bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disperse dyeing of polyester fibers: Kinetic and equilibrium study
Authors: Georgiadou K. L. , Tsatsaroni E. G. , Eleftheriadis I. C. , Kehayoglou A. H. 
Published: August 2002

AbstractThe effect of temperature on the dyeing rate constant k, diffusion coefficient D, and time of half‐dyeing t1/2 was evaluated for the dyeing of polyester fibers with two disperse dyes, an azo and an anthraquinone dye. Activation energies of diffusion E were calculated. The polyester dyeing equilibrium was also studied and the partition coefficient K and standard affinity Δμ° at various temperatures were determined for the anthraquinone dye. Standard enthalpy ΔH° and standard entropy ΔS° of dyeing were also obtained. The same equilibrium parameters were not obtained for the azo dye because of its dyeing behavior. A similar kinetic and equilibrium study was made for the pure azo and anthraquinone compounds free from the dispersing agents present in the commercial dyes and the results are discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 123–128, 2002
Characterization of alkali‐treated jute fibers for physical and mechanical properties
Authors: Ray Dipa , Sarkar B. K. 
Published: August 2002

AbstractChanges occurring in jute fibers when treated with a 5% concentration of a NaOH solution for 0, 2, 4, 6, and 8 h were characterized by weight loss, linear density, tenacity, modulus, FTIR, and X‐ray measurements. A 9.63% weight loss was measured during 2 h of treatment with a drop of hemicellulose content from 22 to 12.90%. The linear density value showed no change until 2 h of treatment followed by a decrease from 33.0 to 14.5 denier by 56% after 6 h of treatment. The tenacity and modulus of the fibers improved by 45 and 79%, respectively, and the percent breaking strain was reduced by 23% after 8 h of treatment. X‐ray diffractograms showed increase in crystallinity of the fibers only after 6 h of treatment, while FTIR measurements showed much of the changes occurring by 2 h of treatment with an increased amount of OH groups. By measuring the rate of change of the modulus, tenacity, and percent breaking strain with the time of treatment, a clear transition was apparent at 4 h of treatment with the dissolution of hemicellulose, causing a weight loss and drop in the linear density before and development of crystallinity with an improvement in the properties after the transition time. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1013–1020, 2001
Polymers from renewable resources. XIII. Interpenetrating polymer networks derived from castor oil–hexamethylene diisocyanate and polymethacrylamide
Authors: Nayak P. , Mishra D. K. , Sahoo K. C. , Pati N. C. , Jena P. K. , Lenka S. , Nayak P. L. 
Published: August 2002

AbstractSeveral castor oil‐based polyurethanes (PUs) samples were synthesized using various diisocyanates such as hexamethylene diisocyanate (HMDI) with varying NCO/OH ratios. All the PUs were reacted with methacrylamide (MAM) using an ethylene glycol dimethacrylate (EGDM) crosslinker and benzoyl peroxide as an initiator. Thermogravimetric analysis of the polymers was followed using a computer analysis method for assigning the kinetic mechanism. The degradation steps are discussed in the light of kinetic parameters. The scanning electronic microscopy of some of the interpenetrating polymer networks (IPNs) were studied and the morphology was examined. The samples were subjected to wide‐angle X‐ray diffraction analysis. Ruland and Vonk's method was used to calculate the degree of crystallinity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1349–1353, 2001
Polymer‐based self‐lubricating material
Authors: Shiao Shin Jen , Fu Wei Shung , Tuo Chin Lin , Cheng Un I 
Published: August 2002

AbstractA low‐friction coefficient material with color based on proper selection of polar conditions of pigment and liquid lubricant was developed. Bush‐type bearings were made from poly oxymethylene reinforced with inorganic fillers, including polar compounds of white carbon and glass powder, and nonpolar compounds of carbon black and graphite. The fillers were coated with different levels of titanate, and with polar lubricants such as cetyl alcohol and palmitic acid, and nonpolar lubricants of motor oil, and paraffin. The frictional properties at constant velocity and at constant loading, and the relationships between materials polarity are discussed. An excellent self‐lubricating material of frictional coefficient less than 0.02 was obtained. That is superior to the most current commercial products claiming μ = 0.05 ∼ 0.06. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1514–1519, 2001
Grafting of poly(acrylic acid) on polyamide yarn
Authors: Bucheńska Jadwiga 
Published: August 2002

AbstractGraft copolymerization of acrylic acid onto PA6 yarn was examined in this study. Prior to the grafting process, the fibers were activated with a benzene solution of benzoyl peroxide. Next, the fibers were put into a bath containing acrylic acid, a dispersing agent, and the activator of reaction. The effects of the main process parameters and auxiliary additives on the degree of grafting, quantity of the homopolymer formed during grafting, effectiveness of grafting, extent of conversion, and grafting ratio were determined. Using calculation factors such as the reaction efficiency, the extent of reaction, and the ratio of grafting, the conditions of grafting were found that made possible the reduction or elimination of the by‐product. Also determined were the influence of the degree of grafting on the moisture sorption and the swelling of modified fibers. In addition, the value of apparent activation energy was calculated (49.123 kJ/mol). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1914–1919, 2001
Compatibilization of PA6/PPO blend with carboxylated poly(styrene) compounds
Authors: Kelnar I. , Stephan M. , Jakisch L. , Janata M. , Fortelný I. 
Published: August 2002

AbstractPA6/PPO 70/30 blends were reactively compatibilized using carboxylated polystyrene (PS) and poly(styrene‐block‐4‐methylstyrene) with various degrees of carboxylation. The high carboxylation of PS (up to about 50%) caused a decrease of dispersed PPO dimensions with a simultaneous deterioration of properties, especially of toughness and elongation. The best mechanical behavior was found for PS with 1% degree of carboxylation and for neat PS. On the other hand, degrees of carboxylation higher than 50% caused an increase in particle size. This was most significant for block copolymers, where a marked change in size and shape occurred, from spherical particles of about 1 μm in size to large, elongated particles about 50 μm long or a similar rough cocontinuous structure. The deteriorated mechanical behavior is tentatively explained by unsuitable properties of the reactively formed compatibilizer and thus of the interface. The enhanced rigidity of highly carboxylated poly(4‐methylstyrene) chains (and its product of grafting with PA6), causing its decreased emulsification ability together with the expected rigid interface, which probably suppresses breakup of the PPO phase, may be responsible for the increase of the dispersed PPO dimensions found. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2273–2280, 2001
Preparation and characterization of polyurethane flame‐retardant coatings using pyrophosphoric lactone‐modified polyesters/isophorone diisocyanate–isocyanurate
Authors: Park Hong‐Soo , Kim Dae‐Won , Hwang Kyu‐Hyun , Yoon Byung‐Seon , Wu Jong‐Pyo , Park Jin‐Woo , Hahm Hyun‐Sik , Im Wan‐Bin 
Published: August 2002

AbstractPyrophosphoric lactone‐modified polyester containing two phosphorous functional groups in one structural unit of base resin was synthesized to prepare a nontoxic, reactive flame‐retardant coatings. Then, the pyrophosphoric lactone‐modified polyester was cured at room temperature with isocyanate and isophorone diisocyanate (IPDI)–isocyanurate to get a two‐component polyurethane flame‐retardant coatings (TAPPU). Comparing the physical properties of the films of TAPPU with the film of nonflame‐retardant coatings, no deterioration of physical properties was observed with the incorporation of a flame‐retarding component into the resin. Three kinds of flame retarding tests were conducted, including the 45° Meckel burner method, limiting oxygen index method (LOI method), and oxygen combustion method with Cone calorimeter. It was observed that the char lengths were 3.1∼4.5 cm and LOI values were 27∼30%. These results indicate that the prepared coatings are good flame‐retardant ones. It was also found that the flame retardancy of those coatings was increased with the contents of phosphorous. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2316–2327, 2001
Crystallization of poly(ethylene terephthalate) modified with codiols
Authors: Bouma Krista , Regelink Marc , Gaymans Reinoud J. 
Published: August 2002

AbstractThe nucleation of poly(ethylene terephthalate) (PET) by codiols and olefinic segments was studied. The codiols 1,5‐pentanediol, 1,8‐octanediol, 2,5‐hexanediol, and 1,3‐dihydroxymethyl benzene were copolymerized into PET in a concentration range of 0–10 mol %. The melting (Tm), crystallization (Tc), and glass‐transition (Tg) temperatures were studied. These codiols were found to be able to nucleate PET at low concentrations, probably by lowering the surface free energy of the chain fold. However, the codiols also disturbed the structural order of the polymer, resulting in a decrease in both the Tm and Tc values. The optimum codiol concentration was found to be at around 1 mol %, which is lower than previously reported. A diamide segment N,N′‐bis(p‐carbo‐methoxybenzoyl)ethanediamine (T2T) was found to be a more effective nucleator than the codiols; however, no synergy was observed between the nucleating effect of the diamide segment T2T and that of the codiol. An olefinic diol (C36‐diol) with a molecular weight of 540 g/mol was also copolymerized into PET in a concentration range of 0–21 wt %. Only one Tg was observed in the resulting copolymers, suggesting that the amorphous phases of PET and the C36‐diol are miscible. The main effect of incorporating the C36‐diol into PET was the lowering of the Tg; thus, the C36‐diol is an internal plastifier for PET. The C36‐diol had little effect on the Tm value; however, the Tc value actually increased in the 11.5 wt % copolymer. As the Tg decreased and the Tc increased, the crystallization window also increased and thereby the likelihood of crystallization. Therefore, the thermally stable C36‐diol appears to be an interesting compound that may be useful in improving the crystallization of PET. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2676–2682, 2001
Ring‐opening metathesis polymerization of dicyclopentadiene catalyzed by titanium tetrachloride adduct complexes with oxygen‐containing ligands
Authors: Qian Yanlong , Dono Keleypette , Huang Jiling , Ma Haiyan 
Published: August 2002

AbstractRing‐opening metathesis polymerization of dicyclopentadiene catalyzed by TiCl4 · 2L/CH3Li system [where L is tetrahydropyran (1), dioxane, 2,5‐dimethylfuran, or tetrahydrofurfyl alcohol] is reported. The obtained polymer was characterized by IR and 1H‐NMR. These catalytic systems effectively promoted the polymerization reaction. Seven influencing factors are discussed. When the aging temperature was 0°C, the aging time was 90 min, the polymerization temperature was 60°C, Li/Ti was 1.5–2, and the monomer/catalyst molar ratio ranged between 30 and 50, the polymerization reaction catalyzed by complex 1 yielded better results within a shorter period of time. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 662–666, 2001
Miscibility and phase structure of binary blends of poly(L‐lactide) and poly(vinyl alcohol)
Authors: Shuai Xintao , He Yong , Asakawa Naoki , Inoue Yoshio 
Published: August 2002

AbstractBlend films of poly(L‐lactide) (PLLA) and poly(vinyl alcohol) (PVA) were obtained by evaporation of hexafluoroisopropanol solutions of both components. The component interaction, crystallization behavior, and miscibility of these blends were studied by solid‐state NMR and other conventional methods, such as Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC), and wide‐angle X‐ray diffraction (WAXD). The existence of two series of isolated and constant glass‐transition temperatures (Tg's) independent of the blend composition indicates that PLLA and PVA are immiscible in the amorphous region. However, the DSC data still demonstrates that some degree of compatibility related to blend composition exists in both PLLA/atactic‐PVA (a‐PVA) and PLLA/syndiotactic‐PVA (s‐PVA) blend systems. Furthermore, the formation of interpolymer hydrogen bonding in the amorphous region, which is regarded as the driving force leading to some degree of component compatibility in these immiscible systems, is confirmed by FTIR and further analyzed by 13C solid‐state NMR analyses, especially for the blends with low PLLA contents. Although the crystallization kinetics of one component (especially PVA) were affected by another component, WAXD measurement shows that these blends still possess two isolated crystalline PLLA and PVA phases other than the so‐called cocrystalline phase. 13C solid‐state NMR analysis excludes the interpolymer hydrogen bonding in the crystalline region. The mechanical properties (tensile strength and elongation at break) of blend films are consistent with the immiscible but somewhat compatible nature of these blends. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 762–772, 2001
Blends of vinylic copolymer with plasticized lignin: Thermal and mechanical properties
Authors: Feldman D. , Banu D. , Campanelli J. , Zhu H. 
Published: August 2002

AbstractThe article presents an investigation into the use of plasticizers for reducing the degree of association existing within lignin molecules, in order to overcome adverse effects on the mechanical properties of its blends with a vinyl chloride–vinyl acetate (VC–VAc) copolymer. Infrared spectroscopy and differential scanning calorimetry were performed to examine the effect of the plasticizer type and concentration in plasticizing Alcell, an organosolv lignin. The results show that the compatibility and efficiency of a plasticizer are strongly influenced by the solubility parameter, which should be close to that of the lignin. Polyblends prepared with several plasticizers, Alcell lignin, and the VC–VAc copolymer were also investigated by thermal analysis and mechanical testing. Variations in the mechanical properties of these blends were found to correlate with the lignin dispersion quality and with the plasticizer efficiency in Alcell lignin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 861–874, 2001
Synthesis, characterization, and glass transition temperature of poly(styrene‐b‐butyl methacrylate) block copolymers by stable free radical polymerization
Authors: Fernández‐García M. , Cuervo‐Rodríguez R. , Madruga E. L. 
Published: August 2002

AbstractThe synthesis of controlled polystyrenes with different molecular weights has been performed in the presence of 1‐phenyl‐1‐(2,2,6,6‐tetramethyl‐1‐piperidinyloxy)ethane (PETEMPO). The polystyrenes have served as macroinitiators for the formation of poly(styrene‐b‐butyl methacrylate) block copolymers. Using differential scanning calorimetry (DSC) it has been shown that all block copolymers synthesized do not present phase segregation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 14–21, 2001
Thermal degradation of flax and jute fibers
Authors: Gassan Jochen , Bledzki Andrzej K. 
Published: August 2002

AbstractThe thermal degradation of jute and flax fibers under temperatures between 170 and 210°C for a maximum of 120 min was studied in detail. This article will analyze the effects of the thermal exposure on mechanical properties (tenacity) as well as on fiber fine structure (degree of polymerization and degree of crystallinity). It was found that temperatures below 170°C only slightly affects fiber properties, while temperatures above 170°C significantly dropped tenacity and degree of polymerization. Because of chain scissions, a slight increase in degree of crystallinity was observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1417–1422, 2001
Glass‐transition behavior of poly(methacrylonitrile)
Authors: Katircioğlu T. Y. , Güven O. 
Published: August 2002

AbstractThe glass‐transition temperatures (Tg) of some polymers reported in the literature have always been a source of great uncertainty. The values reported for poly(methacrylonitrile) (PMAN, 100 and 120°C) are well above the value determined in this study (67°C). It is clearly shown by FTIR and DSC work that formation of cyclic structures during the drying of PMAN, even at low temperatures, is the main reason for the high Tg values observed. The contributions of naphthydrine type cyclic structures and intermolecular crosslinks in the increase of the Tg are determined over an aging temperature interval of 90–300°C. The combined effects of intra‐ and intermolecular linking cause an increase in the Tg from 67 to 116°C. The hardness measurements also confirm the value determined by DSC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1936–1943, 2001
Utilization of cellulose‐triacetate‐blended membranes for carrier‐mediated transport of some metal ions
Authors: Abdelaal Magdy Youssef 
Published: August 2002

AbstractIn this study, cellulose triacetate was used as a suitable base polymer for polymer‐blended membranes for ion sensing and separation. Polymer‐blended membranes were prepared with the solvent casting technique in the presence of mixed plasticizer and a metal ion carrier known as an ionophore. 7‐Dodecenyl‐8‐hydroxy‐quinoline and N,N′‐diphenylethyl Kemp's triacid diamide, in addition to the newly synthesized 8‐[N‐acetyl‐O‐(4‐tert‐butyl benzyl)‐L‐tyrosylamino] quinoline, were used as representative examples for ionophores. The membranes were evaluated through the transport of copper and lead ions into 0.1M nitric acid as the receiving phase. The concentrations of the investigated metal ions in both phases were assayed by atomic absorption spectrometry. From this study, it can be concluded that the efficiency of the membrane, either as an ion‐transporting or as an ion‐extracting condidate, is controlled by the amount of the immobilized ionophore, the immobilization time within the membrane matrix while in contact with the receiving phase, the nature of the ionophore–metal ion complex, and so on. The carrier‐mediated transport mechanism was also investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2008–2015, 2001
Effects of glass‐fiber content and coolant temperature on temperature and crystallinity profiles of PP melt during cooling
Authors: Sombatsompop N. , Tangsongcharoen A. 
Published: August 2002

AbstractThis investigation studied the temperature gradients and degree of crystallinity of polypropylene melt across a circular duct during the cooling process, where the coolant used was chilled water. The effects of glass‐fiber content, varying from 0 to 44 wt %, and coolant temperature, varying from 5 to 20°C, were our main interest. The results suggested that the rate of cooling of the polymer of each position across the duct was not significantly affected by the temperature of the coolant and glass‐fiber contents, although the rate of cooling was influenced by the size of the duct. The crystallization temperature and degree of crystallinity of the polymer increased with increasing glass fiber contents and the coolant temperature. These phenomena were associated with the heat transfer between the coolant and the polymer, crystallization temperature, exothermic crystallization process, and thermal properties of the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2087–2097, 2001
Quantitative characterization of dispersed particle size, size distribution, and matrix ligament thickness in polypropylene blended with metallocene ethylene–octene copolymers
Authors: Premphet K. , Paecharoenchai W. 
Published: August 2002

AbstractThe average rubber particle size, size distribution, and matrix ligament thickness between particles in polypropylene blends containing metallocene catalyzed ethylene–octene copolymers have been quantitatively analyzed, as functions of blend composition and phase viscosity ratio. Comparison has been made between experimental data and those predicted from a number of theoretical models. All blends showed two‐phase morphology, with interestingly a bimodal distribution of the rubber particle size. The ranges and averages of rubber particle size were mainly determined by blend composition and viscosity ratio between the phases, irrespective of comonomer content along the rubber chains. The logarithmic relationship between the matrix ligament thickness and rubber concentration was observed. The values of ligament thickness obtained from the experiments and theoretical models were not in agreement. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2140–2149, 2001
Sulfonation of poly(ether ether ketone)(PEEK): Kinetic study and characterization
Authors: Huang R. Y. M. , Shao Pinghai , Burns C. M. , Feng X. 
Published: August 2002

AbstractHydrophobic poly(ether ether ketone) (PEEK) were modified by sulfonation at different temperatures (22, 36, 45, and 55°C) and varying period of time with concentrated sulfuric acid used as solvent. A kinetic study was carried out based on the assumption that sulfonation reaction is a second‐order reaction, which takes place preferentially in the aromatic ring between the two ether (O) links (the first type substitution), and there is only one substituent attached to each repeat unit of the PEEK before the complete substitution of this preferred aromatic ring. More than 100% substitution was observed in experiment. All the data with substitution degree less than 95% agree fairly well with the kinetic behavior of the second‐order reaction. The reaction rate coefficient and activation energy for first type substitution were obtained. The sulfonated PEEK samples were characterized in terms of ion‐exchange capacity (IEC), 1H‐NMR, contact angle, and solubility. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2651–2660, 2001
Crystallization behavior of polytetrafluoroethylene (PTFE)
Authors: Wang Xiao Qun , Chen Da Rong , Han Jie Cai , Du Shan Yi 
Published: August 2002

AbstractFor some polymers such as PTFE, the crystallization is so rapid that it is difficult to observe isothermal crystallization by differential scanning calorimetry (DSC). In this investigation, first, isothermal crystallization kinetics of PTFE was followed by DSC and the results were analyzed by the Avrami method, which showed that PTFE crystallizes one‐dimensionally from preexisting nuclei, presumably impurities. Furthermore, the crystallization activation energy, the equilibrium melting point, and the nucleation rate parameter Kg were calculated in the isothermal crystallization. Second, nonisothermal crystallization was also studied and the result was in accordance with the results of isothermal crystallization. Then, the Kissinger method was used to investigate the activation energy of PTFE in the nonisothermal crystallization. Third, the effect of glass fiber (used as filling) was investigated on crystallization of PTFE matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 990–996, 2002