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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Electrospun PVA Fibers as Precursor to Synthesize Hydroxyapatite
PVA (Polyvinyl alcohol) with various molecular weights (Mw) were electrospun with a Calcium Phosphate based sol. Fibers on the order of 2 ?m with uniformly distributed sol particles were obtained. Electrospinning process may be facilitated with high molecular weight polymers. The distribution of sol in the electrospun structure may depend on polymer/sol ratio. XRD results indicate that the fibers after calcination consisted predominantly of hydroxyapatite.
Impact Properties of Recycled PET Prepared by Reactive Compounding
We’ve aimed to develop high impact strength materials from waste PET. Recycled PET with impact strength as high as polycarbonate (PC) was successfully developed by reactive compounding with polymer with epoxy group. Structure development of the recycled PET in the reactive compounding was discussed on the basis of fracture surface observation by scanning electron microscope (SEM), Dynamic Mechanical Analyzer (DMA) analysis, Gel Permeation Chromatography (GPC), and Differential Scanning Calorimetry (DSC).
Preparation of Polystyrene/Carbon Nanofiber Conductive Composite Film
An efficient and inexpensive approach was developed to prepare conductive polystyrene (PS) films via a simple solution dispersion method. Carbon nanofiber (CNF), which has a similar structure as multiwall carbon nanotubes and a high performance/price ratio, was used as the filler in this research to achieve conductivity in polystyrene films. A good dispersion was achieved within the polystyrene solution system even without using any surfactants. A low percolation threshold at about 0.75wt% has been achieved.
Nano-Clay Tethered Shape Memory Polyurethane Nanocomposites
The magnitude of recovery force in shape memory polymers is usually low and must be augmented. In this work, a network is introduced in shape memory thermoplastic polyurethane (PU) by the addition of reactive nanoclay in an effort to improve the recovery force. In this case, nanoclay particles were allowed to tether to PU chains by chemical bonding. This report covers preliminary results on thermal, mechanical, and shape memory properties of clay-PU nanocomposites.
Multivariate Analysis (MVA) for Quality Detection in Injection Molding Systems in the Medical Device Community
We describe a new method of point-of-origin quality detection for injection molding systems. The method encompasses data acquisition, Multivariate modeling, reject control and data reporting, provides in-line quality detection of injection molded parts, and real-time reports on fault contributors. We discuss real-world production applications in which MVA is applied using real-time molding parameters to predict quality, with a goal of Parametric Release.
Electrorheological Properties of Carbon Black Filled PDMS
The electrical conductivity and rheological properties under steady shear flow of carbon black-filled PDMS are measured as a function of filler loading, matrix viscosity and shear rate, upon application of an AC electric field. The effects of electric field are most notable at low filler loadings and low matrix viscosities.
Mechanical Properties from the INV6 Closure for Short-Fiber Suspensions
Applications of orientation tensors for short-fiber polymer composites introduce a dependence upon higher-order orientation tensors alleviated through a closure. Current fourth-order closures have been demonstrated to neglect shear-extensional and shear-shear coupling effects in material stiffness predictions whereas sixth-order closures are capable of representing this advanced behavior. The newly introduced invariant based sixth-order fitted closure (INV6) is investigated and results demonstrate the INV6 closure accurately captures the complete material stiffness behavior.
Effect of Specimen Thickness on PC/ABS Spiral Flow Injection Moldings
The morphology of PC/ABS blend injection moldings is investigated using a spiral flow test mold. The results show that the specimen thickness would significantly affect the internal structure. Effect of specimen thickness on morphology of dispersed ABS phase in skin and core layers is extensively discussed in the relation to the mechanical properties.
Visualization of PP Foaming with Nitrogen
In this research, we observed the cell nucleation and initial growth behaviours of PP foaming with N2 under various experimental conditions in a batch foaming simulation system. We found that the nucleating agent content, initial temperature, initial pressure (i.e., gas content), and pressure drop rate during foaming had significant effects on cell density and cell growth. The branched PP (WB130)/N2 had a higher cell density than the linear PP (HE351)/N2.
Determination of Barrier Properties of Poly(Lactide) Polymers Using a Quartz Crystal Microbalance
Barrier properties of Poly (lactide) polymers were studied using a Quartz Crystal Microbalance (QCM). For this purpose, a new system was built up using QCM to measure the sorption of water vapor on polymer films spin coated on a quartz crystal. Sorption experiments were conducted at 23 °C and relative humidity of 20% and 60%. PLA films produced had a thickness of 0.12±0.02 ?m. Water diffusion coefficient values between 0.9 to 1.1 x 10-17m2.s-1 at 20 and 60% RH and permeability coefficients between 0.98 and 2.42 x 10-23 kg.m.m-2.s-1.Pa-1 were determined.
PP Melt Swelling Due to Gas Dissolution
Foaming of thermoplastic is gaining interest because of its potential to decrease the weight of automotive parts. Understanding of the thermophysical properties of PP/gas mixtures is critically important in this context. This paper presents a newly developed experimental technique that captures the melt pendent drop images locally, determines the boundary locations precisely and then reconstructs those images to accurately measure the swelling of the polymer due to gas dissolution at elevated temperatures and pressures.
Pressure Profile in Annular Die Using PP/CO2 Solution Viscosity
In this paper, a rheological die with a slit channel was designed to determine the solution viscosity of supercritical CO2 in non-crosslinked high-melt-strength (HMS) polypropylene (PP). The shear viscosity was modeled as a function of temperature, pressure, gas content, and shear rate. With interest in producing highly expanded foam sheets using an annular die, an analysis of the annular die pressure profile using the measured viscosity data was also conducted.
Fine-Celled Foaming of HDPE Using Nitrogen
Foaming experiments were performed in extrusion using HDPE and Nitrogen. Talc was used as a nucleating agent, and three levels of pressure drop rate were applied. The use of talc significantly increased the cell density and reduced the role of pressure drop rate in cell nucleation.
A Fiber and Film Simulation Package as a Learning Tool
The Center for Advanced Engineering Fibers and Films, an NSF Engineering Research Center, has developed a modeling package which couples polymer process stages and a materials database in a visualization-based environment. We will describe the no-cost academic version of this code, including a discussion of the background of the modules, along with examples of potential student projects.
Measurment and Prediction of Cooling Efficiency with CAE Software
A cooling system is applied to improve the cooling efficiency in the field of the injection molding. In this paper, the cooling system was simulated by commercial injection molding and heat transfer CAE software. The conditions of simulated cooling system were classified for the mold base material and cooling channel. After experiments of the injection molding using the simulated results of the cooling conditions, cooling efficiencies were analyzed.
Interfacial Failure of Composites at Cryogenic and Elevated Temperatures
Interfacial failure between carbon-fiber/polyimide composites under high and low temperature exposures was characterized. Based on microscopic photos taken after exposures at -196°C and 250°C and thermo-elastic failure analysis, transverse microcrack formation of composites was investigated.
Improving the Properties and Economics of Fiber Reinforced Parts Using Glass Beads
Mechanical, thermal, and physical properties of five thermoplastic resins compounded using solid glass beads and fibers as additives was studied. Melt flow index is found as the most affected property as a function of bead size and bead-to-fiber ratio. Criticality of bead-to-fiber ratio in relation to product quality and processing is discussed. Material costs are also examined with respect to key property changes and a selection method is suggested to find an optimum.
Peculiarity of Formation of the HDPE Phase Oxidized (Gel) by Processing
Change of physical and chemical, reological and physicomechanical properties of High Density Polyethylene (HDPE), exposed by thermal oxidation in shift current conditions with using of the rotational viscosimeter, is considered.It is shown, that products of oxidation form in the polymer melt and solid polymer an independent phase (gel), and have sharply distinguished from initial HDPE polarity, fluidity, physical and chemical properties.
Wood/Plastic Composites (WPC) with Glass Fiber Reinforcement (GRF)
The usage of WPC is rapidly growing, but these still suffer from lack of toughness, which can be improved by adding a small amount of GFR. Tensile tests of WPC specimen with varying amounts of wood-fiber content and 5% GRF were carried out. Significant improvements in properties were observed.
Surface Modification of PVDF Porous Membranes by Electron Irradiation
Poly (vinylidene fluoride) (PVDF) membranes were irradiated by electron beam and then grafted by acrylic acid (AA) and sodium 4-Styrenesulfonate (SSS). The degree of grafting was affected by irradiation dose, grafting time, grafting temperature, monomer concentration, monomer ratio, and pH of solution. The composition and microstructure were characterized by Fourier transform infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). The modified membranes were characterized through water contact angle, water flux measurement and fouling-resistant experiment.
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