Polymer Engineering and Science articles from January 2005

Polymer Engineering and Science archives from January 2005

Curing kinetics and reaction-induced homogeneity in networks of poly(4-vinyl phenol) and diglycidylether epoxide cured with amine.
January 1, 2005... INTRODUCTION Thermosetting epoxies possess various desirable properties, such as high tensile strength and modulus, excellent chemical and solvent resistance, dimensional and thermal stability, good creep resistance, and excellent fatigue...

In-line optical detection in the transient state of extrusion polymer blending and reactive processing.
January 1, 2005... INTRODUCTION It is important to determine the residence time distribution (RTD) curve of a polymer inside an extruder because it is related to the polymer's level of dispersion (in terms of variance) and the time the fluid is exposed to...

Structural relaxation and evolution of yield stress in epoxy glass aged under shear strain.
January 1, 2005... INTRODUCTION Because of its high specific strength and stiffness, epoxy glass is widely used as a structural material, such as in adhesives and as a matrix substance in fiber-reinforced plastics. However, these high-quality characteristics...

White spirit permeation resistance of polyethylene, polyethylene/modified polyamide, and polyethylene/blends of modified polyamide and ethylene vinyl alcohol bottles.
January 1, 2005... INTRODUCTION It is well known that many hydrocarbon solvents (e.g., xylene, toluene, white spirit, etc.) are commonly available products that easily permeate polyethylene (PE) containers. Such permeation results in pollution, and safety...

On-line detection of the gate freezing-off time for injection molding.
January 1, 2005... INTRODUCTION In injection molding, packing-holding commences at the end of filling. Additional polymer is packed into the mold at high pressure to compensate for the material shrinkage associated with solidification. Ideally, the packing...

An irreversible thermodynamic model for semicrystalline polymers submitted to multisequence loading at large strain.
January 1, 2005... INTRODUCTION The aim of this work is to contribute to the mechanical behavior simulation of semicrystalline polymers via the distribution of nonlinear relaxation (DNLR) formalism, as developed by Cunat et al. [1-15]. This thermodynamic...

Microstructure and crystallography in microcellular injection-molded polyamide-6 nanocomposite and neat resin.
January 1, 2005... INTRODUCTION With microcellular injection molding (also commercially known as the MuCell process), one can produce microcellular parts with excellent dimensional stability using lower injection pressures, shorter cycle times, and less...

Experimental study on the flow and deposition of powder particles in rotational molding.
January 1, 2005... INTRODUCTION Several polymer processing operations, such as rotational molding, powder coating, and slush molding, use resins in granular form. At various stages within each of these processes, particle technology influences the production...

Spherulitic crystallization behavior of linear low-density polyethylene.
January 1, 2005... INTRODUCTION The crystallization kinetics of linear low-density polyethylenes (LLDPEs) depends on the molecular structure, such as the molecular weight (MW) and MW distribution (MWD), short chain branching content (SCBC), short chain...

Relationship between the rheology and morphology of dynamically vulcanized thermoplastic elastomers based on EPDM/PP.
January 1, 2005... INTRODUCTION Since dynamically vulcanized thermoplastic elastomers (TPVs) were first presented by Fisher [1, 2], they have been widely used in the rubber and plastic industries [3-5]. These materials behave, to a good approximation, like...

Comparison of four methods for monitoring the kinetics of curing of a phenolic resin.
January 1, 2005... INTRODUCTION The kinetics of oligomer curing govern both the duration of the process and the properties of the final product. In fact, the meaning of the term "kinetics" is somewhat ambiguous because of uncertainty about which process is...

Cyclic deformation behavior of an epoxy polymer. Part II: predictions of viscoelastic constitutive models.
January 1, 2005... INTRODUCTION Polymers and polymeric composites in engineering service are usually subjected to multiaxial stress states with complex loading histories, and in many cases, the loading is of a cyclic nature. With increasing applications of...

Enhancement of convective heat transfer to polymer manufacturing molds.
January 1, 2005... INTRODUCTION The applications of modern-day plastics range from commonplace domestic articles to sophisticated scientific and medical instruments. Due to the combinations of properties not available in any other materials, such as...

Dynamic finite element analysis of nonlinear isotropic hyperelastic and viscoelastic materials for thermoforming applications.
January 1, 2005... INTRODUCTION In the thermoplastic forming industry, it is a common practice to mostly rely on trial and error methods based on a high number of test specimens in order to assess the actual mass production planning and schedule, a procedure...

Barrier and mechanical properties of injection molded montmorillonite/polyesteramide nanocomposites.
January 1, 2005... INTRODUCTION Nanocomposites have attracted considerable attention [1-3] since the discovery of their potential in improving polymer properties [4-6]. Two major findings have triggered interest in these materials. First, the report from the...

In situ generated diphenylsiloxane-polyimide adduct-based nanocomposites.
January 1, 2005... INTRODUCTION Polyimides (PIs) represent a class of high-performance polymers that have many beneficial attributes due to the high degree of molecular orientation associated with the PIs' macromolecular chains. Their use in a number of...