Open Access. Powered by Scholars. Published by Universities.®
![Digital Commons Network](http://assets.bepress.com/20200205/img/dcn/DCsunburst.png)
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Investigation Of The Synthesis And Polymerization Behavior Of Vinyl Benzoate, Selim Mehmet Erhan
Investigation Of The Synthesis And Polymerization Behavior Of Vinyl Benzoate, Selim Mehmet Erhan
Dissertations
The goal of this study is to present a method that gives higher conversions and molecular weights for the polymerization of vinyl benzoate than obtained in previous investigations.
Polyvinyl benzoate has benzene rings attached to the backbone chain, therefore is hard and rigid. This is a characteristic which has a large application area. However previous studies in polymerizing vinyl benzoate with bulk and solution polymerizations reported low yields and troublesome crosslinking, which has limited its application. Emulsion polymerization method has the advantage of giving high polymerization rates together with high molecular weights, and therefore was chosen as the method for …
Investigation Of Complex Formation By Oligomers Of Cytosine And Guanosine, Steven Roberts Davis
Investigation Of Complex Formation By Oligomers Of Cytosine And Guanosine, Steven Roberts Davis
Chemistry & Biochemistry Theses & Dissertations
Duplex formation between oligo(C:G) n where n=3 to 4 was shown not to occur under conditions favorable for duplex formation between poly G and poly C. Instead, a stable guano sine self-structure was found to form which a Tm of 50°C for (Gp)3 and 80°C for (Gp)4 at strand concentrations of 10-5M in 1M NaCl. Neither a duplex nor a self-structure formed in the absence of salt.
Oligomers of guanosine and cytosine were obtained by basic hydrolysis and separated according to chain length using DEAE Sephadex column chromatography. Separation of cytosine oligomers with chain lengths …
Gas Permeation Measurements On Small Polymer Specimens, Karen S. Burns
Gas Permeation Measurements On Small Polymer Specimens, Karen S. Burns
Chemistry & Biochemistry Theses & Dissertations
Mass spectrometry was used to measure oxygen and nitrogen permeabilities while polarography was used to measure oxygen permeabilities for several contact lens materials. Applicable sample holders were designed and fabricated to accommodate curved and flat specimens with surface areas of 0.5 cm2 and 1.0 cm2 and thicknesses between 0.025 mm and 0.500 mm. A prepared standard was used to calibrate the mass spectrometric analyses.
The oxygen permeability values determined by mass spectrometry were significantly greater than those determined by polarography. This was attributed to the phase boundary phenomena and the limiting oxygen permeance of water inherent in the …
Studies Of Radiation Effects In Three High Polymers, Heidi Rene-Mitchell Ries
Studies Of Radiation Effects In Three High Polymers, Heidi Rene-Mitchell Ries
Physics Theses & Dissertations
Three high polymers, Mylar®, Ultem®, and Kapton®, were irradiated to total doses of 1, 5, and 9.5 gigarad using 1-MeV electrons. The glass transition temperatures (Tg) of the materials before and after irradiation were measured using an AC electrical dissipation factor technique. From the Tg data, it was found that the electron radiation at these total doses results in net chain scissioning in Mylar and net crosslinking in Ultem, while self-mending is predominant in Kapton. The dielectric constant was measured before and after irradiation, but no significant changes due to irradiation were observed. Electron paramagnetic resonance (EPR) …