Polymer Engineering and Science articles from December 2005

Polymer Engineering and Science archives from December 2005

Effects of injection-molding conditions on the gloss and color of pigmented polypropylene.
December 1, 2005... INTRODUCTION A satisfactory visual impression of the end product is one of the basic quality criteria for polymer injection molding. The assessment of surface appearance is increasingly important, including not only appearance-related...

Properties of polypropylene/aluminum trihydroxide composites containing nanosized organoclay.
December 1, 2005... INTRODUCTION Flame retardancy is commonly introduced to polymers by adding metal hydroxide filler, such as aluminum trihydroxide (ATH). Typically about 60 wt% of filler is required, however, and this creates problems in compounding and...

Dielectric properties of an epoxy-amine system at a high microwave frequency.
December 1, 2005... INTRODUCTION Microwave processing of polymers has been studied as an attractive alternative to conventional thermal processing [1]. Dielectric properties of polymers are important for controlling microwave processing of the materials....

Cure kinetics and modeling of an epoxy resin cross-linked in the presence of two different diamine hardeners.
December 1, 2005... INTRODUCTION Epoxy thermosets (TS) are most well known from the cross-linking reaction of an epoxy oligomer with a diamine or anhydride or else phenol hardeners (i.e., the cross-linking agents) [1]. The choice of a hardener depends, for...

Minimum wet thickness for double-layer slide-slot coating of poly(vinyl-alcohol) solutions.
December 1, 2005... INTRODUCTION Coating methods can be generally divided into two categories: self-metered and premetered coating operations [1]. For self-metered coating, such as dip, blade, roll coating, etc., the coating thickness is a result of the...

New description of viscoelasticity that can be applied to mechanical properties such as constant strain rate, creep, and stress relaxation analysis.
December 1, 2005... INTRODUCTION Viscoelasticity in polymers has been simulated over the last half century [1-4] by utilizing a mixture of both elastic and viscous components. Most of the simplified viscoelastic models that have been developed typically...

Weld lines in nylon 6 melt-blended nanocomposites.
December 1, 2005... INTRODUCTION In recent years, layered silicate nanocomposites have attracted a great deal of interest from researchers, being a new class of composite that contain nanoparticles dispersed in a polymer matrix [1]. Nylon 6 nanocomposites are...

Fabrication and characterization of biodegradable poly(lactic acid)/layered silicate nanocomposites.
December 1, 2005... INTRODUCTION In the past decade significant attention has been focused on the biocompatible and biodegradable polymers, both from ecological and biomedical perspectives [1]. In general, synthetic polymers that are produced from...

Hydrocarbon stability of perfluorinated polyether rubbers at elevated temperatures.
December 1, 2005... INTRODUCTION Materials used in the construction of o-rings for aircraft fuel lines and hydraulic systems must perform in these aggressive chemical environments over a very wide range of temperatures and operating forces. The o-rings used...

The effect of the volume fraction of dispersed phase on toughness of injection molded polypropylene blended with SEBS, SEPS, and SEP.
December 1, 2005... INTRODUCTION Frequent studies have been made on the toughness improvement in isotactic polypropylene (i-PP), for example, by melt-mixing the polymer with suitable elastomers [1-3]. The study results suggest that the morphology of the blend...

Effect of C[O.sub.2] sorption and desorption on the creep response of polycarbonate.
December 1, 2005... INTRODUCTION In an earlier work, Wing et al. [1] reported on the creep response of polycarbonate (PC) and microcellular polycarbonate (MCPC). MCPC is a novel cellular material with cells on the order of 10 [micro]m and a cell density on...

Morphology, viscoelastic properties, and mechanical behavior of epoxy resin modified with hydroxyl-terminated poly(ether ether ketone) oligomer with pendent tert-butyl groups.
December 1, 2005... INTRODUCTION Epoxy resins are well known for their properties such as good adhesive strength, mechanical and thermal properties, and chemical resistance [1]. They are commercially very important due to the flexibility in changing the...

Injection molding-induced morphology of thermoplastic polymer blends.
December 1, 2005... INTRODUCTION In the past two decades, polymer blends, due to economic reasons and simple manipulation, etc., are widely used. Injection molding, one of the most important fabrication processes, is applied to a broad spectrum of polymer...

Ultrasonic improvement of weld line strength of injection-molded polystyrene and polystyrene/polyethylene blend parts.
December 1, 2005... INTRODUCTION Injection molding is one of the most attractive polymer processes in industry. It is especially used to produce a wide variety of complex geometry articles. However, injection molding of such parts usually produces weld lines...

Investigation of odd-odd nylons based on undecanedioic acid. 2: crystal structures.
December 1, 2005... INTRODUCTION Aliphatic polyamides, named nylons, present three basic crystal structures at room temperature according to the differences in the disposition of the amide groups and the methylene concentration in the repeat unit, based on...