Polymer Engineering and Science articles from September 2008

Polymer Engineering and Science archives from September 2008

Morphology and glass transition of thin polylactic acid films.(Technical report)
September 1, 2008... INTRODUCTION Polymer thin films are widely used in many different applications such as manufacture of electronic devices to the production of paper, in medical applications, and in packging. Because of these numerous applications, there...

Electrospinning and alignment of polyaniline-based nanowires and nanotubes.(Technical report)
September 1, 2008... INTRODUCTION Conducting polymers constitute an attractive class of materials for electronic, magnetic, and optical applications (1), (2). Among them, polyaniline (PANi) has received a lot of attention due to its environmental stability,...

Properties of new nanocomposite triblock copolymer gels based on expandable graphite.(Technical report)
September 1, 2008... INTRODUCTION Numerous studies reported over the past decade have sought to establish the fundamental relationships between morphology and property development in thermoplastic elastomer gels (TPEGs) as explicit functions of copolymer...

Natural rubber nanocomposite reinforced with nano silica.(Technical report)
September 1, 2008... INTRODUCTION Natural rubber (NR) with excellent chemical and physical properties has been widely used in various areas (1-3). The raw NR is usually reinforced with antiageing agents (4), (5) and inorganic fillers (6), (7) before it is...

Review: increasing the efficiency of the extrusion process.(Technical report)
September 1, 2008... Increasing the efficiency of the polymer extrusion process consists in the increase of the flow rate of the processed polymer and the energy efficiency of polymer processing extruders and the decrease of the specific energy consumption and the...

Miscibility, melting, and crystallization behavior of poly(hydroxybutyrate) and poly(D,L-lactic acid) blends.(Technical report)
September 1, 2008... INTRODUCTION Much interest has been attached to biosynthesis, physical properties, biodegradation, modification, and utilization of bacterial polyesters because of their potential applications as environment friendly materials (1-3). They...

Characterization of viscoelastic fluid flow in a periodically driven cavity: flow structure, frequency response, and phase lag.(Technical report)
September 1, 2008... INTRODUCTION The flow of viscoelastic fluids offers an extremely interesting set of problems and has been the focus of research activities over the last few decades. Because of the complexities of viscoelastic fluid flow, different...

Numerical prediction of phase-change heat conduction of injection-molded high density polyethylene thick-walled parts via the enthalpy transforming model with mushy zone.(Technical report)
September 1, 2008... INTRODUCTION Transient heat conduction problems involving solidification/melting are usually referred to as the "Stefan problems" or "moving-boundary problems," which were raised by Stefan (1) in his works in relation to the ice formation...

Microstructure and water vapor transport properties of functionalized carbon nanotube-reinforced dense-segmented polyurethane composite membranes.(Technical report)
September 1, 2008... INTRODUCTION Since the discovery of C60 by Kroto in 1985 (1) and its large scale synthesis in 1990 (2), carbon nanotubes (CNT) have attracted considerable attention as reinforcing fillers in polymer matrices (3-5) due to their unique...

Multiscale roughness analysis in injection-molding process.(Technical report)
September 1, 2008... INTRODUCTION In microinjection molding, the quality and topography of the machined surface have a significant impact on the replication capabilities (filling) (1). Particularly, the surface topography of polymer influences adhesion and is...

A simplified approach to predict part temperature and minimum "safe" cycle time.(Technical report)
September 1, 2008... INTRODUCTION Injection molding is the most popular process for mass producing plastic parts (1), (2). Several advantages of injection molding are high precision, quick turnaround time, and process flexibility. In today's highly competitive...

In situ compatibilization of maleated thermoplastic starch/polyester melt-blends by reactive extrusion.(Technical report)
September 1, 2008... INTRODUCTION Plastic packaging is now subjected to strong pressure from environmental and disposal regulations in the design of single-use disposable packaging (1), (2). Obviously, there is a need for the development of environmentally...

Chromophore concentration effect on holographic grating formation efficiency in novel azobenzene-functionalized polymers.(Technical report)
September 1, 2008... INTRODUCTION The possibility of inducing changes of structural and optical properties in chromophore containing polymers, by means of light illumination, has stimulated a considerable research activity during the last decades. Research on...

Radiation and postirradiation crosslinking and structure of two unsaturated polyester resins.(Technical report)
September 1, 2008... INTRODUCTION The ionizing radiation produces various changes in polymers, and it offers fast and clean means of reaction initiation. No initiator and/or promoter is needed for radiation polymerization, crosslinking, and grafting reactions....

Formation and characterization of polyurethane--vermiculite clay nanocomposite foams.(Technical report)
September 1, 2008... INTRODUCTION Polyurethane foams are a versatile class of polymeric materials and may be rigid or flexible. Rigid polyurethane foams, having a closed cell structure, are primarily used for thermal insulation and structural applications....

Effect of molecular weight and end capping on poly(lactic-co-glycolic acid) ultrasound contrast agents.(Technical report)
September 1, 2008... INTRODUCTION Ultrasound is emerging as a leading medical imaging modality because it is nonionizing, inexpensive, portable, and allows for real-time imaging. It is estimated that over 100 million ultrasound scans of the heart, abdomen, and...

In situ reactive compatibilization of aramid/polystyrene blends using amine-functionalized polystyrene.(Technical report)
September 1, 2008... INTRODUCTION Reactive compatibilization, potentially presents a simple and cost-efficient route to morphological control in immiscible blends, which may be achieved through various types of functional group interaction (1), (2)....

Three-dimensional simulation of primary and secondary penetration in a clip-shaped square tube during a gas-assisted injection molding process.(Technical report)
September 1, 2008... INTRODUCTION Injection molding, due to its capability to efficiently produce complex plastic parts for various industrial applications, has become one of the most popular manufacturing techniques for mass production purpose since the first...

Pressure and temperature behavior of thermoplastic polymer melts during high-pressure expansion injection molding.(Technical report)
September 1, 2008... INTRODUCTION Plastic products are indispensable in our everyday life. They are made out of different kind of polymeric materials, most commonly out of thermoplastic polymeric materials. Thermoplastic polymeric materials consist mostly...

Mechanical and tribological properties of polyoxymethylene modified with nanoparticles and solid lubricants.(Technical report)
September 1, 2008... INTRODUCTION Polymer nanocomposites have flexible processability, much better magnetic, electric, and optical properties than neat polymer resulting from the high surface energy of nanometer fillers (1-8). Also, nanocomposites have...

Water bamboo husk reinforced poly (lactic acid) green composites.(Technical report)
September 1, 2008... INTRODUCTION Water bamboo (Coba, Gausum) is a water plant that has a preference for warm, humid, and sunny environment. The peak production is during summer (1). Desptie that it is a highly popular vegetable, the water bamboo husk is one...

Prediction of residual stress and viscoelastic deformation of film insert molded parts.(Technical report)
September 1, 2008... INTRODUCTION Film insert injection molding or simply film insert molding (FIM) is a relatively new injection molding technique in which molten polymer is filled into the cavity after a film is attached to one side of the mold walls. More...

The morphology, mechanical properties, and flammability of aligned electrospun polycarbonate (PC) nanofibers.(Technical report)
September 1, 2008... INTRODUCTION Electrospinning is a simple and efficient technique for the fabrication of nano-to microscale fibers (1), (2). It has potential application in filters, tissue engineering scaffolds, wound dressings, drug delivery materials,...

Uniaxial tensile properties underlying plane-stress rapid fracture resistance in polyethylene.(Technical report)
September 1, 2008... INTRODUCTION Polyethylene (PE) grades designed for fuel-gas and water distribution pipe systems are rated primarily on their long-term strength, measured by hydrostatic pressure testing. Thus, ISO 12162 defines a "PE 100" resin as one...

Rheological characterization of starch derivatives/polycaprolactone blends processed by reactive extrusion.(Technical report)
September 1, 2008... INTRODUCTION Replacement solutions of petroleum-derived by biopolymers have focused increasing attention in the past few years, even if they raise new economical problems such as an increasing price of food breeds. Amongst such...