SPE Library
The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.
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Conference Proceedings
EFFECT OF ENVIRONMENTAL STRESS CRACKING AGENTS ON FATIGUE AND CREEP OF A MDPE PIPE
R. Ayyer , A. Hiltner , E. Baer, May 2008
The effect of concentration of Igepal CO 630 on slow crack propagation in MDPE pipe was investigated. The kinetics and mechanism of crack propagation in fatigue at R=0.1 and creep at 50 ?øC were compared to those in air. The fatigue and creep behavior followed the same stepwise crack growth mechanism as in air at all the concentrations used. As the concentration increased to 0.01 vol. % the creep lifetime decreased significantly whereas the lifetime in fatigue gradually increased. At higher concentrations the lifetime was similar in creep and fatigue.
FABRICATION OF POROUS PCL FIBER WITH CO-CONTINUOUS AND SIZE ADJUSTABLE POROUS STRUCTURES FROM IMMISCIBLE POLYMER BLENDS
Pratapkumar Nagarajan , Kathryn Abbott , Donggang Yao, May 2008
Porous polymer fibers can be fabricated using different methods including hollow fiber extrusion multicomponent fiber extrusion (e.g. with islands-in-sea morphology) and solution processing. However with the current technology it is difficult to achieve a continuous porous structure across the entire fiber cross-section and control the pore size. This greatly limits potential applications of such fibers in many emerging biochemical and biomedical applications. We report here a filament extrusion process of immiscible polymer blends for fabrication of highly porous fibers with continuous and size adjustable porous structures.
INVESTIGATION OF THE ACOUSTICAL BEHAVIORS OF MICROCELLULAR CERAMIC FOAMS
M. Y. Serry Ahmed , C. Wang N. Atalla , C.B. Park, May 2008
The processing method for fabricating high porosity microcellular ceramic foams for sound absorption applications is discussed. By controlling the microsphere content and that of the base elastomer it was possible to adjust the porosity with a very high open-cell content (ranging between 43 - 95%) high microcellular cell densities (9E8 ƒ?? 1.6E9 cells/cm3) and desired expansion ratios (3 - 6 folds). Sound absorption testing was performed by using standard test methods followed by a statistical and theoretical study that was performed to investigate the acoustical behavior of this class of materials. The study shows that due the unique structure of these foams localized effects took place and therefore application of the new morphology-based model was necessary to account for the effects of microstructure and morphology on the sound absorption behaviors of ceramic foams.
EFFECTS OF LONG-CHAIN BRANCHING CONCENTRATION OF SUPERCRITICAL CO2 AND PRESSURE ON THE VISCOSITY OF LINEAR AND BRANCHED POLYPROPYLENES
Hee Eon Park , John M. Dealy, May 2008
Supercritical carbon dioxide (CO2) is of interest as a physical blowing agent in the manufacture of plastic foam and as a plasticizer to reduce melt viscosity during processing. The combined effects of concentration (C) of dissolved CO2 pressure (P) and temperature (T) on the rheological properties of the melt were determined to achieve optimum processing conditions. Linear and branched polypropylenes and their blends were chosen. A high-pressure sliding plate rheometer in which the shear deformation T P and C are all uniform was used. It was possible to use shift factors for T P and C to obtain a master curve.
SIMULATION STUDY ON WARPAGE DEVELOPMENT OF MICROELECTRONICS PACKAGING
Yeong K. Kim, May 2008
The effect of viscoelastic material properties on the warpage development of microelectronic packaging was studied. A chip level packaging of ball grid array was considered for the calculation model. The mechanical properties of thin FR-4 for substrate and molding compound were measured and modeled as elastic and viscoelastic. Based on the modeling stress development during cooldown was calculated by numerical methods. It was found that the deformation predictions were strongly dependent on the material properties modeling and the viscoelastic behaviors of the FR-4 and the molding compound had significant influence on the warpage development. The results showed that the warpage development was totally dependent on the interaction of the relaxation behaviors of the materials and in this particular case the relaxation actually increased the deformation. The results were compared with those when the materials were assumed as elastic and discussions were given to analyze the mechanism.
A WAY OF EXPEDITION TO FIND TREASURES HIDDEN IN THE FIELD OF NANOTECHNOLOGY: COMPUTATIONAL NANOTECHNOLOGY
Seung Soon Jang, May 2008
Now we have two reasons driving the application of computational methods for the Nanotechnology". One is the increasing possibility that we may see at a certain point the breakdown of given macroscopic-bulk-phase- based description in understanding the nano-scale systems. This is mainly because the nano-scale systems do not have such "macroscopic-bulk-phases". The surface or interface of the system that has been usually neglected in the given description becomes the most important part of such nano-scale system. Another reason is that the enhanced speed and accuracy of recent computational tools (both sides of hardware and software) now makes it possible to probe the chemical and physical properties of nano-scale system consisting of 1000~1000000 atoms at the atomistic level very quantitatively."
GENERATION OF EXPERIMENTAL POLYMER STRUCTURE-PROPERTY DATA USING COMBINATORIAL AND HIGH THROUGHPUT METHODS
Dean C. Webster, May 2008
Polymers can have a large variety of compositions molecular weights molecular weight distributions monomer sequence distributions chain topologies (architectures) and so on; all of which may influence performance properties. Due to the large number of variables and possible compositions it is difficult to predict performance and determining structure-property relationships relies on experimentation. However conducting the experiments is a tedious and time-consuming process so only limited numbers of samples are prepared and evaluated in most studies. Thus a comprehensive picture of the structure-property relationships in most systems is not achieved. The combinatorial and high throughput approach seeks to address this situation by enabling the rapid synthesis and evaluation of a large number of materials in a single experiment.Methods have been developed for the parallel synthesis of polymers having systematic variation in composition and screening of those materials for their key properties such as modulus molecular weight surface properties etc. Analysis of the resulting data can result in the determination of structure-property relationships.
TRANSPARENT ABS ; SIMULATION APPROACHES TO THE COMPOSITION CONTROL
Joong-In Kim, May 2008
Todays talk will cover the composition simulation and the composition control technique developed from the ƒ??classicalƒ? copolymer composition equation and show the industrial application example transparent ABS.Because ABS(Acrylonitrile-Butadiene-Styrene) is composed of particular rubber dispersion and matrix it is very important to match the refractive indices of both phases when we make it transparent. In order to match the refractive indices of dispersed and matrix phase Methyl methacrylate is generally incorporated with styrene and acrylonitrile and polymerized to the matrix phase. The composition of the matrix phase directly affects the refractive index of the matrix phase and consequently influences on the optical properties like haze and total transmittance thus composition control technique is needed to make the high-quality transparent ABS products.
MULTIWALLED CARBON NANOTUBES (MWNTs) SURFACE MODIFICATION AND CHARACTERIZATION OF FLUOROELASTOMER/MWNT COMPOSITES
V. Sridhar , Thanh Tu Pham , Kwang-Jea Kim , Jin Kuk Kim, May 2008
Multi walled carbon nanotubes(MWNTs) surface are modified with acids and the preparation and properties of MWNT reinforced fluoroelastomer composites using a solution technique are reported. The dispersion and morphology of the nanotubes in the polymer matrix are studied by XRD SEM and TEM. Significant improvements in performance characteristics like modulus and tensile strength have been attained even at low loadings of filler. A 'cross hatched pattern' is observed. The increase in decomposition temperature with increase in MWNT loadings is observed due to the antioxidant nature of nanotubes. The effect of increasingMWNT concentrations on dynamic mechanical property(loss tangent) has also been studied.
VOLATILE EXTRACTIVES EFFECTS ON INTERFACIAL ADHESION OF PINE WOOD FILLED PP COMPOUNDS
Kwang-Jea Kim , Sughun Bumm , James L. White, May 2008
Effects of volatile extractives existing in pine wood (PW) particles on polypropylene (PP)/PW compounds are investigated upon interfacial adhesion nucleation behavior and mechanical properties. Results indicate as the concentration of the PW particles is increased the modulus is increased; however the crystalline peak temperature is increased melting peak temperature is decreased and the tensile yield stress is decreased. Few spherulites are locally developed at the interface between the PW and the PP. The amounts of volatile extractives in the PW are increased as the PW concentrations are increased.
EFFECTS OF THE FOAM MORPHOLOGY IN THE MECHANICAL PROPERTIES OF INJECTION MOLDED THERMOPLASTIC FOAMS
Walter Michaeli , Laura Flórez , Thorsten Krumpholz , Dominik Obeloer, May 2008
The foaming reduces both material and energy consumption in the injection molding while minimizing warpage and shrinkage in the molded part. However until now the design potential of injection molded foams has remained rather unexploited because the relation between foam morphology and resulting mechanical properties is not fully understood. This paper studies the effect of morphological parameters such as cell diameter density distribution and skin thickness on the mechanical properties of injection molded foams.
MECHANICAL AND THERMAL ANALYSES OF DIFFERENT LOTS OF FILM MADE FROM THERMOFORMABLE GLYCOL MODIFIED POLYETHYLENE TEREPHTHALATE (PETG)
T.P. O’Brien , G.M. McNally , W.R. Murphy , B.G. Millar, May 2008
Glycol modified polyethylene terephthalate (PETG) is a clear tough thermoplastic material suitable for ethylene oxide and gamma ray sterilization and is an excellent heat- seal substrate. While PETG has been proven to have good thermoformability mechanical performance can be suspect particularly in medical packaging applications.Batch properties of PETG were assessed through differential scanning calorimetry dynamic mechanical and thermal analysis and uniaxial tensile testing. Results demonstrate how properties can vary significantly to the detriment of intended function.
STRUCTURAL STRENGTH OF BLOW MOULDED PET BOTTLE USING MICROWAVE PRE-HEATED PREFORMS
D.U. Erbulut , S. Vasa , S.H. Masood , Kelvin Davies, May 2008
This paper presents an investigation on injection stretch blow moulding (ISBM) of PET bottles which are heated using microwave (MW) ovens instead of infrared lamps. Comparative simulation studies are carried out on structural strength of PET bottles obtained from three performs heated with different power outputs of microwave along with a preform heated conventionally under different process conditions. The comparisons between microwave and infrared heating were carried out to study the structural strength of the bottle under top loading and pressure conditions using ANSYS simulation software. Results indicate the range of microwave power output to be used for better strength of blow moulded bottles.
STRUCTURAL STRENGTH OF BLOW MOULDED PET BOTTLE USING MICROWAVE PRE-HEATED PREFORMS
D.U. Erbulut , S. Vasa , S.H. Masood , Kelvin Davies, May 2008
This paper presents an investigation on injection stretch blow moulding (ISBM) of PET bottles which are heated using microwave (MW) ovens instead of infrared lamps. Comparative simulation studies are carried out on structural strength of PET bottles obtained from three performs heated with different power outputs of microwave along with a preform heated conventionally under different process conditions. The comparisons between microwave and infrared heating were carried out to study the structural strength of the bottle under top loading and pressure conditions using ANSYS simulation software. Results indicate the range of microwave power output to be used for better strength of blow moulded bottles.
STRACTURE AND INTERFACIAL ADHESION OF PP/PBS SANDWICH INJECTION MOLDINGS
Yuji Fujita , Toshihiro Yoshida , Hironari Sano , Naoya Aoki , Masaya Kotaki , Hiroyuki Hamada, May 2008
Polypropylene (PP) based sandwich injection moldings with biomass based polymers (PBS) in the core were studied. In order to obtain superior surface properties such as high chemical resistance and anti-scratch resistnce improvement of interfacial strength between skin and core parts is important which can be controlled by the additional PP component in the PBS core part. The selection of additional PP and injection conditions were found to be important to improve the interfacial strength of which phenomena was understood by the melt rheology at the injection condition.Scratch tests according to ASTM method was performed to investigate the relationship between scratch behavior and skin/core adhesion. Poor skin/core adhesion caused the skin/core delamination upon the scratch tests.
STRACTURE AND INTERFACIAL ADHESION OF PP/PBS SANDWICH INJECTION MOLDINGS
Yuji Fujita , Toshihiro Yoshida , Hironari Sano , Naoya Aoki , Masaya Kotaki , Hiroyuki Hamada, May 2008
Polypropylene (PP) based sandwich injection moldings with biomass based polymers (PBS) in the core were studied. In order to obtain superior surface properties such as high chemical resistance and anti-scratch resistnce, improvement of interfacial strength between skin and core parts is important, which can be controlled by the additional PP component in the PBS core part. The selection of additional PP and injection conditions were found to be important to improve the interfacial strength, of which phenomena was understood by the melt rheology at the injection condition. Scratch tests according to ASTM method was performed to investigate the relationship between scratch behavior and skin/core adhesion. Poor skin/core adhesion caused the skin/core delamination upon the scratch tests.
ON-LINE OPTICAL MONITORING OF NANOCOMPOSITE COMPOUNDING
Marion McAfee , Wai-Chow Chang, May 2008
On-line monitoring of compounding of PA6 with nanoclay is examined to investigate the level of exfoliation and degradation under a variety of conditions in real-time. On-line rheological and optical reflectance measurements are compared with off-line analyses of compounded samples to investigate the relationship between these readings and exfoliation/intercalation and/or degradation of the nanocomposite. The effect of the processing (twinscrew/ single-screw temperature and screw speed) on the resulting melt quality and the ability to assess this quality in real-time is discussed.
ON-LINE OPTICAL MONITORING OF NANOCOMPOSITE COMPOUNDING
Marion McAfee, Wai-Chow Chang, May 2008
On-line monitoring of compounding of PA6 with nanoclay is examined to investigate the level of exfoliation and degradation under a variety of conditions in real-time. On-line rheological and optical reflectance measurements are compared with off-line analyses of compounded samples to investigate the relationship between these readings and exfoliation/intercalation and/or degradation of the nanocomposite. The effect of the processing (twinscrew/ single-screw, temperature and screw speed) on the resulting melt quality and the ability to assess this quality in real-time is discussed.
RESPONSIVE STARCH-BASED MATERIALS
J. L. Willett, May 2008
Starch a low-cost annually renewable resource is naturally hydrophilic and its properties change with relative humidity. Starchƒ??s hygroscopic nature can be used to develop materials which change shape or volume in response to environmental changes (eg humidity). For example starch-based graft copolymers have been produced using reactive extrusion for potential superabsorbent and hydrogel applications. Besides absorbing large quantities of water some of these copolymers display large volume changes in aqueous alcohol depending on solvent quality. Other examples include starch-poly(methyl acrylate) graft copolymer films which shrink at high humidities. Various levels of shrinkage can be triggered in response to changes in relative humidity. (AAm) and varying amounts of 2-acrylamido-2-methyl- 1-propane sulfonic acid (AMPS) display various degrees of swelling in aqueous solutions and approximately discontinuous volume changes in aqueous ethanol solutions over narrow ethanol concentrations. Blown films of starch-PMA graft copolymers display controlled shrinkage in response to increases in relative humidity.
DEVELOPMENT OF ANTIMICROBIAL PLA NANOCOMPOSITES WITH SILVER CONTAINING LAYERED NANOCLAYS FOR PACKAGING AND COATING APPLICATIONS
M.A. Busolo , M.J. Ocio , J. M. Lagaron, May 2008
This paper presents the development and characterization of the antimicrobial activity of a novel family of commercial food contact compliant silver-modified nanolayered clays and of their nanobiocomposites with polylactic acid. The antimicrobial nanolayered clays showed an antimicrobial effectiveness of 99.99% against Gram-negative Salmonella spp. In addition the PLA-clay nanocomposite also showed a significant antimicrobial activity and a synergistic water vapour permeability reduction of 32% with respect to neat PLA. The results indicate that these novel active nanolayered fillers can potentially exhibit numerous applications in plastic and bioplastic packaging and coatings where simultaneous barrier and antimicrobial performance are desirable.
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