Heterogeneous latices as binders in porous particle structures

Rigdahl, Mikael; Lason, L.; Hagen, R.W.; Karlsson, Ola; Wesslén, Bengt

doi:10.1002/(sici)1097-4628(19970131)63:5<661::aid-app14>3.0.co;2-x

Cited by 7 publications

(7 citation statements)

References 1 publication

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“…Polymer nanoparticles are of increasing interest as a basis for technical products such as coatings, paints, 1 or paper products 2,3 as well as for biotechnological purposes. 4,5 All of these applications are based either on a specific adhesion of the particles on organic or inorganic surfaces or on a specific adsorption of molecules on the polymer particles.…”

Section: Introductionmentioning

confidence: 99%

Adhesion of Spherical Polyelectrolyte Brushes on Mica: An in Situ AFM Investigation

Gliemann¹,

Ballauff

et al. 2006

Langmuir

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We demonstrate that the adsorption of cationic spherical polyelectrolyte brushes (SPB) on negatively charged mica substrates can be controlled in situ by the ionic strength of the suspension. The SPB used in our experiments consist of colloidal core particles made of polystyrene. Long cationic polyelectrolyte chains are grafted onto these cores that have diameters in the range of 100 nm. These particles are suspended in aqueous solution with a fixed ionic strength. Atomic force microscopy (AFM) in suspension as well as in air was used for surface characterization. In pure water the polymer particles exhibit a strong adhesion to the mica surface. AFM investigations of the dry samples show that the particles occupy the identical positions as they did in liquid. They were not removed by the capillary forces within the receding water front during the drying process. The strong interaction between the particles and the mica surface is corroborated by testing the adhesion of individual particles on the dried surface by means of the AFM tip: after a stepwise increase of the force applied to the surface by the AFM tip, the polymer particles still were not removed from the surface, but they were cut through and remained on the substrate. Moreover, in situ AFM measurements showed that particles which adsorb under liquid in a stable manner are easily desorbed from the surface after electrolyte is added to the suspension. This finding is explained by a decreasing attractive particle-substrate interaction, and the removal of the particles from the surface is due to the significant reduction of the activation barrier of the particle desorption. All findings can be explained in terms of the counterion release force.

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Section: Introductionmentioning

confidence: 99%

Adhesion of Spherical Polyelectrolyte Brushes on Mica: An in Situ AFM Investigation

Gliemann¹,

Ballauff

et al. 2006

Langmuir

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“…In a series of articles, we presented results from the preparation of heterogeneous S/isoprene and S/B latex particles 4, 14, 24, 53, 54. In the present work, the aims were to find relations between, on the one hand, the molecular weight and the crosslink density of the seed polymer and, on the other, the reaction kinetics of the second stage of a seeded emulsion polymerization.…”

Section: Introductionmentioning

confidence: 98%

“…A combination of low film‐forming temperature and high modulus and stiffness at ambient temperature is difficult to obtain with conventional S/B latexes. However, heterogeneous latexes offer these binder properties 3, 4…”

Section: Introductionmentioning

confidence: 99%

Influence of seed polymer molecular weight on polymerization kinetics and particle morphology of structured styrene-butadiene latexes

Karlsson¹,

Hassander²,

Wesslén³

2000

J. Appl. Polym. Sci.

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Heterogeneous film-forming latexes were prepared using two-stage, seeded emulsion polymerization. The polymerization was performed in a calorimetric reactor with a control unit that monitored the reaction rate and controlled the charging rate of the monomers. Three types of styrene seed latexes were prepared at 70°C. The first was an unmodified polystyrene (PS) latex. The second had the molecular weight lowered by the use of carbon tetrachloride (CCl 4 ) as a chain-transfer agent, added at the start of the polymerization. For the third one, divinylbenzene (DVB) was used as a comonomer. DVB was added under starved conditions near the end of the polymerization to achieve crosslinked particle shells and to introduce double bonds as possible grafting sites. The second polymerization step was performed at 80°C as a batch operation in a 200-mL calorimeter reactor. The second-stage polymer was poly(styrene-co-butadiene-comethacrylic acid) (S/B/MAA). A fixed S/B ratio was used together with varying small amounts of MAA. Particle morphology and particle-size distributions were examined after the second stage using TEM after staining with osmium tetroxide. The particle morphology was found to depend on both the seed composition and the amount of MAA used in the second stage. Molecular weight and crosslinking of the DVB-containing seed influenced the internal particle viscosity, which gave differences in the polymerization rate and the particle morphology. Crosslinking of the second-stage polymer decreased the monomer concentration in the particles, which could be detected as a change in the slope the pressure/conversion curve. This phenomenon was used to indicate the critical conversion for crosslinking of the second-stage polymer.

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“…For example, polymer gels obtained by radical copolymerization of mixtures of vinyl and divinyl monomers are gaining increasing importance in membranes, superabsorbent materials and macroreticular resins, as well as in diene rubber technology (Chandrasiri and Wilkie, 1996;Rigdahl et al, 1997;Zhou et al, 2002). For example, polymer gels obtained by radical copolymerization of mixtures of vinyl and divinyl monomers are gaining increasing importance in membranes, superabsorbent materials and macroreticular resins, as well as in diene rubber technology (Chandrasiri and Wilkie, 1996;Rigdahl et al, 1997;Zhou et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Mathematical Modeling of Multimonomer (Vinylic, Divinylic, Acidic) Emulsion Copolymerization Systems

Zubitur¹,

Armitage²,

Amor³

et al. 2003

Polymer Reaction Engineering

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A mathematical model for free-radically initiated semi-continuous emulsion polymerizations of a multimonomer system containing vinylic, divinylic and acidic monomers in the presence of chain transfer agent (CTA) was deleloped. In addition to the more traditional aspects of emulsion polymerization, the model takes into account both the presence of water-soluble monomers and the formation of gel due to the polymerization of a divinylic monomer in the presence of CTA. The outputs of the model are the time evolution of monomers conversions, copolymer composition, molecular weight of the sol polymer and gel fraction.

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Heterogeneous latices as binders in porous particle structures

Cited by 7 publications

References 1 publication

Adhesion of Spherical Polyelectrolyte Brushes on Mica: An in Situ AFM Investigation

Adhesion of Spherical Polyelectrolyte Brushes on Mica: An in Situ AFM Investigation

Influence of seed polymer molecular weight on polymerization kinetics and particle morphology of structured styrene-butadiene latexes

Mathematical Modeling of Multimonomer (Vinylic, Divinylic, Acidic) Emulsion Copolymerization Systems

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