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

REALISTIC APPEARANCE OF WOOD GRAINS FORMED WITH SMART BLENDERS ON SURFACES AND INSIDE EXTRUDED PLASTICS

Dave Zumbrunnen , Mike Zumbrunnen, May 2008

Smart blending machines operate by chaotic advection a new sub-field of fluid mechanics. Melts that are introduced into them become converted to multi-layers of controllable average thickness. Upon extrusion patterns can be readily generated inside and on film sheet tubes or other shapes that have the appearance of realistic wood grains. Moreover simulated wood grains can be varied through on-line control. An infinite variety of grains can be formed or a specific grain can be repeated at desired intervals. In this paper the machines and process are described and examples are presented.

REALISTIC APPEARANCE OF WOOD GRAINS FORMED WITH SMART BLENDERS ON SURFACES AND INSIDE EXTRUDED PLASTICS

Mike Zumbrunnen , Dave Zumbrunnen, May 2008

Smart blending machines operate by chaotic advection, a new sub-field of fluid mechanics. Melts that are introduced into them become converted to multi-layers of controllable average thickness. Upon extrusion, patterns can be readily generated inside and on film, sheet, tubes or other shapes that have the appearance of realistic wood grains. Moreover, simulated wood grains can be varied through on-line control. An infinite variety of grains can be formed or a specific grain can be repeated at desired intervals. In this paper, the machines and process are described and examples are presented.

RHEOMETERS FOR HIGH-THROUGHPUT POLYMER CHARACTERIZATION

John M. Dealy, May 2008

High-throughput rheological characterization has applications in many industries but dealing with molten polymers poses special challenges. For purposes of structure determination however rheology has potential advantages over GPC. There is currently no commercial rhometric device that can make rapid measurements on very small samples of molten polymers. However descriptions of several devices designed to accomplish this have been described in presentations and publications. The deformations involved include capillary torsional shear and squeeze flows. Each of these approaches has its advantages and disadvantages and it is not yet clear which if any of them will be able to meet the stringent requirements of high-throughput characterization.

EFFECT OF TIE-LAYER THICKNESS ON THE ADHESION OF ETHYLENE BASED COPOLYMERS TO POLYOLEFINS

R.K. Ayyer , A. R. Kamdar , Y.J. Lin , P.S. Dias , B.C. Poon , A. Hiltner , E. Baer1, May 2008

The effect of chain microstructure on the adhesion of elastomeric ethylene–octene copolymers to polypropylene (PP) and high density polyethylene (HDPE) was investigated using microlayered coextruded tapes having different adhesive tie-layer thicknesses (0.1 ?m – 14 ?m). The adhesive copolymers used were an olefinic block copolymer (OBC) and two statistical ethylene octene (EO) copolymers. The OBC exhibited much higher delamination toughness as compared to the statistical copolymers in T-peel experiments. The dependence of delamination toughness on the tie-layer thickness exhibited two distinct regimes: a fibrillated thin tie-layer regime (0.1 to 1 ?m) and a continuous damage zone in the thick tie-layer regime (2 to 14 ?m). A correlation was found between the damage zone morphology and the critical delamination stress for interfacial failure. The effect of temperature on the delamination toughness was also examined.

EFFECT OF TIE-LAYER THICKNESS ON THE ADHESION OF ETHYLENE BASED COPOLYMERS TO POLYOLEFINS

R.K. Ayyer , A. R. Kamdar , Y.J. Lin , P.S. Dias , B.C. Poon , A. Hiltner , E. Baer, May 2008

The effect of chain microstructure on the adhesion of elastomeric ethyleneƒ??octene copolymers to polypropylene (PP) and high density polyethylene (HDPE) was investigated using microlayered coextruded tapes having different adhesive tie-layer thicknesses (0.1 ?¬m ƒ?? 14 ?¬m). The adhesive copolymers used were an olefinic block copolymer (OBC) and two statistical ethylene octene (EO) copolymers. The OBC exhibited much higher delamination toughness as compared to the statistical copolymers in T-peel experiments. The dependence of delamination toughness on the tie-layer thickness exhibited two distinct regimes: a fibrillated thin tie-layer regime (0.1 to 1 ?¬m) and a continuous damage zone in the thick tie-layer regime (2 to 14 ?¬m). A correlation was found between the damage zone morphology and the critical delamination stress for interfacial failure. The effect of temperature on the delamination toughness was also examined.

CHARACTERISATION OF BIOACTIVE POLYCAPROLACTONE

P. Douglas , G. Walker , D. Jones, May 2008

The effects of a bioactive [Nalidixic Acid - NA] and copolymers [Poly L-Lactic Acid (PLLA) and Polyethylene Glycol (PEG)] on the drug release morphology and mechanical properties of Poly -caprolactone [PCL] were studied. Release of NA increased with the addition of copolymers in the PCL with a maximum release of 55% in a blend containing 5%w/w each of PLLA PEG and NA. The filler effect of the NA was illustrated by an increase in viscosity in the blends. FTIR spectrums showed the blending of the PCL and the NA. The carbonyl bond present in the biodegradable polymers PCL and PEG allowed for some degree of miscibility also confirmed by the decrease in thermal conductivity from 0.26 to 0.2 Wm'C. Mechanical properties were decreased by the copolymers with the Young's Modulus decreasing by 15%.

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.