Polymer Engineering and Science articles from November 2004

Polymer Engineering and Science archives from November 2004

In-situ ultrasonic compatibilization of unvulcanized and dynamically vulcanized PP/EPDM blends.
November 1, 2004... INTRODUCTION Preparation of novel polymer blends is a research area of considerable interest. Most polymer pairs in blends are thermodynamically incompatible; the incompatible blends often give poor mechanical properties due to the lack of...

Shrinkage and warpage prediction of injection-molded thin-wall parts using artificial neural networks.
November 1, 2004... INTRODUCTION Because of the highly competitive nature of 3C (computers, communication devices and consumer electronics) industries, demands for shortening the research and development time, reduction in the size of the products, and better...

Morphology, thermal, and mechanical properties of vinylester resin nanocomposites with various organo-modified montmorillonites.
November 1, 2004... INTRODUCTION Polymer-layered silicate nanocomposites have attracted increasing interest from science and industry because they often exhibit greatly improved mechanical, thermal, barrier, and fire-retardant properties at very low clay...

Rheological evaluation of metallocene polyethylenes with processing aids by multi-wave oscillations.
November 1, 2004... INTRODUCTION Metallocene polyethylenes show very complicated flow behavior within dies of processing equipments or capillary viscosimeters because of certain physicochemical interactions of the mPE with the wall (1). Flow instabilities...

The role of surface modification in digital printing on polymer-coated packaging boards.
November 1, 2004... INTRODUCTION Packaging is an ideal application for digital printing because of the amount of variable information involved. Traditionally, packaging materials have been printed with offset, gravure, or flexography (1), but in this study...

Electroactive polymer patterns with metal incorporation on a polymeric substrate.
November 1, 2004... INTRODUCTION The potential for using electroactive polymers as active materials in optoelectronics (1, 2), microelectronics (3), sensors (4), and related areas (5) has recently stimulated significant research interest. The doped,...

The structure and properties of PA6/MMT nanocomposites prepared by melt compounding.
November 1, 2004... INTRODUCTION Polymer/layered silicate nanocomposites have become an important area of polymer composites research in recent decades since they frequently exhibit unexpected hybrid properties synergistically derived from two components. In...

Effects of oxidation and particle shape on critical volume fractions of silver-coated copper powders in conductive adhesives for microelectronic applications.
November 1, 2004... INTRODUCTION As the demand for smaller, lighter, thinner components and higher performance in electrical and electronic appliances continues to grow, especially in mobile devices, more effort goes into making semiconductor devices ever...

Solubility of butane and isobutane in molten polypropylene and polystyrene.
November 1, 2004... INTRODUCTION Plastic foams are widely used as thermal insulators and shock absorbers throughout various industries. Chlorofluorocarbons (CFC-11 and CFC-12) were used as physical blowing agents for industrial foaming processes for many...

Strain hardening in polypropylenes and its role in extrusion foaming.
November 1, 2004... INTRODUCTION Foamed plastics have garnered a sizable share of the global demand for plastics, with U.S. consumption expected to rise to 7.8 billion lbs in 2005 (1). Applications for foamed plastics are numerous, and new materials and...

Shear-induced migration of conductive fillers in injection molding.
November 1, 2004... INTRODUCTION The commercial success and popularity of conductive polymer compounds are tied to relatively easier control of conductivity by the choice of proper fillers and their contents in compounds. The electrical conductivity of...

Sequential injection overmolding of an elastomeric ethylene-octene copolymer on a polypropylene homopolymer core.
November 1, 2004... INTRODUCTION Sequential injection overmolding, also called two-stage sequential overmolding, is the process by which a rigid substrate is overmolded with a more flexible material. In a single mold with two or more inlets, and moving parts...

Mechanical, thermal, and barrier properties of NBR/organosilicate nanocomposites.
November 1, 2004... INTRODUCTION The pioneering work conducted by Toyota Central Research on nylon-6/silicate nanocomposites has inspired great interest in polymer nanocomposites over the past decade (1-3). This particular interest results from the highly...

Characteristics of antiplasticized thermosets: effects of network architecture and additive chemistry on mechanical fortification.
November 1, 2004... INTRODUCTION Thermosets are commonly used as matrix materials for filled composites. In such applications, filler material is introduced to impart enhanced mechanical properties. It has been well established, however, that the compressive...

Preparation and properties of biodegradable poly(propylene carbonate)/starch composites.
November 1, 2004... INTRODUCTION The utilization of carbon dioxide (C[O.sub.2]) has attracted scientific and practical interest in recent years because of environmental pollution and energy shortages. Global warming, known as the greenhouse effect, is caused...

Structure development in melt-spinning syndiotactic polystyrene and comparison to atactic polystyrene.
November 1, 2004... INTRODUCTION Syndiotactic polystyrene (s-PS) was first announced in 1986 by Idemitsu Kosan (1), who commercialized it in succeeding years. Today it is produced by both Idemitsu and Dow Chemical. s-PS has the same [T.sub.g] (about...

Temperature gradients in the channels of a single-screw extruder.
November 1, 2004... INTRODUCTION The temperature of a molten polymer stream is a key processing parameter to know for all processes. The process temperature affects many critical material parameters including the viscosity, density of the resin, and...

Rheological properties of injection molded LDPE and mPE foams.
November 1, 2004... INTRODUCTION Polymeric foams are gaining commercial importance as lightweight structural materials because of their low density and high impact resistance. They also have good insulation properties because of the entrapped gas. The main...