Polymer Engineering and Science articles from February 2006

Polymer Engineering and Science archives from February 2006

Novel aromatic polyimide fiber with biphenyl side-groups: dope synthesis and filament internal morphology control.
February 1, 2006... INTRODUCTION High-performance polymeric fibers with high-strength, high-modulus, and heat-resistance properties have undergone significant growth and development in the last two decades. Linear aromatic polyimides are finding increasing...

Kinetic analysis of thermo-oxidative degradation of PEEK/thermotropic liquid crystalline polymer blends.
February 1, 2006... INTRODUCTION Poly(aryl ether ether ketone), PEEK, is a high-performance engineering thermoplastic with applications in the aeronautical and aerospace industries [1, 2]. Because of its outstanding properties, it has been frequently employed...

Torque-rheometry investigation of model transreactions involving condensation polymers. I. Polyesters.
February 1, 2006... INTRODUCTION The importance of transreactions for the molecular weight control of condensation polymers was first recognized by Paul Flory about sixty years ago [1]. Shortly afterwards, it was appreciated that the transreactions involving...

Chemically foaming of biodegradable poly(propylene carbonate) derived from carbon dioxide and propylene oxide.
February 1, 2006... INTRODUCTION As a carbon source, carbon dioxide (C[O.sub.2]) has attracted much attention in both scientific and practical interests in recent years. On the other hand, it is a matter of concern that C[O.sub.2] gives about 66% contribution...

On the injection molding of nanostructured polymer surfaces.
February 1, 2006... INTRODUCTION Recent years have shown an ever-increasing interest in topographically nanostructured polymer surfaces. Their current and projected applications include mass storage (Compact Disc/Digital Versatile Disc), nanolithography...

Structure and mechanical properties of compatibilized poly(ethylene terephthalate)/poly(ethylene octene) blends.
February 1, 2006... INTRODUCTION It is known that the applications of many semicrystalline thermoplastics are often limited by their low notched impact strength. This is the reason for the efforts devoted to obtain impact resistant polymers by blending them...

The local thermomechanical conditions and the fracture behavior of an injection-molded poly(oxymethylene).
February 1, 2006... INTRODUCTION The mechanical properties of processed semicrystalline polymers are strongly dependent upon their morphology (e.g., layered microstructure, degree of crystallinity, and level of molecular orientation) [1-3]. This morphology is...

Flexible supercritical C[O.sub.2]-assisted process for poly(methyl methacrylate) structure formation.
February 1, 2006... INTRODUCTION A polymer largely used in biomedical applications is poly(methyl methacrylate) (PMMA). It has a good degree of compatibility with human tissues and can be used for the replacement of intraocular lenses when the original lens...

Effect of the axial vibration of screw on residence time distribution in single-screw extruders.
February 1, 2006... INTRODUCTION Screws are typical parts of polymer processing machines. The mixing effect of melt in the screw channel of a single-screw extruder can directly influence the properties of the extrusion products. For conventional extruders,...

Effect of heat-sealing temperature on the failure criteria of oriented polypropylene/cast polypropylene heat seal.
February 1, 2006... INTRODUCTION Packaging materials made of laminate films are often shaped in the form of bags or pouches. Several types of sealing technologies such as chemical adhesives, ultrasonic welding, heat sealing, impulse heat sealing (IHS), hot...

Hydrothermal effects on the thermomechanical properties of high performance epoxy/clay nanocomposites.
February 1, 2006... INTRODUCTION Epoxy resins are known to exhibit excellent engineering properties, such as high stiffness and strength, creep resistance, and chemical resistance. They have been widely used as matrices of polymer composites with carbon...

High-temperature mastication of raw natural rubber: changes in macrostructure and mesostructure.
February 1, 2006... INTRODUCTION A series of operations are normally necessary before an article of vulcanized rubber could be obtained from raw natural rubber (NR), the regularity and mastery of each of which significantly influences the properties of the...

Elimination of orientation in perfluorinated ionomer membranes.
February 1, 2006... INTRODUCTION Perfluorinated ionomer membranes (PIMs), which consist of sulfonic acid groups periodically substituted along a polytetrafluoroethylene backbone, are of great commercial interest because of their utility as membrane separators...