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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Structural analysis of thick polypropylene moldings

Shindo, Nobuhiko 08 1900 (has links)
No description available.
22

Temporally programmed stretching of polymer films influence of nanoparticles /

Seif, Sylvain. January 2009 (has links)
Dissertation (Ph. D.)--University of Akron, Dept. of Polymer Engineering, 2009. / "August, 2009." Title from electronic dissertation title page (viewed 9/16/2009) Advisor, Mukerrem Cakmak; Committee members, Hendrik Heinz, Arkady Leonov, Yi Pang, Shing-Chung Wong; Department Chair, Sadhan Jana; Dean of the College, Stephen Cheng; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
23

Polymer crystallization enabled carbon nanotube functionalization: morphology, structure and applications /

Li, Lingyu. Li, Christopher Yuren. January 2006 (has links)
Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 165-180).
24

Crystallization and melting behavior studies of un-nucleated and silica-nucleated isotactic polystyrene and isotactic poly(propylene oxide)

Kennedy, Mary A. January 1988 (has links)
No description available.
25

Constant temperature embossing of supercooled polymer films

Kuduva Raman Thanumoorthy, Ramasubramani 21 January 2011 (has links)
In this dissertation work, a constant temperature embossing process was developed and investigated. By softening and crystallizing a supercooled polymer at the same temperature, the embossing and solidification stages can be carried out isothermally without thermal cycling. The new process was demonstrated for replicating rectangular trenches with different aspect ratio for two different polymers PET and PEEK. The raw materials were characterized for their thermal and rheological properties to determine the processing parameters. The polymers were also characterized by a modified tensile testing apparatus to determine the tensile properties of the film during embossing. The processing parameters including embossing temperature, embossing pressure and embossing time were varied based on the material properties and optimized. A semi-empirical model was established to correlate the crystallizing kinetics of the materials to the change in rheological properties during embossing. The model was used as a tool to predict the rheological properties of the polymer at conditions where experimental determination is difficult. Finally, embossing simulations with the semi-empirical rheological model were conducted to study the unique process dynamics of constant-temperature embossing and verify some experimental findings. Different cases of constant-temperature embossing involving low to high rates of crystallization were simulated and compared with the conventional embossing process. Based on the experimental and simulation results, processing strategies for constant-temperature embossing were devised.
26

Exploiting polymer single crystals to assemble and functionalize nanomaterials /

Li, Bing. Li, Christopher Yuren. January 2009 (has links)
Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 222-238).
27

Gas transport properties of side-chain crystalline polymers /

Mogri, Zen, January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 280-288). Available also in a digital version from Dissertation Abstracts.
28

Crystallization and melting behavior studies of un-nucleated and silica-nucleated isotactic polystyrene and isotactic poly(propylene oxide)

Kennedy, Mary A. January 1988 (has links)
The effect of silica on the crystallization and melting behavior of a highly isotactic, well characterized isotactic polystyrene (i-PS) have been investigated. The origins of the various endotherms obtained upon heating have been defined by partial scanning experiments and by a study of the effect of heating rate using differential scanning calorimetry (DSC). The presence of 1 part silica in 100 parts polymer (1 pph) decreases the maximum degree of crystallinity considerably but has a minimal effect on the rate of crystallization. Analysis by the Avrami method shows that the silica does not affect the overall rate of crystallization significantly. The decrease in the crystallinity indicates that silica affects the level of secondary crystallization, thus the crystal perfection. / The surface morphologies and growth rates of i-PS spherulites, as studied by photomicroscopy, were not affected by 1 pph of silica. The experimental data were fitted to a modified form of the Hoffman-Lauritzen equation. / The effect of silica on spherulite growth rates and surface morphologies of isotactic poly(propylene oxide) (i-PPO) have also been investigated by optical microscopy. Two distinct i-PPO samples of different molecular weights were used, each of which was highly isotactic. The addition of silica has a pronounced effect on the morphology of the spherulites, producing dendritic type morphology. Upon step-crystallization, the spherulites exhibited mixed morphologies, i.e., fibrillar and ringed. Silica depresses the spherulite growth rates throughout the entire temperature range. The effects were more profound as the quantity of filler increased. The growth rate-temperature behavior was analysed in terms of the classical Hoffman-Lauritzen equation and a modified version to take into account the polymer-filler interaction.
29

Metal decoration of exfoliated graphite nanoplatelets (xGnP) for fuel cell application

Do, In-Hwan. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Chemical Engineering and Materials Science, 2008. / Title from PDF t.p. (viewed on July 23, 2009) Includes bibliographical references. Also issued in print.
30

Steady dynamics in shearing flows of nematic liquid crystalline polymers

Liu, Fangyu, Wang, Qi. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Qi Wang, Florida State University, College of Arts and Sciences, Dept. of Mathematics. Title and description from dissertation home page (viewed Sept. 27, 2004). Includes bibliographical references.

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