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Virginia Tech

1. Celebi, Oguzhan. Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional  Prepolymers and Block Copolymers.

Degree: PhD, Learning Sciences and Technologies, 2014, Virginia Tech

This dissertation focuses on the synthesis and characterization of functional poly(2-ethyl-2-oxazoline) (PEtOx) containing homo- and block copolymers that are potential materials for membrane-based water purification and gas separation, drug delivery, magnetic resonance imaging and tissue engineering applications. The polymerization of 2-ethyl-2-oxazoline (EtOx) was investigated with regard to the effects of initiator structures and reaction parameters such as polymerization time and temperature on molecular weight control and molecular weight distribution, endgroup functionality, living characteristics, and mechanism and kinetics. The structure of initiators was shown to significantly affect the molecular weight control and molecular weight distribution of PEtOx oligomers. Methyl triflate initiated polymerizations were found to result in oligomers with low polydispersity (PDI) values around 1.10-1.15 and symmetrical chromatograms were obtained via size exclusion chromatography (SEC) studies with the use of refractive index, light scattering and viscosity detectors. However, EtOx polymerizations initiated by halide containing initiators such as benzyl chloride, dibromo- and diiodo-p-xylene, and vinylsilylpropyl iodides yielded PEtOx oligomers with higher PDI values ~ 1.30-1.40. Higher molecular weight distributions can be attributed to the presence of covalent species during polymerization and slower initiation rate as evidenced by kinetic studies when compared to PEtOx prepared from methyl triflate initiators. In all cases, termination reactions with aliphatic cyclic amines were quantitative. Mono- and diamine functional PEtOx oligomers with controlled molecular weight and excellent end-group functionality may be used as prepolymers for incorporation into multiblock and graft copolymer and crosslinked structures for a variety of applications such as membranes and hydrogels for tissue engineering matrices. Poly(2-ethyl-2-oxazoline) containing block copolymers were prepared using the macroinitiator method. First, amphiphilic triblock copolymers with hydrophobic poly(arylene ether sulfone) (PSF) central block and hydrophilic PEtOx side blocks were synthesized via polymerization of EtOx sequences from tosylate functional telechelic PSF macroinitiators. PSFs are well-known engineering thermoplastics with excellent resistance to hydrolysis and oxidation, as well as displaying good mechanical properties, thermal stability and toughness. Phenol functional PSFs were prepared via step-growth polymerization of dichlorodiphenylsulfone and bisphenol-A (slight excess) monomers. Phenolic chain ends were then converted to aliphatic hydroxyethyl endgroups by reaction with ethylene carbonate. Upon treatment with p-toluenesulfonyl chloride, tosylate functional PSF macroinitiators were prepared. PEtOx-b-PSF-b-PEtOx triblock copolymers (pendent acyl groups of PEtOx side blocks) were partially hydrolyzed in an acidic medium to introduce random charged poly(ethylene imine) units to prepare ionomer structures that may show good salt… Advisors/Committee Members: Riffle, Judy S. (committeechair), Turner, Sam Richard (committee member), McGrath, James E. (committee member), Davis, Richey M. (committee member), Esker, Alan R. (committee member).

Subjects/Keywords: Oxazoline; membrane; block copolymer; 2-ethyl-2-oxazoline; prepolymer; cationic ring opening polymerization; size exclusion chromatography; phosphonate

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Celebi, O. (2014). Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional  Prepolymers and Block Copolymers. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/24908

Chicago Manual of Style (16th Edition):

Celebi, Oguzhan. “Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional  Prepolymers and Block Copolymers.” 2014. Doctoral Dissertation, Virginia Tech. Accessed March 19, 2019. http://hdl.handle.net/10919/24908.

MLA Handbook (7th Edition):

Celebi, Oguzhan. “Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional  Prepolymers and Block Copolymers.” 2014. Web. 19 Mar 2019.

Vancouver:

Celebi O. Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional  Prepolymers and Block Copolymers. [Internet] [Doctoral dissertation]. Virginia Tech; 2014. [cited 2019 Mar 19]. Available from: http://hdl.handle.net/10919/24908.

Council of Science Editors:

Celebi O. Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional  Prepolymers and Block Copolymers. [Doctoral Dissertation]. Virginia Tech; 2014. Available from: http://hdl.handle.net/10919/24908


Brno University of Technology

2. Černý, Miroslav. Vinylové předpolymery - metody přípravy a využití .

Degree: 2012, Brno University of Technology

Teoretická část práce se zaměřuje na blokovou radikálovou polymeraci styrenu, methyl methakrylátu, vinyltoluenu a paramethylstyrenu. Shrnuje současné informace o kinetice a možnostech provedení blokové polymerace. Experimentální část se zabývá přípravou polystyrenových předpolymerů blokovou polymerací s cílem nalezení optimálních podmínek přípravy předpolymerů pro následnou polymeraci do téměř 100% konverze. Hodnoty konverze byly stanovovány gravimetricky a molekulové hmotnosti byly získány na základě viskozimetrických měření pomocí Ubbelohdeho viskozimetru. K předpovědi konverze monomeru v daném čase polymerace byly v experimentální části provedeny simulace zaměřené na závislost konverze na času. Rozdíly mezi skutečností a simulací jsou malé ve většině případů a nalezená podoba výpočtů kinetického chování poskytuje uspokojivé výsledky. V závěru práce byl na základě naměřených dat navrhnut nový postup pro přípravu polystyrenových předpolymerů.; The theoretical part of this thesis is focused on bulk radical polymerization of styrene, methylmethacrylate, vinyltoluene and paramethylstyrene. It summarizes actual informations about kinetics and performance possibilities of bulk polymerization. Experimental part deals with polystyrene prepolymers preparation by bulk polymerization. The aim is to find optimal conditions for prepolymers preparation. Prepolymers should be usable for subsequent polymerization nearly up to 100% conversion. Conversion values were gravimetrically determined and molecular weights were obtained by viskosity measurements, which were realized by Ubbelohde viscometer. In the experimental part, there were performed simulations targeted on conversion dependence on time. The purpose was a prediction of monomer conversion at a given time during polymerization. Differences between reality and simulation were low in most of cases and the found form of kinetic behavior calculations provides satisfying results. In the conclusion of this thesis was suggested a new procedure for polystyrene prepolymers preparation. Advisors/Committee Members: Kučera, František (advisor).

Subjects/Keywords: styren; předpolymer; bloková polymerace; radikálová polymerace; 2- a 3-funkční iniciátor; živá polymerace; nitroxid; methyl methakrylát; styrene; prepolymer; bulk polymerization; radical polymerization; bifunctional and trifunctional initiator; living polymerization; nitroxide; methyl methacrylate

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Černý, M. (2012). Vinylové předpolymery - metody přípravy a využití . (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/4704

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Černý, Miroslav. “Vinylové předpolymery - metody přípravy a využití .” 2012. Thesis, Brno University of Technology. Accessed March 19, 2019. http://hdl.handle.net/11012/4704.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Černý, Miroslav. “Vinylové předpolymery - metody přípravy a využití .” 2012. Web. 19 Mar 2019.

Vancouver:

Černý M. Vinylové předpolymery - metody přípravy a využití . [Internet] [Thesis]. Brno University of Technology; 2012. [cited 2019 Mar 19]. Available from: http://hdl.handle.net/11012/4704.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Černý M. Vinylové předpolymery - metody přípravy a využití . [Thesis]. Brno University of Technology; 2012. Available from: http://hdl.handle.net/11012/4704

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.