Polymer Engineering and Science articles from June 2006

Polymer Engineering and Science archives from June 2006

Less-ordered lamellar structure of intercalated poly(L-lactide)/organo-modified montmorillonite hybrids.
June 1, 2006... INTRODUCTION Recent development in polymer/clay hybrids (PCHs) has shown a high potential for ever-expanding versatile applications of polymeric materials [1-3]. The PCHs loaded with several percents of nanometer-sized clay minerals...

Theoretical and experimental studies of anisotropic shrinkage in injection moldings of semicrystalline polymers.
June 1, 2006... INTRODUCTION Shrinkage of injection-molded parts of semicrystalline thermoplastics is affected by the volumetric shrinkage, flow-induced residual stresses and orientation, flow-induced crystallization, and heat transfer. Since all these...

Vapor-induced crystallization behavior of bisphenol-A polycarbonate.
June 1, 2006... INTRODUCTION The crystallization behavior of bisphenol-A polycarbonate (BAPC) is of considerable scientific and technical interest and has been extensively investigated [1-8]. It is well known that the ability of polymers to crystallize...

Influence of processing aids on the uniaxial extensional behavior of metallocene polyethylenes.
June 1, 2006... INTRODUCTION It has been reported in the literature that metallocene polyethylenes (mPEs) exhibit complicated flow behavior within dies of processing equipments and/or capillary rheometers. The causes of these complications could be amid...

On the in-situ polymerization of cyclic butylene terephthalate oligomers: DSC and rheological studies.
June 1, 2006... INTRODUCTION During the last decade, continuous fiber-reinforced thermoset polymer composites monopolized various applications viz. aerospace, aircraft, automotive, sports, and leisure. One of the main advantages of thermoset resins is the...

Mathematical modeling and numerical simulation for nucleated solution flow through slit die in foam extrusion.
June 1, 2006... INTRODUCTION Continuous polymeric foam extrusion process involves flow of gas-dissolved polymer through a die. Producing a well-foamed, freely expanded product requires processing conditions that would shift the foaming point to the die...

Characterization of the fracture behavior of polyethylene using measured cohesive curves. I: effects of constraint and rate.
June 1, 2006... INTRODUCTION The occurrence of crazing in semicrystalline polymers, particularly in polyethylene, is well documented [1, 2]. For recently developed tough grades of polyethylene used for the transportation of gas and water, field failures...

Characterization of the fracture behavior of polyethylene using measured cohesive curves. II. Variation of cohesive parameters with rate and constraint.
June 1, 2006... INTRODUCTION In recent years, the cohesive zone model (CZM) has been put forward to address the limitation associated with linear elastic fracture mechanics in characterizing tough polymers. This is due to the extensive plasticity (plastic...

Characterization of the fracture behavior of polyethylene using measured cohesive curves. III. Structure-property relationships.
June 1, 2006... INTRODUCTION It has been well documented that the long term fracture properties of polyethylene pipe used in the transportation of gas and water are governed by a slow crack growth (SCG) process [1-3]. Investigation [4] has shown that the...

Calcium borate flame retardation system for epoxy molding compounds.
June 1, 2006... INTRODUCTION Epoxy molding compounds (EMCs) are widely used to encapsulate semiconductor devices due to superior properties such as high mechanical strength and high productivity [1, 2]. For application to semiconductor packaging, flame...

Morphology and mechanical properties of melt drawn chopped UHMWPE fiber/HDPE blends.
June 1, 2006... INTRODUCTION Our previous studies of ultrahigh molecular weight polyethylene/polyethylene (UHMWPE/PE) single polymer composites [1, 2] have underlined the critical role of the molding pressure in preventing fiber relaxation. In turn, the...

Mechanical properties of plastic-bonded explosive binder materials as a function of strain-rate and temperature.
June 1, 2006... INTRODUCTION It is well-known that increasing the strain-rate strongly affects the mechanical response of polymers in tension [1-3] and compression [4-6]. Increasing the strain rate leads to higher moduli because the polymer chains have...

Effects of ball milling dispersion of nano-Si[O.sub.x] particles on impact strength and crystallization behavior of nano-Si[O.sub.x]-poly(phenylene sulfide) nanocomposites.
June 1, 2006... INTRODUCTION Most recent studies on poly(phenylene sulfide) (PPS) polymer have been concentrated on its crystal structures and thermal properties [1-6], and only a few studies were focused on improvement in impact performance [7-11]....