Polymer Engineering and Science articles from August 2005

Polymer Engineering and Science archives from August 2005

Peculiarities in the solvent absorption characteristics of epoxy-siloxane hybrids.
August 1, 2005... INTRODUCTION Epoxy-silica hybrids are produced by the sol-gel method from mixtures of epoxy resins and tetralkoxysilanes [1-5]. The organic and inorganic components of these materials are present as co-continuous nanostructured phases,...

Gas assisted injection molding of a handle: three-dimensional simulation and experimental verification.
August 1, 2005... INTRODUCTION Gas assisted injection molding (GAIM) is an important development of the traditional process, which uses pressurized gas to displace molten polymer from the thicker sections of the molding. It is used to produce essentially...

Fracture toughness evaluation of adjacent flow weld line in polystyrene by the SENB method.
August 1, 2005... INTRODUCTION Weld lines that occur wherever two or more melt fronts meet cause reduction of mechanical properties and visual defects in injection moldings. The reduction of mechanical properties is considered to be caused by several...

Reactivity of Si-H and Si-Vinyl end functionalized siloxanes toward PBT: a model system study.(polybutylene terephthalate)
August 1, 2005... INTRODUCTION Thermoplastic elastomers are interesting materials combining the processability and recyclability of thermoplastics with the unique mechanical properties of cured elastomers [1, 2]. Reactive blending is a method of choice to...

Electrospinning of methacrylate-based copolymers: effects of solution concentration and applied electrical potential on morphological appearance of as-spun fibers.
August 1, 2005... INTRODUCTION In recent years, much interest has been paid to the development of and exploration for applying high electrostatic potentials in fabricating ultrafine fibers. This process is known as electrostatic spinning or electrospinning,...

Sulfonated poly(ether ketone ketone) ionomers as proton exchange membranes.
August 1, 2005... INTRODUCTION Fuel cells represent an attractive alternative to conventional methods for generating remote power, such as the combustion of fossil fuels or batteries. They have no moving parts, relatively low fuel costs, and do not emit...

Empirical formulas for distributions of air velocity/temperature along the spinline of a dual slot die.
August 1, 2005... INTRODUCTION Melt-blowing is an important single-step technology for converting polymer resin into nonwoven webs with microfiber structure. The dual slot melt-blowing die is commonly used in industry, having the configuration shown in Fig....

The effect of nanoclays on the processibility of polyolefins.
August 1, 2005... INTRODUCTION In the extrusion of thermoplastics including polyethylenes and polypropylenes to make useful products and articles such as wire coatings, tubes, bottles, and films, it is desirable that the final products have smooth and...

Rheology studies of polyethylene/chemical blowing agent solutions within an injection molding machine.
August 1, 2005... INTRODUCTION Polymeric structural foams have been widely used in automotive, aerospace, construction, electronic, and packaging industries, because of their low density, high impact strength, and insulation properties. However, recent...

Increased flow property of polycarbonate by adding hollow glass beads.
August 1, 2005... INTRODUCTION Filled polymers containing solid particulate fillers dispersed in a polymeric matrix are frequently employed in the plastics industry in order to enhance the mechanical properties and reduce the cost. The processibility of...

Prediction of residual stresses in cross-linked polyethylene cable insulation.
August 1, 2005... INTRODUCTION Cooling of polymer products is often a problematic manufacturing stage as it introduces residual stresses into the material. In particular, for high-voltage cable insulation the knowledge of such stresses is desirable as it...

Crystallization and melting behavior of homogeneous and heterogeneous linear low-density polyethylene resins.
August 1, 2005... INTRODUCTION Polymer molecular structural characteristics and processing conditions have significant effects on the crystallization behavior of semicrystalline polymers. Linear low-density polyethylene (LLDPE) has complex molecular...

Thermal and rheological properties of maleated polypropylene modified asphalt.
August 1, 2005... INTRODUCTION The limitations to the applications of asphalt binder in the paving industry are due to its intrinsic properties and inherent weaknesses that make the maintenance of a pavement system difficult and expensive. Since the...

Defining the configuration of co-rotating twin-screw extruders with multiobjective evolutionary algorithms.
August 1, 2005... INTRODUCTION The progressive use of plastics in applications with more stringent specifications requires the development of systems with innovative polymer matrices and additives. This is usually accomplished through compounding and/or...

Nucleation effect of polyamide on polyoxymethylene.
August 1, 2005... INTRODUCTION In the mold processing of polymers, crystallization is a universal phenomenon, especially for polymers with regular molecular chains. Differences of crystallinity, crystal structure, and morphology will influence the...

Evaluation of mechanical properties of Adjacent flow weldline.
August 1, 2005... INTRODUCTION Weldlines that occur wherever two or more melt fronts meet cause reduction of mechanical properties and visual defects in injection moldings. The reduction of mechanical properties is considered to be caused by several factors...