Advertisement

Topics

Enthalpy relaxation and annealing effect in polystyrene.

08:00 EDT 1st July 2013 | BioPortfolio

Summary of "Enthalpy relaxation and annealing effect in polystyrene."

The effects of thermal history on the enthalpy relaxation in polystyrene are studied by differential scanning calorimetry. The temperature dependence of the specific heat in the liquid and the glassy states, that of relaxation time, and the exponent of the Kohlrausch-Williams-Watts function are determined by measurements of the thermal response against sinusoidal temperature variation. A phenomenological model equation previously proposed to interpret the memory effect in the frozen state is applied to the enthalpy relaxation and the evolution of entropy under a given thermal history is calculated. The annealing below the glass transition temperature produces two effects on enthalpy relaxation: the decay of excess entropy with annealing time in the early stage of annealing and the increase in relaxation time due to physical aging in the later stage. The crossover of these effects is reflected in the variation of temperature of the maximum specific heat observed in the heating process after annealing and cooling.

Affiliation

Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.

Journal Details

This article was published in the following journal.

Name: Physical review. E, Statistical, nonlinear, and soft matter physics
ISSN: 1550-2376
Pages: 012605

Links

DeepDyve research library

PubMed Articles [12186 Associated PubMed Articles listed on BioPortfolio]

Memory Effect Manifested by a Boson Peak in Metallic Glass.

We explore the correlation between a boson peak and structural relaxation in a typical metallic glass. Consistent with enthalpy recovery, a boson peak shows a memory effect in an aging-and-scan proced...

Interplay Between the Relaxation of the Glass of Random L/D-Lactide Copolymers and Homogeneous Crystal Nucleation: Evidence for Segregation of Chain Defects.

Random L-isomer rich copolymers of poly (lactic acid) containing up to 4 % D-isomer co-units have been cooled from the molten state such to obtain glasses free of crystals and homogenous crystal nucle...

The Enthalpy-Entropy Compensation (EEC)Effect: A Revisit.

A short account of the developments and perspectives of IKR (iso-kinetic relation) and EEC (enthalpy (H) - entropy (S) compensation) has been presented. The IKR and EEC are known to be extra thermodyn...

Relationship between Segmental Relaxation of Polystyrene Films and Stick-Slip Behavior during Dynamic Wetting of Liquid Droplets on Their Surfaces.

A novel method was previously reported for detecting the glass transition of thin polystyrene (PS) films by correlating the relationships between the temperature-dependent viscoelasticity of the PS fi...

Enthalpy Effect of Adding Cobalt to Liquid Sn-3.8Ag-0.7Cu Lead-Free Solder Alloy: Difference between Bulk and Nanosized Cobalt.

Heat effects for the addition of Co in bulk and nanosized forms into the liquid Sn-3.8Ag-0.7Cu alloy were studied using drop calorimetry at four temperatures between 673 and 1173 K. Significant differ...

Clinical Trials [1352 Associated Clinical Trials listed on BioPortfolio]

Phase II Study of the Pathophysiology and Treatment With Enalapril and Polystyrene Sulfonate for Pseudohypoaldosteronism, Type I

OBJECTIVES: I. Establish the sodium and potassium intake that will maintain a normovolemic state in a patient with pseudohypoaldosteronism. II. Determine the effect of extracellular flu...

Effect of the Subconscious on Mohs Micrographic Surgery

The goal of this study is to determine if relaxation therapy improves patient satisfaction with Mohs micrographic surgery.

Relaxation Response With Acupuncture for HIV Patients

Advances in treatment has turned HIV/AIDS into a chronic illness. Relaxation response is a state in which individuals evoke a bodily calm, effecting physiological changes that are shown t...

Virtual Reality and Relaxation for the Treatment of Generalized Anxiety Disorders: a Comparative Study With Standard Relaxation

The purpose is threefold: Assess the anxiety reduction, the mood positive effect and the rise of quality of life when using methods of relaxation combined with virtual reality with patient...

The Effect of Relaxation Response Training on Declarative Memory and Learning in High School Students

Stress contributes to health and behavioral issues in students, but will not be integrated into schools without evidence of benefit. This study was conducted to determine if a 6-week relax...

Medical and Biotech [MESH] Definitions

An effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion.

A colorless, toxic liquid with a strong aromatic odor. It is used to make rubbers, polymers and copolymers, and polystyrene plastics.

A quaternary skeletal muscle relaxant usually used in the form of its bromide, chloride, or iodide. It is a depolarizing relaxant, acting in about 30 seconds and with a duration of effect averaging three to five minutes. Succinylcholine is used in surgical, anesthetic, and other procedures in which a brief period of muscle relaxation is called for.

A synthetic PGE2 analog that has an inhibitory effect on gastric acid secretion, a mucoprotective effect, and a postprandial lowering effect on gastrin. It has been shown to be efficient and safe in the treatment of gastroduodenal ulcers.

A strongly basic anion exchange resin whose main constituent is polystyrene trimethylbenzylammonium Cl(-) anion.

Quick Search
Advertisement
 
DeepDyve research library

Searches Linking to this Article