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.
The rheological, thermal and mechanical behavior of polypropylene (PP) and high density polyethylene (HDPE) filled with sea shells composites at different concentrations of filler were investigated. The composites were prepared by extrusion and injection molding. Most filler addition to composites promoted a slightly increase on the melt viscosity, improve the tensile modulus and the thermal stability in all composites studied.
A new class of fiber-reinforced composite materials was designed in our laboratory by using a hybrid of thermoplastic and thermosetting polymers. The thermosetting polymer phase separates upon curing reaction and creates morphology on the fiber surfaces. Effect of the morphology is studied on the fracture toughness of the composite, with the aim of enhancing the mechanical properties of the resulting fiber reinforced composite.
Finding very small amounts of a secret compound in complex mixtures presents a big challenge for analysts. A dispute between two companies involved building plasters with a polymer viscosity modifier. The case hinged on confidential information about the exact structure of the polymer, which one company had apparently taken illicitly from the other. FTIR revealed little, so NMR was used to identify the compound in deuterated DMF extracts from the plasters. They showed that the plasters possessed compounds of identical structure. The case was settled without trial.
Tape sensors were mounted on the adherends and the health of the adhesive bonds was studied by electrochemical impedance spectroscopy. Results show that EIS measurements can discriminate bonded and unbonded areas in CFRP-Al systems. The EIS measurements are also sensitive to the weakening of adhesive bonds caused by exposure to humidity at high temperatures.
Optical and Scanning electron microscopy (SEM) techniques, coupled with energy dispersive X-ray analysis (EDS) are effective tools in investigating the cause of failures in articles made from plastics. Practical examples and findings are reviewed that have been used to solve customer problems in real world applications.
Commercially available isotactic polypropylene (iPP) was modified by various amounts of a specific ?- nucleating agent. Isothermal crystallization and subsequent melting behavior were analyzed using differential scanning calorimetry (DSC). The findings resulting from this work (such as crystallization halftimes, other kinetics parameters, glass transition temperatures, etc.) can significantly assist to explain not a few open questions concerning ?-nucleated polypropylenes and their processing.
A new method for crystallization kinetics of stretched polymer samples and real size polymer articles under isometric conditions is developed. The internal shrinkage force caused by the volume contraction of the sample during crystallization is measured incessantly. The kinetics parameters of isometric crystallization are calculated by the Avrami equation and discussed in terms of controlled molecular structure and design of large polymer sheet samples and of patient fixation devices for medical application in radiation therapy.
The viscosity of a blowing agent laden polymer was measured using a Helical Barrel Rheometer (HBR). Temperature, pressure and shear rate dependence of viscosity at a fixed blowing agent concentration was computed from the experimental data. Technique was developed to identify the onset of bubble nucleation by measuring the shear viscosity as function of hydrostatic pressure.
It has been demonstrated for the first time that microcellular foam structures can be produced using the microlayer coextrusion technology. Cell size can be reduced considerably by increasing the number of layers without adversely affecting the density. Unique mechanical properties can be achieved through material choice and layer structure. The cell morphology and the compressive response of these multilayered foam/film structures are similar to that of cork.
This paper presents a study on the processing condition and characterization of foamed HDPE/PP blends. The blends were foamed with different blowing agent concentrations using a twin-screw extruder. A chemical blowing agent (azodicarbonamide) and activator agent (ZnO) were selected and the morphological, rheological and mechanical properties of the resulting foams are presented.
In this study we assessed the specific properties including tensile, compression and flexure strengths and moduli for syntactic foam as a function of various microstructures. Preliminary results revealed that the specific compressive strength and the specific tensile, compressive and flexural moduli depended on the type of microsphere, which varied in density. Mechanical properties are critically evaluated in light of their microstructures.
The extrusion behavior of ?–aluminium oxide– silicone oil pastes were investigated via capillary rheometry. Several parameters affecting the paste behavior were considered, including the viscosity of the fluid phase, the solids concentration (35 to 55 Vol. %), the extrusion rate (10-2 to 103 mm/s) and the addition of pigment. The flow curves and wall slip behavior were determined under the extrusion conditions.
A semi-crystalline copolymer was synthesized with block-like structures by ring-opening polymerization (ROP) using L,L-lactide (LLA) and 5-methyl-5- benzyloxycarbonyl-1,3-dioxan-2-one (MBC). Analysis of the copolymer revealed retention of crystallinity and melting transition temperatures. The copolymer exhibited an upper limit to compositional incorporation of MBC before crystallinity was disrupted. The physical properties (Tg, Tc, Tm) were increased after hydrogenation.
Unique additives enable increases in the Gardner impact strength of polyolefins by a factor of 10 while maintaining up to 90% of the material flexural modulus. The effects of resin and additive loading level are addressed in a statistically designed experiment. Physical performance, rheological effects, thermal characterization, and morphological characterization are reported.
The dynamic rheological properties of two types of thermoplastic elastomer (TPE) compounds were studied at ambient and processing temperatures. The linear viscoelastic properties of Thermoplastic Vulcanisates (TPV) and PP/SEBS compounds can be described using models based on mechanical mixing rules. The results were evaluated as a function of composition.
The article discuss the evaluation of ways of investment occasions on a capital market, taking under consideration the availability and cost of investment money. It is considering the time-factor related to the actual market environment an describing the specific possibilities of the trading tools as the technological conciliator of the investment in the chemical and plastic industry.
The supply chain for polymeric materials is a drastically changing environment. This paper will focus on the types of trade names used. Changes of ownership along with historic trade names will be discussed. Predictions of future uses and types of trade names will be made.
The condition for the breakup, of a power-law non-Newtonian slender drop in a Newtonian liquid in an axisymmetric extensional flow, has been theoretically studied. The problem is governed by four dimensionless numbers: The capillary number, the Reynolds number, the viscosity ratio and the power-law index. The results suggest that the critical capillary number for drop breakup increases as the Reynolds number, the viscosity ratio and the power-law index decrease.
In this work the rheological properties of polymer have been studied by molecular dynamics simulation. Couette flow with various shear rates are used to investigate the degree of slip, shear viscosity and normal stress difference. The fluid consists of chains of n-hexadecane and is confined between two structured gold atomic walls. Isothermal simulations (350K) of 4 to 1 unsteady extrusion flow with various extrusion rates are conducted.
Geometry of a flat die for polymer sheet extrusion is optimized to obtain a uniform velocity distribution across the exit of the die. While optimizing the exit velocity distribution, the constraint optimization algorithm used in this work enforced a limit on the maximum allowable pressure drop in the die. Effect of the shear as well as elongational viscosity of the polymer on the flow in the flat die is taken into account.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
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