Polymer Engineering and Science articles from November 2007

Polymer Engineering and Science archives from November 2007

Crystallization behaviors and mechanical properties of poly(ethylene 2,6-naphthalate)/multiwall carbon nanotube nanocomposites.(Technical report)
November 1, 2007... INTRODUCTION Poly(ethylene 2,6-naphathalate) (PEN) is an aromatic polyester having a similar chemical structure to poly(ethylene terephthalate) (PET) that is widely utilized in the industries. The introduction of naphthalene ring into the...

Effect of thermal aging on the crystal structural characteristics of poly(tetra fluoro ethylene).(Technical report)
November 1, 2007... INTRODUCTION Study on the thermal aging behavior of polymeric materials has been a topic of interest [1-3] primarily because of the possible influence of such aging on their initial properties, subsequent behavior, and performance. In the...

Ultrasonic measurement of residual wall thickness during gas assisted injection molding.(Technical report)
November 1, 2007... INTRODUCTION An ultrasonic measurement technique has been employed during gas assisted injection molding (GAIM). GAIM is a high added value injection molding process involving partial filling of the injection-molding cavity with polymer...

Influence of different process and material parameters on chemical foaming of fluorinated ethylene propylene copolymers.(Technical report)
November 1, 2007... INTRODUCTION Though physical foaming of fluorinated ethylene propylene copolymers, e.g., for coaxial cables, is state-of-the-art in many manufacturing processes today, rather no fundamental knowledge is available about its foaming by means...

Preparation and properties of benzophenone chromophoric group branched polymer for self-decontamination.(Technical report)
November 1, 2007... INTRODUCTION Advances in science and technology have enabled humans to exploit natural resources to a great extent, generating unprecedented disturbances in global elemental cycles. The relatively recent introduction of anthropogenic toxic...

Synergistic effects of expandable graphite with magnesium hydroxide on the flame retardancy and thermal properties of polypropylene.(Technical report)
November 1, 2007... INTRODUCTION Traditionally, halogen containing compounds, alone or in conjunction with antimony trioxide, are the main flame retardants (FR) of polyolefins (PO). There is an increasingly restriction about the use of halogen containing...

Photoinitiated crosslinking of Ethylene-vinyl acetate copolymers and characterization of related properties.(Technical report)
November 1, 2007... INTRODUCTION Ethylene-vinyl acetate (EVA) is a random copolymer consisting of ethylene and vinyl acetate (VA) as repeating units [1], which has excellent ozone resistance, weather resistance, and excellent electrical properties [2]. EVA is...

Eco-plastics: morphological and mechanical properties of recycled poly(carbonate)-crushed rubber (rPC-CR) blends.(Technical report)
November 1, 2007... INTRODUCTION Because of both economical and environmental reasons, there is an important need to find a second life use for all wastes. Among all end of life rubber goods, used tires constitute one of the largest source of rubber wastes....

Dynamic viscoelastic properties of fluoroelastomer/clay nanocomposites.(Technical report)
November 1, 2007... INTRODUCTION Polymer-clay nanocomposites possess unique properties because of their nanometer sized features. They show improved mechanical properties [1-3], ionic conductivity [4], flammability resistance [5], and gas barrier properties...

Anisotropic shrinkage of injection molded Poly Vinylidene Fluoride samples.(Technical report)
November 1, 2007... INTRODUCTION The dimensions of injection-molded products, measured after molding, differ from the corresponding local mold dimensions, and these differences depend on material characteristics as well as on processing conditions. The...

Flexural and tensile moduli of polypropylene nanocomposites and comparison of experimental data to Halpin-Tsai and Tandon-Weng models.(Technical report)
November 1, 2007... INTRODUCTION Nanocomposites were first introduced to the scientific community in 1987 by a research group at Toyota who fabricated a nylon 6-clay platelet nanocomposite [1, 2]. Since then nanocomposites research has flourished and a...

Crosslinking of rotational molding foams of polyethylene.(Technical report)
November 1, 2007... INTRODUCTION The rotational molding processing of plastics is commonly employed to obtain one-piece hollow plastic articles. This is a relatively simple process where large hollow objects with low levels of residual stress are obtained....

Thermal and mechanical degradation during polymer extrusion processing.(Technical report)
November 1, 2007... INTRODUCTION The processing of polymers generally induces consistent thermal and mechanical stresses to the materials. In high productivity processes such as extrusion, calendering, injection moulding the polymers are heated at temperature...

Poly(ethylene terephthalate) nanocomposite fibers with new organomica via in situ intercalation.(Technical report)
November 1, 2007... INTRODUCTION Nano-scale composites of polymers with organoclays have been studied extensively [1-3]. Nano-structured materials often possess a combination of physical and mechanical properties that are not present in conventional polymer...

Evaluation of the interfacial state in high impact polystyrene through dynamic mechanical analysis as a function of the synthesis conditions.(Technical report)
November 1, 2007... INTRODUCTION Rubber-modified polystyrene often called high impact polystyrene (HIPS), is a complex toughened heterophase composite consisting of a continuous rigid polystyrene (PS) phase and a disperse rubber phase. The particle size of...

A stochastic flow model for a tubular solution polymerization reactor.(Technical report)
November 1, 2007... INTRODUCTION The engineering of polymerization reactors may constitute a very complex issue, as it depends on countless aspects, such as the polymerization kinetics (reaction mechanism), physical properties related to transport phenomena...

Effect of melt processing conditions on the morphology and properties of nylon 6 nanocomposites.(Technical report)
November 1, 2007... INTRODUCTION Research on polymer-layered silicate nanocomposites has been intense over the last few years as a result of the potentially superior properties that these materials can exhibit compared to conventional composites. Numerous...

Controllable fabrication and properties of polypropylene nanofibers.(Technical report)
November 1, 2007... INTRODUCTION Polypropylene (PP) and modified PP fibers have a wide range of applications such as filter media, sanitary textiles, soft tissue replacement materials, antistatic materials, and reinforced composite materials [1-7]. The size...

Mechanical properties of wollastonite-reinforced polypropylene composites modified with SEBS and SEBS-g-MA elastomers.(polystyrene-b-ethylene-co-butylene-b-styrene triblock copolymer)(SEBS grafted with maleic anhydride)(Technical report)
November 1, 2007... INTRODUCTION The multicomponent polymer composites have gained a huge interest for a quite long time in comparison with other materials. They are used in large quantities, especially in automotive and construction industry. The...

Modification of epoxy resin by addition of bismaleimide and diallyl phthalate.(Technical report)
November 1, 2007... INTRODUCTION Epoxy resins are used in a large number of applications such as surface coatings, adhesives, electronics, and laminates, and to a small extent in molding powders and in road surfacing [1-4]. These are a highly versatile class...

The effect of nanoclays on the nucleation, crystallization, and melting mechanisms of isotactic polypropylene.(Technical report)
November 1, 2007... INTRODUCTION Polymeric clay-based nanocomposites are one of the newest polymeric systems. They consist of a polymeric matrix and a disperse nanometric layerlike additive, such as montmorillonite, the combination representing the...

Extruded starch-nanoclay nanocomposites: effects of glycerol and nanoclay concentration.(Technical report)
November 1, 2007... INTRODUCTION There have been an increasing number of studies focusing on using melt intercalation to produce polymernanoclay composites. Melt intercalation occurs when polymer chains penetrate into the clay interlayer during processing....

Rheological, mechanical and thermal properties of propylene-ethylene block copolymer/polyalphaolefins blends.(Technical report)
November 1, 2007... INTRODUCTION Isotactic polypropylene (iPP) is widely used in many applications because of its outstanding properties such as high heat resistance, high mechanical strength, easy processability, and low price. However, its application for...

Localized effects of dynamic melt manipulation on flow induced orientation and mechanical performance of injection molded products.(Technical report)
November 1, 2007... INTRODUCTION Injection molding processing is one of the most common manufacturing techniques for polymer products. While there are many types of molded plastic products that affect our daily lives, the 10 largest molders in the U.S. focus...

Comparison between surface renewal devolatilizing performances of different screw extruders.(Technical report)
November 1, 2007... INTRODUCTION The polymer devolatilization (DV) in screw extruder mainly includes the following three contents: flash DV, stripping-agent-added DV and surface renewal DV (SRDV). These separating techniques are jointly or severally used...

Comparison of vertical and horizontal slot die coatings.(Technical report)
November 1, 2007... INTRODUCTION Slot die coating technology was invented by Beguin [1] for the production of photographic films and papers. It is a versatile and flexible means of coating for many industrial products. Recently, this method has been modified...

Development of freeze flow apparatus to study filled polymer melts.(Technical report)
November 1, 2007... INTRODUCTION The addition of filler particles to a transparent polymer melt, even in small quantities, severely hampers the use of optical techniques, as transmission of light through the material is restricted. To study the orientation of...

Influence of epoxy resin on the morphological and rheological properties of PBT/ABS blends compatibilized by ASMA.(polybutylene terephthalate, acrylonitrile-butadiene-styrene, styrene-acrylonitrile-maleic anhydride)(Technical report)
November 1, 2007... INTRODUCTION As a commodity crystalline polymer, polybutylene terephthalate (PBT) has been widely used in the automotive and electronic industries due to its excellent properties in terms of rigidity, hardness, abrasion resistance,...

Slow crack growth-notches-pressurized polyethylene pipes.(Technical report)
November 1, 2007... INTRODUCTION A general method for predicting the lifetime of a structure that consists of linear polyethylene (PE) and fails by slow crack growth (SCG) has been developed by Brown [1]. For example, SCG failures can be predicted in gas...

A short review on rubber/clay nanocomposites with emphasis on mechanical properties.(Technical report)
November 1, 2007... INTRODUCTION The words "nanocomposites," "nanomaterials," and "nanofillers" are fairly recent but such materials were in use from the beginning of this century (for example, carbon black is being used as a reinforcing filler in rubbers...