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 21 for “"Radical Initiator"”.
-
Compatibilisation and stabilisation of immiscible polymer blends by reactive processing
… (less than 0.01 molar ratio) of a free radical initiator. Various methods were used to purify MA-functionalised PP and the grafting yield was determined using either FTIR or titrametry. The grafting yield of MA alone, which due to its low free-radical reactivity towards polymer …
-
UV-curable organic-inorganic hybrid polyurethane coating
… a single ultraviolet (UV) trigger but two photo-initiators. Upon UV irradiation, the free-radical initiator initiated a free-radical reaction for acrylate cross-linking, and the photo-latent base initiated a sol-gel reaction for condensation of the silanes. This study explored the cure extent of …
-
A tour-de-force in polymer crosslinked aerogels
… polymerization (SIP) with a bidentate free-radical initiator structurally related to azobisisobutyronitrile (AIBN) and confined on mesoporous silica surfaces. Different monomers were introduced in the mesopores and upon heating at 70⁰C, all mesoporous surfaces throughout the entire skeletal …
-
Synthesis and cycloaddition chemistry 1,3-Bis(phenylsulfonyl)propadiene
… under thermal conditions in the presence of a radical initiator to obtain (E)-2-iodo-1 ,3-bis(phenylsulfonyl)prop-I-ene. Triethylamine induced dehydroiodination of the above addition product afforded high quality 1,3bis( phenylsulfonyl)propadiene after an aqueous reverse quench procedure …
-
SELECTIVE OXIDATION OF CYCLOHEXANE TO K-A OIL USING HETEROGENEOUS CATALYSTS
… influence of the initial concentration of the radical initiator, the stirring and the sampling methodologies. Moreover, the difficulties existing in products analysis were addressed by the utilization of different techniques (GC, GC-MS, HPLC). All the new catalysts were tuned and tested to work …
-
Selective oxidation of cyclohexane to k-a oil using heterogeneous catalysts
… influence of the initial concentration of the radical initiator, the stirring and the sampling methodologies. Moreover, the difficulties existing in products analysis were addressed by the utilization of different techniques (GC, GC-MS, HPLC). All the new catalysts were tuned and tested to work …
-
Conformationally Immobile Calix[6]arenes as Negative Resists in Electron Beam Lithography
… by AFM. Formulations involving the use of a radical initiator (benzoyl peroxide) were exposed for both conformers, and no significant change in pattern quality or sensitivity from nonintiator formulations was observed. The exposure characteristics of the conformationally immobile …
-
Aerogels and films through free radical polymerization
… process we synthesized a bidentate free radical initiator (Si-AIBN) that gets attached on the skeletal nanoparticles and induces crosslinking by surface initiated polymerization (SIP). Here, we extend the scope of Si-AIBN in two directions: (a) we demonstrate extremely adhering, …
-
Studies of the Evaluation of Solid Phase Dispersants in Polymer Blends
… which the preformed hydroperoxide acts as a free radical initiator for the graft copolymerisation. 2. By grafting of styrene into LDPE in the presence of free radical generators such as benzoyl peroxide (BPO) and cumene hydroperoxide (CHP). 3. By mechano-chemical synthesis, involving …
-
DEVELOPMENT OF NOVEL SENSORS FOR ANIONS OF ENVIRONMENTAL INTEREST
… (40 % m/m) and dicumyl peroxide (DCP) as free radical initiator (10% m/m). The Nemstian slope was -59.1 mV per decade over a linear range of 1 x 10'^-5 x 10"^ mol dm'^ nitrate, a limit of detection of 0.34 pmol dm'^ nitrate and a selectivity coefiBcient for nitrate against chloride ( ^ ° N 0 3 …
-
Single wall carbon nanotubes as viscosity modifiers in polypropylene matrix nanocomposites
… systems, benzoyl peroxide was used as the free radical initiator which could facilitate the covalent bonding of single walled nanotubes to the polymer chains in the melt. Both non-functionalized and functionalized hybrid nanocomposites were evaluated for their rheological properties; and for …
-
A study of the vapour phase pyrolysis and alkaline hydrolysis of chloroform
… could not be detected. Neither the addition of a radical initiator (azobisisobutyroni trile) nor an inhibitor (phenol) affected the breakdown, and so we have rejected the idea that the main reaction mechanism is of a radical nature. From the results obtained by varying the surface to volume ratio …
-
Radical Approaches to Alangium and Mitragyna Alkaloids
… (c). The approaches include the use of a key radical cyclisation to form the tri-cyclic core. Chapter 1 gives a general overview of radical chemistry and it focuses on the application of radical intermolecular and intramolecular reactions in synthesis. Consideration is given to the mediator of …
-
Investigation Of Parameters Enabling Admicellar Reversible Addition-Fragmentation Chain Transfer (Raft) Polymerization
… The effect of oxygen on the requisite amount of initiator and the polymer formed through the admicellar polymerization of styrene on silica particles was studied using cetyltrimethylammonium bromide (CTAB) as the adsorbed surfactant bilayer template, 2,2'-azobisisobutyronitrile (AIBN) as a …
-
The chemical modification of polymer blends by reactive processing
… in PS/EPDM blends via peroxide-initiated free radical reactions during melt mixing. From a comprehensive survey of previous studies of compatibility enhancement in polystyrene blends, it was recognised that reactive processing offers opportunities for technological success that have not yet …
-
The mechanochemical modification of polyolefins using reactive modifier systems
… processed with the modifier and a free radical initiator. The objective of this stage was to bind the modifier to the PP. In the second stage the modified PP was reactively processed with the glass fibre. The objective in this stage was to form a chemical bond between the bound modifier …
-
Synthesis and Characterization of Tailored Macromolecules via Stable Free Radical Polymerization Methodologies
The stable free radical polymerization methodology for production of controlled macromolecules was investigated using a novel monomer, 2-vinylnaphthalene. Initial polymerizations resulted in molecular weight distributions typical of conventional free radical polymerization techniques (>2.0). …
-
Hydrophosphination of Vinylcyclopropane & Quinine for Metal Coordination Chemistry
… by-products and can proceed with or without free radical initiators (highly reactive species with an unpaired electron), using either heat or light. This dissertation focuses on preparing new phosphine ligands through hydrophosphination. Chapter one details the UV light-induced ring opening of …
-
The development of bioabsorbable hydrogels on the basis of polyester grafted poly(vinyl alcohol)
… Hydroxyethyl methacrylate was used as an initiator which enables the simultaneous introduction of double bonds into the system. In the second step the hydroxy end groups of the polyesters were transferred into carboxylic groups by reaction with succinic anhydride. The third step was the …
-
Thermo-analytical and physico-chemical characterisation of organoclays and polymer-clay nacomposites.
… a current theory that structural iron acts as a radical trap. This is thought to significantly reduce the catalytic activity of the clay's acid sites until higher temperatures. The formulation of polystyrene-clay nanocomposites (PSCNs) by in-situ polymerisation led to various results pertaining …
Page 1 of 2