Polymer Engineering and Science articles from March 2003

Polymer Engineering and Science archives from March 2003

Theoretical influence of polyester molecular weight distribution variation on melt viscosity during injection molding and extrusion as influenced by ester-ester interchange.
March 1, 2003... INTRODUCTION In the last several decades a number of polyester polymers have been made available commercially, such as polyethylene terephthalate) PET, poly(hexam-ethylene terephathalate), poly(butylene terephthalate) PBT, poly(carbonate)...

Microcellular model evaluation for the deformation of dynamically vulcanized EPDM/iPP blends.(ethylene-propylene-diene monomer )
March 1, 2003... INTRODUCTION Thermoplastic vulcanizates have a unique morphology due to the process of dynamic vulcanization (1-3). This morphology, which has been investigated by many authors (4-10). consists of a chemically crosslinked rubber phase...

Ternary miscibility in blends of three polymers with balanced binary interactions.
March 1, 2003... INTRODUCTION Truly miscible ternary blends composed of three polymers differing in properties might offer a unique opportunity to develop a new polymer material with flexible combination from three constituents. An approach via ternary...

Essential Work of Fracture (EWF) analysis for short glass fiber reinforced and rubber toughened nylon-6.
March 1, 2003... INTRODUCTION With increasing demands for high fracture resistant polymers, impact modifiers, such as rubbers are added to brittle or semi-brittle polymers for toughening. However, the stiffness and yield strength of the rubber toughened...

A study on the use of phenoxy resins as compatibilizers of polyamide 6 (PA6) and polybutylene terephthalate (PBT).
March 1, 2003... INTRODUCTION In the past few decades, the rate of introduction of new polymers in the commercial market has declined as a result of usually unfavorable economics. instead, polymer blending and alloying has become a favorite alternative for...

Simulation of injection-compression molding for optical media.
March 1, 2003... INTRODUCTION Injection-compression molding is widely used in manufacturing of optical media, such as CD's and DVD's, using engineering thermoplastics. There are basically two types of injection-compression molding. One type is often...

Influence of intermolecular entanglements on crystallization behavior of ultra-high molar mass polyethylene.
March 1, 2003... INTRODUCTION Entanglement between macromolecular chains is a very important structural factor influencing the physical properties of polymers, and yet it is not fully understood from the perspective of both fundamental knowledge and...

In-situ microfiber reinforced composite based on PET and PE via slit die extrusion and hot stretching: influences of hot stretching ratio on morphology and tensile properties at a fixed composition.(polyethylene terephthalate)
March 1, 2003... INTRODUCTION It is well known that both the size and the shape of the dispersed phase in an incompatible polymer blend can significantly affect the mechanical properties, such as impact strength, tensile strength and impermeability to...

Multiple melting behavior of syndiotactic 1,2-polybutadiene.
March 1, 2003... INTRODUCTION Syndiotactic 1,2-polybutadiene, a typical thermoplastic elastomer, is widely used in various products such as wrapping films and shoe soles. The crystalline portion of syndiotactic 1,2-polybutadiene acts as a hard segment to...

Improvement of the mechanical properties of an HDPE/PS blend by compatibilization and incorporation of [CaCO.sub.3].(high density polyethylene)
March 1, 2003... INTRODUCTION Nowadays, most plastic wastes are made up of mixed plastics. Grinding, washing and sorting operations generally lead to industrial mixtures of two or more kinds of polymers. The production of materials based on polymer blends...

Synthesis and mechanical properties of unsaturated polyester based nanocomposites.
March 1, 2003... INTRODUCTION Polymer nanocomposites are a new class of composites in which the filler dimensions are in the range of 1 to 100 rim. Owing to the high aspect ratio of the fillers, mechanical, thermal, flame retardant and barrier properties...

Comparison between five experimental methods to evaluate interfacial tension between molten polymers.
March 1, 2003... INTRODUCTION When working with polymer blends, it is important to obtain at least partial compatibility between the components of the product. Polymer compatibility governs the adhesion and the condition of the interface and, therefore,...

Microstructure analysis of high performance fibers in compression.(polymers )
March 1, 2003... INTRODUCTION Continuous efforts to meet the requirements necessary for advanced composite systems have resulted in the development of high performance fibers such as carbon, DuPont Kevlar[TM], PBO, and M5. PBO fiber has recently been...

The influence of power-law rheology on flow distributions in coathanger manifolds. (1).
March 1, 2003... INTRODUCTION Sheeting dies are widely used in the plastics industry for manufacturing products as sheets and flat films. Although there are several types of sheeting die geometries, this paper focuses on the coathanger die geometry. The...

Transport of aromatic solvents through nitrile rubber/epoxidized natural rubber blend membranes.
March 1, 2003... INTRODUCTION The aim of blending two elastomers is to combine desirable attributes not available in a single elastomer, but often the outcome appears to be a combination of the weaknesses of the component elastomers rather than of their...

All-optical switching modulation in poly(vinyl carbazole)--based azobenzene blends.
March 1, 2003... INTRODUCTION In recent years, azobenzene-containing polymer systems have received increasing attention because of their unique and unexpected properties, which allow various applications triggered by light (1-5). One of the attractive...

Deformation behavior of an epoxy resin subject to multiaxial loadings. Part I: experimental investigations.
March 1, 2003... INTRODUCTION Polymer resins are widely used as adhesives or matrices in fiber-reinforced composites, with applications in a variety of industries, e.g., automotive, aerospace, oil and gas, and marine industries. Among the various types of...

Deformation behavior of an epoxy resin subject to multiaxial loadings. part II: constitutive modeling and predictions.
March 1, 2003... 1. INTRODUCTION The results presented in the companion paper, Part I (1), indicated that the tested epoxy had a similar behavior as other thermoset polymers, such as highly nonlinear viscoelasticity and loading path dependency. These...

Scratch visibility of polymers measured using optical imaging.
March 1, 2003... INTRODUCTION The automotive industry has been increasingly concerned about scratch and mar performance on exterior as well as interior automotive parts. A critical factor in the choice of materials (painted steel, plastics) will be the...