Polymer Engineering and Science articles from July 2006

Polymer Engineering and Science archives from July 2006

Conformational and visometric behavior of quaternized polysulfone in dilute solution.
July 1, 2006... INTRODUCTION Polysulfones (PSF) represent a class of polymers containing sulfone groups and aromatic nuclei, characterized by good optical properties, thermal and chemical stability, mechanical strength, and resistance to extremes of pH...

Ethylene propylene diene terpolymer/ethylene vinyl acetate/layered silicate ternary nanocomposite by solution method.
July 1, 2006... INTRODUCTION In recent years, polymer nanocomposites containing inorganic nanosized layered clay materials and organic polymers have achieved a great attention to the researchers for their unique properties originating from the nanoscale...

Effect of machine compliance on mold deflection during injection and packing of thermoplastic parts.
July 1, 2006... INTRODUCTION A major issue in manufacturing precise plastic parts through injection molding is the deflection of the mold. In fact, for ultra-precise parts, such as fiber optic connectors, a final part deformation of a few microns is...

Frictional properties of thermally bonded 3D nonwoven fabrics prepared from polypropylene/polyester bi-component staple fiber.
July 1, 2006... INTRODUCTION The frictional properties of textile fabrics are of considerable importance in technical applications and in the subjective assessment by consumers. The frictional behavior of textile fabrics has been known to affect comfort...

New clay-reinforced nanocomposites based on a polycarbonate/polycaprolactone blend.
July 1, 2006... INTRODUCTION The preparation and characterization of polymeric materials mineral filled at the nanoscale is nowadays one of the most attractive research fields in the development of new polymeric materials [1]. This is because...

Experimental set-up and characterization of a mLLDPE-PP co-extruded bilayer system.(linear low density polyethylene)
July 1, 2006... INTRODUCTION In the 1990's, the development of metallocene catalysts (homogeneous single site catalysts) made possible the synthesis of polyolefins with structure and properties different from those of traditional Ziegler-Natta ones. The...

Process-induced long-term deformation behavior of semicrystalline PBT*.(polybutylene terephthalate)
July 1, 2006... INTRODUCTION Material characteristics and injection molding process interactively affect the quality of the resulting molded part. Although the overall process is governed by the thermodynamic principles, which make it possible to manage...

Phase separation in polypropylene and metallocene polyethylene blends.
July 1, 2006... INTRODUCTION The properties of a polymer material can be changed by the modification of its chemical structure. An alternative way is to blend it with other polymers. Although chemical modification of a polymer, for instance,...

Plastic shaping by means of IR heating and direct pellet molding.
July 1, 2006... INTRODUCTION In recent years the wide application of plastics has led to the development of a lot of studies about polymer processing, to improve the product quality. In fact, it deeply depends on the manufacturing method and on process...

Crystallization and thermal behavior of microcellular injection-molded polyamide-6 nanocomposites.
July 1, 2006... INTRODUCTION Polyamide-6 (PA6)/montmorillonite (MMT) nanocomposites have attracted much attention because of the inherent compatibility between the polymer and the silicate nanoclay that involves ionic bonds and of their outstanding...

Development of a constitutive relation for elastomers exhibiting self-reinforcement.
July 1, 2006... INTRODUCTION Elastomers and hydrogels are promising materials for many bioengineering applications, such as balloon catheters, electronic lead insulation, lubricious coatings, and cartilage replacements. A difficulty in implementing...

Dynamic-mechanical behavior of hydrophobic-hydrophilic interpenetrating copolymer networks.
July 1, 2006... INTRODUCTION The poor mechanical properties of polymer hydrogels are a major problem in the expansion of their applications. Nevertheless polymeric materials with microphase-separated morphologies such as block copolymers in which...

High-frequency proximity heating for injection molding applications.
July 1, 2006... INTRODUCTION It is a common practice in thermoplastic injection molding that the mold temperature stays at a preset constant temperature well below the softening temperature of the thermoplastic polymer. Auxiliary heating and chilling...

Utilization of flyash as filler for Polybutyleneterepthalate-toughened epoxy resin.
July 1, 2006... INTRODUCTION Epoxy resins are considered to be the most important class of thermosetting polymers and are extensively used in coatings, adhesives, and in several other engineering applications. Once these epoxy resins are cured, they...

Electric current as a control variable in the electrospinning process.
July 1, 2006... INTRODUCTION Electrospinning is an effective process to make submicron-diameter polymer fibers. In conventional fiber spinning processes, such as melt spinning, dry spinning, or wet spinning, mechanical forces are used to extrude a viscous...

Modeling of rotational molding process: multi-layer slip-flow model, phase-change, and warpage.
July 1, 2006... INTRODUCTION Rotational molding or rotomolding is a method for producing hollow, one-piece articles by using heat and biaxial rotation. The kinematics of the mold and the energy exchange of the polymer with its surroundings are the key...

Simulation of the percolation of water into rigid polyurethane foams at applied hydraulic pressures.
July 1, 2006... INTRODUCTION Rigid polyurethane foams are used primarily for thermal insulation, construction, and packaging [1, 2]. Rigid polyurethane foams, which are resistant to penetration by water at high hydraulic pressures, can be used for...