Effect of annealing history on free volume in thermoplastics

by Jag J. Singh

Publisher: National Aeronautics and Space Administration, Langley Research Center, Publisher: For sale by the National Technical Information Service in Hampton, Va, [Springfield, Va

Written in English
Published: Downloads: 950
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Subjects:

  • Polymerization.,
  • Polymers.,
  • Thermoplastics.
  • Edition Notes

    StatementJag J. Singh and Terry L. St. Clair.
    SeriesNASA technical memorandum -- 87734.
    ContributionsSt. Clair, Terry L., Langley Research Center.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL17835610M

Annealing would decrease Zn interstitial concentration, introduce O vacancies and non-irradiated centers, and induce a blue shift of the undoped film UV emission, which is sensitive to the annealing ambient. Annealing results in a decrease of lattice site Al concentration, but it has a little effect on the UV emission of Al-doped by: In this study doped SnO2 thin films have been prepared by spray pyrolysis technique using an alcoholic precursor solution consisting of stannic chloride (SnClH2O), ammonium fluoride (NH4F) and palladium chloride (PdCl2). Optimization on the deposition parameters was done so as to obtain high quality thin films. The effect of varying the Fluorine content on the optoelectronic properties of F.   While the two-volume work Chemical Resistance of Thermoplastics covers chemical resistance of high-volume commercial (commodity) thermoplastics, this volume focuses on high performance 'engineering' or 'specialty' thermoplastics. These thermoplastics are usually consumed in smaller volumes, but have desirable characteristics for demanding and high-value Edition: 1. Handbook of Thermoplastics (Plastics Engineering, Volume 41 Olagoke Olabisi Offers coverage of all known commodity, transitional, engineering, high-temperature and high-performance thermoplastics, and analyzes emerging developments in the creation of new thermoplastics.

  The Handbook of Molded Part Shrinkage and Warpage is the first and only book to deal specifically with this fundamental problem. Jerry Fischer’s Handbook explains in plain terms why moldings shrink and warp, shows how additives and reinforcements change the picture, sets out the effect of molding process conditions, and explains why you never Author: Jerry Fischer. of annealing on mechanical dynamical properties a part of samples were annealed in the air at temperature C. In the test the annealing rate was 0C/s, time s per 1mm thickness and the cooling rate 0C/s. Before examinations test specimens were conditioned at 23 20C temperature and 50 5% relative humidity, during 16 h. Handbook of Engineering and Specialty Thermoplastics, Volume 4 by Sabu Thomas, , available at Book Depository with free delivery worldwide. Processing of Thermoplastic Materials. Ernest C. Bernhardt From inside the book. What people are saying - Write a review. We haven't found any reviews in the usual places. constant cooling cycle deformation Density at 23°C diameter dielectric dielectric heating dimensionless drag flow du/dr effect elastic energy ENTRY L/D equation.

Thermosets also have higher thermal, chemical and creep resistance than thermoplastics. Thermoset materials may contain filler materials in form of powder or fibers, providing improvement of specific material properties (strength, stiffness, Modulus of Elasticity, thermal resistance, lubricity). The annealing of the films was performed at different temperatures like , , and 9 0 0 ∘ C and found that the films annealed at 9 0 0 ∘ C turned out to be crystallized into a pure garnet phase. All of the films were bearing grains of nanometer in size. Increasing the annealing temperature gave extra energy to the grains causing to be Author: N. B. Ibrahim, Ftema W. Aldbea, Mustaffa Hj Abdullah.   Another thermal history effect, the effect of molding temperature, has been shown to change the dynamic mechanical spectra, as well as HDT, for PPS/glass composites (7). The purpose of this paper is to present results of annealing effects on neat PPS and how they effect the dynamic mechanical spectra of these materials. Application of Differential Scanning Calorimetry to the Characterization of Biopolymers. By Adriana Gregorova. K is an empirical parameter related to the free volume in polymer and M n is a number-average molecular weight of polymer. The clear effect of the thermal annealing on the PLA melting behavior is shown in Figure by:

Effect of annealing history on free volume in thermoplastics by Jag J. Singh Download PDF EPUB FB2

Get this from a library. Effect of annealing history on free volume in thermoplastics. [Jag J Singh; Terry L St Clair; Langley Research Center.]. Offers coverage of all known commodity, transitional, engineering, high-temperature and high-performance thermoplastics, and analyzes emerging developments in the creation of new thermoplastics.

The text examines: important issues in the field for each substance discussed, including history, development and commercialization; polymer formation mechanisms and process technologies; the 4/5(2). The regularities of annealing of an excess free volume in amorphous alloys have been investigated.

It is shown that the mechanism for the healing of excess free volume is associated with the viscous flow. It is revealed that a decrease in this volume at high temperatures or pressures leads to an increase in the strength and provides an explanation for the features of its temperature by: Annealing effects of polymers and their underlying molecular mechanisms* G.

Yeh University of Michigan, Ann Arbor, MichiganUSA annealing temperature, time and rate, prior thermal history and the physical state (drawn vs. undrawn or single crystal. Thermoplastics represent appx 90% by weight of all plastics consumed world-wide.

We know them mainly in the form of polythenes, polyolefins, polystyrenes, nylons and acrylics. Under different heating conditions and by varying the composition of the plastic it is possible to make many different products with differing properties.

Annealing, treatment of a metal or alloy by heating to a predetermined temperature, holding for a certain time, and then cooling to room temperature to improve ductility and reduce brittleness. Process annealing is carried out intermittently during the working of a piece of metal to restore ductility lost through repeated hammering or other working.

Chemical Resistance of Thermoplastics is a unique reference work, providing a comprehensive cross-referenced compilation of chemical resistance data that explains the effect of thousands of exposure media on the properties and characteristics of commodity thermoplastics.

The two volumes cover thermoplastics grouped within the following parts. The study of dependence of the proportion of and fibre on heat treatment by Demakov et al.

[6] exhibited changes in volume fraction of fibres radially and with annealing temperature in. In the present work magnetic properties, phase structure and evolution of free volumes in the rapidly solidified Fe 65 Pr 9 B 22 W 4 alloy ribbons in as-cast state and those subjected to short-time annealing were investigated.

The base alloy was prepared by arc-melting of Cited by: We use cookies to make interactions with our website easy and meaningful, to better understand the use of our services, and to tailor advertising.

For the annealed system, it was relaxed at K for ns followed by cooling to K. Due to the limited annealing time in MD simulation, annealing temperature was Cited by: While the two-volume work Chemical Resistance of Thermoplastics covers chemical resistance of high-volume commercial (commodity) thermoplastics, this volume focuses on high performance 'engineering' or 'specialty' thermoplastics.

These thermoplastics are usually consumed in smaller volumes, but have desirable characteristics for demanding and high-value applications. Several investigators have demonstrated that thermal history has a pronounced effect on the morphology of the segmented urethanes (4–10).

Changes in crystallinity of the hard segment as well as rearrangment of the domain structure has been reported to occur with suitable heat treatments (4).Cited by: 9. 1 Material Properties of Plastics Formation and Structure The basic structure of plastics (or polymers) is given by macromolecule chains, formulated from monomer units by chemical reactions.

Typical reactions for chain assembling are polyaddition (continuous or step wise) and condensation polymer-ization (polycondensation) [1] (Figure ).

Fused filament fabrication (FFF) is one of the most popular additive manufacturing (AM) techniques used to fabricate polymeric structures. However, these polymeric structures suffer from an inherent deficiency of weak inter-laminar tensile strength. Because of this weak inter-laminar strength, these parts fail prematurely and exhibit only a fraction of the mechanical properties of those Author: Rhugdhrivya Rane, Akhilesh Kulkarni, Hardikkumar Prajapati, Robert Taylor, Ankur Jain, Victoria Chen.

The effect of degree of constraint was more significant than that of the annealing temperature on tensile and dynamic mechanical properties. For both the homopolymer and the copolymer, annealing of partially constrained annealed fibers led to lower tensile modulus, strength, and E' values compared with unannealed and fully constrained annealed.

Handbook of Engineering and Specialty Thermoplastics, Volume 2: Water Soluble Polymers [Fink, Johannes Karl] on *FREE* shipping on qualifying offers. Handbook of Engineering and Specialty Thermoplastics, Volume 2: Water Soluble PolymersPrice: $   3. A process for surface annealing thermoplastics in accordance with claim 2 wherein said outer film layer of the thermoplastic is no more than about mil thick.

A process for surface annealing thermoplastics in accordance with claim 1 wherein said heating source is a hot plate, heated segmented belt, or microwave oven. Final annealing was carried out in a continuous annealing furnace, under hydrogen atmosphere, at temperatures in the range of °C to °C.

The final structure was characterised by optical microscopy and the texture was analysed by X-ray diffraction, at an intermediate position between centre and surface, and by EBSD at a longitudinal. The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased.

An amorphous solid that exhibits a glass transition is called a glass. Thermal annealing behavior and structure development of crystalline hard segment (HS) (43 wt%) domains in a melt-quenched multi-block thermoplastic polyurethane (TPU) have been investigated using differential scanning calorimetry, atomic force microscopy, wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS).Cited by: Dr.

Dmitri Kopeliovich Annealing of plastics is a heating of a polymeric part to below it’s glass transition temperature in order to relieve the internal stresses introduced into the part during its fabrication (molding, cooling after molding, machining, welding)/ In order to mold a plastic it is soften by heating and then forced into a cavity where it cools down and shrinks.

Atom-probe analysis shows the depletion of chromium from the surface of stainless steel tips subjected to heating in vacuum. Times necessary for depletion are lower by a factor of 10 4 than those found by Park et al. in which planar surfaces were analyzed by the x-ray appearance potential technique.

This is explained on the basis of the great sensitivity of depletion rate upon the surface Cited by:   Thermoplastics and Thermosettings Polymers are basically divided into: 1.

Thermoplastics Solids at room temperature that are melted or softened by heatin g, placed into a mould and then cooled to give the desired shape Can be reshaped at File Size: 1MB.

Technology of plastics annealing Annealing temperatures for plastics. Technology of plastics annealing. General annealing process includes the following stages: Placing the plastic part in an annealing oven.

Heating the part to the annealing temperature at a controlled rate. The heating rate is commonly not greater than ºF/hour (~ File Size: 57KB. Annealing and Thermal History Relaxations of Polymer Nanocomposites Effect of Hyperbranched Particles and Annealing Annealing for 1 h gives a higher free volume than at equilibrium, while increasing ta allows the free volume and mobility to slowly Size: KB.

What is annealing. Annealing is the process of exposing a product to a specific heat for a specific amount of time. What are the advantages of annealing medical plastics. A standard heat treatment process is designed to relieve the inherent stress created during the extrusion process.

If annealed properly, the extrusion should not change in diameter over time, or when exposed to elevated. Summary. This new edition of the bestselling Handbook of Thermoplastics incorporates recent developments and advances in thermoplastics with regard to materials development, processing, properties, and applications.

With contributions from 65 internationally recognized authorities in the field, the second edition features new and updated discussions of several topics, including.

/ Effect of annealing temperature on electromagnetic absorption properties of crystalline Fe-Si-Al alloy powder-polymer composites.

In: Physica Status Solidi (A) Applications and Materials Science. ; Vol.No. Cited by: 5. It is found that significantly different structural changes occur for oil‐annealing and air‐annealing. Retractive forces measured in hot oil are characterized by a high initial force, followed by a rapid decay and a second, more gradual, increase which is also followed by a decay at sufficiently high temperatures.

Annealing effects on microstructure and mechanical properties of chromium oxide coatings Xiaolu Panga,b, Kewei Gaoa,⁎, Fei Luoa, Huisheng Yanga, Lijie Qiaoa, Yanbin Wanga, Alex A. Volinskyb a Department of Materials Physics and Chemistry, University of Science and Technology Beijing, BeijingChina b Department of Mechanical Engineering, University of South Florida, Tampa, FL .Thermal annealing plays an important role in controlling morphologies of polymer thin films and consequently the device performance, such as emission spectra, turn-on voltages, quantum efficiency of photoluminescence~PL!

and electroluminescence ~EL!. In thermal annealing there is a tradeoff between hole-injection efficiency and PL efficiency.Glass is a non-crystalline, often transparent amorphous solid, that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and is most often formed by rapid cooling of the molten form, some glasses such as volcanic glass are naturally most familiar, and historically the oldest, types of manufactured glass are "silicate.