Doctoral Dissertations

Keywords and Phrases

Supercritical carbon dioxide

Abstract

"Research into polymer-clay nanocomposites (PCN's) has been ongoing for decades as a result of the property enhancements offered by clay. To fully exploit these property enhancements, organically modified clays (organoclays) are utilized to promote clay delamination by reducing the disparity between the hydrophilicity of the clay and the hydrophobicity of the highly used polyolefin polymer. Since the organic modification of organoclays can degrade at temperatures typical to many polymers during melt-mix processing, this work utilizes the low-temperature processing fluid supercritical carbon dioxide (scCO₂) to disperse an organoclay into the highly used polymer LLDPE and ascertains the associated processing conditions for achieving this goal. Investigations into the LLDPE resin size, scCO₂ processing time, scCO₂ capability and the processing component compatibility were undertaken to better understand the important parameters to achieving organoclay dispersion, in terms of infusion and intercalation/exfoliation behavior. A LLDPE pellet resin showed improved dispersion and obtainable information over that of a granule resin, securing the choice of resin for subsequent experiments. Experiments undertaken with pellet resin exhibited that a 1-hr processing time was insufficient for organoclay infusion into LLDPE, however when infusion occurs, intercalation/exfoliation can be affected by scCO₂. Increasing the compatibility of LLDPE with clay and the processing fluid revealed that the increased compatibility had altered the effect of scCO₂. Further analysis with the 93A-infused samples was conducted in order to gain a better understanding of the effect of scCO₂ processing, such as the quantity and size of clay particles dispersed and changes to the polymer incurred by processing"--Abstract, page iii.

Advisor(s)

Ludlow, Douglas K.
Lee, Sunggyu

Committee Member(s)

Xing, Yangchuan
Dogan, Fatih
Westenberg, David J.

Department(s)

Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering

Sponsor(s)

United States. Department of Education. Graduate Assistance in Areas of National Need

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2012

Pagination

xiii, 115 pages

Note about bibliography

Includes bibliographical references (pages 110-114).

Rights

© 2012 Matthew John Factor, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Nanocomposites (Materials)PolyethylenePolymer clay

Thesis Number

T 10001

Print OCLC #

815668052

Electronic OCLC #

793741016

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