Polymer Engineering and Science articles from April 2004

Polymer Engineering and Science archives from April 2004

Relationships between processing conditions and rheological behavior of polyethylenes.
April 1, 2004... INTRODUCTION Despite numerous papers describing the rheological properties of polyethylenes (PEs), the interest in this popular class of polymers remains rather strong, especially with respect to processing-properties and molecular...

Formation of a fibrillar morphology of crosslinked epoxy in a polystyrene continuous phase by reactive extrusion.
April 1, 2004... INTRODUCTION The morphology of immiscible polymer blends has a great influence on their mechanical and specific properties. This is the reason why studies seeking to elucidate morphology development and control are numerous in the...

Processing characteristics and mechanical properties of metallocene catalyzed linear low-density polyethylene foams for rotational molding.
April 1, 2004... INTRODUCTION The total amount of plastic foam used in the United States has increased 30 times within twenty-five years (1), penetrating the automotive, transport, building, construction, marine, medical, sports, and leisure markets....

Reactive blending of functionalized polypropylene and polyamide 6: in situ polymerization and in situ compatibilization.
April 1, 2004... INTRODUCTION The development of new materials through polymer blending has become an increasingly important industrial activity over the past two decades. This method allows for the tailoring of product properties in a way that is more...

Rheological study of the influence of branch content on the miscibility of octene m-LLDPE and ZN-LLDPE in LDPE.
April 1, 2004... INTRODUCTION The miscibility of blends of polyethylenes has received a great deal of attention during the past decade, due to its significance to the understanding of processing and final properties of blends containing different types of...

Study of injection molded microcellular polyamide-6 nanocomposites.
April 1, 2004... INTRODUCTION Polyamide-6 (PA-6) has been widely used in electronics, consumer products, and engineering parts. PA-6/clay nanocomposite also represents a new type of high-performance material, in which platelets of montmorillonite (MMT)...

Interface evolution and penetration behavior during two-component transfer molding. Part I: modeling and formulation.
April 1, 2004... INTRODUCTION Transfer molding is mainly utilized to mold products from thermosetting resins and rubbers. It is related to compression and injection molding. The method is like compression molding in that the plastic is cured into an...

Interface evolution and penetration behavior during two-component transfer molding. Part II: simulation and experiment.
April 1, 2004... INTRODUCTION Transfer molding is a process for molding thermosets and rubber products. Thermoset resin is placed into a transfer chamber where the resin is heated until a point of plasticity. A plunger then forces the liquid resin,...

Comparison of methods for the detection of cocontinuity in poly(ethylene oxide)/polystyrene blends.
April 1, 2004... INTRODUCTION Polymer blends offer an important route to materials with unique combinations of properties not available in a single polymer (1). In many cases, the polymers are immiscible, leading to phase separation at equilibrium (2)....

Simulation and experimental study of microwave heating of single lap adhesive-bonded polypropylene joint.
April 1, 2004... INTRODUCTION Adhesive bonding is one of the most widely used and successful methods of joining a variety of materials of engineering interest for structural and non-structural applications. Since engineering plastics are increasingly used...

Effect of composition on the solution rheology of stearyl methacrylate-co-styrene-co-vinyl pyrrolidinone in paraffinic base oil.
April 1, 2004... INTRODUCTION Research in lubricating oil technology throughout the world is increasingly directed towards additives, which can have more than one purpose and act not only as VII but also as pour-point depressants, dispersants,...

Composite droplets with core/shell morphologies prepared from HDPE/PS/PMMA ternary blends by twin-screw extrusion.
April 1, 2004... INTRODUCTION Blending two or more polymers is a common approach to develop new polymeric materials with customized properties. Generally, these systems are composed of two immiscible polymers and display a matrix/dispersed phase...

Vibration welding of nylon 6 to nylon 66.
April 1, 2004... INTRODUCTION Vibration welding is used in the automotive industry to manufacture various components such as air intake manifolds and resonators. These components are often injection molded as two or more nylon subcomponents and then...

Structure-property relationship in polyaniline-filled castor oil based chain extended polyurethanes.
April 1, 2004... INTRODUCTION The physical and chemical properties of polymer mixtures are of commercial and academic interest, since they provide a convenient route for modifying polymer properties to meet specific needs. Among these methods, chain...

Study of particle trajectories, residence times and flow behavior in kneading discs of intermeshing co-rotating twin-screw extruders.
April 1, 2004... INTRODUCTION The problem of polymer mixing involves the aspects of fluid dynamics and rheology. Mixing is usually obtained through a combination of mechanical motion of the mixing device and the resulting deformation induced in the flowing...

Improved properties of blends of ultrasonically treated unfilled polyurethane rubber.
April 1, 2004... INTRODUCTION One of the most crucial problems faced in this era of rapid development and economic growth is the problem of waste management. The major problem encountered with the recycling of thermosets is that, unlike thermoplastics,...

Real-time monitoring of fluorescence anisotropy and temperature during processing of biaxially stretched polypropylene film (1).
April 1, 2004... INTRODUCTION Biaxially stretched polyolefin films are used extensively in packaging applications. For food packaging in particular, barrier properties for oxygen and water vapor are critical for maintaining shelf life, and mechanical and...

Birefringence prediction of optical media.
April 1, 2004... INTRODUCTION Optical media such as compact discs (CDs) and digital video discs (DVDs) are typically injection-compression molded with an optical grade of polycarbonate (PC). One critical quality of the mass produced optical media is...