bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus‐Containing polymers. I. Low temperature polycondensation of phenylphosphonic dichloride with bisphenols
Authors: Kim Ki‐Soo 
Published: April 2003

AbstractThis paper describes the synthesis of aryl polyphosphonates from the reactions of phenylphosphonic dichloride [benzene phosphorus oxydichloride (BPOD)] with 4,4′‐thiodiphenol (TDP) and with 4,4′‐sulfonyldiphenol (SDP) employing a dry chlorinated hydrocarbon polymerization solvent, an amine acid acceptor and under low temperature conditions. The glass transition temperatures of the polymers from BPOD/TDP are 146°C and 83°C, respectively, and the polymers begin to lose weight at about 395°C in a nitrogen atmosphere. These polymers have good flame retardancy (FR), as indicated by high limiting oxygen indices (LOI) of 50–60. Thermoplastic polybutylene terephthalate containing 7% BPOD/SDP or BPOD/TDP polymer as an FR additive has LOI values of 29 and 30, respectively.
UV absorber progenitors: Photo‐fries rearrangements of sulfonate esters of hydroxyphenylbenzotriazoles
Authors: Olson Daniel R. 
Published: April 2003

AbstractBenzenesulfonate esters of hydroxyphenylbenzotriazole UV absorbers are described as UV absorber progenitors which can be used in UV‐curable coating formulations. During UV exposure, they undergo a photo‐Fries rearrangement to form the corresponding o‐benzenesulfonyl phenol derivatives. These derivatives are formed in good chemical yield during bulk solution photolyses and are also readily formed in polymer films during exposure to sunlight. The reaction is specific for benzenesulfonate esters; little or no rearrangement takes place with benzyl, naphthyl, or alkylsulfonate esters or with benzoate esters.
Thermal decomposition kinetics of iodine‐doped polyacetylene in vacuum
Authors: Osterholm J.‐E. , Yasuda H. K. , Levenson L. L. 
Published: April 2003

AbstractThe thermal stability of iodine‐doped polyacetylene films, (CHIy)x, has been studied by means of electrical conductivity measurements, measurements on weight loss, and mass spectrometric analysis of desorbing species. When heated between room temperature and 125°C in vacuum, these films proved to be of poor thermal stability, being unstable at temperatures above 20°C. During the thermal treatments, molecular iodine desorbs from the films, resulting in an appreciable dopant weight loss with accompanying decrease in the electrical conductivity. The decomposition process does not follow simple kinetics.
Preparation of photoresponsive polymeric adsorbent containing amphiphilic polymer with azobenzene moiety and its application for cell adhesion chromatography
Authors: Ishihara Kazuhiko , Kim Munsok , Shinohara Isao , Okano Teruo , Kataoka Kazunori , Sakurai Yasuhisa 
Published: April 2003

AbstractIn order to develop a new type column chromatography, a polymeric adsorbent was prepared by grafting a photoresponsive polymer containing an azobenzene moiety on the surface of controlled pore glass beads. The polarity of the surface of the polymeric adsorbent was increased by UV irradiation because of trans–cis isomerization of azobenzene moiety. Adhesion chromatography of erythrocytes was carried out using the photoresponsive polymeric adsorbent. The erythrocytes were adhered to the adsorbent in the dark and separated from the adsorbent by UV irradiation. This behavior appears to be caused by the photoresponse of the polarity change on the surface of the polymeric adsorbent. The morphology of the erythrocytes which adhered on the surface of the photoresponsive polymeric adsorbent remained unchanged both in the dark and after UV irradiation. The amount of erythrocytes which adhered to the adsorbent increased with increasing the molecular weight of the grafted polymer and the hydrophobicity of the surface.
Studies of synthesis and permeabilities of special polymer membranes. LI. Active transport of halogen ions through chitosan membranes
Authors: Uragami Tadashi , Yoshida Fumihiko , Sugihara Mizuho 
Published: April 2003

AbstractAnion exchange membranes containing amino groups, insoluble in acidic and alkaline aqueous solutions, were prepared from chitosan, poly(vinyl alcohol), and glutaraldehyde. Using the membrane in a diaphragm cell, one side being adjusted to be acidic and the other alkaline, it was possible to transport actively halogen ions through the membrane from the acidic side to the alkaline side against the concentration gradient between both sides of the membrane. The active transport of halogen ions through the membrane was significantly influenced by the pH difference and electric potential difference between both sides of the membrane.
Swelling behavior of cotton fibers in benzylamine and 4‐amino acetophenone
Authors: Lokhande H. T. , Nikte V. V. , Shukla S. R. 
Published: April 2003

AbstractSwelling and decrystallizing action of aqueous solutions of benzylamine and mixtures of 4‐amino acetophenone with methanol was studied on cotton fibers. The extent and type of swelling were studied by determining various characteristics of the swollen cotton, viz., moisture regain, acetyl number, infrared crystallinity index, and water of imbibition values. Benzylamine was found to be an intracrystalline swelling agent, while 4‐amino acetophenone brought about changes in the accessible regions only. Benzylamine has been regarded as substituted methylamine, and its swelling and decrystallizing action on cotton fibers has been explained on the basis of its ability to form specific hydrates with water. The intercrystalline swelling action of 4‐amino acetophenone resulted in further opening up of the accessible portions of the fiber. This was explained on the basis of its inability to form any specific complexes with methanol as well as its low basicity. The weak basic character of 4‐amino acetophenone was attributed to the substitution of deactivating and meta‐directing acetyl group in the para‐position to the amino group of aniline.
Introduction of polymers into fibrous structures by solution impregnation
Authors: Rigdahl M. , Westerlind B. , Hollmark H. , De Ruvo A. 
Published: April 2003

AbstractDry‐formed networks of cellulose fibers, produced with a laboratory device, have been impregnated with aqueous solutions of poly(vinyl alcohol) or solutions of poly(vinyl acetate) in acetone. In both cases, the strength and stiffness of the networks increase several times compared with the unmodified structure. When aqueous solutions are used, it appears that a minimum amount of poly(vinyl alcohol) is required (ca. 2 wt %) to increase the strength appreciably, but when poly(vinyl acetate) dissolved in acetone is used, as a binder, the strength improves even at the lowest level of polymer addition. For the systems studied here, the elongation at rupture increased with increasing polymer concentration. In most cases, the amount of polymer in the network structure was less than 10 wt %. Some results from impregnations using other polymeric systems, e.g., latices, are also reported.
Spectroscopic elucidation of chemical structure of plasma‐polymerized pyridine
Authors: Hozumi K. , Kitamura K. , Hashimoto H. , Hamaoka T. , Fujisawa H. , Ishizawa T. 
Published: April 2003

AbstractChemical structure of the plasma‐polymerized pyridine film produced on a glass reactor wall by means of the plasma technique in which the pyridine vapor was electronically excited by high‐frequency power under a reduced pressure was elucidated. The polymer was highly hydrophilic and was soluble to some of the polar organic solvents so that nitrogen‐containing polar functional groups were predicted to participate in the chemical structure of the polymer molecules. 1H‐NMR, 13C‐NMR, and IR spectroscopies, high‐resolution mass spectral data, and number‐average molecular weight determination with some aid of microelemental analysis revealed the presence of various functional groups such as imine, nitrile, amine, pyridine ring, its N‐oxide, and even amide. The oxygen atoms involved in the last two groups were supposedly introduced by contact with ambient air after the plasma process. The hydrophilic nature of the polymer which was essential for preparing reverse osmosis membrane was therefore due to the overall hydration effect of these polar functional groups.
Acid distribution in carboxylated vinyl‐acrylic latexes
Authors: Gajria C. , Vijayendran B. R. 
Published: April 2003

AbstractDistribution of acid groups in carboxylated vinyl‐acrylic latexes has been determined by a combination of aqueous conductometric and nonaqueous potentiometric titrations. Titrations analysis of vinyl acrylic latexes, in comparison to earlier reported studies with carboxylated polystyrene and all acrylic latexes, is complicated by the presence of acetic acid which originates from the hydrolysis of polyvinyl acetate. Most of the copolymerized carboxylic acid is located at the latex particle surface with some of it being buried within the particle. No serum phase polymeric carboxylic acid is detected. Polymerization conditions and the choice of the carboxylic monomer affect acid distribution. Effect of acid distribution on some latex properties is also discussed.
Diluent diffusion in polymer‐diluent systems near Tg: Migration of phthalic esters from PVC to water
Authors: Zieminski Kenneth F. , Peppas Nikolaos A. 
Published: April 2003

AbstractA new mathematical model is presented for the description of certain types of diluent diffusion (migration) through diluent–polymer systems. The model describes anomalous diluent transport into a container of finite volume, and it incorporates mass transfer limitations at the polymer/extractant interface. The extractant is assumed to diffuse slowly or negligibly into the polymer. The model is applied to experimental data obtained with two plasticizers, di(2‐ethyl‐n‐hexyl) phthalate and benzyl butyl phthalate, migrating from poly(viny1 chloride) to water.
Influence of hydrati ability of monomer on immobilization of microbial cells by radiation polymerization
Authors: Kumakura Minoru , Kaetsu Isao 
Published: April 2003

AbstractThe influence of the hydrratin ability of monomer on the immobilization of microbial cells by radiation polymerization was studied using various acrylate and diacrylate monomers. The heats of mixing of the monomers in water were determined, and the hydratin abilities of monomer and polymer were evaluated by heat of mising and water content. The shape of the immobilized cell composites varied with the hydratin ability of monomer. The enzymatic activity of the immobilized cell composites varied with the number of ethyleneglycol or methylene units in the monomers. In the immobilization using acrylate monomers, the increase of the hydration ability of the monomer introduced a spongelike composite to the formation of the immobilized cells, and, in diacrylate monomers, the increase of the hydration ability of the monomer introduced a flakelike composite to the formation of the immobilized cells, by which enzymatic activity increased.
Optimal temperature profiles for nylon 6 polymerization in plug‐flow reactors
Authors: Ramagopal A. , Kumar Anil , Gupta Santosh K. 
Published: April 2003

AbstractOptimal temperature profiles for nylon 6 polymerization in plug‐flow reactors have been obtained under different conditions using a reasonable objective function which gives more flexibility to a designer than those studied earlier. Computations suggest that the temperatures at the feed end of the reactor must be maintained at the highest permissible level (determined by the boiling point of the ϵ‐caprolactam) so as to force the degree of polymerization rapidly to the desired value. Thereafter, the temperatures should be reduced in order to minimize the undesirable cyclic dimer concentration, and, finally, near the exit of the reactor, the temperature must once again be increased in order to attain higher monomer conversion. The effect of a systematic change of values of the various design variables, one by one, is studied. The profile obtained differs substantially from those obtained by earlier workers because of the difference in the objective function as well as in the kinetic mechanism associated with the formation of the cyclic oligomer. Attempts are also made to obtain a global optimal scheme to produce a polymer of a desired degree of polymerization.
DSC study of the polyurethane formation from poly(ethylene adipate) and toluene diisocyanate
Authors: Ferrillo R. G. , Arendt V. D. , Granzow A. H. 
Published: April 2003

AbstractThe reaction of poly(ethylen adipate) (PEA) and toluene diisocyanate (TDI) is studied by means of isothermal DSC. The reaction has the stoichiometry of PEA/TDI = 0.5 and a reaction enthalpy of ΔH = −65.0 kJ/mol hydroxyl group. The kinetic order is unity over a wide range of temperature and composition of the reaction mixture. The temperature dependence of the first‐order rate constant yields an apparent activation energy of 61.1 kJ/mol. The kinetic data are accommodated by the following rate law:

A mechanism involving a mobile preequilibrium to accommodate the experimental results is proposed.
Flame retardance in polyester fabric radiolytically grafted with bromostyrene
Authors: Mey‐Marom A. , Rajbenbach L. A. , Levy M. 
Published: April 2003

AbstractIonizing radiation was employed to graft bromostyrene (BSy) onto poly(ethylene terephthalate) (PET) fabric. The fire‐retardant effect of the polymerized monomer on PET fabric was evaluated both by LOI tests and by DTA and TGA methods under conditions of controlled total combustion. The yields of HBr and BSy evolved during pyrolysis in the presence and absence of oxygen were determined. A linear correlation was found between ΔOI values and yields of HBr, and the implications of this finding are discussed. It is suggested on the strength of DTA and TGA results under total combustion conditions that the fire‐retardant effect of poly(bromostyrene) manifests itself mainly by a physical‐mode mechanism through a significant reduction in the release of flammable gases.
Influence of the stiffness of testing machines on the adherence of elastomers
Authors: Barquins Michel 
Published: April 2003

AbstractIt is shown that the introduction of the fracture mechanics concepts, such as the strain energy release rate G, to solve the problem of the adherence of elastomers, the edge of contact being seen as a crack propagating in mode I in the interface, allows one to predict the dependence of the adherence force with the stiffness of testing machines. Moreover, it is shown the general equation of the kinetics of adherence proposed in 1978 by Maugis and Barquins, G–w = wϕ(atv), where w is Dupré's work of adhesion and ϕ a dissipation function characteristic of the material only depending on temperature and crack speed, is confirmed whatever the stiffness of the testing machine and the instantaneous deformation imposed on the system. Experiments realized with a hemispherical glass lens in contact on a polyurethane surface verify theoretical predictions with an accuracy better than 1%.
Tear strength theory of semicrystalline polymers
Authors: Rohn C. L. 
Published: April 2003

AbstractA theroretical model describing how the tear strenght of semicrystalline polymers depends upon the interaction of the crystalline and amorphous phases is presented. It is based upon the “freevolume“ theory and a “Hooke's law ‐lattice energy” treatment. The strength TM is hypothesized to be partitioned between the crystalline Qc and amorphous Qa phases. Therefore TM∝︁ Qc. Qa, TM = To.Qc.Qa, where Qc = NKTE/bY2 and e−v/vf =G/Goτ. Proof of this theory is obtained by measuring the oxygen transmission rates of 11 polyethylene film samples varying in tear strenght. Good agreement exists between TM (experimental) and TM (theroetical) for 9 of the polyethylene samples. The other 2 Samples differ from the theory by factor of 2. One explantion of this departure is the τ varies from unity.
Rheology‐processing‐property relationships in tubular blown film extrusion. I. High‐pressure low‐density polyethylene
Authors: Han Chang Dae , Kwack Tae Hoon 
Published: April 2003

AbstractThree different grades of high‐pressure low‐density polyethylene resin were used to establish relationships between tubular film blowability and the molecular parameters, namely, the molecular weight distribution (MWD) and the degree of long‐chain branching (LCB), and also between the processing conditions and the mechanical properties of the tubular blown films produced. For the study, both the shearing and elongational flow properties of the resins were determined. During the tubular film blowing experiment we measured the freeze‐line position, the tubular bubble diameter, the takeup speed, the axial tension, the pressure inside the tubular bubble, and the mass flow rate of the resin. The thickness of the tubular blown films was measured from the samples collected. In order to determine the tubular film blowability, we measured the maximum takeup speed at which the tubular blown bubble broke, for various blowup ratios. The measurements described above permitted us to calculate the tensile stresses at the freeze line, in both the machine and transverse directions, and they were found to be correlatable to the processing conditions employed. It has been found that the tubular film blowability is increased as the resin's MWD becomes narrower and the degree of LCB is less. It has been found further that a resin having lower elongational viscosity tends to give a greater draw‐down ratio, indicating a better tubular film blowability. Finally, the tensile properties of the tubular blown films were found correlatable to the processing variables, namely, blowup and takeup ratios.
Rheological properties of branched low‐density polyethylene
Authors: Han Chang Dae , Kim Yong Joo , Chuang Hsiao‐Ken , Kwack Tae Hoon 
Published: April 2003

AbstractThe shear flow properties of six commercially available long‐chain branching low‐density polyethylene resins were determined, using a cone‐and‐plate rheometer at low shear rates and a capillary rheometer at high shear rates. Also determined were the elongational viscosities of the resins, using an apparatus developed by Ide and White. Interpretation of the rheological measurements is given with the aid of the molecular parameters, namely, molecular weight and molecular weight distribution.
The mechanics of tubular fiber: Theoretical analysis
Authors: Gupta Dinesh K. 
Published: April 2003

AbstractA mathematical model of a tubular fiber is analyzed to predict its rigidity and some of its physical properties which are essential in textiles. The change in the properties of a tubular fiber with increase in the size of hollow core is considered and compared with the cylindrical fiber of the same outside diameter, the same denier, and the same rigidity as that of the tubular fiber. The equations are developed in dimensionless quantities to make them invariant to the units of fiber dimensions. The analysis revealed that having a hollow core of 4/10th the size of the outside diameter, in a solid fiber, could reduce the fiber weight by 16% without making any significant change in the rigidity of the fiber.
Studies of tetrazoles as rubber chemicals. I. Preparation and characterization of reactive antioxidants based on tetrazoles
Authors: Otomo S. , Sako T. , Yamamoto Y. , Yamashita S. 
Published: April 2003

AbstractThe novel reactive antioxidants based on tetrazoles that are stable at room temperature and convertible into the highly reactive nitrileimines by pyrolysis were prepared and the reactivity for carbon–carbon double bonds was evaluated. Antioxidants, i.e., 2‐substituted phenyl‐5‐(3′,5′‐di‐tert‐butyl‐4′‐hydroxyphenyl)tetrazoles (PHPT) were prepared with the reaction of p‐toluenesulfonylhydrazone of 3,5‐di‐tert‐butyl‐4‐hydroxybenzaldehyde and substituted phenyl diazonium chloride in a mixed solvent of pyridine, ethanol, and water at −10°C to −20°C in 31‐61% yields. To evaluate the reactivities of PHPT for carbon–carbon double bonds, m‐chloro‐substituted PHPT was pyrolyzed in an excess of styrene at 160–170°C for 0.5 h to give the 1‐(3′‐chlorophenyl)‐3‐(3″,5″‐di‐tert‐butyl‐4″‐hydroxyphenyl)‐5‐phenyl‐2‐pyridazoline in a 44.1% yield by 1,3‐dipolar addition reaction of the nitrileimine formed from the m‐chloro‐substituted PHPT. The thermogravimetric analysis of a mixture of proton isomer of PHPT and liquid polybutadiene showed that PHPT attached to liquid polybutadiene with an accompanying evolution of nitrogen.
Equilibrium acid concentrations in hydrolyzed polyesters and polyester–polyurethane elastomers
Authors: Brown Daniel W. , Lowry Robert E. , Smith Leslie E. 
Published: April 2003

AbstractEquilibrium acid concentrations, [Ae], were determined in butylene adipate and caprolactone polyesters, of low molecular weight, and in thermoplastic polyurethane elastomers based on these polyesters. Values of [Ae] of the polyesters at 85°C were 0.7, 1.3, and 3‐4 × 10−3 mol/g at relative humidities (RH) of 25%, 50%, and 93%, respectively. [Ae] of the thermoplastic elastomers at 85°C were about 3 and 7 × 10−4 mol/g at 10% and 25% RH, respectively. Values of [Ae] were not very dependent on temperature at constant RH. Equilibrated thermoplastic elastomers had low molecular weights and poor physical properties. Consequently, equilibration does not set a practical limit on hydrolytic degradation, even at low RH. Equations were developed that described the variation in acid content with time. Rate constants for hydrolysis and esterification increased as RH decreased. Reesterification in the elastomers in the absence of water is too slow to be a useful method of decreasing hydrolytic damage.
Ionomeric blends. IV. Miscibility of urethane elastomers with styrene–styrene sulfonic acid copolymer
Authors: Rutkowska M. , Eisenberg A. 
Published: April 2003

AbstractBlends were prepared from two kinds of urethane elastomers, containing 1,4‐butanediol or 3,3′‐dichloro‐4,4′‐diamino‐diphenyl‐methane as chain extenders, with lightly sulfonated polystyrenes. Dynamic mechanical studies show that strong interactions occur between the sulfonic acid and the urethane or urea moieties on the polyurethane chains. These strong interactions are clearly seen in the composition dependence of the loss tangent peaks (due to the glass transitions) for both the high temperature and the low temperature glass transitions of the blends. They are further confirmed by model studies.
The preparation of multiaxially oriented polyethylene morphologies with high mechanical properties in planar direactions
Authors: Zachariades Anagnostis E. 
Published: April 2003

AbstractThe development of multiaxially oriented films of low molecular weight (Mw ≈ 59,000) high density polyethylene with high mechanical properties in planer directions has been pursued by inducing fibrillar crystallization under curvilinear flow conditions in a contained geometry using an extrudomolding process and by simulating similar crystallization conditions in an optical plate–plate rheometer. The films, like the uniaxially drawn morphologies of the same low molecular weight high density polyethylene by solid‐state extrusion, had a high modulus (12–20 GPa) and strength (0.25 GPa) along the residual flow lines but they exhibited also a modulus enhancement (5 GPa) in the transverse direction as a result of the orientation gradient of the molecular chains in the thickness directions.