Poly(styrene‐co‐acrolein) latex particles: Copolymerization and characteristics

Abstract

SynopsisReactive microspheres suitable for binding proteins were prepared using emulsifier-free emulsion copolymerizations of styrene (St) and acrolein (AL) with various molar ratios of monomers St and AL. A maximum polymerization rate was obtained when the molar ratio of the monomers was 1 : 1. The diameter of the latex particles increased with increase in the amount of monomer AL. The amounts of aldehyde groups on the latex particle surfaces were determined by conductometric titration. The binding capacity of the copolymer latexes with spacer molecules was also examined. INTRODUCTIONImmunomicrospheres have been widely used in the biomedical and biochemical fields.' Several types of polymeric microspheres with various functional groups on their surfaces have been synthesized as carriers of protein^.^-^ Recently polyacrolein (PA) microspheres were synthesized by aqueous polymerization under alkaline conditions and by aqueous radical p~lymerization.~.~ PA microspheres have many aldehyde groups on their surfaces, and aldehyde groups can be used for the covalent binding of amino group-carrying biological materials, e.g., proteins, drugs, and enzymes, by the formation of Schiff base a t room temperature. Polyacrolein microspheres, however, have some problems: Monodisperse particle size cannot be achieved easily, and the specific gravity of the particles is too high to keep them in suspension for a long time without sedimentation.A copolymerization of acrolein with styrene seems to be, on the contrary, advantageous, because the copolymer particles obtained have a lower specific gravity than the polyacrolein particles, and are expected to be highly monodisperse. In this paper, poly(styrene-co-acrolein) latex particles were synthesized by emulsifier-free emulsion copolymerization. The amount of aldehyde groups localized on the latex particle surfaces (surface -CHO) was determined by conductometric titration. The polymerization process was examined in detail. The binding capacity of the latex particles with spacer molecules (6-amino-n-caproic acid) was also examined.*To whom all correspondence should be addressed. EXPERIMENTALS MaterialsStyrene (St) and acrolein (AL) were purified by distillation in vacuo. 6-Amino-n-caproic acid (8ACA), hydroxylamine hydrochloride and sodium borohydride were of analytical grade, and used without further purification. Sodium borohydride was used as a reducing agent for the introduction of spacer groups into latex particles. l-Ethyl-3-(3-dimethylamino-propyl) carbodiimide hydrochloride (EDC) was used for the coupling of proteins with latex particles? Other reagents were commercially available. Water was doubly distilled before use. Preparation of Latex ParticlesA series of poly(styrene-co-acrolein) (PSt/AL) latexes were prepared by an emulsifier-free emulsion copolymerization. The polymerization recipes are listed in Table I. All polymerization reactions were carried out in a 250-mL round-bottomed four-necked flask. The prescribed amounts of St and AL were copolymerized in 125 mL of water...

Electrokinetic Behavior of Polystyrene Latexes with Different Surface Groups: Effect of Heat Treatment

“…Since the aldehyde groups have the commercial device Zeta-Sizer 4 (Malvern Instruments, England). The electrophoretic mobility values were obtained no charge we followed the method of the hydroxylamine hydrochlorate reported by Yan et al (10). The titrations for by taking the average of (at least) six measurements at the stationary level in a cylindrical cell, changing the suspension AD-1 latex were shown and described in a previous paper (11).…”

Acetal-functionalized polymer particles useful for immunoassays

“…and the amounts of the CHO surface groups were determined after acid cleavage of the acetals and The reaction mixture was kept for 1 h at room temperature to swell the seed particles with the titration with hydroxylamine hydrochloride. 4 The determination of the surface charge dentermonomers. Once the reaction temperature (70ЊC) was reached, the initiator aqueous solution sity (s) was made as follows: was charged into the reactor to start the polymerization.…”

“…Polymer latex particles ter of the test, the reactivity, and the stability of with adsorbed antibodies or antigens are used as immunoassays. carriers of diagnostic reagents for the clinical Recently some authors 4,7,8 have indicated that evaluation of a great variety of analytes. 1,2 A new the use of aldehyde groups on the surface of the generation of functionalized latex particles have latex particles could simplify the covalent bonding been synthesized to bond covalently the amino of the protein due to the direct reaction between groups of biomolecules.…”

“…1,2 A new the use of aldehyde groups on the surface of the generation of functionalized latex particles have latex particles could simplify the covalent bonding been synthesized to bond covalently the amino of the protein due to the direct reaction between groups of biomolecules. [3][4][5][6] the aldehyde groups of the particle surface and the amino groups of the protein molecules. …”

Synthesis of functional magnetic porous SrFe12O19/P(St-DVB-MAA) microspheres by a novel suspension polymerization

“…There are three different slopes in the potentiometric curve (Fig. 3) caused by: (i) the titration of NaOH for neutralization of the HCl previously added, (ii) the titration of the carboxyl groups of the magnetic particles surface, and (iii) the excess of titration agent (NaOH).The amount of COOH groups on the surface is calculated from the break in curve and expressed in terms of milliequivalent of COOH groups per 1 g of the magnetic microspheres [20]:…”