Polymer Engineering and Science articles from March 2008

Polymer Engineering and Science archives from March 2008

Investigations on the morphology and melt crystallization of poly(L-lactide)-poly(ethylene glycol) diblock copolymers.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Polymeric biomaterials are increasingly used in medicine for both permanent and temporary therapeutic applications. Among the various biodegradable polymers reported in literature [1, 2], linear aliphatic polyesters appear the...

Machining of plastics: a new approach for modeling.(Report)
March 1, 2008... INTRODUCTION Dealing with plastics, machining is becoming the most competitive process for small quantity production or for extremely complex and accurate shapes. In these cases, the ordinary molding processes are too expensive or not...

Effects of interactions among polyaniline, camphorsulfonic acid and silica on the structure and properties of their conductive hybrids.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Polyaniline (PAn) has attracted considerable attention because of its electrochromic, anti-static, reversible doping/dedoping, and environmentally stable properties [1-3]. It is different from other conjugated conducting...

High-density polyethylene reinforced with submicron titania particles.(Report)
March 1, 2008... INTRODUCTION In conventional microparticle-filled composites, a large amount of fillers (>20 vol%) is generally required to appreciably increase the elastic modulus and reduce the creep compliance of thermoplastic matrices [1]. However,...

Thermodynamic hydrogen bonding in poly(styrene-co-acrylic acid)/poly(styrene-co-4-N,N-dimethylacrylamide) blends.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Most polymer pairs do not mix in the absence of specific interactions; this limits the elaboration of new materials with improved properties from polymer mixtures. It is now a well-known method to enhance the miscibility of...

The structure-property relationship of novolac cured epoxy resin/clay nanocomposites.(Report)
March 1, 2008... INTRODUCTION Polymer/clay nanocomposites (PCNs) have been studied extensively since past two decades due to their outstanding improvement in the physical, mechanical, and chemical properties [1-7]. It has been shown that by incorporating...

Influence of phase modifiers on morphology and properties of thermoplastic elastomers prepared from ethylene propylene diene rubber and isotactic polypropylene.(Report)
March 1, 2008... INTRODUCTION There have been substantial developments in the field of polymer blends in the last three decades or so [1]. In such two-phase or multiphase polymeric materials, there is a strong relation between phase structure and end-use...

Experimental investigation of key parameters on the effects of cavity surface roughness in microinjection molding.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION In recent years, plastic microparts have been used extensively in various fields such as medical technology, biotechnology, optics, telecommunication, and microfluidics. Examples of products include pressure sensors,...

Anomalous mechanical behavior upon recycling of poly(phenylene-ether)-based thermoplastic elastomer.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Thermoplastic elastomers (TPEs) are one of the rapidly growing classes of materials because of their improved properties, easy processability, and economical advantages. These materials bridge the gap between the conventional...

PAN based quasi carbon whiskers reinforced PI polyblends: microhardness, mechanical, hydraulic, and morphological study.(Polyimide, Polyacrylonitrile)(Report)
March 1, 2008... INTRODUCTION Among the organic polymers, aromatic polyimide (PI), have various advantages, such as high thermal stability, high glass transition temperature ([T.sub.g]), high mechanical strength, etc. [1-3]. Most of the useful properties...

Characterization and crystallization behavior of poly(ethylene-co-trimethylene terephthalate) copolymers.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION As well-known, copolymerization is a successful way to obtain polymer materials which could combine the characteristics of each component or show a unique property [1-3]. Aromatic polyesters, including poly (ethylene...

Microdomain composition and properties differences of biodegradable polyurethanes based on MDI and HDI.(methylene diphenyl diisocyanate, hexamethylene diisocyanate)(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Segmented thermoplastic polyurethane elastomers (STPUE) have drawn the attention of many researches working in different fields due to the tunable properties of these materials. These copolymers can be described with a...

Microstructure changes in poly(ethylene terephthalate) in thick specimens under complex biaxial loading.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Poly(ethylene terephthalate) is a polymer that is widely used, in its semi-crystalline state, for tensile draw, roll drawing, or blow-molding processes. There are many reasons that can account for its popularity, (in...

Model-based melt flow virtual sensors for filling process of injection molding.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Motivated by users' demand on precision and quality molding, process sensing has become an active research focus in molding control community since around 1990. Currently, all commercially available sensors are for pressure...

Miscibility, crystallization behavior and specific intermolecular interactions in thermosetting polymer blends of novolac epoxy resin and polyethylene glycol.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Miscibility and thermal properties of binary thermosetting polymer blends containing a crystallizable component have attracted considerable interests during the past decades because of their academic and technical importance...

Nonuniformity of phase structure in immiscible polymer blends.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION It is well known that the phase structure of immiscible polymer blends strongly affects their properties. Therefore, is very important to control the phase structure during blend mixing and processing. At the beginning of the...

Properties of recycled material containing poly(vinyl chloride), polypropylene, and calcium carbonate nanofiller.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION The easiest way to recycle mixed plastic waste from laminates and composites is in the form of blends. The approach is attractive, because of avoiding the task of separation. But, the mechanical properties of such blends are...

Polylactide-pine wood flour composites.(Report)
March 1, 2008... INTRODUCTION Plastics have been one of the most highly valued materials mainly because of their extraordinary versatility and low cost [1]. However, the widespread use of plastics has become a significant concern due to their negative...

Phase separation in the polyurethane/poly(2-hydroxyethyl methacrylate) semi-interpenetrating polymer networks synthesized by different ways.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Interpenetrating polymer networks (IPNs) are materials based on two or more polymers, each of them is chemically crosslinked or at least one network is synthesized in the presence of the others [1-5]. The properties of IPNs...

Real-time measurement of flow front kinematics using quantitative visualization in injection molding process.(Report)
March 1, 2008... INTRODUCTION Injection molding is a widely used process for production of various plastic parts of simple to complex geometries. The process has various aspects of research interest particularly in the filling stage (flow behavior)....

Ethylene polymerization over (nBuCp)[.sub.2]Zr[Cl.sub.2]/MAO catalytic system supported on aluminosilicate SBA-15 mesostructured materials.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Olefin polymerization catalysis has undergone an extraordinary transformation in the last 20 years with the development of metallocene polymerization catalysts. These catalysts combine high activity with excellent...

Modeling particle inflation from poly(amic acid) powdered precursors. III. Experimental determination of kinetic parameters.(Author abstract)(Technical report)
March 1, 2008... INTRODUCTION Although publications on polyimide foams and methods to produce them have been available in the patent literature for several decades [1-4], it has been only recently that archival publications have been published on the topic...