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
Morphology and Rheology of Polycaprolactone/Thermoplastic Starch Blends
Gang Li, Pierre Sarazin, Zhenhua Yuan, Basil D. Favis, May 2005
Polycaprolactone (PCL)/thermoplastic starch (TPS) biodegradable blends were prepared via a one-step extrusion system over the entire range of composition at different viscosity ratios. A detailed morphology analysis of the PCL/TPS blends was investigated by electron microscopy after selective extraction. Through a judicious combination of concentration control and processing conditions, the volume average diameter of TPS droplets can be closely controlled from 0.5 to 16?m. The rheological behavior of these blends is also examined in depth.
The Effect of Uni-Axial Stretching on the Gas Permeation Properties of LDPE/LLDPE Silage Wrap Films
C. Laffin, G.M. McNally, P.D. Forristal, P. O’Kiely, C.M. Small, May 2005
This work investigates the effect of uni-axial stretching on the gas permeation properties of LLDPE/LDPE films. The results show improved gas barrier properties with increasing uni-axial stretch as a result of increasing film crystallinity and molecular orientation.
A Study on Nalidixic Acid/Polycaprolactone Blends for Medical Device Applications
J. Godinho, I. Moore, L. Donnelly, C.Y. Lew, P. Douglas, D. Jones, G.M. McNally, W.R. Murphy, May 2005
The incorporation of an antibacterial agent within the polymeric matrix can prevent bacterial colonisation on the surface of implanted medical devices. In this study, nalidixic acid was melt blended with polycaprolactone at different concentrations. Its effect on the processability, crystallisation, mechanical properties and drug release were investigated.
Dielectric Properties of Self-Reinforced Polymers
Paul J. Jones, Nick Malkovich, David B. Thomas, Sarah E. Morgan, May 2005
The dielectric constants of two compositions of a new class of rigid rod polymers (Parmax® Self Reinforced Polymers (SRPs)) were measured and demonstrate potential for use in multiple electronic applications. Dielectric measurements were made over a range of frequencies using a Hewlett Packard 4192A LF Impedance Analyzer. At 1MHz the two samples displayed very low dielectric constants of 2.31 and 1.96.
The Optimal Parameters of the Water Assisted Injection Molding Process with ABS Material
Kuo-Zoo Liang, Chin-Chang Yeh, Chein-Chung Chen, May 2005
In this paper, the Water Assisted Injection Molding (WAIM) technology is applied to the design of a new mold. Two kinds of the ABS materials are utilized to undertake tests for the above new designed mold. Good results for the great decrease in the deformation as well as Warpage of the ABS products can be obtained. Finally, the Taguchi Method and Grey Theory are applied to finding the optimal parameters of injection molding process.
Branched Modifiers for High Melt Strength Applications
Lawrence J. Effler, Kim L. Walton, Michael K. Laughner, May 2005
Poly(?-olefin) elastomers (POEs) are used to modify the performance of polypropylene (PP). All the POE modifiers were found to enhance both the room and subambient temperature impact performance. However, POEs containing high levels of long chain branching improved the melt elasticity of the PP. Thus, giving an increase the melt strength of the PP making it more suitable for applications such as thermoforming and blow molding.
Synthesis of Elastomeric Nanoparticles via Microemulsion Polymerization
M. Esther Treviño, Yolanda del Angel, Raúl G. López, Luis F. Ramos, May 2005
Copolymerization of buyl acrylate with dimethyl meta-isopropenyl benzyl isocyanate (TMI) was carried out at 40°C in microemulsions stabilized with a mixture of sodium dodecyl sulfate / sodium bis (2-ethylhexyl) sulfosuccinate (3/1 w/w). The mixture of monomers was dosed during the polymerization. An inverse dependence of particle diameter (DP) on dosing rate of monomers and TMI concentration was found. Polymer content close to 25 wt. % and DP between 30 and 40 nm were obtained.
Structure-Property Relationship and Processing of Nanocomposites
Hemi N. Nae, May 2005
Exfoliated organophilic clays dispersed in a polymeric matrix such as polyolefin, epoxy or polyamide form nanocomposites that exhibit improved mechanical, thermal, flame resistance and barrier properties. The effect of the organoclay’s chemical structure, its polarity and surface chemistry and how it is dispersed in the polymeric matrix determine the properties of the nanocomposite. Various characterization techniques are discussed as well as the effect of processing parameters on the properties of the nanocomposite.
Polymer Degradation and Filling Incompletion Monitoring for Micromolding Using Ultrasound
B.R. Whiteside, E.C. Brown, Y. Ono, C.-K. Jen, P.D. Coates, May 2005
Polymer degradation was successfully probed by measuring the ultrasonic velocity in the polymer at the barrel and mold insert of a micromolding machine with ultrasonic pulse-echo technique. Filling incompletion of the mold cavity was also detected by monitoring the ultrasonic energy variation transmitted into the part at different points along the melt flow length. The presented ultrasonic sensors and technique enable optimizing the micromolding process to improve quality of the molded parts.
The True Cost of Snaps
Norman Staller, Stephen Petrie, May 2005
Snap fit assembly has many advantages over non-integral fastener techniques. Snaps can improve product cost by part reduction and reduced assembly labor. However, the cost and time for engineering and tooling for snaps probably are increased. While the piece part and assembly cost may be reduced by snaps, the up front time and costs may wipe out this gain unless the manufacturing volumes are very high.
Antioxidant Performance of Mixed Tocopherols in Styrenic Block Copolymers
R.M. Suffield, J.E. Kiesser, S.H. Dillman, May 2005
Mixed tocopherols containing a predominance of ?- tocopherol were evaluated for antioxidant performance in polybutadiene and polyisoprene based styrenic block copolymers using oxidative induction time as a measure of antioxidant performance. A conventional hindered phenolic antioxidant and ?-tocopherol (vitamin E) were evaluated in comparison. Mixed tocopherols exhibited significantly higher performance than the controls in both SIS and SBS polymers.
Benefits of Using Secondary Guide Rod with Lifter Core Assembly
Trevor D. Pruden, May 2005
Reactionary forces and bending moments within conventional lifter core rods require smaller rod angles, which can increase mold die height and foot print. A new approach to designing lifter cores utilizes a second guide rod that is parallel to the lifter rod. The resulting parallelogram results in the elimination of the bending moment seen in conventional single-rod lifter configurations. This approach allows for a greater lifter angle, reducing the necessary die height and mold footprint.
Experimental Measurements of Degree of Fill in a Co-Rotating Twin Screw Extruder
Yingping Zhang, Costas Tzoganakis, May 2005
Degree of fill is a key factor in extruders because it can affect pressure profiles, residence time distributions, and mixing performance. In this paper, the fully filled length and pressure profiles in a co-rotating twin screw extruder were measured experimentally. The fully filled length in a conveying section prior to a kneading block shows a linear relationship with specific throughput. We also explored the effect of the kneading disk configurations (staggering angles and thickness) on the fully filled length.
Structure and Properties of Elastomeric Propylene-Based Fibers and Film
P. Dias, H. Wang, R. Nowacki, A. Chang, J. Van Dun, P. Ansems, S. Chum, A. Hiltner, E. Baer, May 2005
The solid state structure and mechanical properties of fibers and oriented films made from a new class of propylene based elastomers (PBE) are investigated. The effect of processing conditions on the solid state structure is probed with density, WAXS, DSC and OM birefringence measurements. Relationships between fiber and film process conditions, solid state structure, and mechanical behavior are described.
Improved Solvent Stress Testing for Polycarbonate
Mark Yeager, Ignacio Osio, Christopher Bright, May 2005
Solvent stress testing has proven to be an effective method for identifying areas of elevated stress in parts and assemblies made from polycarbonate. Dilutions of various stress-cracking agents have been developed to quantify the levels of molded-in and/or applied stresses. Unfortunately, there has not been good correlation between the various test solutions. Calibration tests were performed for this study to develop guidelines to improve the resolution and accuracy of solvent stress testing, particularly at low stress levels.
Controlling Intra-Cavity Melt Flow and Weld Strength through New Runner Design Technology
John Beaumont, Christopher Stewart, Mark Ezzo, May 2005
The development of high sheared laminates are shown to have a significant effect on filling pattern. New methods are shown to manage these hotter high sheared laminates to control filling pattern and position them so as to increase weld line strength.
Molecular-Scale Reinforcement of Glassy Networks
Kevin J. Calzia, Alan J. Lesser, Anne Forcum, May 2005
Improvements in mechanical and thermal properties of glassy networks have been made through the use of a unique class of molecules that reinforce the network at the molecular scale, commonly referred to as fortifiers. In our studies, fortifiers are incorporated either as an additive or as a reactive monomer in the network. Each approach provides different benefits in properties. Several mechanisms of fortification are discussed and correlated to the observed improvements in properties.
Effect[GTLim1] of Slip Agent and Talc Surface Treatment on the Scratch Behavior of TPOs
B. Browning, G.T. Lim, A. Moyse, H.-J. Sue, May 2005
A set of model TPO systems, with and without slip agent and talc surface treatment, was investigated using a linear load increase scratch test methodology. Our findings suggest that both the presence of slip agent and surface treatment of talc fillers[GTLim2] can greatly reduce scratch visibility. The underlying mechanisms are discussed.
Synthesis of Uniform ZnO Nanorods via Wet Chemistry Approach
Kwang-Jik Lee, Y. Li, H.-J. Sue, May 2005
ZnO nanords were synthesized using spherical ZnO nanoparticle precursor solution. Our unique wet chemistry approach can produce uniform ZnO nanorods at a much lower concentration than expected. We used transmission electron microscopy to characterize the rodlike shape evolution of ZnO quantum dots. The underlying mechanisms for the formation of ZnO nanorods are described and discussed.
Creep Behavior of Sisal Reinforced Starch Based Blends
V.A. Alvarez, V.P. Cyras, A. Vázquez, May 2005
Creep measurements were carried out on starch based blend reinforced with sisal short fibers. The selected matrices were MaterBi-Y (cellulose acetate) and MaterBi-Z (polycaprolactone). The studied temperatures were higher than Tg for MaterBi-Z and lower of Tg for MaterBi-Y and as expected, the behavior was different. Different models were applied and allowed the comparison with other materials.
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