Synthesis of amino-functionalized latex particles by a multistep method (original) (raw)
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Journal of Polymer Science Part A: Polymer Chemistry, 2005
Monodisperse latex particles with different amounts of surface amino and amidine groups were synthesized by means of a semicontinuous seeded cationic emulsion polymerization of styrene and a cationic monomer. High partial overall conversions for styrene and limited ones for the cationic monomer were achieved. A reliable method for the quantification of surface amidine and amino groups was developed. It was found that the amount of surface amidine groups provided by the cationic initiator was higher when the amount of cationic monomer added increased. The value for the partition coefficient of the cationic monomer indicated that this polymerizes with the same probability in the water phase as in the particle. The colloidal stability, in terms of critical coagulation concentration, shows that the latexes would be useful as polymeric supports in immunoassays. V
Modeling the emulsion polymerization of amino-functionalized latex particles
Polymer, 2006
A mathematical model for a semicontinuous seeded cationic emulsion polymerization was developed. The model includes the most distinctive features of the copolymerization of a cationic hydrophilic monomer with a hydrophobic one, including polymerization of the hydrophilic monomer in the outer shell of polymer particles and in the aqueous phase, and the possibility of having radical concentration profiles in the polymer particles. The reactions were carried out by means of a semicontinuous seeded cationic emulsion polymerization under starved conditions for styrene, which was the main monomer employed. The model predicts the evolution of the fractional overall conversions, the thickness of the outer shell, the total surface charge density and the partial conversions for the semicontinuous seeded cationic emulsion polymerization of styrene and aminoethyl methacrylate hydrochloride. Furthermore, the model can distinguish between the surface charge density provided by the cationic monomer than that given by the cationic initiator. Therefore, this model can predict the best conditions to obtain well-defined latexes with specific amounts of surface amino and amidine groups useful for immunoassays.
Polystyrene latex particles bearing primary amine groups via soap‐free emulsion polymerization
Polymer International, 2020
Polystyrene latexes were prepared in the presence of an amino-containing functional comonomer, i.e. N-(3-aminopropyl) methacrylamide hydrochloride (APMH), via soap-free batch emulsion polymerization initiated by the cationic initiator 2,2'-azobis (2-amidino propane) di-hydrochloride (V50). These latexes were characterized through studying the influence of ionic comonomers on the polymerization kinetics, particle size, surface charge density and colloidal properties. The synthesized latexes were monodisperse with a final size between 100 and 600 nm depending on the APMH concentration. The initial polymerization rate and the particles number increased in accordance with the Smith-Ewart theory for soapfree styrene emulsion polymerization with a hydrophilic functional comonomer. The final functionalization rate of the particles has been particularly studied with the intention of fitting the prepared latexes to be utilized in the immobilization of biological molecules for biological sample preparation and diagnostic applications.
Synthesis and characterization of amphoteric latex particles
2003
Amphoteric terpolymers composed of acrylamide, 2-methylacryloylxyethyl trimethyl ammonium chloride, and 2-acrylamido-2-methyl-1-propane sulfonate were prepared via free-radical polymerization in aqueous solution of ammonium sulfate (AS), using poly(2-methylacryloylxyethyl trimethyl ammonium chloride) as stabilizer to yield terpolymers with random distributions. The particle size of the synthesized amphoteric polyacrylamide (AmPAM) ranged from 1 to 8 μm and the intrinsic viscosity ranged from 5.6 to 14.2 dL/g. The influences of aqueous solution of AS concentration, stabilizer concentration, initiator concentration, monomer concentration on the conversion of monomer, the intrinsic viscosity, and the particle size were systematically investigated. The characteristic of amphoteric polymer was also be studied. Throughout the study, we found that the isoelectric point of the amphoteric polyelectrolyte we synthesized is about 7. With the increase in sodium chloride, the reduced viscosity of AmPAM increased. Among the different type of inorganic salt, the degree of influence of anionic is I > Br > Cl.
Synthesis and characterization of saccharide-based latex particles
Journal of Polymer Science Part A: Polymer Chemistry, 2006
The synthesis of new polymer colloids based on renewable resources, such as sugar-derived monomers, is nowadays a matter of interest. These new polymeric particles should be useful in biomedical applications, such as drug delivery, because of their assumed biodegradability. In this work, two new families of polymer latex particles, based on a sugar-derived monomer, 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-a-D-glucofuranose (3-MDG), were produced and characterized. The syntheses of poly(3-MDG) crosslinked particles and those obtained by copolymerization with methacrylic acid (MAA), poly(3-MDG-co-MAA) crosslinked particles, were prepared by surfactant-free emulsion polymerization in a batch reactor. The average particle diameter evolutions, the effect of pH of the dispersion medium on the final average diameters, together with the microscopic and morphological analysis of the particle's surface and inner dominium, were analyzed. Poly(3-MDG-co-EGDMA) stable particles were obtained by adding low amounts of initiator. The surface-charge density of these particles corresponded to the sulfate groups coming from the initiator. In the second family of latices, poly(3-MDG-co-MAA-co-EGDMA) particles, DCP measurements and SEM and TEM observations showed that the sizes and surface characteristics depended on the amounts of MAA and crosslinker used in the reaction mixture.
Functionalized Polymer Colloids: Synthesis and Colloidal Stability
Current Organic Chemistry, 2005
Functionalized polymer colloids were synthesized by emulsion polymerization having specific ionic groups on surface. In this review, a comprehensive study on the synthesis of functionalized polymer colloids is carried out. Monodisperse polymer colloids with acetal, aldehyde, chloromethyl, and amino functionalities were synthesized by a multi-step emulsion polymerization process. In the first step, the seeds were synthesized by batch emulsion polymerization of styrene; and in the following steps, onto the previously formed polystyrene latex particles, the functional monomers were co-and/or ter-polymerized. Some of the synthesized latexes were chosen as the polymeric support to carry out the covalent coupling with a protein and to test the utility of the latex-protein complexes formed in immunoassays. In addition, the colloidal stability of polymer colloids is theoretically and experimentally analyzed. This study shows that classical DLVO (Derjaguin, Landau, Verwey, Overbeek) theory can explain the stability of weakly charged polymer colloids. This is not sufficient in the case of highly charged polymer colloids using hydrophilic monomers. In such a system, the steric repulsion is not negligible and an electrosteric repulsion mechanism must be considered. Our interest has centered on studying this effect from a quantitative point of view. Although the method used contains five variables, it is possible to considerably reduce this number if some of them are calculated by alternative methods (ψd, δ) or taken from literature (A, χ).
Journal of colloid and …, 2002
Following a previous work (J. L. Luna-Xavier et al., Colloid Polym. Sci. 279, 947 (2001)), silica-poly (methyl methacrylate) (PMMA) nanocomposite latex particles have been synthesized in emulsion polymerization using a cationic initiator, 2,2-azobis (isobutyramidine) dihydrochloride (AIBA), and a nonionic polyoxyethylenic surfactant (NP 30). Silica beads with diameters of 68, 230, and 340 nm, respectively, were used as the seed. Coating of the silica particles with PMMA was taking place in situ during polymerization, resulting in the formation of colloidal nanocomposites with a raspberry-like or a core-shell morphology, depending on the size and nature of the silica beads. The amount of surface polymer was quantified by means of ultracentrifugation and thermogravimetric analysis as extensively described in the first article of the series (see above reference). The influence of some determinant parameters such as the pH of the suspension, the initiator, silica, monomer, or surfactant concentration on the amount of coating polymer and on the efficiency of the coating reaction was investigated in details and discussed in light of the physicochemical properties of the seed mineral. Electrostatic attraction between the positive end groups of the macromolecules and the inorganic surface proved to be the driving force of the polymer assembly on the seed surface at high pH, while polymerization in adsorbed surfactant bilayers (so-called admicellar polymerization) appeared to be the predominant mechanism of coating at lower pH. Optimal conditions have been found to reach high encapsulation efficiencies and to obtain a regular polymer layer around silica.
Elaboration of hydrophilic aminodextran containing submicron magnetic latex particles
Colloid and Polymer Science, 2009
Aminodextran containing submicron magnetic latex particles were prepared in two steps: (a) transformation of oil-in-water magnetic emulsion into structured magnetic latex particles via combination of seed and miniemulsion-like polymerization process and (b) immobilization (adsorption and chemical grafting) of prepared aminodextran onto negatively charged seed magnetic latex particles. The elaborated magnetic latex particles were characterized in terms of particle size, size distribution, morphology, surface charge density, chemical composition, magnetic properties, and also colloidal stability. The results showed that the morphology of the prepared seed magnetic latex is core–shell like and the cationic latex particles are hydrophilic and of high colloidal stability, irrespective of the aminodextran immobilization process.