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Cryo-electron microscopy, atomic force microscopy, and light microscopy investigations provide experimental evidence that amphiphilic emulsion copolymerization particles change their morphology in dependence on concentration. The shape of the particles is spherical at solids content above 1%, but it changes to rod-like, ring-like, and web-like structures at lower concentrations. In addition, the shape and morphology of these particles at low concentrations are not fixed but very flexible and vary with time between spheres, flexible pearl-necklace structures, and stretched rods.

Various models have been proposed in order to understand different physical and chemical events taking place during emulsion copolymerization. One of the important processes involved is the entry of radicals into particles, which is often described using the model of Maxwell and Morrison. For emulsion homopolymerization, experimental data partly support this model, while for emulsion copolymerization not many experimental data are available. Here, the different models that have been established over the past decades are reviewed with an emphasis on the propagational mechanisms involved during the entry of oligomeric radicals into latex particles in emulsion homopolymerization. An answer is given to the title question: "Can the existing models be verified?".

We report on the fabrication of multifunctional ratiometric probes for glucose and temperatures based on thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) microgels covalently incorporated with glucose-recognizing moieties, N-acryloyl-3-aminophenylboronic acid (APBA), fluorescence resonance energy transfer (FRET) donor dyes, 4-(2-acryloyloxyethylamino)-7-nitro-2,1,3-benzoxadiazole (NBDAE), and rhodamine B-based FRET acceptors (RhBEA). P(NIPAM-APBA-NBDAE-RhBEA) microgels containing FRET pairs and APBA were synthesized via free radical emulsion copolymerization. The spatial proximity of FRET donors and acceptors within microgels can be tuned via thermo-induced microgel collapse or glucose-induced microgel swelling at appropriate pH and temperatures, leading to the facile modulation of FRET efficiencies. APBA moieties within P(NIPAM-APBA-NBDAE-RhBEA) microgels can bind with glucose at appropriate pH to form cyclic boronate moieties, which can decrease the pKa of APBA residues and increase the volume phas...

Amphoteric polyacrylate containing long hydrophobic aliphatic chain in the presence of poly(vinyl alcohol) (PVA) was synthesized. The influences of PVA on the properties of the emulsion and its film were investigated in details. In addition, the emulsion and the film were characterized by various examining methods. Furthermore, the applied properties of paper sized by amphoteric polyacrylate in the presence of poly (vinyl alcohol) were measured, in contrast to acrylic polymer prepared with the conventional low molecular weight emulsifier, the physical indexes were all improved.

The apparent reactivity ratios of hexafluoropropylene (HFP)/vinylidene fluoride (VDF) emulsion copolymerization were studied by nonlinear fitting according to the copolymer composing equation, which, according to the calculation, are 1.88 and 0.86 respectively. The constitution of mixed gaseous monomers was measured through the gas chromatography. The copolymer compositions before and after reaction were measured by 19F-NMR. The calculated contents of VDF and HFP have nice accordance with the results from 19F-NMR analysis, which demonstrates that the method reported here is fairly reliable, and shed a light on the industry-scale consideration for the emulsion copolymerization of HFP and VDF.

Monodispersed core-shell particles 290–315 nm in diameter were prepared by seed emulsion copolymerization of styrene with divinylbenzene in the presence of luminophore-containing comonomers. The capability of the particles obtained to sorb toluene vapor was shown by solid-state 1H and 13C NMR spectroscopy.

It has been long recognized that emulsion polymerization is a complex heterogeneous process involving transport of monomers, free radicals, and other species between aqueous phase and organic phase. Though there are a number of models available in the literature, most of them deal only with specific aspects in emulsion polymerization and are far from being general. To simulate this complicated process and to achieve an adequate level of understanding, a Polymers Plus software from Aspen Technology. Inc. was used. The objective of this work is to illustrate the principle of use of Polymers Plus, simulate, and analyze the free-radical seeded emulsion copolymerization of styrene­butadiene process model in a semi-batch reactor. The base case simulation can be used to gain process understanding by analyzing how process variables and operating conditions during the course of a semi-batch reactor affect the product quality. Keywords: Polymers Plus, Emulsion Copolymerization, Simulation, Semi Batch Reactor, Styrene/ butadiene Abstrak Telah diketahui sejak lama bahwa polimerisasi emulsi merupakan sebuah proses heterogen yang kompleks, yang meliputi perpindahan monomer, radikal bebas, dan senyawa lainnya dalam fasa air dan fasa organik. Walaupun dalam literatur terdapat berbagai model, sebagian besar hanya membahas tentang aspek-aspek khusus dalam polimerisasi emulsi yang belurn berlaku umum. Untuk melakukan simulasi serta meningkatkan pemahaman tentang proses yang kompleks ini, digunakan perangkat lunak Polymers Plus dari Aspen Technology, Inc. Penelitian ini bertujuan untuk memberikan ilustrasi tentang prinsip penggunaan Polymers Plus serta melakukan simulasi dan analisis tentang model untuk proses kopolimerisasi emulsi styrene-butadiene dengan free radical seeded dalam reaktor semi batch. Simulasi ini dapat digunakan untuk memperoleh pemahaman proses dengan menganalisis pengaruh variabel-variabel proses dan kondisi operasi dalam reaktor semi batch terhadap kualitas produk. Kata Kunci: Polymers Plus, Kopolimerisasi Emulsi, Simulasi, Reaktor Semi Batch, Stiren/ butadien

This work presents a mathematical model for the vinyl acetate and n-butyl acrylate emulsion copolymerization process in batch reactors. The model is able to explain the effects of simultaneous changes in emulsifier concentration, initiator concentration, monomer-to-water ratio, and monomer feed composition on monomer conversion, copolymer composition and, to lesser extent, average particle size evolution histories. The main features of the system, such as the increase in the rate of polymerization as temperature, emulsifier, and initiator concentrations increase are correctly represented by the model. The model accounts for the basic features of the process and may be useful for practical applications, despite its simplicity and a reduced number of adjustable parameters.

The incorporation of magnetic properties allows the in situ formation of sensor spots by magnetic separation and, consequently, optical readout from the outside. Several magnetic MIPs have been syn...

Two types of emulsifier were studied to compare the colloidal and physicochemical properties of vinyl acetate (VAc)/(BuA) emulsions. Emulsions were prepared by varying the composition and the concentration of the anionic and nonionic emulsifiers. An increase in the total emulsifier concentration of anionic and nonionic emulsifier percentage leads to dispersions with smaller particles and higher viscosities. Using anionic and nonionic emulsifiers in copolymer latexes, it was observed that the viscosity goes through a maximum which is located at total emulsifier concentration of about 3.6 wt% The surface tension of the copolymers shows a drastic increase at a concentration above 3.5% for mixed emulsifier systems. Copyright © 2008 John Wiley & Sons, Ltd.

A sensitivity study of particle size distribution (PSD) and molecular weight distribution (MWD) responses to perturbations in initiator, surfactant, monomer and chain transfer agent in a semi-batch emulsion polymerisation is presented. The objective is to provide a systematic study on the ability to simultaneously control both PSD and MWD, towards inferential control of end-use product properties. This would lead towards identification of the practical feasible regions of operability. All inputs appeared to have an intrinsic and simultaneous influence on end-time PSD and MWD. Trends shown in experimental results have been explained in a mechanistic sense and also compared to simulation results from a combined PSD/MWD population balance model. The preliminary comparison between experiment and simulation highlights areas to be focussed on with respect to model improvement.

Latexes have many product applications including functioning as a binder in coatings. For many years, coatings researchers in industry as well as in academe have been exploring various modes of crosslinking latexes. Quite often, the goal of preparing crosslinked latexes is to upgrade film properties relative to the film properties of uncrosslinked latexes. In the present report, the synthesis and properties of crosslinkable acrylic latexes prepared with either an internal crosslinker (1,3-butylene glycol dimethacrylate)—“precoalescence crosslinking”—or an external crosslinker (adipic dihydrazide)—“postcoalescence crosslinking”—at various levels of crosslinking were studied. For postcoalescence crosslinking, diacetone acrylamide was copolymerized into the latex to provide sites for subsequent reaction with adipic dihydrazide. Fundamental properties of films cast from the two types of latexes were systematically compared. These properties included gel content, dynamic mechanical properties, nano-indenter hardness and modulus, stress–strain properties as well as the characterization of latex morphology by atomic force microscopy (AFM). In addition, some specific end-use properties were determined. This study assesses the effect of type (precoalescence or postcoalescence) and level of crosslinking on the film formation process and the resulting fundamental and end-use properties as well as resulting latex film morphology.

A facile and effective method was successfully developed to prepare the highly cross-linked monodispersed PS particles via soap-free emulsion polymerization, in which the cross-linking agent (DVB) was delayed addition by varying time (Delayed Addition Method, DAM). Through this method, the highly cross-linked monodispersed particles with functional groups on its surface can be prepared. The particles prepared by DAM had a uniform size distribution for the St/DVB and St/HEMA/DVB system. For the St/DVB system, when the cross-linking agent (DVB) was added delay 3 or 7 h, cross-linked PS particles could be successfully prepared without a significant change in the narrow particle size distribution even containing up to 40 wt% of DVB. Similarly, for the St/HEMA/DVB system, by delayed addition of DVB for 3 h, stable and monodispersed polymer particles still could be prepared even the containing of DVB reach to 60 wt%. Moreover, when the feed composition of the DVB kept constant, the longer the delayed addition time of DVB, the better the monodispersity of the cross-linked particles were.

Production of polymeric latexes by miniemulsion techniques is clearly attracting more and more attention for a number of reasons. However, one of the limiting factors in the acceptance of miniemulsion polymerisation as a commercialisible technique was that in early laboratory studies ultrasonication was the only method considered for the generation of polymerisable droplets. It is shown in the current paper that rotor stator mixers are an promising alternative. In addition to demonstrating the feasibility of these techniques, an investigation of the evolution of the particle size distribution during polymerisation revealed that controlled coalescence can occur for reasons that are difficult to identify.

Three poly[(vinyl acetate)-co-N-methylolacrylamide] (VAc–NMA) latex adhesives were synthesized, each containing the same total amount of NMA. In each of the three co-polymerizations, the NMA was fed into the reactor according to a unique feed profile. NMA distribution in the latexes, as determined via both 13C and 15N variable temperature solution nuclear magnetic resonance (NMR) spectroscopy, differed among the three adhesives. When NMA monomer was added via injections (latex I), predominantly surface-NMA (62.7%) was detected, with significant amounts of water-phase NMA (20.8%) and core NMA (16.5%). Delayed NMA injections (latex DI) led to a very high proportion of surface NMA (82.3%) with less core (10.6%) and water-phase NMA (7.1%). A continuous feed of NMA (latex C) gave predominantly core NMA (84.7%), some surface NMA (13.4%) and very little water-phase NMA (1.9%). NMA distribution findings from 15N-NMR and 13C-NMR analyses were consistent.

New anion surfmers of the family of maleic acid asymmetrical esters have been synthesized. Some of its features in the process of emulsion copolymerization with styrene have been studied. The characteristics of covering, obtained on the basis of such latexes of new generation have been investigated as well.

This article theoretically investigates the reduction of off-specs generated during changes of grade in an emulsion copolymerization of acrylonitrile (A) and butadiene (B) performed in an industrial train of eight continuous stirred tank reactors (CSTRs). The investigated nitrile rubber (NBR) grades exhibit differences in the copolymer composition, molecular weights, and levels of branching. In the Normal plant configuration, all the reagents are fed into the first reactor. In the Improved plant configuration, intermediate additions of A, B, and chain-transfer agent (CTA) are admitted along the train for increasing production and reducing chain branching, polydispersity, and compositional drift. Optimal transitions between the Normal steady states and the Improved steady states were calculated. They involved changes between two typical copolymer grades and the application of “bang−bang” feed profiles onto A, B, and CTA. According to the model, the bang−bang strategies reduce the off-specs 35%−60%, with re...

Dependence of the apparent transfer constant of diisopropyl xanthogen disulfide on the rate of emulsion copolymerization of butadiene with styrene was followed up in various emulsifiers. On the basis of data obtained the relation was derived between both the relative and apparent transfer constant and the rate of polymerization.

Effect of Carboxylic Acid Monomer Type on Particle Nucleation and Growth in Emulsifier-free Emulsion Copolymerization of Styrene-Carboxylic Acid Monomer

Model reactive latices were synthesized by semicontinuous emulsion copolymerization of n-butyl methacrylate and acetoacetoxyethyl methacrylate or dimethylaminoethyl methacrylate. The two functional latices were then blended in various ratios to study the influence of blend composition on crosslinking and mechanical properties of the resulting films. Crosslinking was quantified through swelling measurements. It was found that the crosslink density increased with increasing amounts of acetoacetoxy-functional polymer. In addition, the crosslink density exhibited two maxima, at 30/70 and 70/30 (acetoacetoxy-functional latex/amino-functional latex) blend compositions. The mechanical properties of the films were quantified by dynamic mechanical analysis (DMA). It was shown that optimal mechanical properties occurred when the particles packed most efficiently at the 30/70 and 70/30 blend compositions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3774–3779, 2007

A mid-course correction (MCC) policy has been shown as a practical approach to compensate the effects of the new disturbances on the final particle size distribution (PSD) in the emulsion polymerization process. However, the development of control model remains immature in the practical sense. In this paper, a control strategy to control the bi-modal particle size distribution in an emulsion copolymerization process within the MCC approach is presented. The strategy proposes a controlled adaptive perturbation (CAP) to develop the MCC control model while minimizing the off-specification batches generation during the perturbation. The scheme utilizes the particle size polydispersion index (PSPI) as the control objective to simplify the development process. In addition, it is also shown that the final PSD can be estimated by PLS model with an adequate accuracy by using on-line calorimetry-based conversion measurements as predictor. This eliminates the requirement of off-line analysis thus faster predictions can be made.

Experimental results obtained during investigation of emulsion co-polymerization of styrene (ST) and ethylhexylmethacrylate (EHA) in the presence of cationic or mixtures of cationic and nonionic surfactants are presented in this paper. Potassium persulfate is used as an initiator and hexadecyltrimethylamonium chloride as cationic and ethoxilated benze-nealkane (Triton, N-101) as nonionic surfactant. The influence of concentration of initiator and surfactant, as well as the influence of temperature on copolymer yield and stability of the obtained product was investigated. The electrical charge of the synthesized copolymer particles was determined by electrophoresis. It was found that the particles were positively charged. The zeta potential was equal to 2.5-1CT2 V, which made copolymer dispersion stable for one year. Besides, the possibility of hydrophobization of cellulose fibers by using dispersion of synthesized poly(ST-co-EHA) was qualitatively determined. It was shown that the dispersion could be used for Wet End and surface Sizing Agents of Paper.

Based on experimental studies, a method for obtaining a powdered silicone-acrylic polymer by emulsion copolymerization of acrylic acid and 3-methacryloxypropyl-trimethoxysilane using a reaction initiator (ammonium persulfate) for implementing the modifications in the polymer cross-link to impart improved physicochemical properties to the final product was presented in the paper.The optimum conditions of synthesis were determined. Based on the study of the kinetics of the copolymerization reaction by the graviometric method, it was found that it is advisable to conduct the reaction for 4.5 hours at a temperature of 90 oC, since the copolymer yield after this time was 45.3 %.During the synthesis, silicone-acrylic polymer, which is a white powder without strong smell, insoluble in organic solvents was obtained. The copolymer was characterized using IR spectrum analysis and dispersion determination.The obtained silicone-acrylic copolymer is recommended for use in paints and varnishes as a surface modifier., Приведены результаты исследований синтеза порошкообразного силиконакрилового сополимера методом эмульсионной сополимеризации акриловой кислоты (АК) и 3-метакрилоксипропил-триметоксисилана (ТМОПТМС). На основании экспериментальных данных определены оптимальные условия проведения синтеза для получения порошкообразного продукта. С помощью ИК-спектроскопии исследованы и охарактеризованы свойства полученных силиконакриловых сополимеров., Наведені результати досліджень синтезу порошкопобібного силіконакрилового кополімеру методом емульсійної кополімеризації акрилової кислоти (АК) і 3-метакрилоксипропіл-триметоксисилану (ТМОПТМС). На підставі експериментальних даних визначено оптимальні умови проведення синтезу для отримання порошкоподібного продукту. Досліджено та охарактеризовано властивості отриманих силіконакрилових кополімерів за допомогою ІЧ-спектроскопії.

The method for preparing silicone acryl polymer by emulsion copolymerization of acrylic acid and 3-methacryloxypropyl-trimethoxysilane with a reaction initiator (ammonium persulfate) is presented in the article on the basis of experimental studies. The optimum conditions of synthesis are determined. Based on the study of the kinetics of the reaction by gravimetric copolymerization method, it was found that it is desirable to conduct the reaction for 4,5 hours at 90 oC, since after this time yield of copolymer was 53,3 %.During synthesis it is obtained silicone acryl polymer that is a viscous transparent liquid without sharp odor, soluble in organic solvents. The properties of the silicone acryl polymer are investigated and characterized: molecular mass is calculated, determined the composition of the copolymer is determined and IR spectral analysis is conducted. This polymer is suitable for use in paints and varnishes as a surface modifier., В статье приведены результаты исследований синтеза силиконакрилового сополимера методом эмульсионной сополимеризации акриловой кислоты (АК) и 3-метакрилоксипропил-триметоксисилана (ТМОПТМС). Установлено влияние температурно-временного фактора и концентрации инициатора (персульфата аммония) на ход реакции сополимеризации. На основании экспериментальных данных определены оптимальные условия проведения синтеза для получения геле- и порошкообразного продукта. Исследованы и охарактеризованы свойства полученных силиконакриловых сополимеров., В статті наведені результати досліджень синтезу силіконакрилового кополімеру методом емульсійної кополімеризації акрилової кислоти (АК) і 3-метакрилоксипропіл-триметоксисилану (ТМОПТМС). Встановлено вплив температурно-часового чинника та концентрації ініціатора (персульфату амонію) на протікання реакції кополімеризації. На підставі експериментальних даних визначено оптимальні умови проведення синтезу для отримання геле- та порошкоподібного продукту. Досліджено та охарактеризовано властивості отриманих силіконакрилових кополімерів.

We present new evidence that the formation of pore throats (windows) or pore interconnects in polymerised High Internal Phase Emulsions (polyHIPEs) is most likely due to a mechanical action exerted during the post-synthesis processing of the porous polymer monolith. We would like to invite researchers interested in this field to reopen the discussion on the mechanism which lead to the formation of pore throats during the polymerisation of concentrated emulsion templates.

Monodisperse polymer particles with diameters from 230 to 420 nm have been synthesized by the emulsifier-free emulsion copolymerization of styrene with methacrylic acid. It has been shown that an initiator, chain regulators, comonomer ratio, and pH of a medium influence the dispersity of latexes, the distribution of carboxyl groups in polymer particles, as well as their swelling behavior and electrophoretic mobility. These characteristics of polymer particles are substantial for designing perfect lattices of three-dimensional photonic crystals on their basis.

A perfluorooctylated acrylate monomer (FAC) containing a urethane linkage was synthesized, and fluorinated polymers [perfluorooctylated polyacrylate (PFAC)] were obtained from the copolymerization of FAC with other acrylate monomers by emulsion polymerization. The size of the emulsion particles was about 40–60 nm. PFAC was applied to cotton fabrics by a pad–dry–cure process. The treated fabrics that were dried at 100°C after being washed showed good water and oil repellency: the water repellency rating and the oil repellency rating were 100 and 5, respectively. Those dried at room temperature also showed water and oil repellency: the water repellency rating was 70 and the oil repellency rating was 3. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 222–226, 2005

The emulsion copolymerization of butyl acrylate (BA) with a trifunctional cross-linker, diallyl maleate (DAM), was investigated. The effect of the monomer feeding time and the amount of cross-linker on the microstructural properties (branching, cross-linking, gel formation, and sol MWD) of the seeded semicontinuous emulsion copolymerization of BA with DAM was investigated. It was found that the gel content was not significantly affected by increasing feeding time, but the level of quaternary carbons (an indication of the branching density) increased. On the other hand, increasing the amount of DAM in the feed composition caused gel content, level of quaternary carbons, and the cross-linking density to increase. Interestingly, the level of quaternary carbons and the cross-linking density sharply increased during the cooking period. The molecular weight of the sol decreased as DAM increased in the feed. In addition, the effect of process type, batch versus semibatch, was also considered and important differences in the level of quaternary carbons, cross-linking, and gel content were found. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4684–4694, 2005

Triethoxysilyl-modified polychloroprene (CR) latex was synthesized by the emulsion copolymerization of 2-(3-triethoxysilylpropyl)-1,3-butadiene with chloroprene. This latex was mixed with unmodified CR latex and tetraethoxysilane to obtain CR-silica composites by sol-gel reaction in the latex. SEM observation showed that the silica particles in unvulcanized composites have various diameters ranging from 0.1 to 0.6 μm, and their size became larger with the decrease of the silica content. Vulcanized CR-silica composites showed that the tensile modulus and tear strength improved with an increase of the amount of modified CR.

Modified polyacrylate‐based latexes containing silicone were prepared by the emulsion copolymerization of three acrylic monomers [methyl methacrylate (MMA), n‐butyl acrylate (BA), and acrylic acid ...

This work addressed the viability of using a pulsed sieve-plate column reactor to carry out continuous vinyl acetate/butyl acrylate emulsion copolymerization reactions. A rigorous mathematical model of emulsion copolymerization reactions in a tubular reactor with axial dispersion was used for this purpose. Operational conditions were defined to attain high monomer conversions at the reactor outlet in a relatively short residence time and, at the same time, produce a copolymer with a more homogeneous composition.

The comparison of the mathematical model and experimental results of the free radically initiated semi-continuous emulsion polymerization of styrene/butadiene/acrylic acid in the presence of chain transfer agent (CTA) is presented. The mathematical model takes into account the mechanism of gel formation and the effect of acidic monomers. It has also been included the inhibition caused by oxygen and monomer inhibitor. The experimental results (solids content, unreacted amount of monomer and gel content) and those obtained by the model are in rather good agreement.

This paper reports preparation of mechanically cross-linked polystyrenes using cyclic macromonomer as a nonbonding cross-linking agent. Emulsion and thermal self-initiated copolymerizations of styrene with a well-defined cyclic macromonomer based on a cyclic polystyrene were carried out to obtain mechanically cross-linked polystyrenes with high swellability. Mechanically cross-linked chloromethylated polystyrene was prepared by thermal self-initiated terpolymerization of the cyclic macromonomer, styrene, and 4-vinylbenzyl chloride.

Recently, emulsion polymers have grown in interest. On the one hand, environmental pressures are jeopardizing the use of hazardous volatile compounds, favoring the industrial practice of emulsion polymerization. On the other hand, emulsion polymerization is long known for its outstanding capacity to produce products with a myriad of properties. Emulsion polymers are the base of a well-established industry. Synthetic rubbers alone account for the production of over 8000 million tonnes per year of emulsion polymers. It is widely recognized how technical progresses on the polymerization field can benefit companies. Nevertheless, not much has been said about the environmental impact of those progresses. This work intends to shed light into this promising field, using the principle of the inventory step of the life cycle assessment analysis.

The development of a model-assisted methodology for the synthesis of high solids-low viscosity latexes is presented. A simplified polymerization model for systems with a polydisperse particle size distribution, PSD, was developed. The polymerization model was then coupled with an equation for the computation of the viscosity. Their combination resulted in a powerful tool that helped to screen strategies for the synthesis of high solids-low viscosity latexes. Furthermore, using the model-assisted methodology it was possible to determine the workable viscosity boundary for a given formulation. The evolution of the viscosity with the volume fraction was calculated for different polymerization strategies.

Research regarding chemically modifying the wood in order to prevent its deterioration is an alternative to the protection of wood with toxic chemicals. The paper presents the research concerning the chemical modification of pine wood sawdust by esterification with acrylic monomers, in order to improve its biological resistance.

We succeeded in introducing cation exchange groups quantitatively into a porous resin having an open-celled monolith structure. The resulting new cation exchange resin had the following advantages compared with conventional ion exchange resins having a bead structure. First, it was easier to pack it in a column. Second, the ion exchange rate of the new cation exchange resin was much higher than that of the conventional ion exchange resins, and the ion exchange band length of the new resin was smaller than that of the conventional ones. In addition, the electric conductivity was about five times higher than that of the conventional ones, although they had similar ion exchange capacities. These unique properties of the new cation exchange resin were caused by the quantitative introduction of ion exchange groups into the resin having the open-celled monolith structure.

The influence of nonionic emulsifier, included inside styrene-methacrylic acid copolymer [P(S-MAA)] particles during emulsion copolymerization, on the formation of multihollow structure inside the particles via the alkali/cooling method (proposed by the authors) was examined in comparison to emulsifier-free particles. It was clarified that the nonionic emulsifier included inside the P(S-MAA) particles eased the formation of multihollow structure.

In this work, the optimal surfmer feeding profile for stabilizing a high-solid-content acrylic latex with a non-ionic alkenyl functional TM Maxemul 5011 was calculated. For this purpose, the model developed by de la Cal and Asua (J. Polym. Sci., Part A: Polym. Chem. 39 (2001) 585) was used. It was observed that, in spite of the low reactivity of the surfmer, it was possible to increase substantially the surfmer conversion using an optimal surfmer addition policy. To cite this article: E. Aramendia et al., C. R. Chimie 6 (2003).

Heterogeneity in the formation of multihollow structure among submicron-sized styrene-methacrylic acid copolymer particles, which were produced by batch emulsion copolymerization, by the alkali/cooling method under partial neutralization of carboxyl groups was investigated. There was a threshold of the acid content to form the multihollow structure. The heterogeneity among the particles was based on the heterogeneity of the acid content among the original particles.