Polymer Synthesis and Characterization - ScienceDirect
The chemical reaction between Zn(CH3COO)2 and NaOH was carried out in the presence of hexamethylenetetramine (HMTA), at room temperature. The resulting precipitate of Zn(OH)2 was washed with water several times, and then underwent thermal treatment in a Teflon-lined autoclave. Based on SEM images, the authors concluded that the HTMA, as a surfactant, plays an important role in the modification of the ZnO particles. The shape of the particles is also affected by the time and temperature of the hydrothermal process. With an increase in time, temperature and surfactant concentration, the size of the particles increases. Hydrothermal processing of the precursor, followed by drying, produced spherical particles of ZnO with sizes in the range 55–110 nm depending on the conditions of synthesis.
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Poly(methyl methacrylate) was also used as a ZnO surface modifier by Hong . Nanoparticles of zinc oxide with a diameter of approximately 30 nm were synthesized by means of homogeneous precipitation followed by calcination. In order to introduce reactive groups onto the ZnO surface, a reaction was carried out between the hydroxyl groups and a silane coupling agent (3-methacryloxypropyltrimethoxysilane). Graft polymerization was effected by means of a reaction between the ZnO, containing silanol groups, and the monomer. Tests showed that the polymerization does not alter the crystalline structure of the ZnO nanoparticles. Their dispersion in the organic solvent can greatly improve the graft polymerization of PMMA, and further improvement can be achieved by the addition of other surfactants. Modification of ZnO nanoparticles by grafted PMMA increases the degree of lyophilicity of the inorganic surface and reduces the formation of aggregates. The work of Hong , showed that ZnO nanoparticles grafted with PMMA can increase the thermal stability of polystyrene.
Description :Most practitioners and students of polymer chemistry are familiar, in general terms at least, with the established methods of polymer synthesis - radical, anionic, cationic and coordination addition p...
Handbook Of Polymer Synthesis Characterization
Stanković  extended their previous study to investigate mechanical-thermal synthesis (MTS)—mechanical activation followed by thermal activation of ZnO from ZnCl2 and oxalic acid (C2H2O4·2H2O) as reactants with the intention of obtaining pure ZnO nanopowder. The study also aimed to examine the effects of oxalic acid as an organic PCA, and different milling times, on the crystal structure, average particle size and morphology of ZnO nanopowders. The mixture of initial reactants was milled from 30 min up to 4 h, and subsequently annealed at 450 °C for 1 h. Qualitative analysis of the prepared powders was performed using X-ray diffraction (XRD) and Raman spectroscopy. The XRD analysis showed perfect long-range order and the pure wurtzite structure of the synthesized ZnO powders, irrespective of the milling duration. By contrast, Raman spectroscopy indicates a different middle-range order of ZnO powders. From the SEM images, it is observed that the morphology of the particles strongly depends on the milling time of the reactant mixture, regardless of the further thermal treatment. A longer time of milling led to a smaller particle size.
Polymer Synthesis: Theory and Practice ..
An example of a hydrothermal reaction is the synthesis of zinc oxide as proposed by Chen , using the reagents ZnCl2 and NaOH in a ratio of 1:2, in an aqueous environment. The process took place by way of reaction (5):
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Edited and authored by top international experts, this first book on conjugated polymers with a focus on synthesis provides a detailed overview of all modern synthetic methods for these highly interesting compounds. As such, it describes every important compound class, including polysilanes, organoboron compounds, and ferrocene-containing conjugated polymers. An indispensable source for every synthetic polymer chemist.