necessary for complete hydrolysis of the ester end groups in the polymers. Polymers prepared using 14C‐benzoyl peroxide either uniformly labeled or labeled in the benzene rings only, contain both labeled benzoyloxy and labeled phenyl end groups. From the behavior of these polymers on hydrolysis, the proportions of the two types of end groups can be determined accurately; these proportions depend upon the conditions under which the polymers are prepared.
Equilibria between polycapramide and water. I
Authors: Fukumoto Osamu 
Published: April 2003

AbstractTo increase the degree of polymerization of polycapramide, there are two processes: addition of cyclic lactam to linear polymer, and condensation between linear polymers with each other. But after the equilibrium between linear polymer and cyclic lactam is attained, the degree of polymerization is determined only by the condensation. Since the solubility of water in molten polycapramide is less than 0.5%, Henry's law holds well. The equilibrium constant of the condensation is expressed by logK= −0.30 + 1495(1/T). Under any constant vapor pressure of water, the degree of polymerization is increased as the temperature rises. When no stabilizer other than water is used, the number‐average degree of polymerization is determined by logP̄n= 5.97 − 1253(1/T) − ½ logp.
Association and entanglement in high polymers. I. Effect on viscometric properties of dimethylpolysiloxanes
Authors: Merker R. L. 
Published: April 2003

AbstractA theory of association and entanglement explaining many of the anomalous physical properties of linear high polymers has been evolved. The theory was developed from a Carothers type of relationship in which the apparent molecular weight resulting from entanglement and/or association of long polymer chains was related to the true molecular weight of the free molecules. The effects of molecular weight and association or entanglement have been related to the viscometric behavior of linear polymers. Good agreement between theory and experiment was obtained by introducing experimentally determined constants into the theoretical expression relating molecular weight and zero shear bulk viscosity for dimethylpolysiloxanes and polyisobutylenes. Theory predicts the observed increase in energy of activation for viscous flow and increase in non‐Newtonian behavior with increasing molecular weight.
Density, infrared absorption, and crystallinity in 66 and 610 nylons
Authors: Starkweather Howard W. , Moynihan Robert E. 
Published: April 2003

AbstractThe intensities of crystalline and amorphous infrared bands of 66 and 610 nylon films were plotted against density. The curves were extrapolated to zero intensity to give revised values for the amorphous and crystalline densities which are probably more accurate than those previously used. The amorphous density of 610 nylon was in agreement with the value previously measured on quenched films, but the amorphous density of 66 nylon was about 2% lower. The new values for the crystalline densities are somewhat lower than those calculated from x‐ray diffraction data.