bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of additive‐epoxy interaction of thermally reworkable underfills
Authors: Wang Lejun , Wong C.P.
Published: October 2004

Underfill is the material used in a flip‐chip device to dramatically enhance its reliability as compared to a nonunderfilled device. Current underfills are mainly epoxy‐based materials that are not reworkable after curing, which is an obstacle in flip‐chip technology developments, where unknown bad die is a concern. Reworkable underfill is the key to address the nonreworkability of the flip‐chip devices. The ultimate goal of this study is to develop epoxy‐based thermally reworkable underfills. Our previous work showed that when incorporated into epoxy matrix, special additives could provide the epoxy formulation with die‐removal capability around solder reflow temperature. The additive‐epoxy interactions were studied and the results show that the additives do not adversely affect the epoxy properties. Moreover, when the additive decomposition temperature is reached, the decomposition of the additive causes a microexplosion within the epoxy matrix. Subsequently, the adhesion of the epoxy matrix is greatly reduced. Among the four additives studied, Additive1 and Additive2 may be used in reworkable underfills that can be reworked around solder reflow temperature, Additive3 cannot be used in underfill because it greatly reduces the shelf life of the underfill, and Additive4 may be used to develop reworkable underfill that withstands multiple reflows. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1868–1880, 2001
Surface modification strategies for multicomponent polymer systems. III: Effect of diblock copolymer‐modified rutile on the morphology and mechanical properties of LLDPE/PVC blends
Authors: Wang Weidong , Liang Hua , Favis Basil D. , Schreiber Henry P.
Published: October 2004

Rutile pigment was surface‐modified by the adsorption of various diblock copolymers and used as a component in two‐ and three‐component polymer blends involving the incompatible pair of linear, low‐density polyethylene (LLDPE) and poly(vinyl chloride) (PVC). Stress–strain analyses and electron microscopy show that the copolymer tethered to the rutile surface affects both mechanical and morphological properties of the blends. Inverse gas chromatography was used to evaluate dispersion surface energies and acid–base interaction parameters of the various solids. The mechanical and morphological characteristics of the blends can be rationalized by the concepts of acid–base and dispersion–force interaction. Of the copolymer modifiers used, the diblock based on polyisoprene and poly(4‐vinyl pyridine) (PIP‐P4VP) was best suited for use in LLDPE/PVC blends, ostensibly because of strong acid–base interaction between PVC and P4VP and mechanical interlocking between LLDPE and the PIP moiety. The properties of ternary blends were shown to be dependent on the method used for mixing the components. All mixing procedures used here resulted in time‐dependent variations of mechanical properties, suggesting that none gave rise to equilibrium morphology in the compounds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1891–1901, 2001
Dynamic mechanical analysis study of the curing of phenol‐formaldehyde novolac resins
Authors: Markovic Slobodanka , Dunjic Branko , Zlatanic Alisa , Djonlagic Jasna
Published: October 2004

The curing reaction of typical commercial phenol‐formaldehyde novolac resins with hexamethylentetraamine (HMTA) was followed by dynamic mechanical analysis. The evolution of the rheological parameters, such as storage modulus G′, loss modulus G″, and tanδ (G″/G′), as a function of time, for samples of the phenolic resins on cloth, was recorded. The curing reaction, leading to the formation of a crosslinked structure, is described by a third‐order phenomenological equation. This equation takes into account a self‐acceleration effect, as a consequence not only of the chemical reaction of crosslinking after the gel point but of phase segregation as well. This rheokinetic model of the curing of phenolic novolac resins permits the determination of the numerical values of the kinetic equation constants. The influence of the composition, structure, and physical treatment on the curing kinetics of the novolac resins is evaluated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1902–1913, 2001
Structural characterization of electron‐beam crosslinked thermoplastic elastomeric films from blends of polyethylene and ethylene‐vinyl acetate copolymers
Authors: Chattopadhyay S. , Chaki T. K. , Bhowmick Anil K.
Published: October 2004

Films were prepared from a blend of low‐density polyethylene (LDPE) and ethylene‐vinyl acetate (EVA) containing 45% VA and ditrimethylol propane tetraacrylate (DTMPTA). Electron‐beam initiated crosslinking of these films was carried out over a range of radiation doses (20–500 kGy), concentrations of DTMPTA (1–5 parts by weight), and blend compositions. The IR studies revealed that oxidation and crosslinking dominated up to an irradiation dose of 100 kGy. At higher irradiation doses chain scission and disproportionation predominated among all the competitive processes for the 50:50 blend without DTMPTA. The gel fraction of the films increased with the increase in irradiation dose, DTMPTA level, and EVA content of the blends. X‐ray diffraction and differential scanning calorimetry studies showed that the crystalline portion of the blends was only affected by radiation at higher irradiation doses (≥200 kGy). Scanning electron microscopy studies indicated that in the 50:50 blend the LDPE formed the continuous phase, which was further confirmed by atomic force microscopy and transmission electron microscopy studies. However, a co‐continuous morphology was formed when the EVA content was increased. When DTMPTA was added to the blends (≥3 wt %), the 50:50 blend exhibited a co‐continuous morphology. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1936–1950, 2001
Modeling of the sheet‐molding process for poly(methyl methacrylate)
Authors: Zhou Fangbin , Guptam Santosh K. , Ray Ajay K.
Published: October 2004

The sheet‐molding process for the production of poly(methyl methacrylate) (PMMA) involves an isothermal batch reactor followed by polymerization in a mold (the latter is referred to as a “sheet reactor”). The temperature at the outer walls of the mold varies with time. In addition, due to finite rates of heat transfer in the viscous reaction mass, spatial temperature gradients are present inside the mold. Further, the volume of the reaction mass also decreases with polymerization. These several physicochemical phenomena are incorporated into the model developed for this process. It was found that the monomer conversion attains high values of near‐unity in most of the inner region in the mold. This is because of the high temperatures there, since the heat generated due to the exothermicity of the polymerization cannot be removed fast enough. However, the temperature of the mold walls has to be increased in the later stages of polymerization so that the material near the outer edges can also attain high conversions of about 98%. This would give PMMA sheets having excellent mechanical strength. The effects of important operating (decision) variables were studied and it was observed that the heat‐transfer resistance in the mold influences the spatial distribution of the temperature, which, in turn, influences the various properties (e.g., monomer conversion, number‐average molecular weight, and polydispersity index) of the product significantly. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1951–1971, 2001
Reactive extrusion of polycaprolactone compounds containing wood flour and lignin
Authors: Nitz Hansjörg , Semke Hinnerk , Landers Rüdiger , Mülhaupt Rolf
Published: October 2004

Biodegradable polycaprolactone (PCL) was melt‐compounded in a Werner & Pfleiderer twin‐screw extruder (ZSK25) together with wood flour (WF) and lignin with maleic anhydride‐grafted polycaprolactone (PCL‐g‐MA) used as a compatibilizer. The grafting of maleic anhydride onto PCL was achieved with reactive extrusion in the presence of 2,5‐dimethyl‐2,5‐di‐(t‐butylperoxy)hexane as an initiator. The graft copolymers were analyzed with size exclusion chromatography and titration. As a function of the initiator and maleic anhydride addition, the grafted maleic anhydride content varied from 1.4 to 3.1 wt %. Compounds compatibilized with PCL‐g‐MA exhibited improved mechanical properties: a compatibilized PCL compound containing 40 wt % WF gave a Young's modulus of 2300 MPa with respect to 400 MPa for neat PCL and a 100% increase in yield stress. The content of WF, lignin, and PCL‐g‐MA was varied systematically to examine stress–strain and impact behavior. Low contents of grafted maleic anhydride and PCL‐g‐MA were required to improve both mechanical properties and interfacial adhesion. Biodegradation was investigated. Lignin addition was found to retard biodegradation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1972–1984, 2001
Study on the redox adsorptive properties of fiber containing iso‐thiourea group toward Au(III)
Authors: Tang Shunqing , Lu Yun , Zeng Hanmin
Published: October 2004

Functional fiber containing iso‐thiourea group was prepared by reactive chloromethylated poly(vinyl acetate)‐graft‐polystyrene–divinylbenzene (PVA‐g‐PS–DVB) being reacted with thiourea. The functional group content of the fiber was 2.90 mmol/g. The chloromethylated PVA‐g‐PS–DVB reacted with sulfur atoms in the thiourea molecules; this made the fiber containing iso‐thiourea group. The results of static adsorption experiments showed that the adsorption amount of the fiber toward Au(III) reached a maximum amount, 1000 mg/g, at pH 1.5. It reduced the adsorbed Au(III) into Au(0), and the maximum reduction percentage was 90% at pH 2.0. The amount of Au(III) adsorbed by the fiber increased with increasing solution temperature but decreased with the increasing ionic strength of the solution. It was proven by electron spectroscopy for chemical analysis that some of the sulfur atoms in the fiber were oxidized into sulfone groups or sulfate ions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1985–1990, 2001
Preparation and characterization of blends of high density polyethylene and poly(ethylene‐co‐1‐octene) elastomer
Authors: Guimarães Maria José O. C. , Coutinho Fernanda M. B. , Rocha Marisa C. G. , Garcia Maria Elizabeth F.
Published: October 2004

Mechanical, thermal, and morphological properties of blends of high density polyethylene and poly(ethylene‐co‐1‐octene) (PEO) were evaluated. The blends were prepared in a single screw extruder at 230°C and 50 rpm with volume fraction of elastomer varying in the range from 0.05 to 0.8. Factors such as chemical similarity and melt viscosity favor the interdiffusion process of phases, resulting in better interfacial adhesion. A synergistic effect on the strength at break and elongation at break for a particular range of blend composition was observed. Blends with a volume fraction of PEO higher than 5% presented a super tough behavior at room temperature. Thermal analysis showed that there is a certain degree of interaction between high density polyethylene and PEO. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1991–1995, 2001
Synthesis of thermoset plastics by Lewis acid initiated copolymerization of fish oil ethyl esters and alkenes
Authors: Marks David W. , Li Fengkui , Pacha Chad M. , Larock Richard C.
Published: October 2004

The Lewis acid initiated cationic homopolymerization of Norway fish oil ethyl ester (NFO) or the corresponding conjugated fish oil (CFO) and their copolymerization with various alkene comonomers is investigated. Among the Lewis acids employed, boron trifluoride diethyl etherate (BFE, BF3 · OEt2) is found to be the most effective initiator for cationic polymerization of the NFO and CFO systems. The BFE‐initiated homopolymerization of NFO generally results in low molecular weight viscous oils, while that of CFO leads to a solid elastic gel with a gel time of more than 72 h at room temperature. Copolymerization of the NFO or CFO with some alkene comonomers significantly facilitates gelation. The gel times are largely dependent upon the stoichiometry, the type of fish oil, and the alkene comonomer. After postcuring at elevated temperatures, the cationic copolymerization affords polymers ranging from soft rubbery materials to rigid plastics. These NFO and CFO polymers are composed of highly crosslinked materials and a certain amount of free oils and are found to be fully cured thermosets. Generally, CFO polymers appear to be harder than the corresponding NFO polymers. However, the thermal properties of the bulk polymers are similar to each other, and their insoluble extracts exhibit much higher thermal stability than the bulk thermosets. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2001–2012, 2001
Starch derivatives with high degree of functionalization. III. Influence of reaction conditions and starting materials on molecular structure of carboxymethyl starch
Authors: Heinze TH. , Pfeiffer K. , Lazik W.
Published: October 2004

Carboxymethyl starch (CMS) was prepared in a completely heterogeneous procedure in a methanol/water slurry activated with aqueous sodium hydroxide (45%, w/v) using monochloroacetic acid as the etherifying agent. The influence of the reaction conditions and the type of starting starch (amylose content and preactivation) was evaluated in regard to the formation of the main repeating units (i.e., unfunctionalized and mono‐, di‐, tri‐, and tetra‐O‐carboxymethylated) and the pattern of functionalization within the anhydroglucose units (AGU). The reproducible synthesis gave products with a maximal degree of substitution of CM groups (DSCM) of 0.66, which was reached in a one‐step synthesis. Repeated carboxymethylation led to products with a DSCM of 0.88. As revealed by means of HPLC analysis after complete acidic depolymerization, in any sample the mono‐O‐carboxymethylated glucose (mono‐O‐CMglc) was preferably present while the di‐O‐CMglc was formed to a very low extent only. The tri‐O‐CMglc was found in some samples while tetra‐O‐CMglc was not detected. The mole fractions determined did not follow the simple Spurlin statistic as shown for CM cellulose synthesized under comparable conditions. Within the carboxymethylated AGUs a preferred functionalization at position 2 was analyzed by means of 1H‐NMR spectroscopy after hydrolytic chain degradation. Consequently, the CMS samples synthesized contained mainly 2‐mono‐O‐CM‐AGU. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2036–2044, 2001
Surface/interfacial changes during polyurethane crosslinking: A spectroscopic study. V *
Authors: Han Qiwen , Urban Marek W.
Published: October 2004

Crosslinking reactions and stratification processes in polyurethane films were investigated using attenuated total reflectance (ATR) FTIR spectroscopy. The HDI trimer levels near the film–substrate (F–S) interface appear to increase at the early stages of reactions, and after reaching a maximum, decrease. This is attributed to solvent depletion and subsequent film shrinkage, thus causing local NCO concentration changes. At the later stages of crosslinking reactions, stratification of the 1,6‐hexamethylene diisocyanate (HDI) trimer occurs, with higher concentration levels at shallower penetration depths from the F–S interface. At the same time, NCO‐containing groups assume preferentially parallel orientation to the F–S interface. On the other hand, H‐bonded carbonyl groups tend to orient themselves in a perpendicular direction. Quantitative analysis indicates that at extended reaction times the amount of H‐bonded CO groups at shallower penetration depths increases and their orientation tends to be more random, which is correlated with migration toward the F–S interface. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2045–2054, 2001
Kinetic and property parameters of poly(ethylene naphthalate) synthesized by solid‐state polycondensation
Authors: Sun Yih‐Min , Shieh Jeng‐Yueh
Published: October 2004

A low molecular weight prepolymer with reactive end groups was annealed at temperatures between 200 and 245°C to obtain kinetic parameters for solid‐state polymerization of poly(ethylene naphthalate) (PEN). An equation was developed to describe the relationships among time, temperature, and final molecular weight for PEN. The intrinsic viscosity and melting point during polymerization were used to monitor the molecular weight and the thermal stability of the resulting resins. The effect of moisture concentration on solid‐state polymerization was also investigated. Hydrolytic degradation caused initial reductions of the molecular weight if prepolymers were solid‐stated without being dried. With increased exposure to solid‐state conditions, however, the hydrolytically degraded resin dried and repolymerized at rates similar to those samples that had undergone hydrolysis. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2055–2061, 2001
Synthesis and modification of epoxy‐based divinyl ester resin
Authors: Gawdzik B. , Matynia T.
Published: October 2004

Syntheses of epoxy‐based divinyl ester resin and its modification with toluene diisocyanate (TDI) are presented. The resin was obtained from commercially available epoxy resin Epidian 5 and methacrylic acid during graduated heating. Three different resin solutions were obtained by adding 45, 50, and 55% of styrene; then, each solution was modified with TDI at room temperature. Properties of the resins before and after modification were studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2062–2067, 2001
Acoustic analysis of composite soft materials. I. Characterization of the core and boundary layer from compressibility of core/shell particles dispersed in poly(vinyl chloride)
Authors: Koda Shinobu , Tsutsuno Naoki , Yamada Gen , Nomura Hiroyasu
Published: October 2004

The sound velocity of butyl acrylate rubber particles modified by poly(methyl methacrylate) in poly(vinyl chloride) was measured as a function of particle concentration. A model for estimating the adiabatic compressibility of the particle and the boundary layer was proposed. From the model, the partial specific adiabatic compressibility of the particles and the rubber core were evaluated. The adiabatic compressibility of the rubber core was estimated as 3.82 × 10−10 Pa−1. The adiabatic compressibility of the poly(methyl methacrylate) shell is discussed based on the modified model. The study indicates that the shell, including the boundary layer between butyl rubber and poly(methyl methacrylate), is perturbed by the butyl acrylate molecules and is so soft as to be comparable to the rubber. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2089–2094, 2001
An application of micro‐thermal analysis to polymer blends
Authors: Song M. , Hourston D. J. , Grandy D. B. , Reading M.
Published: October 2004

Micro‐thermal analysis (micro‐TA) is a new subsurface thermal analysis technology. The average of the DC signal is a function of the thermal conductivity, and the response to the AC modulation signal is a function of the thermal diffusivity of the subsurface. Using this technique, three images based on topography, thermal conductivity, and thermal diffusivity are obtained simultaneously. Specific areas and domains in these images can then be characterized by simply positioning the probe and performing a localized thermal analysis experiment. The technique has been used to study the phase separation process in a 50:50 (by weight) polystyrene (PS)–poly(vinyl methyl ether) (PVME) blend and natural rubber–nitrile rubber blends. For these polymer blends, considerable contrast between phases is obtained, based on thermal conductivity, whereas optical and electron microscopy would show them as being very similar. For example, it is difficult to image the morphology of natural and nitrile rubber blends by means of transmission electron microscopy, because of their similar chemical structures. Micro‐TA gives an excellent image of the morphology of these natural–nitrile rubber blends. This opens a new way for rubber industries to study morphologies of rubber–rubber blends in general. In the 50:50 PS–PVME blend, annealed at 125°C, spinodal decomposition occurred. With increasing time, the domain size and the glass transition temperature of PS‐rich domains increased, indicating that the concentration of PVME in the PS‐rich phases decreases. The results imply that micro‐TA can be used to image the composition in the near‐surface or surface regions in multicomponent materials, if the resolution is high enough. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2136–2141, 2001
Effects of initial structure on the deformation behavior of PP hollow fiber in continuous drawing
Authors: Lee Moo Seok , Kim Sang Yong
Published: October 2004

The effects of the microcrystalline structure of undrawn fibers on the rheological behavior in the process of the polypropylene (PP) hollow fiber formation system were studied by a simple model describing the continuous drawing process. The predicted and observed drawing behaviors were explained in view of a simple approach based on the concept of strain‐rate sensitivity and strain‐hardening parameters. Various parametric studies showing the interactive nature of the strain‐rate sensitivity and strain‐hardening parameters on the drawing behavior were also numerically performed. Strain‐rate sensitivity affects mainly the intensity of the neck, and strain hardening has more effects on the position of the inflection point in continuous drawing. Details of the necking mechanism in the drawing process were studied by observing the deformation behavior of the specimens with different initial microcrystalline structures. The distinctive initial structure of undrawn PP hollow fibers can be formed by controlling the quenching condition in melt spinning. It was shown that the water‐quenched PP fiber exhibited an unstable smectic form, whereas the stable monoclinic phase was observed for the fiber prepared without quenching by forced convection. The experimental results of the drawing behavior indicated that the strain‐rate sensitivity of the fiber with a smectic form was larger than that with the monoclinic form. It was also shown that the hollowness was affected by the quenching condition in melt spinning and the deformation behavior in the drawing process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2170–2182, 2001
Substitution of corn starch with polycaprolactone via chlorination and water resistance of the substituted starch
Authors: Kweon Dong‐Keon , Lim Seung‐Taik
Published: October 2004

Corn starch was chlorinated using methanesulfonyl chloride in dimethylformamide (DMF) and then substituted with polycaprolactone (PCL) in various solvents [dimethylsulfoxide (DMSO), water and dimethylacetamide (DMAc)] containing a catalyst [sodium hydroxide (NaOH) or lithium chloride (LiCl)] to improve water resistance. The reaction yield based on the product weight was highest (85%) when DMAc and LiCl were used. Fourier transform infrared (FTIR) spectra showed that starch was monosubstituted with PCL in the aqueous NaOH solution, whereas it was to crosslink by PCL in the case using DMAc and LlCl. The intrinsic viscosity of the products in DMSO supports these trends. By introducing the hydrophobic PCL onto starch, solvent resistance of the substituted starches to water and other aqueous media increased. The crosslinked starch displayed higher water resistance than the monosubstituted starch. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2197–2202, 2001
Surface tailoring of biomedical polymers: An FTIR study
Authors: Stern T. , Cohn D.
Published: October 2004

A multistep, surface‐tailoring process of polymeric materials was developed with two consecutive plasma treatments and followed by derivatization reactions. In the first step, tetrafluoroethylene was plasma‐polymerized, generating a highly crosslinked perfluoric surface layer. The next step introduced amine groups into the plasma polymer through exposure of the surface to plasma of ammonia. The reactive amine moieties were then used as anchoring sites for further derivatization. Finally, poly(ethylene glycol) chains were grafted onto the surface via a hexamethylene diisocyanate spacer. This method, aimed at the chemical modification of polymers for biomedical applications, was first demonstrated with poly(ethylene terephthalate) (PET) as a substrate in a previously published study (Cohn, D.; Stern, T. Macromolecules 2000, 33, 137). The aim of this study was to demonstrate the applicability of the method described previously to different polymers: poly(lactic acid), poly(ethylene) (PE), polystyrene (PST), poly(methyl methacrylate), a polybutadiene‐based polyurethane (PEUOXAB‐20), and Lycra. Fourier transform infrared (FTIR) spectroscopy was used to characterize the surface‐modified substrates and the various control treatments. The results obtained were consistent with the derivatization scheme and in full agreement with the FTIR and ESCA results previously obtained for PET. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2203–2209, 2001
Mechanochemical solid‐phase reaction between polyvinylidene fluoride and sodium hydroxide
Authors: Zhang Qiwu , Lu Jinfeng , Saito Fumio , Baron Michel
Published: October 2004

Grinding a mixture of polyvinylidene fluoride (PVDF) and NaOH was conducted by a planetary ball mill at atmospheric condition to investigate mechanochemical reaction between the two substances. The grinding stimulates the reaction to form NaF and organic composites. Yield of fluorine converted from PVDF to NaF increases with an increase in grinding time and reaches 90% at 60 min or more. As for the organic phase, oxygen‐bearing compounds are formed due to substitution of fluorine by OH base. The organic compounds are classified into water‐soluble and insoluble ones, depending on their structures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2249–2252, 2001
The rheological and structural behavior of silylcellulosics derivatives
Authors: Bontea D.
Published: October 2004

The trimethylsilylcellulose (TMSC) samples were characterized in solution by osmometry, viscometry, and gel permeation chromatography. The Mark‐Houwink‐Sakurada (M‐H‐S) equation coefficients were determined in chloroform, 1,1,1‐trichloroethane, and o‐xylene, in all cases the exponent “a” being higher than unit, this indicating a great stiffness of the macromolecules in solution. Also, the temperature dependence of the limiting viscosity number and M‐H‐S coefficients respectively for TMSC in o‐xylene were studied. The exponent from M‐H‐S equation is also higher than unit, and increases linearly with the temperature. The GPC studies indicates a relative high polydispersity of the studied samples; the polydispersity index being situated between 2 and 3. The change of the crystalline structure as the result of silylation reaction was evidenced, the crystallinity of silyl derivatives depending on the substitution degree (DS), and the molecular weight. The viscous flow parameters for dilute solutions of trimethylsilylcellulose in o‐xylene were determined in the temperature range 30–70°C. The temperature dependence of the dynamic viscosity of the solutions obeys an Arrhenius‐type equation in which the apparent activation energy is linearly dependent on both the solution's concentration and molecular weight. For preexponential factor no significant dependence on concentration and molecular weight was found. This behavior was attributed to the very great stiffness of the macromolecular chains. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2277–2285, 2001
Co(III) acetylacetonate‐complex‐initiated grafting of N‐vinyl pyrrolidone on cellulose in aqueous media
Authors: Gupta K. C. , Sahoo Sujata
Published: October 2004

The graft copolymerization of N‐vinyl pyrrolidone (N‐VP) onto cellulose was carried out with a cobalt acetylacetonate complex Co(acac)3 as an initiator under a nitrogen atmosphere at 50 ± 0.1°C. The graft yield percentage (%G) obtained as a function of the concentrations of N‐VP and Co(acac)3 and the temperature was used to calculate various other grafting parameters and the grafting rate dependence on the concentrations of monomer, Co(acac)3 and reaction temperature. The energy of activation (ΔEa) for the grafting of N‐VP onto cellulose was 22.7 kJ/mol within 40–60°C. The molecular weights of the grafted chains and homopolymers were determined viscometrically with a Ubbelohde‐type viscometer. Graft yield (%G) in the presence of various additives such as sodium lauryl sulfate, cetyltrimethylammonium bromide, and methanol was studied, and the results are suitably explained. On the basis of the experimental results, a reaction scheme for graft copolymerization is proposed, and a kinetic rate expression is presented. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2286–2296, 2001
Properties of polypropylene filled with synthetic sodium aluminum silicate
Authors: Upadhyay R. D. , Kale D. D.
Published: October 2004

The effect of synthetic sodium aluminum silicate (SSAS) on the mechanical, physical, electrical, optical, and rheological properties of two different grades of polypropylene (PP) homopolymer with melt flow indexes (MFIs) of 3 and 11 was studied. Incorporation of SSAS improved the flexural strength and modulus of PP. At a given loading of SSAS, the mechanical properties of MFI 3 PP were better than those of MFI 11 PP. The presence of significant slip at the wall was observed for SSAS filled PP. The addition of a fluoropolymeric processing aid increased the slip effect further. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2297–2303, 2001
Isomerization behavior of aromatic azo chromophores bound to semicrystalline polymer films
Authors: Sarkar Nabin , Sarkar Anjana , Sivaram Swaminathan
Published: October 2004

The cis–trans isomerization of azo chromophores covalently bound to semicrystalline polymer films was investigated. Various azo chromophores were introduced onto the functionalized semicrystalline polymer films by a chemical transformation reaction and their isomerization behavior was investigated by UV‐visible spectroscopy and a contact‐angle goniometer. The thermal Z → E isomerization rate of the azo moiety covalently bound to low‐density polyethylene (LDPE) and polypropylene (PP) films was determined. The rate of thermal isomerization was also compared between amorphous and semicrystalline polymer films bearing azo chromophores. The effect of the intramolecular steric factor and the nature of chromophores was studied on the thermal isomerization rate of the polymer films. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2923–2928, 2001
Alkaline depolymerization of poly(trimethylene terephthalate)
Authors: Kim Joon Ho , Lee Joon Jung , Yoon Ji Young , Lyoo Won Seok , Kotek Richard
Published: October 2004

The purpose of this study was to investigate the effects of reaction media, composition, and temperature on the rate of the alkaline depolymerization of poly(trimethylene terephthalate) (PTT). The alkaline depolymerization of PTT was carried out at 160–190°C in ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), ethylene glycol monobutyl ether (EGMBE), diethylene glycol monoethyl ether (DEGMEE), and a mixture of these solvents. During the reaction, PTT was quantitatively converted to disodium terephthalate and 1,3‐propanediol. The alkaline depolymerization reaction rate constants were calculated based on the concentration of sodium carboxylate, which was equivalent to the molar amount of sodium hydroxide. The depolymerization rate of PTT was increased by increasing the reaction temperature and by adding ethereal solvents. Moreover, the depolymerization rate was significantly accelerated in the order of EG < DEG < TEG < EGMBE < DEGMEE. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 99–107, 2001
Cellulose furoate. III. Properties and applications
Authors: Yan Hui , Hon David N.‐S.
Published: October 2004

Cellulose furoates synthesized by a homogeneous reaction was used to make film and fiber. Either colorless or light yellow, transparent cellulose furoate film can be made by solvent cast. Cellulose furoate film with a DS of 2.56 and 20% PEG‐400 as the plasticizer displayed 5441 psi maximum tenacity and 21.5% maximum strain. The film without plasticizer has a water vapor permeability of 0.124 ng · m/m2 · s · Pa. DMTA study identified the Tg of cellulose furoate with a DS of 2.77 was 225°C. As the DS decreased, the Tg shifted toward higher temperature. The success of wet‐spun fibers from LiCl/DMAc solution of cellulose and cellulose furoate substantiated cellulose furoate is compatible with cellulose. Unfortunately, the wet‐spun fibers lost their mechanical and surface properties, and bioresistant property against Myrothecium verrucaria, Cheatomium globosum, and Aspergillus terreus. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 253–257, 2001
Effects of plasma treatment and metal‐ion chelation on lightfastness of dyed polyester/cotton fabric
Authors: Jahagirdar C. J. , Srivastava Yasmin
Published: October 2004

Polyester/cotton blend fabric was dyed with Chemistron dye—a mixture of reactive/disperse dyes. Dyed fabrics were subjected to radiofrequency (RF) plasma treatment of different duration and were subsequently treated with metal salts. The effect of surface modification by plasma and dye–metal complex on colorfastness to light is discussed. Evaluation of the improvement in lightfastness was made using the CIE system of color measurement with a standard illuminant D65 and 10° standard observer. The color parameters and color deviations were obtained by Data flash–100 color measurement spectrophotometer with chroma QC 3.0 color quality control software. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 292–299, 2001
Formation of antibiotic, biodegradable polymers by processing with Irgasan DP300R (triclosan) and its inclusion compound with β‐cyclodextrin
Authors: Lu Jin , Hill Marcus A. , Hood Miriam , Greeson Dale F. , Horton John R. , Orndorff Paul E. , Herndon April S. , Tonelli Alan E.
Published: October 2004

The inclusion compound (IC) between the FDA‐approved antibacterial Irgasan DP300 (Trichlosan), and β‐cyclodextrin (CD) has been formed. When the Irgasan–β‐CD–IC is embedded in biodegradeable/bioabsorbable films of poly(ϵ‐caprolactone) (PCL) at low levels (a few wt %), they are rendered resistant to the growth of E. coli bacteria. When these same PCL films embedded with Irgasan–β‐CD–IC are used as the adhesive for laminating cotton fabrics, we observe the resulting cotton laminates to also be resistant to the growth of E. coli bacteria. These results hold promise for the fabrication of bacteria‐resistant polymer films and fibers, as well as antibacterial fabrics, by means of simple melt processing with Irgasan–β‐CD–IC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 300–309, 2001
Synthesis, characterization, and electrical conductivity of polyaniline derivatives: Study with the metal ions Cu(II), Ni(II), and Co(II)
Authors: Rivas B. L. , Sánchez C. O.
Published: October 2004

Poly(2‐aminophenol), poly(3‐aminophenol), poly(2‐aminobenzyl alcohol), and poly(3‐aminobenzyl alcohol) were synthesized by using ammonium persulphate as oxidizing reagent in HCl and HCl/CH3CN mediums in the presence and absence of Cu(II), Ni(II), and Co(II) ions. The polymers were characterized by Fourier transform infrared spectroscopy, ultraviolet‐vis spectroscopy, thermal analysis, and electrical conductivity measurements. The substituent in 2‐ and 3‐positions decreases the yield regarding aniline. Poly(2‐,3‐aminobenzyl alcohol) are obtained in an intermediate redox state and polymerized as aniline. On the contrary, poly(aminophenols) are obtained as overoxidated structures. The presence of metal ion produces an important increase of the polymerization yield. The metal cations would act as oxidizing agents. The incorporation of these metal ions depends on the reaction medium. The metal ion increases the thermal stability. Poly(2‐aminobenzyl alcohol)‐copper ions also increases the electrical conductivity. The electrical conductivity is higher by acid doping than by the incorporation of metal ions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 330–337, 2001
Study on aging of clay–rubber masterbatch from modified clay
Authors: Chen Mei , Ao Ning‐Jian , Chen Ying , Yu He‐Ping , Qian Hong‐Lian , Wang Chen , Zhou Hui‐Ling , Qu Ju‐Lan , Guo Chen‐Kun
Published: October 2004

Clay was modified by using a polymeric coating agent, a silicane coupling agent, and a titanate coupling agent together with the antioxidant for preparing the clay–rubber masterbatch. After the thermooxidative, photooxidative, and ozone aging, the properties of the masterbatch were also determined. The results indicate that, under the synergistic actions of the polymeric coating agent, antioxidant, and coupling agent, the thermooxidative and photooxidative aging resistances of the masterbatch were greatly improved. The properties of ozone aging resistance of the masterbatch can be increased by 50% under the combined action of a new kind of amine antioxidant with a titanate coupling agent. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 338–342, 2001
Elastic interlayer toughening of potassium titanate whiskers–nylon66 composites and their fractal research
Authors: Lü Jiazhen , Lu Xiaohua
Published: October 2004

Potassium titanate whiskers–nylon66 composites were effectively toughened with an elastic interlayer of epoxy resin. The optimal fraction of epoxy resin was 1.5 wt % of whiskers, which corresponded to an interlayer thickness of 3% of the radius of whiskers. SEM images showed that interfacial adhesion was improved with elastic interlay. The impact strength of the composite increased 132% compared with neat nylon66, whereas the bending and tensile strengths increased 55 and 48%, respectively. Digital image method was adopted to carry out fractal research of fracture surfaces of the composites. Fractal dimensional calculations were based on perimeter–area relation. It was found that with the sizes of measured slit islands increasing, calculated fractal dimensions increased first and became stable after area threshold reached about 500 η2 (η was a yardstick). The toughness of composites increased with fractal dimensions, which was explained from the point of fracture mechanism. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 368–374, 2001
Development of novel polymeric flocculant based on grafted sodium alginate for the treatment of coal mine wastewater
Authors: Tripathy Tridib , Karmakar N. C. , Singh R. P.
Published: October 2004

Sodium alginate‐g‐polyacrylamide (SAG) was synthesized by ceric ion induced redox polymerization technique. Six grades of graft copolymers were prepared by varying as well as monomer concentrations. The graft copolymers were characterized by intrinsic viscosity measurements, IR, and 13C‐NMR spectroscopies. Of the above grades, the graft copolymer of grade six (SAG‐VI), which has longer polyacrylamide chains, was used for flocculation study. Two coking and noncoking coal fine suspensions were selected for the flocculation study. The flocculation performance of the graft copolymer was compared with commercial flocculants. In all cases, it was found that the graft copolymer showed better performance than the commercial flocculants. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 375–382, 2001
Characteristics of PPG‐based thermoplastic polyurethane doped with lithium perchlorate
Authors: Wen Ten‐Chin , Fang Jui‐Chin , Lin Hung‐Jye , Yang Chien‐Hsin
Published: October 2004

Segmented thermoplastic polyurethane (TPU) was synthesized from methylene bis(cyclohexyl isocyanate) (H12MDI), ethylenediamine (EDA), and poly(propylene glycol) (PPG) with a molecular weight of 1000. The ratio of hard segment to soft segment (NCO/OH) is changed to test the chemical and physical properties. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and impedance spectroscopy (IS) were utilized to monitor the phase change of these TPU samples with various lithium perchlorate (LiClO4) concentrations. Significant changes occur in the FTIR spectrum of the TPU with LiClO4 concentration above 0.5 mmol/g TPU, indicating that an interaction existed between the lithium cation and the hard segment or soft phase. The soft‐segment Tg increased with increasing LiClO4 concentration through the examination of DSC. IS results indicate an increase in bulk conductivity as the salt concentration is increased. Electrochemical stability of the TPU sample was studied by cyclic votammetry (CV). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 389–399, 2001
Copolymerization of methyl methacrylate and N‐alkyl methacrylamide
Authors: Chen Yu , Zhang Guangli , Zhang Hongzhi
Published: October 2004

A new approach to the preparation of colorless and high transparent methacrylic resins was described. N‐Alkyl methacrylamide, the alkyl substituent of which was methyl, cyclohexyl, or isobornyl, was employed to copolymerize with methyl methacrylate, giving the copolymer with enhanced glass transition temperature around 10–15°C higher than that of homo‐poly(methyl methacrylate). The comonomers, N‐cyclohexyl methacrylamide and N‐isobornyl methacrylamide, were prepared by reaction of methacrylonitrile with cyclohexene and camphene, respectively. All the three kinds of copolymers showed the water absorption similar to that of homo‐poly(methyl methacrylate) after the samples were immersed in water for 2–8 days. The copolymers also showed high weather resistance toward sunshine in atmosphere for 16 months. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 400–405, 2001
Radical polymerization of N‐[(1‐n‐butoxycarbonyl)ethyl]maleimide
Authors: Ai Jiaoyan , Liu Pengsheng , Tan Hongyan , Lei Rengui
Published: October 2004

Poly(N‐[(1‐n‐butoxycarbonyl)ethyl]maleimide) (PBAM) was synthesized by solution polymerization with 2,2′‐Azobis(isobutylronitrile) (AIBN) as radical initiator. The resulting polymer(PBAM) was characterized by infrared spectroscopy (IR), themogravimetry (TG), and differential thermal analysis (DTA). The initial decomposition temperature of PBAM is 321.6°C; the glass transition temperature of PBAM was 240.5°C. The effects of solvent, temperature, initiator concentration ([I]), and monomer concentration ([BAM]) on polymerization were also discussed. The overall activation energy (Ea) of homopolymerization was determined (Ea = 93.5 kJ/mol). It was revealed that the rate of polymerization (Rp) can be expressed as Rp ∝ [I]0.58[BAM]. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 424–427, 2001
Mechanical, morphological, and thermal properties of poly(ethylene 2,6‐naphthalate) and copolyester LCP blends
Authors: Xie W. B. , Tam K. C. , Yue C. Y. , Hu X. , Lam Y. C. , Li L.
Published: October 2004

Binary blends of a liquid crystalline polymer (LCP) and poly(ethylene 2,6‐naphthalate) (PEN) were melt blended and injection molded. The mechanical properties were studied as a function of LCP content. Both the ultimate tensile strength and Young's modulus are higher than the theoretical values predicted by the rule of mixtures and they display a synergistic behavior at 70 wt % LCP content. However, the tensile strength decreases with LCP content and Young's modulus remained unchanged at lower LCP contents (10 to 30 wt %). The poor mechanical property is attributed to the immiscibility between PEN and LCP and the fibrillation behavior of LCP as revealed by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) results. However, LCP and PEN are found to be partially miscible at higher LCP content, ascertained by DSC and dynamic mechanical analysis (DMA). This is attributed to the transesterification reaction between PEN and PET moiety in the LCP molecules. SEM micrographs reveal a skin/core morphology in the tensile bars, that is, the LCP is better oriented in the skin than in the core region. At lower LCP content, the dispersed LCP phase is spherical in the core and ellipsoidal in the skin, with long axes oriented in the flow direction. DSC studies show that the crystallization rate is significantly enhanced by the presence of LCP up to 50 wt %, where the LCP acts as a nucleating agent for PEN crystallization. The melting temperature decreases with LCP content, probably as a result of imperfect crystals formed in the presence of LCP heterogeneous nucleating centers and the increasing miscibility between LCP and PEN. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 477–488, 2001
Preparation of carbon black/natural rubber latex masterbatch in bead form
Authors: Tangboriboonrat P. , Rakdee C.
Published: October 2004

Carbon black/natural rubber latex masterbatch in the form of spherical beads was prepared according to the acid‐precipitation method. High‐loading carbon black (40 phr) was incorporated in natural rubber with the aid of a nonionic surfactant (Nonidet P40). Shearing the beads in an internal mixer provided good integration of carbon black in the rubber matrix and hence the high bound rubber content. Results confirmed the contribution of chemical interaction to the bound rubber content. By an oxidation process, the size of modified carbon black was reduced, whereas the large agglomeration took place in the case of partially graphitized carbon black. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 489–498, 2001
Synthesis, X‐ray structure, and polymerization of 1‐vinyl‐3‐cyanomethylimidazolium chloride
Authors: Evsyukov Sergey E. , Gautheron Franck , Höffken H. Wolfgang , Böhn Karlheinz
Published: October 2004

A new monomer, 1‐vinyl‐3‐cyanomethylimidazolium chloride (1), was synthesized via quaternization of 1‐vinylimidazole with chloroacetonitrile. The monomer was characterized using 1H– and 13C–NMR as well as Raman spectroscopic techniques; its crystal structure was studied by means of X‐ray analysis. The radical polymerization of 1 in aqueous solution brought about the formation of a polyelectrolyte that retains cyano groups intact and possesses film‐forming properties. The structure of the polymer was characterized by NMR and Raman spectroscopy. The high viscosity of aqueous solutions and chemical structure of the polymer obtained suggest its possible applications as a thickener and/or detergent additive. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 499–509, 2001
Effects of low molecular weight compounds with hydroxyl groups on properties of poly(L‐lactic acid)
Authors: He Yong , Asakawa Naoki , Li Jianchun , Inoue Yoshio
Published: October 2004

The effects of low molecular weight compounds with hydroxyl groups on the properties of poly(L‐lactic acid) (PLLA) were investigated. The specific interaction between PLLA and 4,4′‐thiodiphenol (TDP) was investigated by Fourier transform IR spectroscopy. The spectra of the blends suggested that there were interassociated hydrogen bonds between the PLLA chains and TDP molecules. The thermal and dynamic mechanical properties of PLLA/TDP blends were investigated by differential scanning calorimetry and dynamic mechanical thermal analysis, respectively. The results revealed that the thermal and dynamic mechanical properties of PLLA were greatly modified through blending with TDP and that PLLA/TDP blends possessed eutectic phase behavior. The effects of the thermal history on the formation of hydrogen bonds and the thermal and mechanical properties were evaluated. It was found that the properties of the blends were strongly dependent on the thermal history. In addition to TDP, PLLA blends with other low molecular weight hydroxyl compounds, including aromatic and aliphatic compounds, were also characterized. The effects of the chemical structure of the low molecular weight compounds on the properties of PLLA were discussed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 640–649, 2001