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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.
1

Fourier-transform rheology on anionically synthesised polymer melts and solutions of various topology

Neidhöfer, Thorsten. January 2003 (has links) (PDF)
Mainz, University, Diss., 2003.
2

Mikroreaktionstechnik als Syntheseverfahren zur Darstellung von innovativen Materialien

Getze, Julia. Unknown Date (has links)
Univ., Diss., 2008--Marburg.
3

Reaktive Extrusion und Charakterisierung von in situ hergestellten Polyamid-12-Blends und -Compositen

Wollny, Andreas. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2001--Freiburg (Breisgau).
4

Untersuchungen zum Polymerisationsmechanismus der Gilch-Reaktion

Wiesecke, Jens. Unknown Date (has links)
Techn. Universiẗat, Diss., 2004--Darmstadt.
5

Masse- und Blockcopolymere durch retardierte anionische Polymerisation von Styrol und 2-Vinylpyridin

Scheunemann, Sven. Unknown Date (has links)
Techn. Universiẗat, Diss., 2004--Darmstadt.
6

Synthesis and characterization of polymacromonomers based on polyethers

Mendrek, Aleksandra 24 April 2006 (has links) (PDF)
The synthesis and polymerization of macromonomers containing a polymerizable styrene head group and a tail of ethylene oxide derivatives of different character were investigated. The synthesis of macromonomers was based on living anionic polymerization of oxiranes. Two monomers were used: 1-ethoxyethyl glycidyl ether (glycidol acetal), which after hydrolysis forms hydrophilic glycidol blocks and glycidyl phenyl ether forming hydrophobic blocks. Polymerizable double bonds were introduced by terminating the living chain with p-(chloromethyl)styrene. However, MALDI-TOF-MS end group analysis showed that all synthesized macromonomers were a mixture of the macromonomer and the non-functionalized oligomer. The degree of functionalization varied from 55 to 75 %. The obtained macromonomers showed amphiphilic properties and formed micelles in water. The determined critical micellization (CMC) concentration for poly(glycidol) macromonomer (DP = 50) was ca. 10 g/L, while the poly(glycidol) block macromonomers with hydrophobic spacer showed CMC on the level 0,7 g/L. The conventional free radical and controlled free radical polymerisation (ATRP) were used for preparation of polymacromonomers with different properties. The radical polymerization of the macromonomers was carried out in water using AVA as initiator and in the mixture of water/benzene (10/1 v/v) using AIBN. Core-shell polymers of different character and molar masses with polydispersity indices from 1,4 -3,0 were obtained. The ATRP carried out in water using PEO macroinitiator led to polymacromonomers with polydispersity indices from 1,1 to 1,3 and desiried molecular weight. In all cases the conversion of macromonomer (able to polymerization) was close to 100%. The polymerization product could easily be separated from the unable to reaction residue.
7

Synthesis and characterization of polymacromonomers based on polyethers

Mendrek, Aleksandra 23 May 2006 (has links)
The synthesis and polymerization of macromonomers containing a polymerizable styrene head group and a tail of ethylene oxide derivatives of different character were investigated. The synthesis of macromonomers was based on living anionic polymerization of oxiranes. Two monomers were used: 1-ethoxyethyl glycidyl ether (glycidol acetal), which after hydrolysis forms hydrophilic glycidol blocks and glycidyl phenyl ether forming hydrophobic blocks. Polymerizable double bonds were introduced by terminating the living chain with p-(chloromethyl)styrene. However, MALDI-TOF-MS end group analysis showed that all synthesized macromonomers were a mixture of the macromonomer and the non-functionalized oligomer. The degree of functionalization varied from 55 to 75 %. The obtained macromonomers showed amphiphilic properties and formed micelles in water. The determined critical micellization (CMC) concentration for poly(glycidol) macromonomer (DP = 50) was ca. 10 g/L, while the poly(glycidol) block macromonomers with hydrophobic spacer showed CMC on the level 0,7 g/L. The conventional free radical and controlled free radical polymerisation (ATRP) were used for preparation of polymacromonomers with different properties. The radical polymerization of the macromonomers was carried out in water using AVA as initiator and in the mixture of water/benzene (10/1 v/v) using AIBN. Core-shell polymers of different character and molar masses with polydispersity indices from 1,4 -3,0 were obtained. The ATRP carried out in water using PEO macroinitiator led to polymacromonomers with polydispersity indices from 1,1 to 1,3 and desiried molecular weight. In all cases the conversion of macromonomer (able to polymerization) was close to 100%. The polymerization product could easily be separated from the unable to reaction residue.
8

Synthese und morphologische Charakterisierung von Blockcopolymeren aus metallorganischen und organischen Segmenten

Kloninger, Christian. Unknown Date (has links)
Techn. Universiẗat, Diss., 2004--Darmstadt.
9

Synthesis and self-assembly of organometallic semiconducting PMMA-b-PFS-b-PS-b-PFS-b-PMMA pentablock copolymers

Datta, Uttam. Unknown Date (has links)
Techn. University, Diss., 2005--Darmstadt.
10

Synthesis and characterization of stimuli-responsive microgels based on poly(glycidol)block copolymers / Synthese und Charakterisierung von stimuli-sensitiven Mikrogelen basierend auf Polyglycidol-Blockcopolymeren

Mendrek, Sebastian 24 April 2006 (has links) (PDF)
New water soluble, attainable to ATRP polymerization Cl-terminated poly(glycidol) macroinitiators were prepared by modification of (Omega)-hydroxyl group of poly(glycidol acetal) using 2-chloropropionyl chloride fallowed by selective acidic deprotection of acetal groups. The obtained macroinitiators of different molar masses were successfully employed in ATRP of NIPAM and 4VP to give well-defined stimuli sensitive block copolymers of targeted molar ratio of blocks. The results obtained from light scattering methods showed formation of stable aggregates upon stimuli (pH or temperature) by all the obtained polymers. Additionally, photocrosslinkable block copolymers of glycidol and NIPAM having incorporated moieties of chromophore (2-(dimethyl maleinimido)-N-ethyl-acryl amide) were prepared using macroinitiator technique and used to synthesis of temperature sensitive microgels. Conjunction points have been successfully formed by UV irradiation of polymer water solution above cloud point. The influence of such parameters like block ratio, block length, amount of chromophore, concentration, irradiation time, temperature and heating rate on the properties of obtained microgels was investigated. The obtained core-shell structures were stable under critical conditions and showed continuous volume phase separation process upon increase of temperature, fully reversible and reproducible (no hysteresis effect). Thus, the proposed method not only gave the opportunity to control size or swelling degree of microgels, but also diminished gradient in crosslinking density (random chromophore distribution in polymer backbone), improved colloid stability (poly(glycidol) shell) and completely eliminated additives (surfactants, initiators, stabilizers).

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