Polymer Engineering and Science articles from January 2008

Polymer Engineering and Science archives from January 2008

PEDOT-PSS/singlewall carbon nanotubes composites.(polyethylenedioxythiophene- polystyrene sulfonic acid)(Technical report)
January 1, 2008... INTRODUCTION Transparent electrical conductors (TCs) are essential parts for opto-electrical applications such as flat-panel display devices, lasers, or solar cells [1-3], and most of the TCs consist of metals or metal oxides [3]. The...

The effect of recycling on LDPE foamability: elongational rheology.(low density polyethylene)(Technical report)
January 1, 2008... INTRODUCTION It is now known that the foaming process is highly dependent on the molecular structure of the base polymer. Good foaming performance is usually associated with a high degree of long-chain branching [1, 2]. Low density...

Local residence time, residence revolution, and residence volume distributions in twin-screw extruders.(Technical report)
January 1, 2008... INTRODUCTION Twin-screw extruders are one of the most important types of equipment for both food and polymer processing. In the field of polymers, they are mainly used as mixers/reactors for blending, compounding, and reactive processing...

A simple constitutive model for cyclic compressive ratchetting deformation of polyteterafluoroethylene (PTFE) with stress rate effects.(Technical report)
January 1, 2008... INTRODUCTION Polymer is widely used in industry. Polymer and plastic are typical materials with viscoelastic properties, and their majorities exhibit complex nonlinear and time-dependent response. Polytetrafluroethylene (PTFE) has low...

The experimental observation and numerical modeling of cast film deformation using novel capillary markers.(Technical report)
January 1, 2008... INTRODUCTION Film casting is an important industrial process that is used to continuously produce plastic films and ribbons [1]. Its roots date back about 65 years [2] and consists of the extrusion of a thin polymer film through either a...

Temperature, conversion, and phase separation profiles during mold cure of a modified vinyl-ester resin.(Technical report)
January 1, 2008... INTRODUCTION Vinyl-ester (VE) is one of the most important thermosetting resins for composite formulations in industrial applications and in biomedical uses [1]. The materials formulated with these resins show valuable properties, such as...

Discrete particle simulations of solids compaction and conveying in a single-screw extruder.(Technical report)
January 1, 2008... INTRODUCTION The flow of granular materials in engineering processes is poorly understood owing to the complex dynamics displayed. Composed of discrete particles that are encompassed by fluid (i.e. liquid or gas), granular matter often...

Reinforcement of polydimethylsiloxane through formation of inorganic-organic hybrid network.(Technical report)
January 1, 2008... INTRODUCTION Polydimethylsiloxanes (PDMS) has been widely used as adhesives, wire and cable coverings, tubing and automotive boots, seals, and electrical connectors because of its excellent elasticity, compression set, dynamic fatigue,...

Optimizing the balance between impact strength and stiffness in polypropylene/elastomer blends by incorporation of a nucleating agent.(Technical report)
January 1, 2008... INTRODUCTION Isotactic polypropylene (iPP) is one of the most important commodity polymers due to its excellent properties, such as good processability, high chemical resistance, low density, and low cost. However, iPP is a thermoplastic...

Prediction of the influence of flow-enhanced crystallization on the dynamics of fiber spinning.(Technical report)
January 1, 2008... INTRODUCTION In addition to accurately fitting and predicting steady-state behavior, an important aspect of fiber spinning modeling is determining the stability and sensitivity of a given system to changes in processing conditions....

Polyetherimide substrates for future high density optical data storage.(Technical report)
January 1, 2008... INTRODUCTION As optical storage densities increase, improvements of substrate properties have received much attention to cope with elaborate operating conditions. Specifically, surface states and mechanical properties of the substrate...

Prediction of molecular weight scale and molecular weight distribution of cellulose using a rheology-based method.(Technical report)
January 1, 2008... INTRODUCTION Gel permeation chromatograghy (GPC) method is a widely used and accepted method for measuring the molecular weight (MW) and molecular weight distribution (MWD) for polymers. However, the method has its limitations. The key of...

Numerical simulation of a polypropylene foam bead expansion process.(Technical report)
January 1, 2008... INTRODUCTION In manufacturing expanded polymer foam bead products, tiny beads of a polymer are expanded and consolidated in a process of steam heating and pressure treating [1]. Because of their nature, with a superiority in weight...

Thermal behaviors of a novel UV cured flame retardant coatings containing phosphorus, nitrogen and silicon.(ultraviolet)(Technical report)
January 1, 2008... INTRODUCTION Fire retardant coatings have been widely used as one of the easiest and most efficient way to protect materials against fire [1] because of their several advantages, including no influence on the intrinsic properties of the...

Evaluation of mechanical properties of epoxy-guar gum composites.(Technical report)
January 1, 2008... INTRODUCTION Guar gum (GG) is a natural polymer extracted from the endosperm of the plant Cyamopsis tetragonalobus and chemically is a galactomannan with a galactose to mannose ratio of 1:2 [1]. There has been some discussion regarding the...

An inverse estimation of initial temperature profile in a polymer process.(Technical report)
January 1, 2008... INTRODUCTION Over the past three decades numerical methods have been developed to analyze the complex flow of polymer melt in arbitrary geometries under various processing conditions where viscous dissipation plays an important role....

Organic-inorganic hybrid materials derived from epoxy resin and polysiloxanes: synthesis and characterization.(Technical report)
January 1, 2008... INTRODUCTION Sol-gel manufacturing of organic-inorganic hybrids has gained increased interest in the last decade because of its versatility and the easy access to conditions in carrying out the process [1]. This technique uses a mixture of...

Mechanical, thermal, and fire behavior of bisphenol a polycarbonate/multiwall carbon nanotube nanocomposites.(Technical report)
January 1, 2008... INTRODUCTION Carbon nanotubes, with their unique structure and properties, offer promising potential as molecular electronic conductors, high-performance fibers and hence for using them in nanotechnology. They are under discussion for...

A practical approach to modeling time-dependent nonlinear creep behavior of polyethylene for structural applications.(Technical report)
January 1, 2008... INTRODUCTION Polyethylenes (PEs) are increasingly used in many aspects of our lives, including infrastructure and building construction. The rationale for the research presented herein is the need for rational structural analysis and...

Viscoelastic evaluation of effects of fiber size and composition on cellulose-polypropylene composite of high filler content.(Technical report)
January 1, 2008... INTRODUCTION Wood-plastic-composites (WPC) have attracted attention as an effective method of utilizing low quality and/or waste wood and plastic in recent years. As a result, the Industrial Standard (JIS) for WPC prepared from recycled...

Effects of crystallization on dispersion of carbon nanofibers and electrical properties of polymer nanocomposites.(Technical report)
January 1, 2008... INTRODUCTION Polymer composites filled with carbonaceous nanofillers such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs) have attracted increasing interest recently due to their unique properties such as excellent mechanical...

Diffusion dynamics of ionic liquids during the coagulation of solution spinning for acrylic fibers.(Technical report)
January 1, 2008... INTRODUCTION Acrylic fiber is a very versatile fiber, which has emerged not only as a major substitute for wool but also as the important precursor for carbon fiber. So far, the spinning process most commonly used for acrylic fiber is...

Uniaxial ratchetting behavior of vulcanized natural rubber.(Technical report)
January 1, 2008... INTRODUCTION Rubbers are extensively used in many applications because of their large reversible elastic deformation, excellent damping, and energy absorption characteristics [1]. Typical applications include engine mounts and tires for...

Organic vapor permeation through natural rubber/poly(ethylene-co-vinyl acetate) blend membranes.(Technical report)
January 1, 2008... INTRODUCTION A clear understanding of permeation mechanism is required in order to succeed in the application of polymers as protective barriers in chemical and food industries, in membrane separation processes, in recovery or recycling of...

The friction and wear properties of clay filled PA66.(polyamide)(Technical report)
January 1, 2008... INTRODUCTION In recent years, organic-inorganic nanocomposites have attracted great attention both in industry and academia. One of the most promising composites systems would be hybrids based on organic polymers and inorganic clay...