bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compatibilizing effect of styrene–sodium methacrylate ionomers on nylon‐6–polystyrene blends
Authors: Lee Baek‐Hyun , Park Jung‐Ki , Song Hae‐Young 
Published: April 2003

AbstractThe compatibilizing effect of styrene–sodium methacrylate (S‐NaMA) ionomer on nylon‐6 (N6) and polystyrene (PS) blends was studied. The dispersed particle size of these blends containing the ionomers was significantly reduced compared with that of the blends without the ionomer. The reduction of the particle size was more pronounced when the ionomer with lower ionic content was added to the blend. The blends using ionomer with the lower ionic content showed higher tensile strength than the blends using ionomer with the higher ionic content. It is suggested that these results are caused by the proper combination of specific interactions and structural similarity between the component polymers and the ionomers. © 1994 John Wiley & Sons, Inc.
Graft copolymers and ionomeric associations from mixtures of phenoxy with acid functionalized polyolefins—Part II: Compatibilizers for HDPE/PET blends
Authors: Mascia L. , Bellahdeb F. 
Published: April 2003

AbstractGraft copolymers and coionomeric mixtures produced by mixing a phenoxy polymer (polyhydroxyether of bisphenol A) respectively with ethylene–propylene copolymers, containing grafted maleic anhydride groups (EP‐g‐MA), and the sodium ionomers of the terpolymers of ethylene, an alkyl acrylate and a carboxylic acid, the ionomeric character of which being enhanced by the addition of either sodium benzoate (weak base) or sodium ethoxide (strong base), were used as compatibilizers for blends of PET and HDPE in different ratios and with varied molecular weight of the HDPE component. The preparation of the compatibilizer and the production of the blends were carried out on a twin‐screw extruder. Both types of compatibilizers acted as effective surfactants for the dispersion of the two polymers, at all weight ratios, and the blends exhibited a substantial increase in melt viscosity as a result of the addition of the compatibilizer. Only the coionomeric compatibilizers, however, produced substantial improvements in both tensile strength and elongation at break, irrespective of the ratio of the two polymers in the blends. This was attributed to the strong nucleating effects on the crystallization of the polymer components and to a strong interfacial adhesion between the two polymer phases. © 1994 John Wiley & Sons, Inc.
The use of generalized eulerian–lagrangian formulations in composite materials processing
Authors: Alexandrou Andreas N. , Ahmed Alauddin 
Published: April 2003

AbstractThe advantages of the Generalized Eulerian–Lagrangian (GEL) formulations in modeling and numerical solution of unsteady flow of fiber suspensions are discussed. This formulation offers the flexibility of selectively applying an Eulerian (Spatial), a Lagrangian (Material), and any combination of these two frames of reference in the same computational domain. This flexibility offered by the GEL formulation is exploited to exactly determine the shape and location of the free surfaces and moving boundaries in the numerical simulation of various manufacturing processes. The application of the GEL formulation to the solution for the flow field and fiber orientation in the unsteady flows of dilute and semiconcentrated fiber suspensions are presented. The flow field and fiber orientation predicted by this method agree well with the available theoretical and experimental results. © 1994 John Wiley & Sons, Inc.
Calorimetric and rheological analysis of the BMI based resins curing process
Authors: Greco R. , Laurienzo P. , Malinconico M. , Martuscelli E. , Perenze N. , Sorrentino A. 
Published: April 2003

AbstractRubber modified prepolymers were synthetized through a nucleophilic addition of diamines to aromatic bismaleimides, using N,N′bismaleimido‐4‐4′diphenylmethane (BMI), 1,4‐piperazine (PyP), and an amino‐terminated polydimethylsiloxane elastomer (PDMS). Thermal stability was investigated by thermogravimetric analysis (TGA) in order to elucidate the influence of diamines. Physical and rheological changes during the curing process were monitored by differential scanning calorimetry (DSC) and dynamic mechanical tests (DMA). The degree of cross‐linking of the sample with PDMS was higher than that of the sample without PDMS. This effect might be due to a larger chain mobility provided by the rubber during the cure. © 1994 John Wiley & Sons, Inc.
Advances in the technology of fiber reinforced thermoplastics during 1992
Authors: Kelleher Paul G. 
Published: April 2003

AbstractThis article is a review of developments published in the open literature during 1992 on subjects related to the injection molding of fiber reinforced thermoplastics. Topics discussed include high performance polymers, reinforcements, fiber–matrix adhesion, composite properties, data bases, factors involved in injection molding, product design, mold design and manufacture, product manufacture, and applications of fiber reinforced thermoplastic composites. The intent was to include information pertinent to improvements in the engineering, fabrication, and use of these materials. © 1994 John Wiley & Sons, Inc.
Comparison of calculated with measured flow fields in the gap between two rotating rolls
Authors: Klostermann Rainer , Von Bose Stefan , Mewes Dieter 
Published: April 2003

AbstractVelocity, pressure, temperature, and stress fields are calculated for the flow of a polymer between two counterdirectionally rotating rolls. The rheological behavior of the polymer is described by the Carreau equation, while elasticity is neglected. The results of the numerical calculations are compared with measurements. The stress field is measured by the birefringence method. The local principal stresses in the fluid are determined from the measured anisotropy of the sheared fluid for the penetrating monochromatic light by means of the stress optical law. The equations of motion and continuity are solved with a Finite Element Method (FEM) based on the Galerkin weighted residual method. The computer code is combined with a Boundary Element Method (BEM) algorithm using the Dual Reciprocity Method (DRM) to solve the coupled equation of energy. Results are shown for a shear‐thinning polyisobutene melt in a calender with totally submerged rolls. The calculated results for the principal stress differences are compared to the measured results and confirm fairly well. The influence of friction is discussed. © 1994 John Wiley & Sons, Inc.
MWD determination of ultra high MFR polypropylene by melt rheology
Authors: Yoo Hee Ju 
Published: April 2003

AbstractA rheological technique of determining molecular weight distribution (MWD) of ultra high MFR polypropylene (PP) is presented. The development of this new technique was needed for two reasons. First, the advent of high activity catalyst made possible the direct polymerization and thus the commercialization of very high MFR PP. Secondly, the polydispersity index (PI) measurement based on crossover modulus from G′ and G″ curves, which was developed by Zeichner and Patel in 1981, was proven to be inapplicable to resins with MFR higher than about 40, due to instrument limitations. This new technique utilizes G′ and G″ data at low frequencies which are obtained from a dynamic frequency sweep test at 200°C. PI values, a measure of MWD, determined by this method are proven to have an excellent correlation with those obtained by gel permeation chromatography (GPC). This method has been very useful in determining MWD of melt brown fiber resins whose MFR is normally between 30 and 1000. It has also been used as a quality control tool during the resin production in a commercial plant. © 1994 John Wiley & Sons, Inc.
Solvent recycling of poly(methyl methacrylate) decorative sheets
Authors: Gouli S. , Poulakis J. G. , Papaspyrides C. D. 
Published: April 2003

AbstractA model solvent technique for the recycling of poly(methyl methacrylate) (PMMA) decorative sheets is studied. The process comprises dissolution of the sheets in toluene, reprecipitation by n‐hexane, washing and drying. Moreover, the toluene‐hexane mixtures involved are separated by distillation for further reuse. Within our experimental conditions, the polymer was totally recovered in the form of grains with the solvents yields also being very satisfactory. The recycled grades proved to resemble closely the virgin material. © 1994 John Wiley & Sons, Inc.
Response surface modeling in compounding recycled polyolefinic blends
Authors: Adewole Akin , Dackson Keith , Wolkowicz Mike 
Published: April 2003

AbstractQualitative and quantitative response of recycled polyolefinic blend morphology and mechanical properties as a function of polymer component ratio, compatibilizer concentration, and mixing parameters were investigated using response surface methodology. Phase contrast optical microscopy (PCOM) and scanning electron microscopy (SEM) were used to characterize blend micromorphological phase structures for both dispersed and co‐continuous mixtures of HDPE in PP. Full polynomial models up to order 2(y = a0 + a1x1 + a2x2 + a3x3 + a11x12 + a22x22 + a33x32 + a12x1x2 + a13x1x3 + a23x2x3) were generated for each response as a function of the input factors using multiple linear regression (MLR). Optimization techniques were used to develop both processability windows and optimum blend conversions costs for a given balance of properties. © 1994 John Wiley & Sons, Inc.
Compatibilization of refined commingled post‐consumer plastics
Authors: Xanthos M. , Patel A. , Dey S. , Dagli S. S. , Jacob C. , Nosker T. J. , Renfree R. W. 
Published: April 2003

AbstractIn attempts to improve the properties of post‐consumer commingled plastics waste a variety of additives that could potentially act as compatibilizers/impact modifiers were evaluated. The feedstock was representative of a model curbside collection program and contained a variety of polymers, mostly polyethylenes with PET, PP, PVC, etc., in smaller amounts. The ground mixed plastics were first compounded and melt filtered in a counter‐rotating nonintermeshing twin‐screw extruder and then combined with different amounts of additives in a corotating intermeshing twin‐screw extruder. Additives included unmodified and maleated polyolefin elastomers and styrene/olefin block copolymers. Blends were analyzed for thermal and mechanical properties, and processability. The most effective modifier in terms of impact strength improvement was a styrenic block copolymer with very similar rheological characteristics to the commingled plastics matrix. The experimental observations were interpreted by considering the complex morphological features of the injection molded multicomponent, multiphase systems. © 1994 John Wiley & Sons, Inc.
Polycarbonate/ABS blends: A literature review
Authors: Greco Roberto , Sorrentino A. 
Published: April 2003

AbstractA literature review concerning PC/ABS alloys is presented with the aim of providing a background suitable for a systematic investigation on the properties of such materials undertaken in our Institute. This is preceded by an additional survey on PC/SAN alloys. The purpose was to extend the above‐mentioned background furnishing literature information available on these systems (having two components out of three in common with PC/ABS alloys), particularly with respect to the phase compatibility. The articles here presented and discussed offer an almost exhaustive survey of the work done until now on these commercial materials. © 1994 John Wiley & Sons, Inc.
The extrusion and inflation of nonaxisymmetric parisons
Authors: DiRaddo R. W. , Garcia‐Rejon A. , Pecora L. 
Published: April 2003

AbstractOptimization of resin usage in blow molding necessitates the use of nonround or nonaxisymmetric die tooling. These die geometries are referred to as “ovalized.” The extrusion and inflation of parisons formed from nonaxisymmetric dies are complex because of the radial thickness dependency. Four die geometries are considered in this work; one axisymmetric and three nonaxisymmetric. The three nonaxisymmetric dies have one side set at a constant die gap (1.5 mm) and the side rotated 90° from it, set at progressively increasing die gaps (2.0, 2.5, 3.5 mm). A methodology is presented for the measurement of the radial parison diameter and thickness swell profile for ovalized parisons. The methodology employs a simple mass balance approach between an axisymmetric part and the parison it was blown from. Experimental results are obtained for the radial parison diameter and thickness swell at two radial locations. © 1994 John Wiley & Sons, Inc.
Computer aided design of wire coating dies
Authors: Lafleur P. G. , Arpin B. , Lenir V. 
Published: April 2003

AbstractA nonisothermal analysis of wire coating using the lubrication approximation is presented. The flow problem is solved with the broken section method where the extrusion die is broken perpendicularly to the wire axis. The flow variables (velocity, stresses, and temperature) are computed with a finite difference scheme. Any generalized Newtonian constitutive equation can be used and the energy balance includes convection in the flow direction, viscous dissipation, and conduction through the die and wire. Experimental data for inlet pressure and wire tension, obtained on an industrial line, were compared to simulated results. The predictions were satisfactory and the trends predicted by the model were relatively accurate. The main problem comes from the difficulty of measuring viscosity at high shear rates, corresponding to high processing velocity, with standard techniques. © 1994 John Wiley & Sons, Inc.
Prediction of shrinkage by dual kriging for injection molded polypropylene plaques
Authors: Kamanayo G. , Trochu F. , Sanschagrin B. 
Published: April 2003

AbstractThe shrinkage of thermoplastic products has become an important theme of investigation for many researchers during the last two decades. Two approaches have been followed. The first one consists of solving the balance equations (mass, momentum, and energy) that govern the polymer flow and cooling. The shrinkage and warpage of the part are then deduced from this solution. The second approach is empirical and consists of fitting a model to experimental data. In this article, a new empirical method of prediction, based on dual kriging interpolation, is proposed. A theoretical validation is performed on a set of experimental measurements. The results are compared with previous models based on regression, which can be obtained as limit cases of dual kriging. © 1994 John Wiley & Sons, Inc.
Morphology and property relationships in ternary blends of polyethylene/polyamide‐6/compatibilizing agents
Authors: Chandramouli K. , Jabarin S. A. 
Published: April 2003

AbstractThe effects of compatibilizing agents on the morphology and properties of high density polyethylene (HDPE) and polyamide‐6 blends were investigated. The ternary blends were studied with the objective of understanding and optimizing the compatibilization of HDPE and polyamide‐6. The blends were prepared by melt mixing the individual components in a twin‐screw extruder. Mechanical property, rheological property, differential scanning calorimetry, and scanning electron microscopy results are discussed. The addition of compatibilizing agents results in a greatly reduced dispersed phase particle size. The properties of the blends level out after a compatibilizer level of 3 wt% has been reached. The rheological, mechanical, and thermal property results indicate the presence of the compatibilizing agent along the interfacial boundary regions between the other two phases. © 1995 John Wiley & Sons, Inc.
Effects of molecular weights and compatibilizing agents on the morphology and properties of blends containing polypropylene and nylon‐6
Authors: Wu Jeng‐Yue , Lee Wan‐Chung , Kuo Wen‐Faa , Kao Hsin‐Ching , Lee Mao‐Song , Lin Jen‐Lien 
Published: April 2003

AbstractPolymer blends containing nylon‐6 of different molecular weights (MW) and polypropylene (PP) were prepared by using a twin screw extruder in order to examine the effects of molecular weights of nylon and the influences of different types of compatibilizing agents on the phase morphology and the properties. The morphology of the resulting blends was characterized by using both scanning electron microscope (SEM) and optical microscope and the properties measured included Izod impact strength, melt flow index (MI), flexural modulus, and heat distortion temperature (HDT). It was found that the molecular weights of the nylon matrix had a significant effect on the phase morphology. The fracture surface of the low MW nylon blend demonstrated a uniformed phase morphology with the dispersed PP particles of dimensions in the range of 1 μm in diameter embedded in the nylon matrix, suggesting an improved compatibility as compared with the high MW nylon system, even though these two constituents were incompatible in nature. Three different types of compatibilizers, including maleic anhydride modified PP (MA‐g‐PP), acrylic acid modified PP (AA‐g‐PP), and ethylene glycidyl methacrylate copolymer (EGMA), were used to examine their effects. It seemed that blends compatibilized with MA‐g‐PP exhibited the most homogeneous phase morphology and superior mechanical properties among the three. In the blends containing low MW nylon as the matrix phase, the Izod impact strength was shown to have increased by about 40% as compared with the noncompatibilized blend, while a 20% increase of the impact strength was measured in the high MW nylon system. The effects of nylon's molecular weights and the compatibilizers were also studied in systems of PP/nylon blends reinforced with silane‐treated glass fibers. It was shown that the properties of the composites relied on the phase morphology which, in turn, was affected by both the molecular weight of nylon and the compatibilizing agents. © 1995 John Wiley & Sons, Inc.
In‐situ compatibilization of thermoplastic polyurethane and polydimethyl siloxane rubber by using ethylene methyl acrylate copolymer as a reactive polymeric compatibilizer
Authors: Santra Robin N. , Roy Sanjoy , Tikku V. K. , Nando Golok B. 
Published: April 2003

AbstractThe effect of Ethylene Methyl Acrylate (EMA) copolymer as a reactive polymeric compatibilizer in a blend of 50:50 Thermoplastic Polyurethane (TPU)‐Polydimethylsiloxane (PDMS) rubber has been studied. The compatibility was proved by mechanical property measurements and phase morphology studies. EMA reacted with PDMS rubber at 180°C at 100 rpm rotor speed during melt mixing to produce EMA‐g‐PDMS rubber in situ, which acted as the compatibilizer for the binary system of TPU and PDMS rubber. EMA‐g‐PDMS rubber is believed to undergo specific interaction via hydrogen bonding with the TPU matrix through the CO group of EMA and the unassociated NH group of TPU, whereas the PDMS rubber in the EMA‐g‐PDMS disperses well with the bulk PDMS matrix. The phase morphology studies showed a drastic reduction in the size of the dispersed phase at the optimum concentration of EMA. © 1995 John Wiley & Sons, Inc.
The role of the compatibilizer on morphologies and mechanical properties of polyamide 6/(styrene–[ethylene–butylene]–styrene) triblock copolymer blends
Authors: Wu Chung‐Jen , Kuo Jen‐Feng , Chen Chuh‐Yung 
Published: April 2003

AbstractIn this study, the morphologies and the mechanical properties of the ternary blend of PA (polyamide)6/SEBS(styrene–[ethylene–butylene]–styrene triblock copolymer)/maleated SEBS were investigated. Maleated SEBS compatibilizers of various maleic anhydride (MA) content were prepared in the laboratory. The compatibilizer significantly influenced the dispersion of the rubber as well as the crystalline form and spherulites of the polyamide. The effects of the compatibilizer on mechanical properties were correlated with the observations of morphology and stress–strain behavior. The toughness of the blends was found to be increased for those undergoing additional yielding during cold drawing. Finally, a compatibilization mechanism of maleated SEBS for the blends was proposed. © 1995 John Wiley & Sons, Inc.
EMI shielding plastics: A review
Authors: Huang Jan‐Chan 
Published: April 2003

AbstractThe objective of this article is to review the use of conductive plastics in the shielding of electromagnetic interference (EMI). The theory of EMI shielding and evaluation methods of EMI materials are discussed. Different approaches in achieving high conductivity of plastics are reviewed. Emphasis is placed on filled plastics which are a promising way for shielding and do not require a secondary process. Literature on properties and processing of several common conducting plastics is reviewed. Design and processing requirements of such filled plastics are also given. © 1995 John Wiley & Sons, Inc.
Development of moldability diagrams for gas‐assisted injection molding
Authors: Yang S. Y. , Liou S. J. 
Published: April 2003

AbstractGas‐assisted injection molding (GAIM) has proven itself to be a breakthrough in molding technology. However, the process involves additional gas‐related parameters to control the molding process. The interaction between melt and gas makes the gas‐assisted process complicated. To make satisfactory parts, the material, the mold, and process parameters determine the “moldability” of a specific system. The concept of “molding areas” on the critical plane can be extended from thermoplastic injection molding to GAIM. This research is devoted to the development of a proper moldability diagram for GAIM. The first part of this study employs gas‐related parameters to define the molding area. The second part is devoted to identifying the relative importance of process parameters. The results show that melt temperature and short shot are the two factors which most significantly affect the GAIM process. The third part of this study defines the moldability based on critical parameters. The application of the moldability concept is demonstrated in selecting the optimum rib geometry. These moldability studies are intended to give first guidelines for system optimization. © 1995 John Wiley & Sons, Inc.
Neural‐network‐based model approach for density of high‐molecular‐weight esters used as plasticizers
Authors: Keshavaraj Ramesh , Tock Richard W. , Narayan Raghu S. , Bartsch Richard A. 
Published: April 2003

AbstractHigh–molecular‐weight esters are frequently used to plasticize commercial polymers. Because the physical properties of the polymer matrix can be significantly modified by the type of the plasticizer that is used, these high–molecular‐weight esters have been extensively investigated during the last decade. Liquid density, for example, has been found to be a useful bulk property of these liquid plasticizers, since density helps define the internal molecular flexibility. Most of the time, however, experimental difficulties prevent the accurate determination of density. Moreover, the existing empirical models are tedious because of many ill‐defined parameters. In this study a simple artificial neural‐network–based model was utilized for the density of these esters as a function of their chemical structure and temperature. The sum of squared error for densities predicted by this proposed model was within 0.0009. In this study, the density of a series of five different esters was investigated. These were DSEs, DDEs, TGEs, TTEs, and PTEs. © 1995 John Wiley & Sons, Inc.