Polymer Engineering and Science articles from April 2006

Polymer Engineering and Science archives from April 2006

Morphology of compatibilized ternary blends of polypropylene, nylon 66, and polystyrene.
April 1, 2006... INTRODUCTION The scrap or waste plastics available for recycling often contain a number of different polymers. To obtain useful mechanical and physical properties from such mixtures, it is usually necessary to compatibilize various pairs...

Fullerene-functionalized polycarbonate: synthesis under microwave irradiation and nonlinear optical property.
April 1, 2006... INTRODUCTION Fullerene has attracted much attention because of its unique electronic conducting, magnetic, and photophysical properties. However poor solubility and difficulty in processing of fullerene hampers its direct application....

Nonisothermal comprehensive 3D analysis of polymer melt flow in a coat-hanger die.
April 1, 2006... INTRODUCTION Coat-hanger dies are, extensively, used for delivering wide uniform sheets of liquids in polymer processing industries. As we know, they provide a smooth, dead-spot free flow path, and thus produce sheet without weld lines...

Replications and analysis of microlens array fabricated by a modified LIGA process.
April 1, 2006... INTRODUCTION Over the past decades, micromachining technologies have been developed to fabricate sensors, actuators, microstructures, and systems, which were frequently called MEMS (Microelectromechanical Systems) [1]. The LIGA, a German...

Rupture of nanoparticle agglomerates and formulation of [Al.sub.2][O.sub.3]-epoxy nanocomposites using ultrasonic cavitation approach: effects on the structural and mechanical properties.
April 1, 2006... INTRODUCTION Inorganic--organic composites, e.g., epoxy--inorganic particles, are of considerable interest due to the fact that neat epoxy samples exhibit poor toughness and warping or surface cracking under high pressure. It has been...

Manufacturing and foaming of high melt viscosity of polypropylene by using electron beam radiation technology.
April 1, 2006... INTRODUCTION Polypropylene exhibits many good properties, such as high mechanical strength, inertness to various chemical reagents, nontoxicity, high transparency, and high glossiness. However, homopolypropylene (HPP) has been restricted...

Twin-screw extrusion production and characterization of starch foam products for use in cushioning and insulation applications.
April 1, 2006... INTRODUCTION Foam plastic packaging is experiencing growing pressure from existing and proposed environmental and disposal regulations, and from market based sustainability initiatives. It presents a major disposal problem for companies...

Intercalation and exfoliation of clay nanoplatelets in epoxy-based nanocomposites: TEM and XRD observations.
April 1, 2006... INTRODUCTION The use of organo-clay nanoplatelets in polymers to create nanocomposites having properties greater than the parent constituents has been well reported over the past decade [1]. Although nylon 6 has been the primary matrix...

Rheology of wood plastics melt, Part 2: effects of lubricating systems in HDPE/maple composites.
April 1, 2006... INTRODUCTION Wood plastics industry has been experiencing rapid growth in the past decade [1-5]. Among the many factors that lead to this development, the competitiveness of wood over conventional fillers is an important factor. In...

Synthesis of a novel hexaarylbiimidazole with ether groups and characterization of its photoinitiation properties for acrylate derivatives.
April 1, 2006... INTRODUCTION The hexaarylbiimidazoles (HABIs) are a very useful class of photoinitiators that are widely used in proofing papers, photoimaging, photoresists, etc. The dimer formed upon oxidation of 2,4,5-triarylimidazole was first...

Comparative analysis of radical-mediated polyethylene modifications: vinyltriethoxysilane versus mercaptopropyltriethoxysilane addition.
April 1, 2006... INTRODUCTION The addition of alkoxysilane functionality to polyolefins produces value-added resins that bind covalently to siliceous fillers and moisture-cure into thermoset materials [1]. Silane-containing grades of polyethylene (PE) have...

Finite strain 3D thermoviscoelastic constitutive model for shape memory polymers.
April 1, 2006... INTRODUCTION Shape memory polymers (SMPs) have the capability to retain a temporary shape at low temperature that was created during high temperature deformation. When the material in the temporary shape is heated above a critical...

Temperature evolution during stereolithography building with a commercial epoxy resin.
April 1, 2006... INTRODUCTION Stereolithography (SL) is a rapid prototyping technique, leading to the generation of a three-dimensional polymer object by photopolymerization. During the process, a liquid photosensitive resin is cured by a UV laser beam...

Thermoformability study of virgin and regrind high impact polystyrene coextruded sheets: influence of the number of processing cycles on the processing parameters.
April 1, 2006... INTRODUCTION Thermoforming is a process technique used to produce thermoplastic items for different applications like packaging, refrigeration, automotive, and aerospace technology. The simplest form of the process is based on heating a...

Assessing local residence time distributions in screw extruders through a new in-line measurement instrument.
April 1, 2006... INTRODUCTION Extrusion of polymers in a screw extruder is composed of a series of thermal, physical, and eventually chemical histories/changes occurring in a simultaneous or consecutive manner inside the extruder. The time a flow element...

Optical properties of highly transparent polypropylene cast films: influence of material structure, additives, and processing conditions.
April 1, 2006... INTRODUCTION Polymer films used in the packaging industry often have to fulfill high requirements as to their optical properties. Particularly in medical applications, special optical properties such as low haze and high clarity are key...

A study of the effects of postcure treatments on polyester-melamine coating matrices.
April 1, 2006... INTRODUCTION Previous publications in this series have described the thermal characterization of polyester-melamine crosslinked matrices of varying compositions and cure conditions [1], the effect of composition and cure conditions on the...

Injection molding product weight: online prediction and control based on a nonlinear principal component regression model.
April 1, 2006... INTRODUCTION Quality is the ultimate goal of injection-molding control, like any manufacturing process. The quality attributes of injection-molded products can be roughly divided into three categories: (i) the dimensional properties such...

Design and performance analysis of a self-regulating melt pressure valve.
April 1, 2006... INTRODUCTION Feed systems are used in injection molding and other polymer processing operations to deliver the polymer melt from the plastication unit to one or more locations where the melt is formed. In many injection molds, for example,...

Preparation and characterization of new optically active poly(amide-imide)s derived from N,N-(4,4'-Oxydiphthaloyl)-bis-(s)-(+)-valine diacid chloride and aromatic diamines.
April 1, 2006... INTRODUCTION Aromatic polyimides possess many desirable characteristics such as high thermal stability and excellent physical properties. However, they are generally insoluble and infusible after conversion from their poly(amic acid)...

Erratum.(Correction notice)
April 1, 2006... "On the Injection Molding of Nanostructured Polymer Surfaces," by Pranov et al., Polym. Eng. Sci. 46, 160-171 (February 2006). Figures and captions were published incorrectly. The corrected figures and captions 12-15 follow. [FIGURE...