286 results on '"Alain Guyot"'
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2. Polyurethane-acrylate hybrid latexes from miniemulsion polymerization: effect of endgroups on structure and properties
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Liwei Jin, Yuzhi Xu, Alain Guyot, F. Chu, Chunpeng Wang, and Mingtao Lin
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chemistry.chemical_classification ,Acrylate ,Materials science ,Polymers and Plastics ,Polymer ,Isocyanate ,Miniemulsion ,chemistry.chemical_compound ,Polypropylene glycol ,chemistry ,Polymerization ,Polymer chemistry ,Isophorone diisocyanate ,Polyurethane - Abstract
Polyurethanes (PUs) were prepared by condensation of isophorone diisocyanate and polypropylene glycol (PPG) using butane diol as a chain extender. Methoxy or methacrylic endgroups of PUs were obtained upon reacting the residual isocyanate group (NCO) moiety with either methanol or hydroxyethylmethacrylate (HEMA). The resulted PUs were dissolved in mixtures of acrylic monomers, and then the miniemulsion polymerization was conducted. These PUs were quite efficient hydrophobes for polyurethane (PU)-acrylate hybrid miniemulsion polymerization. It was also demonstrated from the results of differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) that the microphase separation of soft and hard phase of PUs in hybrid latexes was more significant than that of original PUs. The PU containing the methacrylic endgroup was almost fully cross-linked during miniemulsion polymerization, resulting in less hard–hard segment of PU hydrogen bond in the hybrid polymer. Some specific morphologies were also discussed from transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The mechanical properties of these films were studied from the strain–stress curves. Copyright © 2008 John Wiley & Sons, Ltd. more...
- Published
- 2008
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Catalog
3. Hybrid polymer latexes
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Chunpeng Wang, F. Joseph Schork, Katharina Landfester, and Alain Guyot
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chemistry.chemical_classification ,Condensation polymer ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Radical polymerization ,Unsaturated monomer ,Emulsion polymerization ,Surfaces and Interfaces ,Polymer ,chemistry.chemical_compound ,Monomer ,chemistry ,Chemical engineering ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Ceramics and Composites ,Polymer blend - Abstract
Hybrid polymer latexes will be defined here as colloidal dispersions in which at least two distinct polymers exist within each particle. The two polymers may form a homogenous blend within the particle or microphase separation may occur. There are two general routes for their preparation. The first involves the use of a mini-emulsion polymerization process, in which a first polymer, most often prepared via polycondensation (or polyaddition), is dissolved in an unsaturated monomer (or a mixture of monomers). The solution is first emulsified into small droplets under a high shear process and then polymerized through a radical polymerization process. A variation of this route involves the synthesis of the polycondensate directly in the mini-emulsion. The second route involves a seeded emulsion polymerization of unsaturated monomer(s), in which the polycondensate is modified for use as a seed in the emulsion polymerization. Most often, styrenic and acrylic monomers are used, while the polycondensate may be alkyd resins, polyesters, epoxy resins, polyurethanes, or other polymers. The two routes are described in detail, as are the properties of the resulting materials (mostly as films). Up to now, there have been very few trials for the comparison of the two main routes. Most often the comparison is related to blends of the two kinds of emulsified polymers. more...
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- 2007
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4. Acrylonitrile copolymerization. VII Solvents effects in styrene copolymerization
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E. Zaganiaris, C. Pichot, and Alain Guyot
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chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Polymer chemistry ,General Engineering ,Solvation ,Copolymer ,Dimethylformamide ,Acrylonitrile ,Photochemistry ,Toluene ,Styrene - Abstract
The styrene-acrylonitrile radical copolymerization kinetics have been studied for polymerizations carried out in two different solvents, toluene and dimethylformamide (DMF), in the whole range of monomer mixture compositions and at various dilutions. The copolymer prepared in toluene solutions are poorer in acrylonitrile than those prepared in bulk. The reverse situation is observed in DMF solution, where the polymerization rate is the highest. In the latter case, also for acrylonitrile rich mixtures, the relative polymerization rate of styrene tends to increase with conversion; this effect is attributed to preferential solvation of styrene. Possible explanation of these facts are briefly discussed. more...
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- 2007
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5. Crystallization of poly(vinyl chloride) at high temperatures
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Alain Michel and Alain Guyot
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Materials science ,Analytical chemistry ,Vinyl chloride ,Ampoule ,law.invention ,Amorphous solid ,chemistry.chemical_compound ,Crystallinity ,chemistry ,law ,Melting point ,Organic chemistry ,Thermal stability ,Crystallite ,Crystallization - Abstract
A sample of poly(vinyl chloride) having a very good thermal stability and a high initial crystallinity was annealed between 80 and 260°C, either as it was or mixed with stabilizers, in sealed ampoules or in KBr pellets, and studied by X-ray and IR techniques. When the sample is treated in glass ampoules, practically no changes in IR spectra are observed up to 240°C; the X-ray diagrams, however, show an increase in the size of the crystallites but no increase in the amount of crystalline material. The melting point is observed by X-ray between 250 and 260°C. If the sample is heated in the KBr pellets, it undergoes some stress which causes an increase of the crystalline IR bands at 604 and 635 cm−1, but no change in the X-ray diagram. At higher temperatures, dehydrochlorination is enhanced by the KBr and involves chiefly the amorphous regions. more...
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- 2007
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6. Radical and ionic polymerization of vinyl chloride with tert-butylmagnesium chloride
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Alain Guyot and Jacques Mordini
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Kinetic chain length ,Living free-radical polymerization ,chemistry.chemical_compound ,Polymerization ,Cobalt-mediated radical polymerization ,Chemistry ,Radical polymerization ,Polymer chemistry ,Reversible addition−fragmentation chain-transfer polymerization ,Ionic polymerization ,Vinyl chloride - Abstract
The earlier results concerning the kinetics of polymerization and initiator consumption, molecular weight distribution, and the nature of the chain ends in the polymerization of vinyl chloride initiated by tert-butylmagnesium chloride (tBuMgCl) in tetrahydrofuran and other solvents are rediscussed in terms of the simultaneous participation of an ionic mechanism and a radical mechanism. The former is operative mainly at the beginning of the process and gives very low molecular weight products. The latter is responsible for the formation of the high polymer. The radicals are generated from the organomagnesium compound giving a tert-butyl group as a chain end for every macromolecule. New experiments support the radical mechanism: comparison with radical polymerizations in the same conditions of temperature and solvent medium, inhibition by NO, copolymerization with vinylidene chloride. Also the high polymer is not obtained if the ionic mechanism is exalted by introduction of a powerful solvating agent, the dimethoxyethane. more...
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- 2007
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7. Sur le Mécanisme d'une Polymérisation Anionique du Chlorure de Vinyle
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Alain Guyot and Pham Quang Tho
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Chemistry - Published
- 2007
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8. Synthesis and characterization of block-copolymer surfactants with specific interactions with associative thickeners
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Nicolas Gaillard, Jerome P. Claverie, and Alain Guyot
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Materials science ,General Chemical Engineering ,Organic Chemistry ,Radical polymerization ,Emulsion polymerization ,Raft ,Surfaces, Coatings and Films ,Hydrophilic-lipophilic balance ,chemistry.chemical_compound ,Polymerization ,chemistry ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Living anionic polymerization ,Acrylic acid - Abstract
It has been theorized that, in order to get some positive interaction with the associative thickeners, the surfactants should have, at the end of the hydrophilic sequence, a short hydrophobic group. On the other hand, in order to control the hydrophilic lipophilic balance (HLB), it is wise to use well controlled polymerization procedures to build the block-copolymer. Then, the safer and simplest way to reach such goal is to use the ring-opening living anionic polymerization of butylene oxide (hydrophobic sequence) and then ethylene oxide (hydrophilic sequence); this living block-copolymer is then killed using an alkyl or aryl chloride (or bromide). However, because such surfactants include at the end of the hydrophilic sequence a hydrophobic group, they tend to adopt, when adsorbed onto hydrophobic latex particles, a back-folded conformation. In order to get for them an extended conformation, the hydrophilic sequence should have charges able to repel each other. This was achieved upon preparing block-copolymers of acrylic acid and butylacrylate, using a controlled radical polymerization with reversible addition fragmentation transfer (RAFT) agents, starting with the poly(acrylic acid) (PAA) sequence. Then, the radical fragment coming from the RAFT agent is at the end of the PAA sequence. A few rheological data actually confirm the interest of the concept. more...
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- 2006
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9. Mechanical Properties of Films from Hybrid Acrylic‐Polyurethane Polymer Colloids
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Chunpeng Wang, F. Chu, and Alain Guyot
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Emulsion polymerization ,Polymer ,Surfaces, Coatings and Films ,Styrene ,chemistry.chemical_compound ,Colloid ,Monomer ,chemistry ,Polymerization ,Polymer chemistry ,Physical and Theoretical Chemistry ,Triethylamine ,Polyurethane - Abstract
A variety of polyurethane based on the polyaddition of isophoronediisocyanate and polypropyleneglycol has been used to prepare acrylic‐polyurethane hybrid polymer colloids, through either mini‐emulsion polymerization of their solutions in a mixture of monomers or seeded emulsion polymerization of this mixture from seeds of modified polyurethane containing dimethylolpropionic acid neutralized with triethylamine. The mixture of monomer is composed of 30% styrene, 30% methylmethacrylate, and 40% butylacrylate. The mechanical properies of films prepared through coalescence of these latexes where studied. The effect of various parameters such as the composition and the amount of polyurethane as well as the synthesis process are discussed. more...
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- 2006
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10. Hybrid acrylic–polyurethane latexes: Emulsion versus miniemulsion polymerization
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Alain Guyot, Chunpeng Wang, F. Chu, Catherine Gauthier, and Fernande Boisson
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Materials science ,Polymers and Plastics ,Butyl acrylate ,Azobisisobutyronitrile ,Emulsion polymerization ,General Chemistry ,Surfaces, Coatings and Films ,Miniemulsion ,chemistry.chemical_compound ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Isophorone diisocyanate ,Polyurethane - Abstract
Two kinds of hybrid acrylic–polyurethane (PUA) latexes are compared according to their synthesis and properties. The acrylic part is a copolymer of styrene, methyl methacrylate, and butyl acrylate. The PUAs are based on the polycondensation of isophorone diisocyanate and poly(propylene glycol) using butanediol and ethylene diamine as chain extenders. The first class result from the polymerization of miniemulsions of solutions of PU in the mixture of monomers using benzoyl peroxide as an initiator at 80°C. In the second class PUs modified by neutralized dimethylolpropionic acid are used as seeds and emulsifiers for emulsion polymerization of the monomer mixtures initiated with azobisisobutyronitrile at 75°C. The polymerization kinetics are compared, as well as the morphology of the latex particles. Films are obtained upon coalescence of these latexes, and the surface composition of these films and their tensile properties are studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3927–3941, 2006 more...
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- 2006
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11. Silicone–polyacrylate composite latex particles. Particles formation and film properties
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Mingtao Lin, F. Chu, Jean-Luc Putaux, Alain Guyot, and Elodie Bourgeat-Lami
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chemistry.chemical_classification ,Acrylate ,Materials science ,Polymers and Plastics ,Polydimethylsiloxane ,Organic Chemistry ,Emulsion polymerization ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Copolymer ,Particle ,Particle size ,Composite material ,0210 nano-technology - Abstract
Composite latex particles with a polydimethylsiloxane PDMS core and a poly(methyl methacrylate-co-n-butyl acrylate) P(MMA-BA) copolymer shell were synthesized by seeded emulsion polymerization using the PDMS latex as the seed. The compatibility between the two polymer phases was changed by introducing vinyl groups in the latex core. Monomer conversions and particle size evolution were monitored to see the influence of the nature of the core functionality on the polymerization kinetics and on the extent of secondary nucleation. Particle morphology was characterized by cryo-transmission electron microscopy. The P(MMA-BA) copolymer formed a regular shell around the PDMS seed, whereas nonuniform coatings were formed when vinyl functionalities were introduced into the seed. Films were produced from the latexes, and their surface property was analyzed by X-ray photoelectron spectroscopy and contact angle measurements. It was shown that the PDMS component segregated to the polymer/air interface and that the extent of segregation depended on the original particles structure. Because PDMS has a very low glass transition temperature, it can easily diffuse throughout the film material. However, protected by an acrylic shell, polymer diffusion is significantly hindered and the film then displays all the characteristic properties of the acrylic copolymer. The surface composition of the films formed by the structured particles which PDMS core was not totally covered by the polyacrylate, was found to be intermediate between the composition of the films issued from the core–shell latexes and that of the films produced from blends of pure polyacrylate and PDMS latexes. more...
- Published
- 2005
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12. Hybrid polymer latexes: acrylics–polyurethane from miniemulsion polymerization: properties of hybrid latexes versus blends
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Jean-Paul Chapel, F. Chu, C. Wang, Catherine Gauthier, Christian Graillat, and Alain Guyot
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Polymer ,Miniemulsion ,Contact angle ,chemistry.chemical_compound ,Monomer ,Polypropylene glycol ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Isophorone diisocyanate ,Polyurethane - Abstract
Hybrid polymer latexes polyurethane/polyacrylic esters, are prepared through miniemulsion polymerization of polyurethane solutions in acrylic monomers. The polyurethanes are prepared by condensation of isophorone diisocyanate on polypropylene glycol (Mn=1000) and butane diol as chain extender. The NCO chain ends being reacted with water (which act as a further chain extender producing some urea bonds). They are miniemulsified in a mixture of methylmethacrylate and butylacrylate monomers, and the miniemulsion are polymerized using benzoylperoxide as initiator. Films were obtained for different hybrid latexes of various compositions. Their mechanical properties have been compared with those of films from the basic components (polyurethane and acrylic latexes), as well as films from blends of these components. Some specific features of the surface of these films are also discussed from microscope images (TEM and AFM) as well as from contact angle measurements. more...
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- 2005
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13. Hybrid polymer latexes?acrylics-polyurethane: II. mechanical properties
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F. Chu, Chunpeng Wang, Alain Guyot, Catherine Gauthier, and Christian Graillat
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Polymer ,Hydrophobe ,Miniemulsion ,chemistry.chemical_compound ,Polypropylene glycol ,chemistry ,Butanediol ,Polymerization ,Polymer chemistry ,Isophorone diisocyanate ,Polyurethane - Abstract
Polyurethanes were prepared from reaction of isophorone diisocyanate (IPDI) with polypropylene glycol (PPG), with chain extension with butanediol (BDO). Their end groups are either methoxy, or methacrylic groups. These polyurethanes (PUs) are dissolved in mixtures of acrylic monomers (methylmethacrylate, MMA, and butylacrylate, BA). The solutions are sonicated to produce miniemulsion droplets, using sodium dodecyl sulfate (SDS) as surfactant, the PU being the hydrophobe. These miniemulsions were polymerized, with an oil-soluble peroxide initiator. Those latexes with methoxy end groups in the PU are fully soluble, while those containing the acrylic end groups are almost fully crosslinked, but can easily form smooth films. The mechanical properties of these films were studied from their stress–strain curves, and compared with those films formed from the uncrosslinked hybrid latexes. Copyright © 2005 John Wiley & Sons, Ltd. more...
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- 2005
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14. Reactions of Maleisomides with Alcohols
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I. Uzulina, Andris Zicmanis, Christian Graillat, Alain Guyot, and Igors Klimenkovs
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chemistry.chemical_classification ,Polymers and Plastics ,Double bond ,Maleic acid ,Cationic polymerization ,Emulsion polymerization ,Surfaces, Coatings and Films ,Styrene ,chemistry.chemical_compound ,chemistry ,Amide ,Critical micelle concentration ,Polymer chemistry ,Copolymer ,Organic chemistry ,Physical and Theoretical Chemistry - Abstract
New surfactants (surfmers) with various amide and ester groups next to C˭C double bonds have been obtained. Maleic acid amidesters (AE) with different hydrophobic groups at the nitrogen atom and hydrophilic substituents at oxygen atoms were synthesized starting with maleic isoimides. 1H KMR and IR spectra were used for their characterization. Some were further characterized for their critical micellar concentration (CMC). A few cationic and zwitterionic surfmers were also prepared from isoimide precursors and characterized. All these surfmers were applied in batch emulsion polymerization of styrene, and in core‐shell seeded copolymerization of styrene and butylacrylate to give latexes with better stability than analogous compounds prepared from hemiesters (HE) of maleic acid. more...
- Published
- 2004
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15. Advances in reactive surfactants
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Alain Guyot
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chemistry.chemical_compound ,Colloid and Surface Chemistry ,Materials science ,chemistry ,Metal coating ,Extraction (chemistry) ,Water uptake ,Acetone ,Emulsion polymerization ,Organic chemistry ,Surfaces and Interfaces ,Electrolyte ,Physical and Theoretical Chemistry - Abstract
The study of reactive surfactants and their applications in the synthesis of latexes for waterborne coatings has been recently boosted by two successive European programmes, involving all together eight academic and five industrial laboratories. The most significant results were obtained using surfactants derived from maleic and related anhydrides, or both nonionic and anionic reactive polymeric surfactants. Such surfactants are able to improve the stability of styrenic and acrylic latexes vs. various constraints, such as electrolyte addition, freeze-thawing tests or extraction with alcohol or acetone. The properties of films used in waterborne coatings are also improved in case of water exposure (less water uptake, dimensional stability), as well as improved weatherability, and blocking properties. Formulations for woodstain varnishes, metal coating of printing inks, based on the use of simple polymerizable surfactants, are now in the market. more...
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- 2004
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16. Emulsion Polymerization of Chloroprene in the Presence of a Maleic Polymerizable Surfactant: Control of Gel Formation at Low Conversion
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Francois Sauterey, Alain Guyot, Francoise Cochet, Jerome P. Claverie, and Christian Graillat
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chemistry.chemical_classification ,Polymers and Plastics ,Chloroprene ,Chemistry ,Radical ,Organic Chemistry ,Emulsion polymerization ,Chain transfer ,Polymer ,Inorganic Chemistry ,chemistry.chemical_compound ,Pulmonary surfactant ,Polymerization ,Emulsion ,Polymer chemistry ,Materials Chemistry - Abstract
Chloroprene was polymerized in emulsion, using a redox system as initiator. With a rosin derivative as surfactant, gel formation was avoided until ca. 70% conversion, but when a reactive maleic hemiester surfactant was used, gel could appear at conversions as low as 5%. The purpose of this paper is to show how this problem of early gel formation can be controlled via the flux of radicals entering the particles. Using more initiator leads to shorter polymer chains, a delayed onset of gel formation, and paradoxically to slower polymerizations. more...
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- 2004
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17. Hybrid acrylic–polyimide latexes from miniemulsion polymerisation
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Alain Guyot, Catherine Gauthier, Christian Grailla, and Michel Bartholir
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chemistry.chemical_classification ,Acrylate ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Polymer ,Hydrophobe ,Miniemulsion ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Ammonium persulfate ,Methyl methacrylate ,Polyimide - Abstract
A rigid polyimide (PI) was dissolved in acrylic monomers (methyl methacrylate, n-butyl acrylate) as a hydrophobe to form miniemulsions stabilized by a mixture of sodium dodecyl sulfate and Triton®, with droplets size in the range 100–300 nm, and PI concentration up to about 30% by weight, which corresponds to its limit of solubility. Upon polymerization initiated with ammonium persulfate, the particle size tends to decrease to the range 80–250 nm. From these hybrid latexes, clear yellowish films were obtained with two glass transitions: one close to that of polybutylacrylate (Tg = −50 °C) and the second between 15 and 40 °C, depending on PI concentration. PI causes a reinforcement of the mechanical properties at room temperature. This reinforcement is enhanced through an appropriate thermal treatment. Copyright © 2004 Society of Chemical Industry more...
- Published
- 2004
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18. Controlled radical polymerization of styrene in miniemulsion polymerization using reversible addition fragmentation chain transfer
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Alain Guyot, Iveta Uzulina, Nicolas Gaillard, and Jerome P. Claverie
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Bulk polymerization ,Chemistry ,General Chemical Engineering ,Radical polymerization ,technology, industry, and agriculture ,Chain transfer ,General Chemistry ,Photochemistry ,Miniemulsion ,Anionic addition polymerization ,Polymerization ,Polymer chemistry ,Reversible addition−fragmentation chain-transfer polymerization ,Ionic polymerization - Abstract
Miniemulsion polymerizations of styrene in the presence of two reversible addition–fragmentation chain-transfer (RAFT) agents were studied. The rates were significantly retarded by the presence of a RAFT agents S -(thiobenzoyl)thioglycolic acid, 1 , or dithiobenzoic acid 1-phenylethyl ester, 2 . Control in miniemulsion polymerization is not as good as for bulk polymerizations. The miniemulsions could also be stabilized against Ostwald ripening by a polymer terminated by a dithiobenzoic moiety. In this case, the polymerization was not controlled because of the generation of renucleated particles. To cite this article: I. Uzulina et al., C. R. Chimie 6 (2003). more...
- Published
- 2003
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19. Anionic surfmers in mini-emulsion polymerisation
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Alain Guyot, Christian Graillat, and Cédric Favero
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chemistry.chemical_compound ,Monomer ,Aqueous solution ,Polymerization ,Chemistry ,General Chemical Engineering ,Polymer chemistry ,Succinic anhydride ,Maleic anhydride ,Emulsion polymerization ,General Chemistry ,Hexadecane ,Styrene - Abstract
Mini-emulsion polymerisation of styrene or methylmethacrylate, initiated with ammonium persulphate, have been carried out, in the presence of hexadecane or of polymethylmethacrylate as hydrophobic costabilizer, and the simple hemiester of linear dodecyl alcohol and maleic anhydride, or polymerisable surfactants (surfmers) derived from the condensation of succinic anhydride and either hydroxy propylmethacrylate (MAES), or hydroxyethylmethacrylate (ABS). While the pure surfmers have not so good surface activity, from surface tension measurements, stable mini-emulsion droplets are obtained using a mixture with low amounts of SDS, which have diameters of about 100–200 nm, which remain stable upon polymerisation. Most of the surfmers remain grafted onto the particle surface, thus conferring to these particles strong stability in the various tests. However, due to the high water solubility of the surfmers, another part remains in the serum as unconverted monomer or water-soluble polymers. To cite this article: A. Guyot et al., C.R. Chimie 6 (2003). more...
- Published
- 2003
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20. Maleic diamide polymerizable surfactants. Applications in emulsion polymerization
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Iveta Uzulina, Igors Klimenkovs, Ilze Zhukovska, Alain Guyot, and Andris Zicmanis
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chemistry.chemical_classification ,General Chemical Engineering ,Butyl acrylate ,Emulsion polymerization ,General Chemistry ,Styrene ,chemistry.chemical_compound ,chemistry ,Polymerization ,Critical micelle concentration ,Polymer chemistry ,Copolymer ,Benzyl group ,Organic chemistry ,Alkyl - Abstract
A series of new polymerizable non-ionic and ionic surfactants (surfmers) with amides groups on both sides of the C=C double bonds have been prepared upon reaction of maleic isoimide carrying a long alkyl chain (or a benzyl group) with a hydrophilic amine derivative. Their critical micellar concentration (CMC) was measured with a surface tensiometer. They have been engaged in batch emulsion polymerization of styrene, and semi-batch seeded copolymerization of styrene and butyl acrylate, giving stable latexes during the polymerization process, and upon extraction with ethanol, showing a high rate of incorporation at the particle surface. However these surfmers do not confer good steric stabilization properties, which may be expected from the use of non-ionic surfactants. To cite this article: I. Klimenkovs et al., C. R. Chimie 6 (2003). more...
- Published
- 2003
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21. High Solids Vinyl Acetate Polymers from Miniemulsion Polymerization
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Alain Guyot and Christian Graillat
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chemistry.chemical_classification ,Polymers and Plastics ,Organic Chemistry ,technology, industry, and agriculture ,Polymer ,Hexadecane ,Inorganic Chemistry ,Miniemulsion ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Chemical engineering ,Polymer chemistry ,Materials Chemistry ,Vinyl acetate ,Ammonium persulfate ,Sodium dodecyl sulfate - Abstract
High solids content (50%) poly(vinyl acetate) latexes have been prepared from miniemulsion polymerization stabilized using SDS (sodium dodecyl sulfate) or a combination of SDS and nonionic surfactant nonylphenol ethoxylate (Triton X 405) and hexadecane as hydrophobe. The conditions for preparing stable monomer miniemulsion in terms of osmotic and Laplace pressures are discussed. Upon polymerization initiated by ammonium persulfate (APS), one observes in about all cases a decrease of the number of polymer particles as compared to the number of monomer droplets. These two numbers are much more close if the solid content is decreased to 20%, so that the discrepancy can be explained from collisions occurring between the polymer particles and the droplets not yet initiated. Conductometric titration of the serum allows to estimate the coverage of the droplets by the surfactants; further, it can be demonstrated that a part of the SDS is desorbed from the polymer particles that are partly stabilized by the charge... more...
- Published
- 2003
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22. Nonionic reactive surfactants. I. Synthesis and characterization
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Menno G. Dufour and Alain Guyot
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Polymers and Plastics ,Ethylene oxide ,Emulsion polymerization ,Maleic anhydride ,Styrene ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Acyl chloride ,Polymerization ,Potassium hydride ,Critical micelle concentration ,Polymer chemistry ,Materials Chemistry ,Organic chemistry ,Physical and Theoretical Chemistry - Abstract
A procedure to prepare nonionic reactive surfactants with different polymerizable groups is described. The synthesis involves the initiation of living anionic ring-opening polymerization of ethylene oxide and propylene oxide (for the hydrophilic part and the hydrophobic part, respectively) by a potassium salt prepared from the stoichiometric reaction of potassium hydride and diethylene glycol monomethyl ether. The resulting anion is reacted with chloride compounds (methacryloyl, allyl, vinylacetoyl) and maleic anhydride, as well as with isobutanoyl chloride, leading to a nonpolymerizable compound having a similar structure. Then, it was possible to produce a range of reactive surfactants more or less reactive with the monomers. These surfactants are expected to be used further in emulsion polymerization processes (styrene and butyl acrylate). This procedure gives good control of both hydrophobic and hydrophilic parts, and the end reaction for the different functionality of surfmers is quite quantitative. All the surfactants were characterized by size-exclusion chromatography and 1H NMR. Physicochemical properties, such as the critical micellar concentration and the specific area, were also measured. more...
- Published
- 2003
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23. Nonionic reactive surfactants. Part 2. Core–shell latexes from emulsion polymerization
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Menno G. Dufour and Alain Guyot
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Polymers and Plastics ,Butyl acrylate ,Emulsion polymerization ,Macromonomer ,Styrene ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Monomer ,chemistry ,Pulmonary surfactant ,Polymer chemistry ,Materials Chemistry ,Acetone ,Particle size ,Physical and Theoretical Chemistry - Abstract
Nonionic polymerizable surfactants (surfmers) with different reactive parts (i.e. methacrylic, allylic, maleic and vinylic) and nonreactive analogs have been applied in emulsion copolymerization of styrene and butyl acrylate in a seeded semibatch process. Stable core–shell latexes at 35% of solid contents with a low level of coagulum and controlled particle size (according to the right amount of surfactant engaged in the emulsion polymerization process) have been obtained. Some of them, owing to the reactivity ratio of the polymerizable group versus the monomers used, are stable to freeze–thaw cycles, electrolytes and organic solvents such as acetone. The incorporation yields of each surfmer were then investigated by precipitation of the latexes in acetone. It was observed that the nonreactive surfactant as well as the maleic one are not incorporated, while the methacrylic surfmer is fully incorporated. The two other surfmers (allylic and vinylic) are partly at the surface of the particles, but also form oligomers soluble in acetone. more...
- Published
- 2003
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24. In situsyntheses of a suspension agent based on a styrene-acrylic acid copolymer for the suspension polymerization of styrene
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Leonardo Rios, Leopoldo Vilchis, Marco A. Villalobos, and Alain Guyot
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Materials science ,Polymers and Plastics ,Radical polymerization ,General Chemistry ,Benzoyl peroxide ,Surfaces, Coatings and Films ,Styrene ,chemistry.chemical_compound ,Chain-growth polymerization ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,medicine ,Copolymer ,Suspension polymerization ,medicine.drug ,Acrylic acid - Abstract
We carried out the suspension polymerization of styrene, initiated with benzoyl peroxide at 80°C, in the presence of the simultaneous polymerization of acrylic acid in the water phase, initiated by potassium peroxidisulfate (KPS) at the same temperature. The polymerization in the water phase was started at certain times after the beginning of the polymerization of styrene. Then, a continuous addition of KPS was carried out at a given landing rate and during variable feeding times. The water-phase polymerization actually produced a copolymer of styrene and acrylic acid, which displayed surface-active properties. The particle size distribution depended on the variables mentioned earlier (starting time, KPS feeding rate, and addition time), being controlled by the molecular weight, and on the composition of the copolymer produced and its availability at the increasing conversion of styrene. A second distribution of submicronic particles was produced. Both families of particles had about the same molecular weight. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3271–3285, 2002 more...
- Published
- 2002
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25. [Untitled]
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Alain Guyot, Ph. Viala, D. Lefebvre, P. Legrand, and E. Bourgeat‐Lamy
- Subjects
Materials science ,Polymers and Plastics ,Hydrogen bond ,Organic Chemistry ,Inorganic chemistry ,Iron oxide ,Emulsion polymerization ,Condensed Matter Physics ,chemistry.chemical_compound ,Monomer ,Pulmonary surfactant ,chemistry ,Polymerization ,Chemical engineering ,Titanium dioxide ,Particle-size distribution ,Materials Chemistry - Abstract
Emulsion Polymerization was carried out in the presence of inorganic pigments such as TiO2, black FexOy, yellow FexOy, and red FexOy, and NP 30 as surfactants, and water soluble AZO compounds or KPS as initiator. Monomers with specific hydrogen bonding interaction must be used in the initial steps of polymerisation, methylmethacrylate and vinylacetate being the most convenient. Then a semi continuous feed of a mixture of monomers was carried out in starved conditions. In order to make the covered pigments water-redispersible a mixture of hydrophobic and hydrophilic monomers should be chosen with proper pH conditions. The amount of surfactant has to be chosen so that no agglomeration of the covered pigments take place. The covered pigments were dried upon lyophylisation, then formulation of powder paints was carried out using commercial powder binders and other additives. Good properties of the paints, such as brightness were obtained in that way. more...
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- 2002
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26. Synthesis and Characterization of Silica/Poly (Methyl Methacrylate) Nanocomposite Latex Particles through Emulsion Polymerization Using a Cationic Azo Initiator
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Alain Guyot, Elodie Bourgeat-Lami, José-Luiz Luna-Xavier, Laboratoire de chimie et procédés de polymérisation (LCPP), and Centre National de la Recherche Scientifique (CNRS)-École Supérieure Chimie Physique Électronique de Lyon more...
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Materials science ,Bulk polymerization ,Colloidal silica ,Emulsion polymerization ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biomaterials ,Colloid and Surface Chemistry ,Polymer chemistry ,[CHIM]Chemical Sciences ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,Cationic polymerization ,Polymer ,021001 nanoscience & nanotechnology ,Poly(methyl methacrylate) ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Polymerization ,Chemical engineering ,chemistry ,visual_art ,Precipitation polymerization ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
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 (NP30). 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. more...
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- 2002
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27. Reactive surfactants in heterophase polymerization. XVII. Influence of the surfactant on the mechanical properties and hydration of the films
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Alain Guyot, Catherine Gauthier, Gérard Vigier, María J. Unzué, Harold A. S. Schoonbrood, J. M. Asua, and Olivier Sindt
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Butyl acrylate ,Emulsion polymerization ,Context (language use) ,General Chemistry ,Polymer ,Dynamic mechanical analysis ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Polymerization ,Pulmonary surfactant ,Materials Chemistry ,Composite material ,Acrylic acid - Abstract
In the context of a European union-supported network on “Reactive Surfactants for Heterophase Polymerization,” different polymerizable surfactants (surfmers) have been synthesized and engaged in the emulsion polymerization of styrene, butyl acrylate, and acrylic acid. The thermomechanical properties of films cast from these different latices are reported in this article. The evolution of the mechanical properties with temperature and the effect of water molecules on these properties are studied. We observed that the studied surfactants do not influence the properties of the dry films. However, some differences due to grafting of reactive surfactants appeared when the films were wet. The amount of water uptake is drastically decreased when only reactive surfactants are present in the film. Concerning the mechanical behavior of the wet films, a decrease of the plastic flow stress is observed for all the samples whatever the nature of the surfactant (reactive or conventional). Hence, calorimetric measurements and dynamic mechanical analysis are used to identify the possible mechanisms that induce the change in the mechanical behavior of the latex films. In the case of reactive surfactant grafted to the polymer, the very low value of water uptake is accompanied by a plasticization of the polymer. In contrast, no plasticizing effect is observed in the case of nonreactive surfactant, even if the amount of water is very large. Finally, the tensile behavior of the styrene–butyl acrylate copolymer versus temperature is analyzed in the frame of the quasi point defects (qpd) model. Both rubber elasticity and chain orientation effects are taken into account to describe the behavior laws at large extensions (i.e., ϵ ≈ 1.2). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1686–1700, 2002; DOI 10.1002/app.10548 more...
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- 2002
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28. High solids content emulsions. IV. Improved strategies for producing concentrated latices
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Christian Graillat, M. Schneider, Timothy F. L. McKenna, Alain Guyot, and I. Betrémieux
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Acrylate polymer ,010407 polymers ,Materials science ,Polymers and Plastics ,Radical ,Nucleation ,Emulsion polymerization ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Viscosity ,Monomer ,chemistry ,Chemical engineering ,Homogeneous ,Particle-size distribution ,Polymer chemistry ,Materials Chemistry ,0210 nano-technology - Abstract
A new means of producing high solids content latices with low viscosity is presented. The replacement of water-soluble initiators that decompose to give charged free radicals is shown to perturb the stability of highly concentrated latices. Their replacement by an oil-soluble initiator during particle growth, then by an activated, water-soluble system to remove residual monomer has been shown to help significantly reduce the number of stable particles generated by homogeneous nucleation. Latices with 73% (v/v) solids have been produced with a bimodal particle size distribution (PSD) consisting of 900 and 110 nm particles. The viscosity of these latices can be as low as 300 mPa s−1 at 20 s−1. Despite the presence of water-soluble monomers, excellent control over the evolution of the PSD allows one to obtain highly reproducible results. In addition, latices produced with the new initiator system have a much lower water uptake and their viscosity is much less sensitive to changes in pH than is the case for latices produced using standard emulsion polymerization techniques. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1935–1948, 2002; DOI 10.1002/app.10514 more...
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- 2002
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29. Recent progress in reactive surfactants in emulsion polymerisation
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Alain Guyot
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Polymers and Plastics ,Ethylene oxide ,Organic Chemistry ,Radical polymerization ,Emulsion polymerization ,Maleic anhydride ,Chain transfer ,Condensed Matter Physics ,Miniemulsion ,chemistry.chemical_compound ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer - Abstract
In the synthesis of latexes for use in waterborne coatings, the benefits of using reactive surfactants are now well known. Improvements are obtained in the stability of the latexes, due to the fact that they are not desorbed from the particle surface. The film properties are also better, chiefly if the films are exposed to humidity, where the water rebound is decreased significantly. This lecture summarises some recent progress obtained in that field through a European programme, including the participation of 10 academic and industrial laboratories. Four topics are considered. The first one is dealt with a series of anionic surmers (polymerizable surfactants) prepared upon reacting a polymerisable alcohol with either maleic, or succinic, or sulfosuccinic anhydride. One of these products, resulting from the addition of Hydroxyethylmethacrylate on maleic anhydride is now available commercially. From maleic anhydride one get bifunctional surfmers with 2 polymerisable groups, while the two other anhydride lead to monofunctional surfiners. All these products are engaged in seeded core-shell polymerisations, resulting in film-forming latexes quite stable during and after the polymerisation. However, because they are simply anionic, they do not provide steric stabilization and the latexes flocculate upon addition of strong electrolytes or in freezing tests, except if they are engaged in miniemulsion polymerisations initiated with KPS. The second topic is concerned with a series of nonionic block copolymer surfmers. A hydrophilic sequence of ethylene oxide units, produced upon ring opening living anionic polymerisation, is followed by a hydrophobic sequence of propyleneoxide, and the living polymer is killed with a polymerisable group attached on a reactive halogen atom. A variety of polymerisable groups have been used: styrenic, methacrylic, vinylic, allylic and maleic. The HLB balance is controlled through the lentgh of the hydrophilic and hydrophobic sequences. The more reactive, associated with an adequate HLB balance allows to prepare core-shell latexes with an excellent steric stabilisation at solid contents up to 40%. It is not the case for the less reactive maleic or allylic, the behaviour of which is close to that of a non reactive surfactant with the same structure. Transurfs, with an addition-fragmentation mechanism, is the subject of the third topic. A first study was carried out by the group of Eindhoven, who produced a new surfactant on the basis of a MMA dimer condensed on a long chain bromoalcohol and then sulfonated. This transurf was engaged in a MMA emulsion polymerisation, and compared with SDS; the polymerisation rate was lower and the molecular weight was broader. Optimisation of the incorporation of the transurf was achieved upon using starved feed conditions. We have carried out styrene miniemulsion using controlled RAFT process with a surfactant belonging to the first family reported above together with a RAFT agent. Finally we have used a RAFT agent derived from the nonionic block copolymer surfactants. The last topic was done in cooperation with the group of the MPI in Golm, who have studied a family of reactive dienic polymeric surfactants able to be grafted onto the polymer particles from the residual double bonds. These polymeric surfactants are working by an electrostatic stabilization mechanism, being flat onto the particle surface. more...
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- 2002
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30. Dispersion copolymerization of styrene with vinylbenzyl-terminated polyoxyethylene macromonomer
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J. Chudej, Ignác Capek, and Alain Guyot
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chemistry.chemical_classification ,Dispersion polymerization ,Materials science ,Polymers and Plastics ,Ethylene oxide ,Organic Chemistry ,technology, industry, and agriculture ,macromolecular substances ,Polymer ,Condensed Matter Physics ,Macromonomer ,Styrene ,chemistry.chemical_compound ,Anionic addition polymerization ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer - Abstract
Macromonomer with styrenic polymerizable group was synthetized by anionic polymerization of ethylene oxide initiated by potassium vinylbenzyl alcoholate, p-Vinylbenzyl-terminated polyoxyethylene macromonomer (PEO-VB) was then copolymerised with styrene in water/alcohol continuous phase. The resulting polymer is chiefly non soluble in that medium, and the final state is polymer particles in the range 500-1000 nm in diameter stabilized by a macromonomer-rich copolymer. The conversion time curve consists of three regions. The length of nucleation period was inversely proportional to the volume ratio ethanol/water (E/W). The dependence of the polymerization rate (Rp) vs. conversion is described by a curve with two-rate intervals. The rate of polymerization increased with increasing PEO-VB and initiator AIBN concentration but was nearly independent of the volume ratio E/W. The particle number slightly increased with increasing PEO-VB and AIBN concentration. The molecular weight of graft copolymer increased with increasing the volume fraction of water, PEO-VB and AIBN concentration. more...
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- 2002
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31. Nonionic Maleic Surfmers
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Christian Graillat, Alain Guyot, I. Uzulina, Andris Zicmanis, and Jerome P. Claverie
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chemistry.chemical_classification ,Polymers and Plastics ,Chemistry ,Glycidol ,Emulsion polymerization ,Surfaces, Coatings and Films ,Styrene ,Surface tension ,chemistry.chemical_compound ,Monomer ,Ethanolamine ,Polymer chemistry ,Organic chemistry ,Physical and Theoretical Chemistry ,Derivatization ,Alkyl - Abstract
A set of nonionic maleic surfactants have been prepared, all coming from the derivatization of maleic hemiesters with a long alkyl chain. They are either amidoesters or diester products. In the case of amidoesters, the acid group was first activated and then reacted with primary or secondary or tertiary ethanolamine compounds. In the case of diesters, the hemiester was reacted directly with glycidol, in acid or basic conditions. These surfactants were characterized for their structure by 1H NMR, and for their surface active properties, by surface tension measurements. They were also used in batch emulsion polymerisation of styrene, and seeded core-shell copolymerisation of a 1/1 mixture of styrene and butylacrylate in a semi-continuous process. In both cases, stable latexes with high monomer conversion, and limited amounts of floc were produced, with about the targetted particle size. It was shown that these reactive surfactants are incorporated with high yields, and they are not extracted with a... more...
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- 2002
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32. Synthesis of Polymer Colloids Using Polymerizable Surfactants
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I. Uzulina, Andris Zicmanis, Alain Guyot, Jerome P. Claverie, and Christian Graillat
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Polymers and Plastics ,Chemistry ,Organic Chemistry ,Succinic anhydride ,Emulsion polymerization ,Condensed Matter Physics ,Styrene ,chemistry.chemical_compound ,Pulmonary surfactant ,Critical micelle concentration ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Polystyrene ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate - Abstract
A series of new anionic surfactants were prepared by reacting a polymerizable alcohol with either maleic or succinic anhydride, as well as sulfosuccinic anhydride, resulting in either bireactive or monoreactive surfactants, either carboxylated or sulfonated. The synthesis presented and the critical micelle concentration (CMC) determined. These compounds were engaged in the emulsion polymerization of styrene in batch and also in semi-batch seeded copolymerization producing core-shell latexes. The core was a polystyrene seed prepared using sodium dodecyl sulfate (SDS), thoroughly purified through ion exchange resins. The seed was then swollen overnight with a small amount of a 1 : 1 mixture of styrene and butyl acrylate, and finally fed with the same mixture together with the reactive surfactant. The amount of monomer was calculated so that, from a seed with a diameter of 100 nm, a core-shell latex of 150 nm was obtained. The amount of surfactant was such that a coverage of 80% was aimed for. The calculated solid content was 9%. Using 3.5 wt.-% of surfactant (versus monomer), the conversion reached about 90%, the floc being limited most often to less than 2%. The target diameter of the core-shell latex was nearly obtained. The latexes were stable only with limited amounts of added electrolytes and failed the test of freeze-thawing. About 40–50% of the surfactant were located on the surface. more...
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- 2001
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33. The role of initiation in the synthesis of silica/poly(methyl methacrylate) nanocomposite latex particles through emulsion polymerization
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Alain Guyot, Elodie Bourgeat-Lami, José-Luiz Luna-Xavier, Laboratoire de chimie et procédés de polymérisation (LCPP), and Centre National de la Recherche Scientifique (CNRS)-École Supérieure Chimie Physique Électronique de Lyon more...
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Polymers and Plastics ,Radical polymerization ,Emulsion polymerization ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Polymer chemistry ,Materials Chemistry ,[CHIM]Chemical Sciences ,Physical and Theoretical Chemistry ,Methyl methacrylate ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,Chemistry ,Cationic polymerization ,Polymer ,Potassium persulfate ,021001 nanoscience & nanotechnology ,Poly(methyl methacrylate) ,0104 chemical sciences ,Polymerization ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
Silica/poly(methyl methacrylate) nanocomposite latex particles have been synthesized by emulsion polymerization of methyl methacrylate using a nonionic surfactant: nonylphenol poly(oxyethylene) and three different initiators, namely: 2,2′-azobis(2-amidinopropane) dihydrochloride (AIBA), potassium persulfate (KPS) and azobis(isobutyronitrile) (AIBN), being cationic, anionic and nonionic, respectively. A silica sol with an average diameter of 68 nm was used as the seed. The polymerization reaction was conducted under alkaline conditions in order to evaluate the role of the surface charge of the hydrophilic silica on the coating reaction. AIBA was found to be adsorbed on the silica surface owing to electrostatic interactions of the amidine function of the cationic initiator with the silanolate groups of the oxide surface, while the anionic and the nonionic initiators did not adsorb on silica under the same conditions. Nonetheless, whatever the nature of the initiator, polymerization took place on the silica particles as evidenced by transmission electron microscopy. The extent of interaction between the inorganic surface and the polymer particles was quantified by means of ultracentrifugation and a material balance. As much as 65% by weight of the total polymer formed was found to be present at the silica surface using AIBA, while only 40% for KPS and 25% for AIBN was found to cover the silica particles under alkaline conditions. We demonstrate that by using a cationic initiator and by controlling the pH of the suspension it is possible to significantly decrease the amount of free polymer. Coating of the silica particles took place through a kind of in situ heterocoagulation mechanism. more...
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- 2001
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34. High solids content latexes with low viscosity
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Alain Guyot and F. Chu
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Polymer ,Total dissolved solids ,Viscosity ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Rheology ,chemistry ,Chemical engineering ,Particle-size distribution ,Materials Chemistry ,Copolymer ,Physical and Theoretical Chemistry ,Composite material ,Mass fraction ,Ionomer - Abstract
The effect of particle size distribution (PSD) on the solids content and viscosity of the multi-sized latex was investigated by blending mono-sized latexes and measuring their rheological properties. The results showed that the maximum packing (highest solids content) was observed at a weight fraction 80% of large particles with respect to total solids content for both bi-modal and tri-modal latexes, and the lowest viscosity was obtained when the ratio of large to medium to small particles was approximately 80/10/10 (by weight). A two-stage technique to prepare high solids multi-sized polymer latex was developed by using a polymer latex previously made as seed and by adding small amount of additional surfactants and/or second group of polymer particles. The PSD of the latex was optimized by varying the amount of the seed, the additional surfactants, and the second group of particles. Film forming latexes with high solids (>65%) and low viscosity were obtained. more...
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- 2001
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35. Bifunctional catalysts supported on polymers for the preparation of Bisphenol A
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Alain Guyot, André Revillon, Isabelle Guibert, and Eric Puccilli
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chemistry.chemical_classification ,Bisphenol A ,Polymers and Plastics ,Chemistry ,Organic Chemistry ,Polymer ,Condensed Matter Physics ,Condensation reaction ,Bifunctional catalyst ,Styrene ,chemistry.chemical_compound ,Acid catalysis ,Materials Chemistry ,Organic chemistry ,Reactivity (chemistry) ,Bifunctional - Abstract
This work is relative to attempts for obtaining acid-thiol supported polymers that may be used as solid bifunctional catalysts, active in the Bisphenol A synthesis. Five approaches are tested with modified sulphonic styrene-based polymers obtained either by multi-polymerisation in one or several steps and derivatization. The objective is to get simultaneously sufficient capacity and high selectivity, by using an adequate acid/thiol ratio, and enhanced sites accessibility via an optimisation of the morphology. Reactivity results are favourably compared to those obtained in a homogeneous process. more...
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- 2001
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36. Synthesis and characterization of monoalkyl maleates and their use in emulsion polymerization of vinyl acetate
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Graciela Flores-Rosete, José-Antonio Trejo-O'Reilly, Alain Guyot, Leonardo Rios-Guerrero, Elodie Bourgeat-Lami, Georgina Montes De Oca-Ramirez, and Jean Guillot
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chemistry.chemical_compound ,Polymers and Plastics ,Polymerization ,Chemistry ,Organic Chemistry ,Materials Chemistry ,Vinyl acetate ,Organic chemistry ,Emulsion polymerization ,Condensed Matter Physics ,Vinyl polymer ,Characterization (materials science) - Published
- 2000
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37. Films from styrene–butyl acrylate lattices using maleic or succinic surfactants: mechanical properties, water rebound and grafting of the surfactants
- Author
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Alain Guyot, Silvija Abele, Christian Graillat, and Catherine Gauthier
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chemistry.chemical_classification ,Acrylate ,Absorption of water ,Materials science ,Polymers and Plastics ,Butyl acrylate ,Organic Chemistry ,Emulsion polymerization ,Polymer ,Styrene ,chemistry.chemical_compound ,chemistry ,Polymerization ,Chemical engineering ,Polymer chemistry ,Materials Chemistry ,Ionomer - Abstract
A series of anionic and zwitterionic maleic surfactants have been synthesized and engaged in styrene–butyl acrylate emulsion polymerization. Some non-reactive succinic analogs have been synthesized in order to perform their comparison with the maleic surfactants in polymerization experiments. Films from the obtained lattices were cast, and their mechanical properties and the water rebound were tested. The results of water rebound demonstrate significant difference between the films prepared with maleic or succinic surfactants. Water rebound of the films after 34 days in the case of succinic surfactants was found to be between 51 and 95%, while for maleic surfactants it is only 25–40% of the initial weight of samples, which is a significant improvement. Mechanical properties do not present essential difference, but a clear tendency has been observed in the three cases investigated—the films prepared using maleic surfactants are less resistant to the deformation and they are more extended at the rupture of the samples. Both series of results could be explained assuming heterogeneous inclusions of non-reactive surfactant (succinic derivatives) having an ionomer character. Both the results of water rebound and mechanical properties can be considered as an indirect proof of grafting of maleic surfactant on the polymer. more...
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- 2000
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38. Reactive surfactants in styrene microemulsion polymerization
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Cédrick Favero, Alain Guyot, and Christian Graillat
- Subjects
chemistry.chemical_compound ,Polymers and Plastics ,Polymerization ,Chemical engineering ,Chemistry ,Organic Chemistry ,Materials Chemistry ,Copolymer ,Microemulsion ,Condensed Matter Physics ,Ionic polymerization ,Styrene - Published
- 2000
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39. Reactive surfactants in heterophase polymerization. XVI. Emulsion copolymerization of styrene-butyl acrylate-acrylic acid in the presence of simple maleate reactive surfactants
- Author
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Olivier Sindt, Alain Guyot, Thierry Hamaide, and Catherine Gauthier
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Materials science ,Polymers and Plastics ,Butyl acrylate ,Emulsion polymerization ,Maleic anhydride ,General Chemistry ,Surfaces, Coatings and Films ,Styrene ,chemistry.chemical_compound ,chemistry ,Polymerization ,Emulsion ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Acrylic acid - Abstract
This study deals with the influence of a copolymerizable surfactant on the stability of lattices. Two main reactive surfactants, one anionic and one nonionic, both containing a reactive part issued from maleic anhydride, were engaged in seeded emulsion polymerizations of styrene-co-butyl acrylate-co-acrylic acid. The importance of the polymerization conditions clearly appears through the incorporation yield of the surfmers: When good conditions are used, this yield can be as high as 80%. Once stable lattices are synthesized, with a great incorporation of the surfactant, the stability of the colloid (against freeze–thawing cycles or in the presence of concentrated divalent electrolyte solutions) is then largely improved. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2768–2776, 2000 more...
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- 2000
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40. Styrenic surfmer in emulsion copolymerization of acrylic monomers. II. Copolymerization and film properties
- Author
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Neal Williams, Jo Grade, Olivier Soula, Alain Guyot, and Trevor Graham Blease
- Subjects
Flocculation ,Materials science ,Polymers and Plastics ,Butyl acrylate ,Organic Chemistry ,Contact angle ,chemistry.chemical_compound ,Pulmonary surfactant ,chemistry ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Particle size ,Wetting ,Acrylic acid - Abstract
Polymerizable styrenic surfactants (surfmers) and nonreactive analogs, have been applied in emulsion copolymerization of acrylic monomers in a seeded semibatch process. Stable core-shell latexes with low levels of coagulum and controlled particle size have been obtained; some of them, with either steric or electrosteric stabilization, display excellent stability to electrolytes, freeze–thaw cycles, and shear flocculation. In addition, the reactive surfactants lead to films with superior performance due to reduced migration of surfactant to the surface (contact angle measurements) and dimensional stability when the films are dipped in water, as well as less water uptake. Some differences also appear in particle morphologies. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4205–4217, 1999 more...
- Published
- 1999
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41. Styrenic Surfmer in Emulsion Copolymerization of Acrylic Monomers: I. Synthesis and Characterization of Polymerizable Surfactants
- Author
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Alain Guyot and Olivier Soula
- Subjects
chemistry.chemical_classification ,Ethylene oxide ,Oxide ,Surfaces and Interfaces ,Condensed Matter Physics ,chemistry.chemical_compound ,End-group ,Hydrolysis ,Anionic addition polymerization ,Pulmonary surfactant ,chemistry ,Polymerization ,Polymer chemistry ,Electrochemistry ,Organic chemistry ,General Materials Science ,Spectroscopy ,Alkyl - Abstract
Two procedures to prepare styrenic reactive surfactants are described. The first one, close to a procedure of Ito et al., involves the initiation of anionic polymerization of ethylene oxide by an alkyl silanolate. Once the ethylene oxide is fully consumed, the anion is condensed on a styrenic alkyl bromide. Then the hydroxyl is recovered by a reaction of deprotection. The second one, on the contrary, starts from the hydrophobic end group. This anionic polymerization is initiated by vinyl benzyl alcoholate. Successively butylene oxide and ethylene oxide are polymerized. In the last step, the anion can be used to open the ring of propane sultone and we produce an anionic reactive surfactant, or the living chain can be hydrolyzed to obtain a nonionic surfactant. This second procedure gives good control of both hydrophobicity and hydrophilicity. The physicochemical properties of the corresponding surfactants are measured. more...
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- 1999
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42. Styrenic Surfmers in Emulsion Polymerization of Acrylic Monomers. 3. Surface Analysis
- Author
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Olivier Soula, Alain Guyot, Marie-France Llauro, and Roger Pétiaud
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chemistry.chemical_classification ,Steric effects ,Polymers and Plastics ,Organic Chemistry ,Ultrafiltration ,Emulsion polymerization ,Polymer ,Inorganic Chemistry ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Proton NMR ,Particle - Abstract
Styrenic block-copolymer polymerizable surfactants, when engaged in emulsion polymer- ization of core-shell acrylic latexes, are forming copolymers containing a large majority of monomer units. These copolymers can be extracted, and analyzed, after extensive washing of the particles by ultrafiltration. Owing to the restricted mobility of the polymer inside the particles, direct 1H NMR analysis, in normal waterswith water suppressionsof the latex itself, in its initial serum, gives selective detection of the water-solvated species and allows to estimate both the amount of surfmer remaining at the surface of the particle and their conformation, thus allowing to determine what part of it participates in the steric and electrosteric stabilization. more...
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- 1999
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43. Small particle size in emulsion polymerization using non-ionic stabilisers
- Author
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J. Chudej and Alain Guyot
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Ethylene oxide ,Organic Chemistry ,Radical polymerization ,Emulsion polymerization ,Polymer ,Macromonomer ,Styrene ,chemistry.chemical_compound ,Anionic addition polymerization ,chemistry ,Polymer chemistry ,Materials Chemistry ,Particle size - Abstract
Macromonomer with styrenic polymerizable group was synthetized by anionic polymerization of ethylene oxide initiated by a mixture of potassium p- and m-vinylbenzyl alcoholate. The corresponding alcohol was prepared by modified two-step method described by Bamford et al. (Polymer 1973;14:330) using vinylbenzyl chloride as a starting material. Emulsion polymerization of styrene was carried out in the presence of either a styrenic macromonomer of poly(ethylene oxide) or conventional surfactants ethoxylated alkylphenol. In all cases small particle size of less than 75 nm in diameter were produced. more...
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- 1999
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44. Reactive surfactants in heterophase polymerization. XXV. Core-shell lattices stabilized with a mixture of maleic anionic and styrenic nonionic surfactants
- Author
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Olivier Soula, Alain Guyot, and Françoise Thenoz
- Subjects
Polymers and Plastics ,Ethylene oxide ,Butyl acrylate ,Organic Chemistry ,Oxide ,Electrolyte ,chemistry.chemical_compound ,chemistry ,Pulmonary surfactant ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Polystyrene - Abstract
Core–shell lattices with a polystyrene core and a polystyrene/butyl acrylate shell with more than 40% solid contents were produced using a combination of sodium dodecyl maleate hemiester as anionic surfactant and styrenic block copolymer of butylene oxide and ethylene oxide as nonionic surfactant. Stable lattices able to resist rather high concentrations of electrolytes can be obtained, provided a careful protocol of the addition of surfactants is used. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2251–2262, 1999 more...
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- 1999
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45. Hemiesters and hemiamides of maleic and succinic acid: synthesis and application of surfactants in emulsion polymerization with styrene and butyl acrylate
- Author
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Christian Graillat, Silvija Abele, Andris Zicmanis, and Alain Guyot
- Subjects
chemistry.chemical_compound ,Materials science ,Polymers and Plastics ,Maleic acid ,chemistry ,Polymerization ,Succinic acid ,Butyl acrylate ,Critical micelle concentration ,Polymer chemistry ,Copolymer ,Emulsion polymerization ,Styrene - Abstract
Hemiesters and hemiamides of maleic acid with different chain lengths of the hydrophobic alkyl group (R = C8H17, C10H21, C12H25, C16H33) have been synthesized and used as surfactants in the emulsion polymerization of styrene and butyl acrylate. The same polymerization experiments were also carried out using nonreactive surfactants with an analogous succinic structure. The chemical structure of the surfactants was confirmed by 1H nuclear magnetic resonance. The melting point and critical micelle concentration of the reactive surfactants described herein were measured. All of the surfactants studied provided good stability of styrene/butyl acrylate latexes, when compared with a reference latex of a styrene/butyl acrylate copolymer prepared with a surfactant sodium dodecyl sulfate. The amount of surfactant grafted onto the particles of the final latex was estimated by conductimetric titration. Between 33 and 68% of surfactant used in emulsion polymerization was found on the surface of latex particles. Electrolyte addition at high concentration and freeze/thaw cycle cause flocculation of latexes. Copyright © 1999 John Wiley & Sons, Ltd. more...
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- 1999
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46. Reactive surfactants in heterophase polymerization
- Author
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Olivier Sindt, P. Lacroix-Desmazes, María J. Unzué, H.A.S. Schoonbrood, Frédéric Vidal, S. van Es, A. C. Hellgren, Klaus Tauer, David C. Sherrington, Alain Guyot, E. Shipper, Catherine Gauthier, A. Montoya-Goni, José M. Asua, M. Sjöberg, Chemical Engineering and Chemistry, and Macromolecular and Organic Chemistry more...
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Dispersion polymerization ,Polymers and Plastics ,Polymer science ,Polymerization ,Chemistry ,General Chemical Engineering ,Radical polymerization ,Emulsion polymerization ,Chain transfer ,Emulsion copolymerization - Abstract
This paper summarizes the work carried out during 3 years in a Network of the program "Human Capital and Mobility" of the European Union CHRX 93-0159 entitled "Reactive surfactants in heterophase polymerization for high performance polymers". A series of about 25 original papers will be published in the open literature under the general title of this feature article from Part I to Part XXV.The synthesis of selected surfactants either anionic or non ionic, and as well inisurfs (both initiators and surfactants), transurfs (both transfer agent and surfactants) or surfmers (both comonomers and surfactants) is shortly described. They were applied in emulsion polymerization and dispersion polymerization, and their behavior in shortly discussed. Finally films have been produced from a few of them, mainly from surfmer with maleic reactivity, and the main properties, and interests of such films are discussed. more...
- Published
- 1999
47. High solid content multisized emulsion copolymerization of styrene, butyl acrylate, and methacrylic acid
- Author
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F. Chu, Christian Graillat, and Alain Guyot
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Butyl acrylate ,Emulsion polymerization ,General Chemistry ,Polymer ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Polymerization ,Chemical engineering ,chemistry ,Particle-size distribution ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Particle ,Particle size - Abstract
Polymer lattices with a multimodal particle size distribution (PSD) polymer latex were prepared by introducing additional surfactants during the semicontinuous emulsion polymerization of styrene, butyl acrylate, and methacrylic acid. The polymerization was investigated by following the variation of the particle size, the size distribution, the number of particles, the Tg of the different particle sizes, and the total conversion at different steps of the polymerization process. The results show that bimodal and trimodal PSD polymer lattices can be obtained by this method and that the secondary generation of particles is greatly influenced by the nature and the amount of additional surfactants, as well as the moment when they are introduced. When the amount of additional surfactants is increased, the diameters of both the small and large particles decrease and the number of particles in each of the populations increases. Earlier introduction of these surfactants favors the generation and the growth of the small particles and thereby leads to a reduction of the relative fraction of large particles in the final latex. On introduction of 7 wt % of additional surfactants, based on the total monomers, 100% of the monomers of the second-stage polymerization were consumed to form the small particles. This fraction decreases with a decreasing amount of the additional surfactants. These results were further demonstrated by measuring the Tg's of both the large and the small particles of two lattices, in which the Tg's of the copolymers produced in each of the stages were different. High solid content (>65%), low viscosity, and coagulum-free lattices have been obtained through secondary nucleation, and a minimum in viscosity was found when the weight fraction of the large particles was around 80%. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2667–2677, 1998 more...
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- 1998
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48. Study of poly(St/BA/MAA) copolymer latexes with bimodal particle size distribution
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Jean Guillot, F. Chu, and Alain Guyot
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Particle number ,Nucleation ,Polymer ,Surface tension ,Chemical engineering ,chemistry ,Polymerization ,Particle-size distribution ,Polymer chemistry ,Copolymer ,Particle size - Abstract
A new strategy was developed for producing a polymer latex with trimodal particle size distribution by adding a second seed of polymer particles and some additional surfactants during polymerization. The polymerization was investigated by following the variation of the particle size, the size distribution, the number of particles, the surface tension and surfactant surface coverage at different stages of the polymerization process. The results showed that both the size and the size distribution can be easily controlled by varying the amount of additional surfactants and the second seed of polymer particles. The secondary nucleation was achieved when the surface coverage of particles was over 70%, and the amount of small particles formed increased with increasing amount of additional surfactants. The introduction of the additional surfactants had no significant effect on the size and number of middle particles, but reduced the size of large particles and caused the number of large particles to remain more stable because of the suppression of limited flocculation. Copyright © 1998 John Wiley & Sons, Ltd. more...
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- 1998
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49. Methacrylic maleic bifunctional stabilizer in emulsion polymerization
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Alain Guyot, Silvija Abele, I. Uzulina, and Andris Zicmanis
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chemistry.chemical_compound ,Materials science ,Polymers and Plastics ,chemistry ,Organic Chemistry ,Polymer chemistry ,Radical polymerization ,Materials Chemistry ,Emulsion polymerization ,Bifunctional ,Emulsion copolymerization ,Stabilizer (chemistry) - Published
- 1998
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50. Reactive surfactants in heterophase polymerization for high performance polymers
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David C. Sherrington, Anton L. German, M.J.W.A. van den Enden, J.J.G.S. van Es, Frédéric Vidal, Alain Guyot, A. Montoya-Goni, H.A.S. Schoonbrood, Thierry Hamaide, O. Sindt, M. Sjöberg, E.T.W.M. Schipper, José M. Asua, L.M. Müller, and P. Lacroix-Desmazes more...
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Dispersion polymerization ,chemistry.chemical_classification ,Azo compound ,Polymers and Plastics ,Oxide ,Polymer ,Styrene ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Anionic addition polymerization ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Physical and Theoretical Chemistry - Abstract
A variety of nonionic reactive surfactants have been prepared from block copolymer precursors. These precursors are formed from a commercially available polyoxyethylene glycol monomethylether as the hydrophilic sequence of the surfactant; this product is used as initiator of ring opening anionic polymerization of butylene oxide. Finally the reactive surfactants are obtained after proper functionalization of the precursor. The reactive surfactants are an inisurf with an asymmetric azo compound, a transurf with a thiol group, and a few surfmers with acrylic, methacrylic, styrenic and α-methyl styrenic reactive groups. These compounds have been engaged in styrene emulsion or dispersion polymerization. Several of them have been found to be useful for preparing stable latices. more...
- Published
- 1998
- Full Text
- View/download PDF
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