Charged stabilized copolymers compositions

When studying the free-radical copolymerization of methacrylic and acrylic acids with vinyl monomers, it was established that the addition of catalytic amounts of SnCl and (C6Hs)3SnH has a marked effect on the copolymer composition. It was found that complexes are formed by charge transfer between unsaturated acids and the above tin compounds. It has been suggested that the change in polymer composition is caused by the interaction of the tin compounds with a transition complex resulting in a decrease of the resonance stabilization of the latter 94,). 

Neoh and co-workers [110] investigated the simultaneous chemical copolymerization and oxidation of pyrrole and A-methylpyrrole by bromine and iodine. By varying the monomer feed ratio, they could in effect control the copolymer composition. Based on elemental analysis of the copolymers, they determined that ri = 1.13 and r2 = 0.35 for pyrrole and 1-methylpyrrole, respectively. In the copolymerization induced by bromine, the electrical conductivity, thermal stability and Br content of the doped copolymer decreased with increasing concentration of A/-methylpyrrole in the copolymer. When iodine was included in the charge, the halogen content of the copolymers did not vary substantially, but the electrical conductivity and thermal stability of the doped copolymer also decreased with an increase in the fraction of A/-methylpyrrole in the copolymer. 

The emulsion polymerisation process strategy, can have a considerable effect on molecular structure and particle morphology. The intrinsic factors as well as the process conditions determine the colloidal aspects of the copolymer latex (particle diameter, surface charge density, colloidal stability etc.), the characteristics of the polymeric material in the particles and the structure of the particles (copolymer composition as a function of particle radius etc.). In turn, these factors determine the properties of the latex and the copolymer product. 

Negatively charged amphiphilic block copolymers, (I), prepared by Seo [2] were effective as cationic drug carriers and provided the advantages of increased blood concentration and improved drug stability. Stable polymeric micelle-type drug compositions were prepared by Seo [3]. 

The type of emulsion stabilized by polymeric surfactants, charged or uncharged, was not investigated in detail, although it has long been understood that it was dependent of the structure of the surfactant macromolecules. In a series of papers, Riess and his coworkers [143-145] have investigated the effect of the composition and architecture of PS-PEO-based block copolymers (PS polystyrene PEO polyethylene oxide) on stability and emul-... 

A novel sulfonated copolymer, claimed to be superior to the aforesaid sulfonated polymers, has been introduced for boiler and cooling water treatment [20]. The polymer is said to have a unique composition based on multiple sulfonic acid containing monomers which provide hydrophobic character and high charge density [20]. This composition has been shown to provide a range of exceptional properties. The new polymer demonstrates not only equivalent or better performance for calcium phosphate and zinc stabilization, but also superior thermal stability when compared to other sulfonated polymers. A notable property of the new polymer is its ability to disperse and resolubilize preexisting scale and corrosion product. 

Another method to create hybrid nanoparticles is encapsulation of smaller nanoparticles, such as dendrimers, into larger nanoparticles, such as polymeric nanoparticle and liposomes using a double emulsion method.[36] Double emulsions may be formed with either the water-in-oil-in-water (W/OAV) or the oil-in-water-in-oil types (O/W/O). The W/O/W double emulsion method is more commonly used as it stabilizes the particles in the aqueous phase and encapsulates hydrophilic materials into a variety of polymers or copolymers with a controlled particle size. [37] This method allows for the preparation of hybrid nanoparticles that have two-size scale, i.e., polymeric nanoparticles of 50-200 nm and encapsulated dendrimers or other polymer conjugates of <10 nm).[36,38] The encapsulation process is affected by several parameters such as the chemical composition of the outer layers, size and surface charges of dendrimers, and ratios of the outer and inner nanoparticles. [36,25]... 

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