Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 54 for “"Polyacrylonitrile"”.
-
Polyacrylonitrile hollow fibre membranes for gas separation
Polyacrylonitrile (PAN) hollow fibres have been spun by a dry-jet wet spinning technique, using a commercial PAN polymer (Courtelle) redissolved in dimethylformamide (DMF). After failure to produce satisfactory porous hollow fibres from PAN/DMF solutions, a series of studies on the porous …
-
The Interaction of Nitrogen Monoxide with Pyrolysed Polyacrylonitrile
… work was concerned with depositing a film of polyacrylonitrile from solution onto a pelletised alumina support and converting this into a supported PAN.P catalyst having optimum NO removal activity. Kinetic studies indicated that at soo⁰c, 5,170 x 10-10 moles s-1m-2 of NO were removed when …
-
High strength carbon nanofibers derived from electrospun polyacrylonitrile
Carbon nanofibers (CNFs) derived from polyacrylonitrile (PAN) have not yet demonstrated the high tensile strength and Young’s modulus of their microscale counterparts. This is due to the current lack of understanding of the effect of electrospinning conditions on the quality of PAN precursor …
-
Wet spinning of porous polyacrylonitrile fibers and affect on fiber oxidation
… wet spinning technique for production of porous polyacrylonitrile fibers. Dimethylformamide was used as the solvent and a 17% by weight dope was extruded through a spinneret having four 118 micron diameter holes. It was found that porous fibers could be produced with reasonable physical …
-
Mechanical characterization of advanced polyacrylonitrile derived carbon fibers reinforced with carbon nanotubes
… nanotubes (CNTs) which were dispersed in the polyacrylonitrile (PAN) precursor. The carbon nanofibers were obtained from the Georgia Institute of Technology and were fabricated in bundles by the “islands-in-a-sea” method. The fiber test specimens, with roughly 1 µm in diameter and 50 or 100 µm …
-
Establishing the Conditions for Stable Extrusion of Melt Spun Polyacrylonitrile with Water Based Plasticizers
Polyacrylonitrile (PAN) fiber is one of the most important synthetic fibers in the world because it is a precursor to carbon fiber. Compared to the traditional solution spinning process, the melting spinning process of PAN is less costly and can further reduce the price of PAN fiber. This …
-
Investigations of Structure–Property Relationships in Semicrystalline Thermoplastic Polymers: Blown Polyethylene Films and Polyacrylonitrile Copolymers
Blown films of high molecular weight high density polyethylene (HMW-HDPE) were produced from two resins of differing molecular weight (MW) and molecular weight distribution (MWD) using a high stalk bubble configuration. The processing conditions were varied such that three film gauges, each …
-
Catalytic Reactions of Highly Conjugated Polymers: the Removal of Nitrogen Monoxide from Gas Streams using Pyrolysed Polyacrylonitrile
This work is concerned with the use of pyrolysed polyacrylonitrile,a highly conjugated organic polymer, as a heterogeneous catalyst for the removal of nitrogen monoxide from motor vehicle exhaust gas. Previous work had shown that the polymer was capable of removing nitro-gen monoxide from gas …
-
Effect of heat treatment on dyeability, glass transition temperature, and tensile properties of polyacrylonitrile fibers (orlon 42)
Deniers of treated and untreated fibers were determined and the „ results were used in calculations of tenacity and initial modulus. Tensile properties were measured on a constant—rate—of—extension machine. Shrinkage of treated and untreated fibers were measured after they were boiled in water for …
-
Advanced Dispersion Strategies of Carbon Nanofillers and their use to enhance Mechanical and Electrical Properties of Polyacrylonitrile Fibers
This study focuses on making next generation of polyacrylonitrile fibers containing carbon nanofillers, namely carbon nanotubes (CNTs) and carbon black (CB). Mechanically strong and electrically conducting poly(acrylonitrile) (PAN) fibers were obtained by incorporating up to (a) 15 wt% single wall …
-
Effects of biological and chemical compounds on the ultrafiltration and mass transfer permeability of polyacrylonitrile artificial kidney membranes
Includes bibliographical references.
-
Chemistry of the Degradation of Vinyl Polymers to give Carbon Fibre Precursors
An investigation of the oxidative degradation of polyacrylonitrile, a precursor for carbon fibre manufacture, has been made by examining the oxidation of 'model* compounds of the polymer. During the attempted preparation of one of these 'models', 2,)-dicyanopentane, it became apparent that this …
-
Design of Advanced Materials With Novel Microstructural Features
… sulfonated poly (ether ether ketone) and polyacrylonitrile in DMF and heating under nitrogen at 380 °C. This novel system offered a possible low-cost alternative to Nafion membranes for fuel cells.
-
Design of Advanced Fibrous Based Material Systems to Meet the Critical Challenges in Water Quality and Carbon Dioxide Mitigation
Aminated polyacrylonitrile activated carbon fibers (N-ACF) coated on a non-woven fiberglass mat, displayed the ability to remove NOM more efficiently than granulated activated carbon or ion exchange beads at concentrations below 50 mg/L. Electrostatic attraction was found to be the dominant …
-
Synthesis and Characterization of Solution and Melt Processible Poly(acrylonitrile-co-methylacrylate) statistical copolymers
Polyacrylonitrile (PAN) and its copolymers are used in a wide variety of applications ranging from textiles to purification membranes, packaging material and carbon fiber precursors. High performance polyacrylonitrile copolymer fiber is the most dominant precursor for carbon fibers. Synthesis of …
Page 1 of 3