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For the first time emulsion polymerization of polyangelicalactone with styrene was carried out. Block copolymers with a molecular weight of 40000-1000000 and containing 5-40 wt. % of styrene were prepared. Polymerization rate constants were evaluated. Mechanical properties were evaluated after the copolymers were cured. The cured block copolymers satisfy the basic requirements for high impact polystyrene, and they are biodegradable

The synthesis of Janus particles has been thriving in recent years, especially effective preparation strategies and amazing properties are the key focus of current academic and practical perspectives. In this work, the mushroom-shaped polymeric Janus particles (MsPJPs) with controllable morphologies and emulsifiabilities were first prepared by facile one-pot soap-free emulsion copolymerization (SfEP) based on swelling process and regulating ratio of common hydrophilic/hydrophobic monomers. Meanwhile, the nano-Ag particles were loaded onto MsPJPs with regioselectivity, which create new opportunities in a wide variety of applications, such as antibacterial medicine and medical instruments, functional coating, and catalytic materials.

Process intensification of vinyl acetate–VeoVa10 latexes production is investigated by synthesizing commercial-like 57 wt% solids waterborne dispersions stabilized with poly(vinyl alcohol) in 2 CSTRs in series. The effect of several process variables (temperature, initiator concentration and emulsifier distribution along continuous stirred tank reactors (CSTRs)) on monomer conversion and polymer microstructure was analyzed. A mathematical model that considers the segregation of the polymer among particles and the effect of the residence time distribution was developed and a good agreement between the experimental data and model predictions was achieved.

Copolymer composition distribution (CCD) is an important parameter of chain microstructure that has significant impact on the material properties of polymer products. Controlled/living radical poly...

A novel emulsion copolymer of vinyl acetate (VAc) and 1-hexene was synthesized at ambient pressure. The feeding technique, initiation system and reaction time of the copolymerization were optimized ...

It is demonstrated that the monomer conversion versus time curves observed in the seeded emulsion copolymerization of styrene and acrylonitrile at 50 °C can be explained very well by the simulation results obtained by employing the kinetic model previously developed for an emulsion copolymerization system by the present authors. In the model predictions, thermodynamic equilibrium equations are used for predicting the monomer concentrations in the copolymer particles, and the free volume theory is applied to account for the diffusion-controlled termination in the copolymer particles that often takes place in the region after the monomer droplets have disappeared from the water phase.

In order to prepare hollow latex particles with optimum morphology based on osmotic swelling principle, three- layer core/shell latex particles with 40 wt% MAA in the core were first prepared via multistep seeded emulsion copolymerization, in which monomers were added by a semi-continuous process with monomer addition under two different forms: pure monomers' mixture (monomer addition), and pre-emulsified monomers (pre-emulsion addition). Then, the hollow latex particles with different morphologies were obtained after alkali post-treatment. Influences of the monomer feeding mode on the emulsion polymerization and the particle morphology were investigated. Results showed that the pre- emulsion addition could significantly improve the polymerization stability in each step, and greatly enhance the uniformity of shell encapsulation. The sizes of the core and core/shell latex particles obtained by the pre-emulsion addition were smaller and more uniform than those synthesized by the monomer addition, and the hollow latex particles with intact morphology were generated by alkali post-treating of the core/shell latexes prepared from the pre-emulsion addition. As the core size increased, the morphology of the post-treated particles underwent evolution from hollow to collapse. Moreover, the mechanism of the particle morphological evolution was proposed.

P(NIPAm-co-TMSPMA)/Silica hybrid microgels were prepared by in-situ sol–gel process of tetraethyl orthosilicate (TEOS) in the presence of thermo-sensitive P(NIPAm-co-TMSPMA) microgels, which were synthesized via surfactant-free emulsion copolymerization (SFEP) of N-isopropylacrylamide (NIPAm) and 3-(trimethoxysilyl)propylmethacrylate (TMSPMA). At preparation temperature above the volume phase transition temperatures (VPTT) of P(NIPAm-co-TMSPMA) microgels, i.e. 50 °C, the silica nanoparticles could not penetrate into the collapsed microgels but uniformly covered on the surface of microgels and the obtained P(NIPAm-co-TMSPMA)/Silica hybrid microgels had the raspberry-like structures. Whereas, at preparation temperature below the VPTT, i.e. 25 °C, the silica nanoparticles were uniformly distributed inside the swelled microgels and the resultant P(NIPAm-co-TMSPMA)/Silica hybrid microgels exhibited uniform organic–inorganic hybrid structures. The presence of silica nanoparticles restricted the swelling–deswelling capability of P(NIPAm-co-TMSPMA)/Silica hybrid microgels and also prevented the merging of hybrid microgels during drying. Macroporous silica with ordered macropores could be easily fabricated by selectively calcinating the organic microgel component after the assembly of the P(NIPAm-co-TMSPMA)/Silica hybrid microgels.

The methods of preparation and characterization of core-shell poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) particles arranged in colloidal crystals are described. The particles were prepared via emulsifier free emulsion copolymerization of styrene and α-tert-butoxy-ω-vinylbenzyl-polyglycidol macromonomer in aqueous medium, initiated by potassium persulfate. The individual polymerizations differed in a way of addition of macromonomer to the polymerization mixture. The particles assemblies were characterized by atomic force microscopy, Secondary Ion Mass Spectrometry (SIMS) and X-ray Photoelectron Spectroscopy (XPS). In-depth distribution of chemical states was determined by XPS combined with argon gas cluster ion sputtering (Ar-GCIB). The morphology of microspheres assemblies reflected the composition of the entire particles. It was found that the method of macromonomer addition to the polymerization mixture affects the particles size, surface and overall morphology. The XPS profiles revealed the chemical composition of the particles arranged in multilayers. It was found that distribution of polyglycidol segments at the particles interfacial layer depends on the time and way of addition of macromonomer. The thickest outer layer composed from polystyrene-polyglycidol segments was obtained for particles when macromonomer was added at the beginning of polymerization.

Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers. The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter. Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail. Results show that the particle size of the latex has the minimum value and the zeta potential of the latex is increased when the amount of DMDAAC is increased. In addition, the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%. However, the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%. The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%. Nevertheless, the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 2.5%.

In this article, a series of carboxylated acrylate copolymer latices were prepared based on the semicontinuous emulsion polymerization via the pure monomer dropwise manner with three different kinds of carboxylic monomers in presence of reactive emulsifier. The effects of the carboxylic monomers [acrylic acid, methacrylic acid, and monobutyl itaconate (MBI)] on the conversion and the properties of acrylate latices and films have been investigated. The carboxylic groups (COOH) distribution of these three kinds of latices were investigated as well. The results show that the concentration of surface COOH (CS) and embedded COOH (Cb) both increase with the increase of the amount of carboxylic monomers. It shows that MBI, the most hydrophobic of the three carboxylic monomers used, tends to be concentrated inside the particle core, and the latex particles have a narrow size distribution. The results of common stability test have demonstrated that the stability of the latex is satisfactory. Moreover, the water absorption and the acid and alkaline resistance of the latex depend on the kind of carboxylic monomer. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

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.

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.