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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Long Fiber Reinforced Post-Consumer Carpet
Post-consumer carpet is sorted by face fiber, shredded and compounded with long glass fibers. Both extrusion compounding and layering of glass mats and carpet fiber mats are explored. The properties of the composites produced exceed typical plastic lumber composites and are comparable to commercial glass mat composites.
Low-Cost Composite Materials from Post-Consumer Plastics and Waste Paper
Composites of post-consumer plastics and high volume fraction waste paper have been studied. Various production techniques have been tested, with an optimum processing method defined, allowing the manufacture of low-cost composites of up to 60% paper content. Results indicate increases in tensile, flexural and creep modulus and flexural strength compared to the matrix can be achieved without the requirement of additives, with only marginally lower tensile strength and brittle impact behavior.
Filament Winding Processing Conditions to Produce Thermoplastic Composites from Towpregs
In the present work cost-effective glass-reinforced thermoplastic matrix towpregs were used to produce composites by filament winding at different processing conditions. The influence of the filament winding speed and mandrel temperature on the composite final properties was studied. An optimized processing window was established by comparing the composite theoretical expected mechanical properties with those experimentally obtained.
The Effect of Surface Active Agent Solution on the Mechanical Properties of Wood-Polymer Composites
A range of wood-polymer composites; containing 0, 20, 40 and 60%w/w of MDF sawdust (212- 850?m) was prepared using polyethylene, polypropylene and rigid PVC. The blends were melt compounded using a Killion 38mm single screw extruder. The composites were then subjected to a surface-active agent (SAA) solution for 7 weeks and percentage water up-take was shown to increase, with a significant reduction in the mechanical properties.
The Study of Using Vetiver Grass as a Filler in Polypropylene Composites
The vetiver-polypropylene (PP) composites were prepared at various ratios of vetiver contents. Vetiver grass was prepared as vetiver leaves and vetiver fiber. The effect of vetiver contents on thermal, rheological, mechanical and morphological properties of the composites were studied. Vetiver grass was treated by chemical treatments and the effect of chemical treatments on these properties was elucidated.
A Injection Molded High Electromagnetic Shielding and Low Cost Carbon Fiber Composites
The high electromagnetic shielding and low cost woven carbon fiber composites were developed. In this study, continuous carbon fibers were woven as a conductive network with different mesh size. For an adequate SE performance that is realistic for an industrial application (40 dB), the required weight percentage of continuous carbon fibers applied in the injection molded composites is about 1%, which is much lower than that of conventional (more than 30%) discontinuous long carbon fiber composites.
Insights into the Formation and Properties of Well-Exfoliated Nanocomposites
The work presented here focuses on two key issue of nanocomposites: how to achieve high levels of exfoliation of the clay platelets and to what extent the resulting benefits can be explained by conventional composite theories, i.e., is there a nano-effect" whereby the platelets significantly alter the local properties of the matrix?"
Producing Polymer Nanocomposites with Exfoliated Pristine Clay
A new technique was developed to promote clay exfoliation in an epoxy matrix. Both XRD and TEM microscopic examination results demonstrated that pristine clay could be well-dispersed and exfoliated in an epoxy resin through this technique. In this paper, the technical details and experimental evidences are presented.
Multiscale Modeling of Biological Nanocomposite Nacre
Nacre, the inner layer of seashells is a biological nanocomposite having extraordinary mechanical properties. A multiscale modeling approach has been used to study the nano and microarchitecture of nacre to gain an understanding of the role of the architecture on the mechanical response. The role of biopolymers, mineral and various nuances in nacre and their effect on mechanical properties are presented in the paper.
Micro-Deformation and Fracture Behavior of Epoxy Based Nanocomposites with Highly Exfoliated Pristine Clay
Fracture behaviors of nanocomposites based on epoxy and highly exfoliated pristine clay were tested using double cantilever beam specimens. Micro-deformation mechanisms of the epoxy/clay composites under load were investigated using SEM and TEM. Numerous micro-cavities associated with clay particles are believed to be the major mechanism for the improved fracture toughness of the epoxy/clay nanocomposites.
Tensile Property, Morphology and Micro-Deformation of Polypropylene/CaCO3 Nanocomposites
Stress-strain relations of polymer nanocomposites at different strain rates were studied using polypropylene (PP) and calcium carbonate nanoparticles. The morphology and deformation mechanisms of nanocomposites were studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Debonding and cavitation at the matrix/particle interfaces were identified as the major deformation mechanisms of the PP/CaCO3 nanocomposites under uniaxial tension.
Fracture Behavior of Core-Shell Rubber-Toughened ?-Zirconium Phosphate-Based Epoxy Nanocomposites
The fracture behavior of core-shell rubber (CSR) toughened ?-zirconium phosphate (ZrP) epoxy nanocomposite is investigated. The combined use of ZrP and CSR can greatly improve both the modulus and fracture toughness of epoxy. The fracture mechanisms change from brittle fracture via ZrP delamination to matrix shear yield after addition of CSR. Approaches for producing toughened high performance polymer nanocomposites are discussed.
Mechanical Properties and Fracture Behavior of Epoxy Nanocomposites with Highly Exfoliated Pristine Clay
A group of epoxy nanocomposites with well-dispersed and highly exfoliated pristine clay was prepared by a new patent-pending technique. The nanocomposites exhibit much-improved modulus as well as fracture toughness compared to the neat epoxy. The morphology, deformation behavior and toughening mechanisms of the nanocomposites were studied.
Comparison of the Effect of Pigments on the Mechanical and Thermal Properties on Two Different Catalysed Propylene-Ethylene Random Copolymers
Two different catalysed propylene-ethylene random copolymers containing a 0-8% red organic pigment were injection moulded. Mechanical analysis showed the Ziegler-Natta catalysed polymer to have lower tensile modulus, higher % elongation, lower break strength and higher impact strength than the metallocene copolymer. Thermal analysis highlighted the differences in the structure between the two propylene-ethylene copolymers.
Effects of Carbon Nanofibers on Polystyrene Nanocomposites and Foams
With extraordinary mechanical properties, carbon nanofibers (CNF) are expected to serve as reinforcements for both lightweight and ultrastrong composite materials. In this study, we used CNF as the reinforcing nanoelements to synthesize polystyrene/CNF nanocomposites by the in-situ polymerization process. The obtained composites were further foamed using supercritical CO2 as the foaming agent. A homogeneous dispersion of CNF was observed and the final PS/CNF nanocomposite foam showed microcellular foam morphology.
On-Line Birefringence Measurement in Film Blowing Process
On-line measurements of velocity, bubble diameter, temperature and three principal birefringences were performed during the tubular film extrusion of polypropylene at various draw ratios and blow-up ratios. Birefringence increased rapidly in the vicinity of the frost line height where the crystallization started. Birefringence between MD and ND showed the maximum value near the solidification position, and then it decreased with increasing distance from the die, and eventually the obtained PP film showed almost uniaxial molecular orientation.
Computational Materials at NASA Langley Research Center
The paper provides details on the structure and implementation of the Computational Materials Program at the NASA Langley Research Center. Examples are given that illustrate the suggested approaches to predicting the behavior and influencing the design of nanostructured materials such as high-performance polymers, composites, and nanotube-reinforced polymers. Primary simulation and measurement methods applicable to multi-scale modeling are outlined. Key challenges including verification and validation of models are highlighted and discussed within the context of NASA's broad mission objectives.
Mechanical Properties of Injection Molded Glass Fiber Reinforced PC/ABS with PC Oligomer
In this study, the effect of PC-oligomer on mechanical properties and internal structure of injection molded glass-fiber reinforced PC/ABS was investigated. The mechanical properties of PC/ABS with PC-oligomer were lower and the difference became larger with increasing GF content. However, the internal structure was different from the surface to the middle layer through thickness direction. It is thought that this difference in structure and the dispersion of GF affected the mechanical properties of the composites.
Modeling of Viscoplastic Constitutive Equation for Inelastic Deformation of Polymer with Unloading
A viscoplastic constitutive equation for inelastic deformation of polymers was formulated by combining the kinematic hardening creep theory of Malinin and Khadjinsky with the nonlinear kinematic hardening rule of Armstrong and Frederick. The nonlinear kinematic hardening rule was modified in order to describe peculiar inelastic deformation of polymers during unloading in particular. Experimental results for polyethylene were simulated by the constitutive equation and the validity of the modification was verified.
Mechanical Properties of PC/ABS Ultra High-Speed Injection Moldings
Effect of the content of PC/ABS and injection speed on the mechanical properties of PC/ABS ultra high-speed injection moldings, in which ABS content was varied, was investigated. Tensile modulus of near the surface evaluated using sliced specimen showed the highest values, and flexural modulus of the specimen was higher.
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