Polymer Engineering and Science articles from July 2007

Polymer Engineering and Science archives from July 2007

Processing and physical properties of native grass-reinforced biocomposites.
July 1, 2007... INTRODUCTION The use of biomass to develop plastic or composite materials for useful applications is becoming a fashion strategy because it is expected to reduce the dependence on nonrenewable resources and to alleviate the crisis of...

Measurement and prediction of thermal conductivity for hemp fiber reinforced composites.
July 1, 2007... INTRODUCTION In the past few years, new research materials are being generated on the potential of cellulosic based fibers as reinforcement for plastics. All researchers who have worked in the area of natural fibers and their composites...

Relaxation behavior of conductive carbon black reinforced EPDM microcellular vulcanizates.(ethylene propylene diene monomer)
July 1, 2007... INTRODUCTION Conductive polymer composites have received considerable attention due to their technological importance in a wide variety of applications such as electrostatic charge dissipate material in pressure sensitive sensor,...

Dynamic mechanical, rheological, and morphological studies of polyacrylate-graft-poly (vinyl chloride) suspension resin.
July 1, 2007... INTRODUCTION Poly (vinyl chloride) (PVC) is now one of the major polymers produced on a large scale in the world and has been extensively used because of its relatively low cost and high versatility. Generally, PVC is inherently ductile...

Mechanism of a one-step method for preparing silane grafting and cross-linking polypropylene.
July 1, 2007... INTRODUCTION The silane cross-linking technique offers technological advantages over radiation and peroxide-cross-linking technique and improves many useful properties of cross-linked polymers (such as polyethylene and propylene--ethylene...

Rheological, thermal, and morphological properties of blends based on poly(propylene), ethylene propylene rubber, and ethylene-1-octene copolymer that could result from end of life vehicles: effect of maleic anhydride grafted poly(propylene).
July 1, 2007... INTRODUCTION Many problems arising for the recycling of polymers are related to the purity of the matter that can be affected not only by the technology of sorting but also by the sticked parts and the formulas used. Polymer blends are...

Effects of polymerization medium on electrical conductivity and optical properties of organic semiconductor-based polypyrrole.
July 1, 2007... INTRODUCTION Electronic and optical properties of [pi]-conjugated polymers are a subject of recent interest and these polymers constitute an emerging new class of materials. Among organic conducting polymers, polypyrrole (PPy) and...

Highly transparent polypropylene cast films: relationships between optical properties, additives, and surface structure.
July 1, 2007... INTRODUCTION Polyolefin films have found widespread industrial use with a main field of application being packaging. Because of economic reasons, this market segment is continually growing, particularly for polypropylene (PP) cast films....

Study of melt compounding conditions and characterization of polyamide 6/metallocene ethylene-polypropylene-diene copolymer/maleated ethylene-polypropylene-diene copolymer blends reinforced with layered silicates.
July 1, 2007... INTRODUCTION Engineering plastics such as polyamides are usually used in industrial applications because of both their thermomechanical properties and processability. However, these materials have a pseudoductile behavior with low impact...

Quantification of the melting process in a co-rotating twin-screw extruder: a hybrid modeling approach.
July 1, 2007... INTRODUCTION Reactive extrusion processes are increasingly used in the polymer processing industry for producing and modifying commercial polymers and blends. These processes involve carrying out chemical reactions deliberately in...

Nonisothermal crystallization behavior and nucleation of LDPE/Al nano- and microcomposites.(low-density polyethylene, aluminum)
July 1, 2007... INTRODUCTION Particle-filled polymer composites are important commercial materials used in a diverse range of applications such as automotive industry, pipes, and electrical insulators. At present, the development of traditional...

Failure characterization of polypropylene block copolymer welded joints.
July 1, 2007... INTRODUCTION The joining or assembly of polymeric components is a critical manufacturing step. With the increasing demands for plastics and their composites used as components, the requirements for joining them have increased. The essence...

Cell structure and dynamic properties of injection molded polypropylene foams.
July 1, 2007... INTRODUCTION Injection of foaming polymers, and especially microcellular foams, has raised much interest over recent years because of its numerous advantages over conventional injection molding, such as part dimensional stability, lower...

Photopolymerization and initiating mechanism of Michael addition oligomers without photoinitiator.
July 1, 2007... INTRODUCTION Ultroviolet (UV) curing technology has been widely used in many industrial applications because of its unique features [1, 2], which include fast cure speed, energy saving, low VOC, and a high quality of the products obtained....

Reclaiming of ground rubber tire by a novel reclaiming agent. I. virgin natural rubber/reclaimed GRT vulcanizates.(ground rubber tire)
July 1, 2007... INTRODUCTION In the twenty-first century, recycling of waste materials is of growing importance for all the industries in the world. The automotive and transportation industries are the biggest consumers of new rubber products. Rubber...

Mechanical and oxygen barrier properties of organoclay-polyethylene nanocomposite films.
July 1, 2007... INTRODUCTION Organoclay consists of particles of one to a few nanometers thick but hundreds nanometers long. When incorporated into polymers, the large aspect ratio nanoparticles are expected to significantly enhance the polymer properties...

Digital image processing method for measuring the residence time distribution in a plasticating extruder.
July 1, 2007... INTRODUCTION Extrusion is one of the most common processing ways in the polymer industry to compound and shape the plastics, rubber, and fibers. The quality of the product is related with the time of the material in the extruder. For...

High performance structured polymer barrier films obtained from compatibilized polypropylene/ethylene vinyl alcohol blends.
July 1, 2007... INTRODUCTION It is a big challenge to tailor a packaging material or a gasoline tank that meets specific requirements such as barrier or mechanical properties, while being easy and cheap to process. The manufacturing of plastic packaging...

Towards textile-based fiber-reinforced thermoplastic nanocomposites: melt spun polypropylene-montmorillonite nanocomposite fibers.
July 1, 2007... INTRODUCTION A wide range of property improvements has been reported in thermoplastic montmorillonite (MMT) clay-based nanocomposites, including increased dimensional stability, heat distortion temperature, stiffness, strength, and flame...

The rheological and physical properties of linear and branched polypropylene blends.
July 1, 2007... INTRODUCTION Polypropylene (PP) is widely used in many processing applications, including extrusion and injection molding. However, PP melts generally do not exhibit the strain hardening behavior necessary for processes that require high...

Effect of processing conditions on morphology and mechanical properties of injection-molded poly(L-lactic acid).
July 1, 2007... INTRODUCTION Poly(lactic acid) (PLA) is a biodegradable aliphatic polyester derived from 100% renewable resources [1]. PLA offers a wide range of properties depending on its stereochemical make up [2]. It exists in two optical isomeric...

Effects of styrene-ethylene-butylene-styrene based additives on the mechanical properties of rice hull/polypropylene composites.(Author abstract)
July 1, 2007... INTRODUCTION Organic filler/polymer composites are widely used as a replacement for inorganic filler/polymer composites in various sectors such as the automotive, construction, and packaging industries. The advantages of organic...

An experimental study on improving the atomic oxygen resistance of epoxy resin/silica nanocomposites.
July 1, 2007... INTRODUCTION Atomic oxygen (AO) is the dominant component and the most active species of the low earth orbit (LEO) atmosphere. When the spacecrafts travel in LEO with a velocity of 7-8 km/s, the AO flux is around [10.sup.12] - [10.sup.15]...

A novel method to prepare zinc hydroxystannate-coated inorganic fillers and its effect on the fire properties of PVC cable materials.(polyvinyl-chloride)
July 1, 2007... INTRODUCTION Poly(vinyl chloride) (PVC) is a kind of thermoplastic, which has been used in various aspects, such as building materials, sealing strip, wire, and cable, etc. However, a large quantity of black smoke is produced when PVC is...

Analysis of row nucleated lamellar morphology of polypropylene obtained from the cast film process: effect of melt rheology and process conditions.
July 1, 2007... INTRODUCTION A row nucleated lamellar structure as an initial morphology has been a matter of concern for developing microporous membranes based on a three-stage process (melt-extrusion/annealing/uniaxial-stretching) [1, 2]. In this...