bluuebunny/crossref_metadata_2025 huggingface dataset:
Grafting of cyclic carbonates onto cotton and modified cottons
Authors: Ward Truman L. , Benerito Ruth R.
Published: April 2003

Cyclic carbonates react with amines to form carbamates, with alcohols to form hydroxyalkylated products, and with dibasic acids or dibasic acids plus a glycol to form polyesters. These types of reactions between ethylene, propylene, or glycerine carbonate and cotton, either unmodified or modified to contain amine or carboxyl groups, were investigated. Effects of method of application, temperature, time of reaction, and pressure were studied. Temperature in excess of 100°C and reduced pressures were satisfactory for removing the water formed. Reaction between cyclic carbonates, dibasic acids, a glycol, and nonaqueously prepared carboxymethylated cotton in a vacuum oven yielded a fabric with conditioned and wet wrinkle recovery of approximately 300(W + F)°. Infrared spectra, wrinkle recovery, and weight gain indicated that crosslinks formed in reactions between unmodified or carboxymethylated cotton and the cyclic carbonate. Reactions with aminized or diethylaminoethylated cotton formed terminal grafts.
Effect of low temperatures on polymorphic structures of cotton cellulose
Authors: Jung Hilda Z. , Benerito Ruth R. , Berni Ralph J. , Mitcham Donald
Published: April 2003

Effects of low temperatures upon fine structures of cotton pretreated with either liquid ammonia or caustic of mercerizing strength were investigated. Temperatures of cotton after impregnation with liquid ammonia were lowered by (1) liquid nitrogen, (2) acetone–Dry Ice, (3) acetone, or (4) simple evaporation. With alkali‐impregnated fabrics, temperature was lowered by immersion in liquid nitrogen. Changes in fine structure of ammonia‐ and alkali‐celluloses were evaluated by x‐ray diffraction before and after removal of each swelling reagent. After treatment with either ammonia or caustic soda, extent of crystalline modification was increased as temperature was reduced. X‐ray diffractograms taken while liquid ammonia was still present indicated that the cellulose I structure of cotton sheeting was converted to cellulose III at liquid nitrogen temperatures; extent of conversion was approximately that obtained when a looser yarn structure was treated with liquid ammonia and the ammonia was removed by evaporation. When ammonia was removed with water, the cellulose I lattice was regenerated. In the presence of 23% NaOH, diffractograms indicated a significant decrease in order after a similar drop in temperature, but patterns were not of cellulose II until the NaOH was removed with water. Conversion to cellulose III or to cellulose II was achieved instantaneously when ammonia‐ and alkali‐impregnated fabrics were immersed in liquid nitrogen.
Origin and role of the luminescent species in the photo‐oxidation of commercial polypropylene
Authors: Allen N. S. , Homer J. , McKellar J. F.
Published: April 2003

The fluorescence and phosphorescence excitation and emission spectra of commercial polypropylene have been examined using a fully compensated spectrofluorometer. This has made possible the comparison of the excitation spectra of the polymer with model chromophores of those believed to be present in the polymer. The fluorescence emission is primarily associated with the presence of enone, and the phosphorescence with dienone chromophoric units. The behavior of the luminescent enones and dienones during irradiation under sunlight‐simulated conditions has also been examined. Possible mechanisms for the participation of these chromophoric units in the photo‐oxidation of polypropylene are discussed.
Fully ordered copolyhydrazides based upon bisacid A2
Authors: Lenk R. S.
Published: April 2003

The preparation of copolyhydrazides containing equimolar quantities of “bisacetyl A2” and terephthaloyl or isophthaloyl groups is described. The resulting copolymers were found to form clear colorless films which, when immersed in concentrated formic acid, softened but rehardened and turned white after subsequent immersion in water. The formic acid treatment did not bring about a morphological change from the amorphous to the crystalline state, but caused changes in the differential scanning calorimetry (DSC) traces which suggest that an α/β transformation had taken place. The possible nature of this transition is discussed. The results of tensile tests on cast film are given.
The influence of hydrophilic and hydrophobic domains on water wettability of 2‐hydroxyethyl methacrylate‐styrene copolymers
Authors: Okano Teruo , Katayama Masato , Shinohara Isao
Published: April 2003

Cooligomers and ABA‐type block copolymers composed of a hydrophilic monomer, 2‐hydroxyethyl methacrylate (HEMA), and a hydrophobic monomer, styrene, were synthesized to study the relation between their microstructure and hydrophilic and hydrophobic functions. Films of cooligomers and ABA‐type block copolymers were cast from DMF solutions at 40°C. The wettability, which was determined from the contact angle with water, increased considerably when HEMA mole fraction reached around 0.8 in the cooligomer system and around 0.9 in the ABA‐type block copolymer system. The microstructures of the copolymer films were observed by electron microscopy using the osmium tetroxide fixation technique. The morphologic change in the domain structure was observed at an HEMA mole fraction of about 0.8 in the cooligomer system and about 0.9 in the ABA‐type block copolymer system. It is suggested that hydrophilic and hydrophobic functions are largely influenced by the state of aggregation of each segment, that is, the size and geometry of the hydrophilic and hydrophobic domains.
Force–displacement evaluation of macromolecular materials in flexural impact tests. II. Influence of rubber content, degree of grafting, and temperature on the impact behavior of ABS resins
Authors: Rink M. , Riccò T. , Lubert W. , Pavan A.
Published: April 2003

The impact behavior of ABS (acrylonitrile–butadiene–styrene) resins was studied by measuring the force–deflection curve generated during flexural impact tests. Each curve is characterized by a limited number of significant parameters. Their dependence on the following constitutive or ambient variables was investigated: content of butadiene rubber, degree of grafting of acrylonitrile and styrene onto polybutadiene, and temperature. The results are analyzed phenomenologically and are tentatively interpreted in the light of possible micromechanical mechanisms.
Microstructure and its relationship to deformation processes in amorphous polymer glasses
Authors: Wellinghoff Stephen T. , Baer Eric
Published: April 2003

The microdeformation morphology of a number of vinyl polymers with bulky side chains (type I) and arylene polymers with flexible oxygen linkages (type II) was studied by electron microscopy. The polyarylenes crazed only near the glass transition while the polyvinyls exhibited a crazing regime that extended to liquid nitrogen temperatures. In addition significantly less plastic strain was localized in type II glass crazes relative to those in type I glasses. In compatible blends of polystyrene (PS) and 2,6‐dimethyl poly(phenylene oxide) (2MPPO), ca. 30% 2MPPO was sufficient to induce a transition from type I to type II crazing behavior. Small amounts of PS suppressed the low‐temperature 2MPPO β relaxation but enhanced the intermediate transition of 2MPPO at higher temperatures. Blending increased the conformational energy of the 2MPPO chain and improved interchain packing. The propensity for the polymer glass to form sharp shear bands at the expense of diffuse bands was increased by a decrease in the conformation energy of the polymer chain and an improvement in the glassy state packing.
Synthesis of metal‐containing cured resins from divalent metal salts of mono(hydroxyethyl) phthalate, anhydrides, and bisepoxides
Authors: Matsuda Hideaki
Published: April 2003

Synthesis of novel metal‐containing cured resins based on divalent metal salts of mono(hydroxyethyl) phthalate were investigated by the metal salt–anhydride–bisepoxide reactions. As the anhydrides, maleic anhydride (MA) and hexahydrophthalic anhydride (HPA) were used, and hexahydrophthalic acid diglycidyl ester (HPDG), bisphenol A diglycidyl ether (BADG), and ethylene glycol bis(glycidyl phthalate) (EBGP) were the bisepoxides used. The reactions were further studied in model reactions using the Ca salt of monoethyl phthalate. The metal carboxylate groups of the metal salts catalyzed the reactions. The reactivity of the bisepoxides decreased in the order HPDG ≫ BADG > EBGP, and MA was more reactive than HPA. Some of the metal‐containing cured resins obtained showed excellent physical properties. Resistance to chemical attack and boiling water, thermal behavior, and electrical resistance are also discussed.
Thermal degradation of polymers. Part XX. The effect of thermal ageing on thermal diffusivity and hardness of polyquinazolones
Authors: Chan H. S. O. , Still R. H.
Published: April 2003

Pre‐polymers prepared from 4,4′‐diaminodiphenyl‐3,3′‐dicarboxylic acid and aromatic diacetamido compounds have been cyclized under optimized conditions. The thermal diffusivity and hardness of these materials have been evaluated. The effect of thermal ageing on these parameters and weight loss has also been investigated. Changes in these parameters have been related to the possible structural changes occurring within these systems. These changes are discussed in terms of the potential use of these materials in tribological applications.
Effect of winding speed on the physical structure of as‐spun poly(ethylene terephthalate) fibers, including orientation‐induced crystallization
Authors: Heuvel H. M. , Huisman R.
Published: April 2003

As‐spun fibers of poly(ethylene terephthalate), PET, made at winding speeds ranging from 2000 to 6000 m/min exhibit quite different physical structures. Yarns wound at relatively low speeds are amorphous, whereas those spun at high speeds contain well‐developed crystals of closely packed molecules. In this study the structures have been characterized by means of various techniques such as differential scanning calorimetry, x‐ray diffraction, density, and pulse propagation measurements. Based on the results obtained, an arrangement of the molecules in the various yarns is proposed. It is shown that these arrangements can account for the extreme wide variety in contraction behavior found experimentally. Finally, the results obtained are compared with those of other investigations into orientation‐induced crystallization.
X‐ray diffraction orientation studies on blown polyethylene films. III. High‐stress crystallization orientation
Authors: Maddams W. F. , Preedy J. E.
Published: April 2003

X‐Ray diffraction orientation measurements have been made on a wide range of films blown from three high‐density polyethylenes, to determine more precisely the conditions which lead to the high‐stress crystallization type of orientation. The most extensive measurements relate to films from Hostalen GM 9955F; the results show that there is a very wide range of orientational behavior. Under very low‐stress conditions there is almost pure a‐axis orientation; with very high stress there is substantial c‐axis orientation, both with reference to the machine direction. Commercial blowing conditions give rather high stress and the a axis is inclined at 60° to 70° to the machine direction in the sheet‐normal—machine‐direction plane. Calcium stearate, used to improve the surface finish, increases the stress for a given set of machine conditions and, of these, a high draw ratio and a low extrusion temperature are most effective in promoting high‐stress crystallization. The less extensive results for an experimental Rigidex grade and Shell LPPE 040 fit into this overall pattern; for a given set of blowing conditions they have lower stress than the Hostalen polymer. Commercial blowing conditions give an a‐axis inclination of about 45°.
Plasma‐deposited polymer films. I. Low‐angle x‐ray study
Authors: Havens M. R. , Mayhan K. G. , James W. J. , Schmidt P.
Published: April 2003

A low‐angle x‐ray scattering technique has been applied to determine the submicrostructure of plasma‐formed polyethylene and polystyrene. The plasma‐formed polymers appear to closely approximate a “filler—binder” structure where polymer spheres constitute the filler material and a lower‐density polymer, the binder. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs confirm the spherical diameters predicted by the low‐angle x‐ray scattering data.
Heavy metal ion scavengers from cyanuric chloride
Authors: Kaeriyama Kyoji , Rokusha Tadanori , Naomi Keiko
Published: April 2003

Cyanuric chloride was reacted with polyamines and thiourea, and subsequent hydrolysis of the isothiouronium salt yielded amine polymers with divalent sulfur. The polymers scavenge cupric, cadmium, lead, and mercuric ions from considerably concentrated hydrogen chloride solutions, and they were compared with polystyrene—sulfonic acid resin. Zinc, cobaltous, and nickel ions are adsorbed only at relatively high pH (4.8–6.8). Removal of cupric, cadmium, and mercuric ions is not affected by the addition of sodium chloride.
Fine structural changes in native and mercerized fibrous cellulose brought about by ethylenediamine and methyl alcohol
Authors: Chidambareswaran P. K. , Sreenivasan S. , Patil N. B. , Lokhande H. T. , Shukla S. R.
Published: April 2003

X‐Ray diffraction (XRD) studies were made on native as well as mercerized ramie and cotton fibers after swelling them in ethylenediamine (EDA) solutions and washing out the swelling agent using methyl alcohol (MeOH). These treatments are shown to convert the cellulose I and II lattices into cellulose IIII and IIIII type lattices, respectively. Treatment of the IIII and IIIII samples in boiling water or hydrochloric acid results in reconversions of their crystal lattices into the respective parent types. Alkali treatment causes a III → II type conversion. Studies using alkali‐swollen fibers as well as fibers of different lateral order as starting materials indicate the importance of the structural organization in the cellulosic materials in the production of the cellulose III lattices. Possible mechanisms involved in the lattice transformations in cellulose brought about by the EDA and MeOH treatments are discussed.
Corona treatment changes some physical properties of cellulose
Authors: Venkateswaran A. , Desai R. L.
Published: April 2003

Moisture absorption, dielectric properties, and x‐ray crystallinity of cellulose handsheets and deacetylated cellulose acetate films have been determined. The moisture absorption of the treated samples was lower than that of the controls. Further, the changes of the electrical properties of the treated samples agreed with the observed decrease in the moisture absorptions of the treated samples: no significant change in their crystallinity was noted.
Lewis acid on polymeric carriers as initiators in carbenium ion polymerizations: Polystyrene–aluminum chloride
Authors: Sivaram S. , Naik K. M.
Published: April 2003

The scope and limitations of aluminum chloride bound to polystyrene matrix as an initiator in carbenium ion polymerizations have been studied and compared with the performance of free aluminum chloride in homogeneous solutions. Under comparable conditions, the resin‐bound aluminum chloride is less efficient than free aluminum chloride; however, the molecular weights of polymers obtained from both classes of initiators are essentially similar.
Polyester–polycarbonate blends. II. Poly(ethylene terephthalate)
Authors: Nassar T. R. , Paul D. R. , Barlow J. W.
Published: April 2003

Melt blends of polycarbonate and poly(ethylene terephthalate) were prepared and examined for their transitional behavior by thermal analysis and dynamic mechanical testing. A single Tg was observed for compositions containing more than 60%–70% PET by weight while compositions below this range showed two glass transitions. From this it is concluded that PC and PET are completely miscible in the amorphous phase for PET‐rich compositions, whereas PC‐rich blends separate into two amorphous phases which apparently contain both components. Melting point and crystallization behavior are conssistent with these conclusions and suggest that very little if any interchange reactions occur between the ester and carbonate groups during melt mixing.
Emulsion of polyurethane having thermosetting properties. I. Preparation
Authors: Matsuda Kazuo , Ohmura Hidemasa , Tanaka Yoshiaki , Sakai Takeyo
Published: April 2003

A method of preparation of an urethane emulsion which provides thermosetting film is described here. By reacting a urethane prepolymer containing terminal isocyanate groups with diethylenetriamine in the presence of ketones, poly(urethane‐urea‐amine) was prepared. In other organic solvents, however, gelation occurred immediately and preparation of polyurethane‐urea‐amine was not successful. The function of ketone was ascribed to the tentative formation of a Schiff base between the primary amino group of diethylenetriamine and ketone in situ, and the reaction of primary amine with isocyanate was partly masked to prevent gelation. Then the free amino group is generated when the polymer is treated with epichlorohydrin and the reaction occurs between them. After the solution was neutralized with an aqueous acid, the solvent was removed in vacuo to give a stable self‐emulsifiable thermosetting urethane emulsion. Typical mechanical properties of film from this urethane emulsion are also given here.
Fiber–fiber coefficient of friction: Effects of modulus and tan δ
Authors: Prevorsek D. C. , Sharma R. K.
Published: April 2003

The technologically important studies on rubber friction and wear give strong support to rubber friction being a viscoelastic phenomenon. However, the basic concepts and conclusions derived from such studies appear to have general validity. Fiber‐to‐fiber friction studies are carried out on a number of polymeric flaments with a view to establishing the relationships between fundamental mechanical properties such as modulus, tan δ, and the coefficient of friction. The relationship between these three quantities is expressed by an equation. The results show that with these fibers adhesive contribution to friction is negligible and that temperature and humidity variations in end uses have a much more important effect in frictional properties than changes in draw ratio, heat setting, and so on.
On free volume of polymers above the glass transition
Authors: Aharoni S. M.
Published: April 2003

The magnitude of the activation energy for diffusion, ED is shown to be inversely dependent on the fractional free volume of the polymer above Tg. From the proportionality of ED above and below Tg, the magnitude of ED below Tg is also inversely dependent on the free volume in that temperature range. While this correlation holds very well for our determinations of fractional free volume above Tg it does not correlate with the Simha‐Boyer fractional free volume below Tg, contrary to expectations.
Characterization of water structure in cellulose acetate membranes by calorimetric measurements
Authors: Burghoff H.‐G. , Pusch W.
Published: April 2003

The heat capacities of homogeneous and asymmetric cellulose acetate membranes have been measured at different water contents within the temperature range of −40 to +20°C. The experimental heat capacity–temperature curves were verified by DTA measurements within a temperature range of −120 to +20°C. The results for the partial heat capacity of water within the membranes as well as for the heat of fusion were interpreted by assuming two different states of water—unfreezing bound water due to a sorption process and unbound water due to capillary phenomena, which freezes with a freezing point depression and a reduced heat of fusion.
Adhesion of evaporated metallic films onto polyethylene and poly(tetrafluoroethylene): Importance of surface crosslinking
Authors: Vogel S. L. , Schonhorn H.
Published: April 2003

Ni, Fe, Ti, Al, Au, and Cu were each evaporated and deposited onto both sides of polyethylene and poly(tetrafluoroethylene) (PTFE) films. Adhesive joint strengths of the different metal–polymer–metal composites were compared and subsequent surface modifications due to metalization were investigated. Studies show no change in wettability of polyethylene or PTFE after a metal layer was deposited onto their surfaces and subsequently removed. There was also no evidence of oxidation or unsaturation of the surface. Gel fractions of polyethylene show a definite correlation between joint strength and crosslink at the surfaces of the different metal–polymer composites. Metals forming the strongest joints with polyethylene yield the greatest amount of crosslinking. Conversely, metals forming the weakest joints result in the least amount of crosslinking.
Polyester–Polycarbonate blends. III. Polyesters based on 1,4‐cyclohexanedimethanol/terephthalic acid/isophthalic acid
Authors: Mohn R. N. , Paul D. R. , Barlow J. W. , Cruz C. A.
Published: April 2003

Melt blends of polycarbonate with Kodel, a homopolyester formed from 1,4‐cyclohexanedimethanol and terephthalic acid, and with Kodar, a copolyester formed by replacing some of the terephthalic acid with isophthalic acid, were prepared and their transitional behavior were examined by thermal analysis and dynamic mechanical testing. Blends formed with either polyester were found to have a single Tg over the entire compositional range. Single composition‐dependent α‐ and β‐relaxation temperatures were also observed for blends made with either polyester at all compositions. From these data it is concluded that both Kodel and Kodar blends with polycarbonate form miscible amorphous phases. The role of ester–carbonate interchange reactions during melt mixing was experimentally examined and found to be unimportant, from which it is concluded that the observed miscible phase formation is due to physical interactions between the blend components.
Polymer polarity and surfactant adsorption
Authors: Vijayendran B. R.
Published: April 2003

The effect of polymer polarity on surfactant adsorption from aqueous solution is discussed. The analysis assumes that surfactant adsorption at the polymer–water interface follows a Langmuir‐type adsorption isotherm and the free energy of adsorption is controlled by the interfacial tension of the interface. Saturation adsorption given by the area per molecule of surfactant at the critical micelle concentration (CMC) of the surfactant is related to the polymer–water interfacial tension and the polarity of the polymer surface, calculated from the polar and dispersion contributions to the polymer surface energy. Available data on the area per molecule of sodium lauryl sulfate on various polymer surfaces have been used to test satisfactorily the above analysis. The analysis is used to interpret some of the observations relating to surfactant adsorption encountered in the emulsion polymerization of polar monomers and particle size determination of latexes by the soap titration method. Further, potential utility of such area per molecule data to characterize the nature of polymer surfaces is also discussed.
Molecular weights of natural rubbers from selected temperate zone plants
Authors: Swanson C. L. , Buchanan R. A. , Otey F. H.
Published: April 2003

Molecular weights and molecular weight distributions are compared by gel permeation chromatography for rubbers from 33 north temperate zone plants, guayule, and Hevea. Rubbers isolated from all the northern plants had much lower weight‐average molecular weight (Mw) values (9.72 × 104–4.95 × 105) than milled Hevea (1.31 × 106) or guayule (1.28 × 106) rubber. Pycnanthemum incanum, Lamiastrum galeobdolon, Monarda fistulosa, and Vernonia fasciculata produced potentially useful natural rubbers having Mw values above 4 × 105 and polydispersity factors of 3.1–4.5.
Pyropolycarboranes: The base for self‐lubricating materials with gas lubricant
Authors: Korshak V. V. , Gribova I. A. , Chumaievskaya A. N. , Mgeladze B. M.
Published: April 2003

This paper reports the results of an investigation of pyropolycarboranes, nondeformable thermally stable cross‐linked polymeric materials obtained by pyrolysis of carborane‐containing polymers. Carborane‐containing polyamides and polyesters were heated in air under pressure and analyzed by thermomechanical and thermogravimetric methods. Moreover, the friction properties of the filled materials have been investigated. The effect of hydrogen liberation on the friction of filled pyropolycarboranes at elevated temperatures was used in developing self‐lubricating materials with friction coefficients at 300–400°C.
Polymerization of methyl methacrylate with H2O2‐thiourea redox initiator system
Authors: Ghosh Premamoy , Banerjee Madhu Sudan
Published: April 2003

Polymerization of MMA was done in aqueous media and in a bulk (nonaqueous) system employing a H2O2‐TU redox initiator system. Kinetic features differ significantly depending on the nature of the reaction media. The redox system is much more efficient as a chain initiator in aqueous media than in bulk MMA, where conversion to polymer, thermally and even under photoactivated conditions, is very slow and sluggish. In the bulk media, pronounced inhibition and retardation effects appear to be due to formation of unstable reaction intermediate presumably through dimerization of Ṡ(:NH)·NH2 radical generated in the primary redox reaction.
Partial miscibility of cellulose–polyacrylonitrile blends
Authors: Savard Sylvain , Lévesque Denis , Prud'Homme Robert E.
Published: April 2003

Cellulose‐polyacrylonitrile (PAN) blends have been prepared by the regeneration of 2% concentration solutions in dimethylformamide–NO2 solvent. The blends are transparent when containing between 0 and 50% by weight of PAN. Dynamic mechanical measurements indicate a shift in glass transition temperature Tg of PAN for the blends, suggesting partial miscibility between cellulose and PAN. Experimental density values larger than those predicted theoretically are also in agreement with this conclusion.
1‐chlorobutadiene–butadiene rubber. III. Determination of hydroxyl group content
Authors: Yamashita Shinzo , Sando Katsumi , Kohjiya Shinzo
Published: April 2003

The hydroxyl group content in 1‐chlorobutadiene–butadiene rubber prepared by emulsion polymerization (CB–BR) was determined by UV spectroscopy. CB–BR was allowed to react with phenyl isocyanate at room temperature, and the resulting N‐phenyl carbamate was assayed by UV measurement. The present method allowed the determination of a very small amount of hydroxyl groups contained in a high molecular weight hydrocarbon polymer. The hydroxyl group content in the hydroxyl‐terminated liquid polybutadiene was also determined. The value agreed closely with that obtained by the usual titration method. Hydroxyl groups in CB–BR are presumed to be produced by the hydrolysis of the active chlorine contained in CB–BR. This hydrolysis is dependent on the work‐up conditions of CB–BR, and the quantitative results were discussed with reference to the microstructure of the 1‐chlorobutadiene unit in CB–BR.
Characterization and use of radio frequency plasma‐activated natural polymers
Authors: Ward T. L. , Jung H. Z. , Hinojosa O. , Benerito R. R.
Published: April 2003

A group of natural materials having anhydroglucose units linked by glycosidic bonds, as well as other related compounds, were irradiated with plasmas generated by a radio frequency field (13.56 MHz). Reactive sites created were characterized by electron spin resonance, chemiluminescence, infrared, and x‐ray photoelectron spectroscopy. The free radicals are related to the number of glycosidic bonds, and their decays result in chemiluminescence. In the absence of moisture and oxygen, however, the radicals are stable. During plasma irradiation, carbonyl groups as well as free radicals are formed on surfaces, and the atom ratio of oxygen to carbon on surfaces increases. Within the reactor, thin films of polymers can be deposited on cotton fabrics by allowing the monomer to enter the reactor above the fabric that is in a horizontal position downstream from the external electrodes.
Durable‐press cotton with improved retentions of strength and abrasion resistance via N‐methylolpolyethyleneurea D.P. 2
Authors: Bertoniere Noelie R. , Rowland Stanley P.
Published: April 2003

Diethylenetriamine was reacted with urea to form a noncyclic analog of ethyleneurea (one of the lowest members of a series of linear polyethyleneureas) which was characterized spectroscopically. Its reaction with formaldehyde to yield the N‐methylol derivative (N‐methylolpolyethyleneurea, degree of polymerization 2; NMP‐2) was investigated. The polymerization characteristics of the NMP‐2 were studied and compared with those of N‐methylol derivatives of cyclic ethyleneurea (related structurally) and melamine (related polyfunctionally). The NMP‐2 was applied to cotton fabrics by a pad–dry–cure process with Al2(OH)5Cl·2H2O as the polymerization crosslinking catalyst. Fabrics treated with the experimental reagent developed high levels of resilience (durable press appearance) and were characterized by significantly higher than conventional levels of retained strength and abrasion resistance. Analyses by electron microscopy of fibers treated with NMP‐2 and with the predominant conventional reagent, dimethyloldihydroxyethyleneurea, are reported. Attractive performance properties are discussed and attributed, at least in part, to rapid polymerization accompanying, or in advance of, etherification of cellulosic hydroxyl groups.
The birefringence of nitrocellulose fibers and pastes
Authors: Lewis T. J.
Published: April 2003

The optical path difference of nitrocellulose fibers and pastes were measured on the polarizing microscope using three different compensation techniques, and a method is suggested for converting these path differences into birefringencies. By taking measurements on a sufficiently large number of fibers it is possible to estimate the average nitrogen content with an accuracy approaching that achieved by other methods on much larger samples. The distribution of nitrogen between individual fibers shows that material prepared by the displacement process differs from that made by the mechanical process and indicates that denitration occurs during displacement process manufacture. Solvents and plasticizers either increase or decrease the birefringence, and the structure of nitrocellulose pastes is discussed.
The beta relaxation in epoxy resin‐based networks
Authors: Williams John G.
Published: April 2003

The dynamic properties of epoxy–amine networks have been studied using a torsion pendulum, and the effect of replacement of resin by monoglycidyl ethers on the beta relaxation has been determined. It is shown that the loss peak is not sensitive to glyceryl units derived from the monofunctional diluents. From the effect of mixtures of aliphatic and aromatic‐based epoxy resins on the relaxation and from the loss properties of systems with varying ratio of resin to curing agent and catalytically cured systems, it is suggested that the loss peak has at least two basic components. One is related to the presence of glyceryl units derived from polyfunctional glycidyl compounds, while the other may be related to the presence of diphenylpropane units in the resin.
Compositional variation as a function of elution volume in gel permeation chromatography of copolymers and physical blends
Authors: Ogawa Toshio
Published: April 2003

This paper is concerned with the theoretical aspects of the gel permeation chromatography of copolymers and physical blends, such as polypropylene homopolymer and copolymers. Such considerations have become important with the advent of modern UV and IR chromatographic detectors. The behavior of the compositional variation observed as a function of elution volume is investigated by a simulation technique. As an example, ethylene–propylene copolymers having a bivariate normal distribution for molecular weight and composition are taken for calculations. We deal with the effects of the molecular weight distribution, the compositional distribution, and the correlation coefficient between molecular weight and composition on the detected compositional variation. It is concluded that these three factors are equally important in evaluating the curves fo the variation. Therefore, the difference between compositional distributions of copolymers is detectable only under limited conditions where the other factors are kept constant.
Crystallization of cyclic oligomers on the surface of nylon 6 fibers
Authors: Fujiwara Yasuharu , Zeronian S. Haig
Published: April 2003

When scoured nylon 6 filament was exposed to either water vapor or n‐alcohol vapor, a portion of the cyclic [NH(CH2)5CO]x, with x = 2 through 7, and the ϵ‐caprolactam present migrated to the filament surface and crystallized. A variety of crystal forms were observed. The variations depended partly on the vapor to which the sample had been exposed. During water vapor exposures, the cyclic dimer migrated more easily to the filament surface than the cyclic monomer and the cyclic tetramer migrated more easily than the cyclic trimer. It is postulated that the secondary valence forces acting between the dimer and the nylon 6 polymer are weaker than that between the ϵ‐caprolactam and the polymer since the dimer forms intramolecular hydrogen bonds. Consequently, the dimer migrates more easily than the monomer, which can form hydrogen bonds with the polymer. Also the cyclic trimer can form hydrogen bonds with the nylon 6 polymer and thus migrates less easily than the cyclic tetramer, which can form intramolecular hydrogen bonds. In alcohol vapor exposures, the n‐alcohol used influenced the concentration of cyclic monomer and oligomer, which migrated to the surface of the nylon 6 filament. The variation of the monomer and oligomer concentration on the fiber surface with the alcohol used in the exposure is discussed.
Bis(diisopropyl)thiophosphoryl sulfides in vulcanization reactions
Authors: Pimblott J. G. , Scott G. , Stuckey J. E.
Published: April 2003

A synergistic combination of bis(diisopropyl)thiophosphoryl disulfide, dimorpholyl disulfide, and sulfur is used to produce an efficient vulcanizing system for a range of rubbers. This produces vulcanizates with the exceptional thermal and thermal‐oxidative stability characteristic of sulfur donor vulcanizates and the rapid and extensive crosslinking reaction normally associated with a conventional sulfur–accelerator combination. A pronounced induction period is noted. The crosslinks initially produced in cis‐1,4‐polyisoprene rubbers are predominantly polysulfide but reduce to mono‐ and disulfides at optimum and extended cures. The crosslinks of the ethylene–propylene terpolymer and the styrene–butadiene vulcanizates are initially mainly disulfide but are rapidly reduced to monosulfides at the high curing temperatures (180°C) used. A comparison with vulcanization systems based on tetramethylthiuram disulfide and bis(diisopropyl)thiophosphoryl tri‐and tetrasulfides as sulfur donors and with a conventional cyclohexylbenthazyl‐2‐sulfenamide–sulfur combination, respectively, shows it to have distinct advantages.
Gel permeation chromatography using controlled‐porosity glass. I. Polyacrylamide–formamide solution
Authors: Onda Nobuhiko , Furusawa Kunio , Yamaguchi Noriko , Komuro Shūgi
Published: April 2003

The process of characterizing polyacrylamide and its partially hydrolyzed materials by gel permeation chromatography was examined. The use of controlled‐porosity glass and formamide as the stationary phase and the eluent, respectively, resulted in chromatographic behavior in accord with the hydrodynamic volume concept for polyacrylamide fractions. The addition of a salt (KCl) to the eluent was found to retard the elution of the hydrolyzed polyacrylamide.
Entanglement network model relating tensile impact strength and the ductile‐brittle transition to molecular structure in amorphous polymers
Authors: Bersted B. H.
Published: April 2003

A model is presented to account for the large variations in tensile and tensile impact strength of amorphous polymers from a consideration of an idealized entanglement network. The material strength under tensile impact conditions is shown to be predictable and to increase with the “fineness” of the entanglement network; a higher entanglement density leading to more molecular chains supporting the stress. The entanglement density is, in turn, shown to increase with number‐average molecular weight and the quotient of the length to the molecular weight of the chemical repeat unit (empirically found to be related to the critical enganglement molecular weight). Ductile behavior is demonstrated to occur under tensile impact conditions when the material strength σB exceeds the yield stress σy and brittle behavior when σy > σB. It is further demonstrated that the large variation in tensile impact strength among the amorphous polymers studied can be adequately accounted for in terms of the large and predictable variation in σB; the larger σB is relative to σy, the more the polymer can draw (absorbing energy in the process) until σB is reached. Surprisingly, the predictions of strength for high‐molecular‐weight polycrystalline materials also gave good agreement with experimental data.
Flame resistant cotton by photoinitiated graft copolymerization
Authors: Harris James A. , Arthur Jett C. , Goynes Wilton R.
Published: April 2003

Photoinitiated, free‐radical reaction of cotton fabric with vinyl phosphonate oligomer (molecular weight 500–1000) and N‐methylolacrylamide monomer from aqueous solutions to form copolymer gave a textile product that had flame resistance (FF 5‐74 test). The initiating free radicals were formed on the cellulose molecule when cotton fabric was exposed to ultraviolet radiation. The effects of wavelengths of ultraviolet radiation (254, 300, and 350 nm), reaction time (0–9 ksec), solids in solution (10%–60%), atmosphere (air, nitrogen, and oxygen), and oligomer‐to‐monomer concentration (1:0.00 to 1:1.20 mole ratio) on efficiency of monomer and oligomer conversion to copolymer (maximum efficiency 70%–80%) were determined. Evaluation of the flame resistant cotton fabric by transmission electron microscopy showed deposits of copolymer throughout the cross sections of the fibers. However, scanning electron microscopy and energy‐dispersive x‐ray analysis showed that copolymer and phosphorus tended to be more concentrated between and on the surfaces of the fibers.
New coating materials and their preparation by radiation polymerization. III. Antifogging coating composition
Authors: Kaetsu I. , Yoshida M.
Published: April 2003

Compositions for good antifogging and mar‐resistant coatings were investigated. A mixture of hydrolyzed aminoalkylalkoxysilane and hydrophilic vinyl monomer was the best combination. Control of suitable viscosity for coating was carried out conveniently by irradiation. The prepolymer was coated and cured by heating to form an antifogging membrane on various base materials such as inorganic glass, CR‐39 resin, and poly(methyl methacrylate). These conditions were studied in relation to some physical properties of the membrane. It was found that antifogging and mar‐resistant properties were inconsistent in many cases. A possible way to achieve the best balance between the two properties is discussed.
Computer optimization of reverse osmosis processing of soy whey with cellulose acetate modules
Authors: Baker E. C. , Moosemiller M. D. , Mustakas G. C.
Published: April 2003

In processing full‐fat soy flour to an acid‐precipitated lipid protein concentrate a byproduct whey fraction results which, because of its high biological oxygen demand, represents a serious disposal problem. Processing of food waste streams by reverse osmosis has received considerable attention because of its low theoretical energy requirement since no phase change is involved. In a previous study at this Center a mathematical model was developed for the diffusive transport of soy lipid protein concentrate whey across cellulose acetate membranes. In this study, pumping energy and power costs combined with membrane life and replacement costs were incorporated into the original model to provide a basis for optimization from an energy cost standpoint. Computer‐simulated runs were compared with experimental pilot‐plant runs, and the agreement between predicted and actual results was quite good. Water flux rates were in the range of 3 to 7 gal/ft2/day. Computer runs were used to optimize the processing of 100,000 gal/day of soy whey at 8000 ppm biological oxygen demand (BOD). Costs were at a minimum with a six‐stage tapered flow primary reverse osmosis treatment over a porous cellulose acetate membrane, followed by a six‐stage tapered flow reverse osmosis over a tighter membrane. BOD reduction was 94% at a cost of $5.45/1000 gal.
Superstructural description of deformation process in uniaxial extension of preoriented isotactic polypropylene
Authors: Yamada Kenji , Takayanagi Motowo
Published: April 2003

The strains on uniaxial extension of preoriented isotactic polypropylene are separated over the whole range of deformation into three processes: crystallite boundary slip (A1 process), uniform shear deformation of crystallites (A2 process), and restoration of molecular orientation from the sheardeformed state (Ā2 process). They are separately evaluated by the use of the parameters of superstructure varying in deformation. Both the A1 and A2 processes predominate before the A2 → Ā2 transition takes place. Wide‐ and small‐angle x‐ray goniometries detect this transition. After the A2 → Ā2 transition takes place, the specimen cannot be deformed by the A1 or A2 process, but by a molecular process such as pulling out the isolated extending chains from the folded chain crystals followed by their refolding. From the quantitative evaluations of the strains associated with the A1 and A2 processes it is deduced that the initial shear compliance for the A1 process is smaller than that for the A2 process.
The effect of additives on impact poly(vinyl chloride)
Authors: Chang Eng Pi , Kirsten Rudolf , Salovey Ronald
Published: April 2003

The two‐phase nature of a graft copolymer of ethylenepropylene‐1:4 hexadiene (EPDM) and poly(vinyl chloride) (PVC) has been established by dynamic mechanical measurements. The interaction of different additives with the isolated graft copolymer has also been inferred from their dynamic mechanical and thermal properties. Carbon black and titanium dioxide act as inert filler, while the effect of including straight‐chain hydrocarbons (e.g., n‐hexadecane and n‐hexatriacontane) is strongly dependent upon the melting point of the hydrocarbons. Sunflex 110 plasticizes the rubber phase of the graft copolymer while dioctyl (di‐2‐ethyl hexyl) phthalate (DOP) plasticizes the PVC phase and reduces Tg. At lower temperatures, however, the elastic modulus is increased by an “antiplasticization” effect. The local environment of PVC chains in the graft copolymer is modified by the presence of the rubber and PVC chains are less mobile.
Radiation‐induced polymerization of ethylene in a pilot plant. I. Bulk process
Authors: Takehisa Masaaki , Machi Sueo , Watanabe Hiromasa , Ueno Takashi , Takahashi Seiichi , Tsuchiya Ryoji , Otaguro Kanji , Motoda Isao , Takasaka Yoshio , Miyanaga Kazukiyo , Kawakami Waichiro , Yamaguchi Kouichi , Sugo Takanobu , Nakajima Hayato , Watanabe Terutaka , Hinachi Chuhei
Published: April 2003

Radiation‐induced bulk polymerization of ethylene was carried out with use of a pilot plant with a 10 liter reactor at pressures of 225–400 kg/cm2, temperatures of 30–95°C, ethylene feed rates of 5–28 kg/hr, and dose rate of 3.8 × 105 rad/hr. Characteristics of the process are mild polymerization conditions and capability of producing medium density polyethylene in powder form. The spacetime yield and molecular weight of polymer were in the range of 3.5 to 13.1 g/liter hr and 2.2 × 104 to 14 × 104, respectively. The space‐time yield increased with mean residence time and 2.4 powders of pressure, and decreased with temperature. Molecular weight changed similarly with the reaction conditions. These results were consistent with those of the bench plant experiment and the scale effect was small. Polymer deposit to the reactor wall limited a period of continuous operation of the plant. The amount of deposited polymer was increased with the square of reaction time. The rate of polymer deposit was proportional to polymer concentration and to the cube of pressure. The polymer deposit cannot be solved in the bulk process.
Ionically crosslinked poly(acrylic acid) membranes. III. Reverse osmosis results for dry cast membranes
Authors: Dickson J. M. , Lloyd D. R. , Huang R. Y. M.
Published: April 2003

The reverse osmosis properties of ionically crosslinked polyacrylic acid membranes were investigated in terms of the salt separation of a 0.1% NaCl solution and water flux. The membranes were synthesized and crosslinked with the metal ion Al3+ via the dry casting technique described in a previous paper. The effect of such variables as the polymer concentration in the casting solution, the ratios of solvents used (DMF/H2O), the ratio of monomer to the crosslinking agent (AA/Al), the evaporation time and temperature, and the nonsolvent nature and treatment times were studied in some detail. The most important variable was found to be the length and nature of the treatment in the nonsolvents acetone and methanol. In the best series of the membranes that were synthesized, fluxes of more than 3.0 gfd, with salt separations at the 80%–85% level, were obtained.
Dynamic measurement of interfilament friction on staple yarns
Authors: Murayama Takayuki
Published: April 2003

A new method is presented which permits the quantitative characterization of interfilament friction of staple yarns using loss tangent tanδ data measured directly from samples nondestructively with the Rheovibron DDV‐II viscoelastometer. The procedure is derived from a phenomenological model of the structure's mechanical behavior in which its energy dissipation capacity consists of both filament internal viscous friction and a filament‐to‐filament coulomb friction mechanism. By treating the coulomb dissipation in terms of an additional effective viscous component, the loss tangent of the model representing the structure can be analytically expressed in terms of the internal filament viscous properties, a fiber‐to‐fiber coulomb parameter, and an undetermined assembly dispersion factor which is representative of strength. By measuring effective loss tangent data for the staple yarn and a constituent filament at two separate frequencies and considering the magnitude of the coulomb mechanism to be independent of the test frequency in the range employed, both the coulomb friction dissipation and the assembly dispersion factor can be quantified. Using this procedure, loss tangent data from tests on a series of staple yarns (nylon, polyester, and acrylic fiber) are used to calculate both assembly dispersion and interfilament coulomb friction factors.
Tributylborane‐initiated grafting of methyl methacrylate onto chitin
Authors: Kojima Kuniharu , Yoshikuni Masako , Suzuki Tominori
Published: April 2003

The grafting of methyl methacrylate (MMA) onto chitin initiated by tributylborane (TBB) was investigated at ordinary temperature. It was found that water was essential to the grafting. No grafting was observed in the usual organic solvents such as n‐hexane, tetrahydrofuran, and cyclohexanone. The total conversion and the percentage and efficiency of grafting increased with increasing chitin content. The extent of homopolymer formation also increased with increasing chitin content. The optimum concentrations of TBB and MMA for the grafting were determined. Activation energies were estimated to be about 22.8 and 27.4 kcal/mole for the grafting and homopolymerization, respectively. On the basis of these results the mechanism of the grafting onto chitin was discussed.