Semi-continuous Seeded Emulsion Polymerization Research Articles

Synthesis and Properties of Cationic Fluorinated Polyacrylate Soap-Free Latex

Cationic fluorinated polyacrylate soap-free latex (CFMBD) was synthesized by semi-continuous seeded emulsion polymerization of dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and dimethylaminoethyl methacrylate (DM) with a novel cationic polymerizable emulsifier, maleic acid double ester-octadecyl poly(ethyleneoxy)20 ether-ethylene trimethyl ammonium chloride (R303), and 2,2′- azobis (2 - methylpropionamidine) dihydrochloride (VA-50) was utilized as the initiator. Effects of some factors, such as VA-50 amount, R303 amount and DFMA amount, on stability and average particle size of the CFMBD were discussed in detail, and the optimal polymerization condition was obtained. In addition, the emulsion and its film were characterized by Fourier transform infrared (FTIR) spectrometry, thermogravimetry analysis (TGA), contact angle goniometer, X-ray photoelectron spectroscopy (XPS), respectively. FTIR confirmed the structure of the CFMBD. With the increasing of DFMA amount, water absorption of the film decreased and water contact angle of the film increased. While the DFMA amount was more than 6 g in the recipe, the water contact angle (107.5°) and the water absorption (7.8 wt%) of the film showed no more changes. Meanwhile, thermal stability of the copolymer was greatly improved with the increasing of DFMA amount. XPS analysis indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface.

Synthesis and Characterization of Large Dimension PBA-P(MMA-ITA) Latex Particles with Core-Shell Morphology

In this paper, a novel large dimension poly(n-butyl acrylate)-poly(methyl methacrylate-itaconic acid) (PBA-P(MMA-ITA)) core-shell latex particles (CSR) with diameter of 200 nm∼300 nm were successfully synthesized via pre-emulsion and semi-continuous seeded emulsion polymerization process. The analysis on the surface tension and coagulation rate of polymeric system, size and distribution of latex particles indicated that the composite emulsifier of sodium dodecyl sulfonate/polyoxyethylene nonyl phenyl ether (SDS/OP-10) had the best emulsified effect. The optimal ratio of SDS/OP-10 was 1:1 and its optimum dosage was 1.0% of monomer amount. FTIR analysis results confirmed that ITA participated in the copolymerization reaction and the chemical bond between P(MMA-ITA) copolymer and PBA core existed in the interfacial of core and shell. DSC analysis results showed that the glass transition temperature (T g) of P(MMA-ITA) copolymer increased with the increase of the ITA dosage and decreased with the increase of the core shell mass ratio. TEM images revealed that CSR particles had core-shell morphology indeed, but the particles’ core-shell morphology would be changed at higher ITA dosage and core shell mass ratio. The size of CSR particles was 330 nm, and the diameter of PBA core was 290 nm. ITA content in the shell of CSR particles was analyzed by non-aqueous acid-base titration. ITA content was the highest at 6% of ITA dosage, ITA amount which chemically bonded with PBA core was the highest at 8% of ITA dosage. When the core shell mass ratio was 60/40, ITA content and ITA amount which grafted onto PBA core were both the highest. ITA content of CSR particles achieved above 1.11% in this work, and it is completely possible for using CSR particles toughening and compatibilizing polyamide 6 (PA 6).

Synthesis and characterization of self-crosslinking fluorinated polyacrylate soap-free latices with core–shell structure

Novel self-crosslinking fluorinated polyacrylate soap-free latices (FMBN) with core–shell structure were synthesized by semicontinuous seeded emulsion polymerization method from dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and N-methylolamide (NMA) in the presence of a polymerizable emulsifier-ammonium allyloxtmethylate nonylphenol ethoxylates sulfate (DNS-86). Effects of the DNS-86 and DFMA amounts on stability and properties of the FMBN emulsions were studied. Besides, the latices and their film were characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (1H NMR) spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analyzer, differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), contact angle goniometer, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. FT-IR spectra and 1H NMR spectrum showed that DFMA successfully participated in soap-free emulsion polymerization and monomers formed the fluorinated acrylate copolymer. The resulted latex particles had the core–shell structure. The films formed from the FMBN latices thus had two Tg. Their thermal stability and Tg of the shell phase increased gradually with augment of DFMA amount in polymer. XPS, AFM and hydrophobicity analyses indicated the fluoroalkyl groups had the tendency to enrich at the film–air interface. This enrichment of fluorine at the film–air interface was more evident after the annealing process. Water contact angles of the FMBN film before and after the annealing process could attain 115.5° and 117.5°, individually.

Synthesis and Characterization of Novel Poly (AN-BA- DFMA) Latex Prepared via Semi-continuous Seeded Emulsion Polymerization

The novel poly (AN-BA-DFMA) was prepared via semi-continuous seeded emulsion polymerization. The resultant novel latex is characterized with FTIR and DSC. The reaction conditions for preparing the novel latex are optimized and studied in detail. Results show that the novel latex with small particle size and good stability and hydrophobicity can be obtained when the amount of emulsifiers is 6.0%, the mass ratio of OP-10 to SDBS is 2.0:1.0, and the amount of initiator and DFMA is 2.5% and 20%, respectively. Under such conditions, the conversion rate is high and the coagulation percentage is low.

Enhancement of Mechanical Properties of Emulsion Copolymers by Gradual Variation in Feed Composition. I: Effect of Particle Size in the Butyl Acrylate-Styrene System

Using a semicontinuous seeded emulsion polymerization process with a gradual variation in feed composition, butyl acrylate (BA)/styrene copolymers were obtained (variable composition copolymers, VCCs). BA seed particles of two different diameters were used to prepare copolymer materials with 50–85 wt.% styrene. In each reaction, cumulative copolymer composition was followed by 1H-NMR; with such data, a histogram showing the relative content of copolymer chains corresponding to each composition interval was built. The VCCs presented higher moduli and ultimate mechanostatical properties than their equivalent core-shell type polymers. The mechanical performance of VCC materials was explained considering the respective histograms.

Synthesis and Characterization of EC / BA / VAc Hybrid Latexes via Pre-Emulsified Semi-Continuous Seed Emulsion Polymerization

Hybrid latexes containing ethyl cellulose (EC), vinyl acetate (VAc) and butyl acrylate (BA) were prepared by pre-emulsified semi-continuous seed emulsion polymerization. Influences of some synthetic parameters on the stability of emulsion polymerization were investigated. The emulsion polymerization is optimum with emulsifier 3 wt%, OP-10/ SDS 1/1 and PVA 0.5 g. The emulsion average particle size increases with EC content increase.TGA and water absorption analysis show that EC/ BA / VAc hybrid latexes films containing more BA display better thermal stability and hydrophobicity. The EC/BA/VAc latex shows good biodegradation, flexility property and is suitable for slow-release material of environmental-friendly coated fertilizer.

Synthesis of a core-shell polyacrylate elastomer containing ultraviolet stabilizer and its application in polyoxymethylene

A core–shell polyacrylate elastomer containing ultraviolet (UV) stabilizer was synthesized via semicontinuous seeded emulsion polymerization from butyl acrylate (BA), methyl methacrylate (MMA), and a polymerizable UV stabilizer 2-hydroxy-4-(3-methacryloxy-2-hydroxylproroxy)benzophenone (BPMA). The core–shell poly(MMA-BA-BPMA) was investigated by Fourier transform infrared spectroscopy, gel permeation chromatography UV–visible (UV–vis) absorption spectroscopy, and transmission electron microscope. Furthermore, the obtained core–shell poly(MMA-BA-BPMA) elastomer was used as a modifier to enhance the UV resistance and impact resistance of polyoxymethylene (POM). As studied by scanning electron microscope, the core–shell poly(BA-MMA-BPMA) elastomer could be well dispersed in POM matrix, indicating that the elastomer had good compatibility with POM. In addition, the POM/poly(MMA-BA-BPMA) blend was examined by differential scanning calorimetry before and after UV irradiation. The results showed that the melting point decreased as the irradiation time increased; however, the crystallinity culminated at 500-h UV irradiation slightly decreased and at last leveled off. The mechanical properties of POM/poly(BA-MMA-BPMA) before and after UV irradiation were also studied. It revealed that the photostabilizing fragments in the elastomer could provide long-term UV resistance to POM. Besides, the impact strength was also improved when compared with pure POM. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Control of particle size and surface properties of fluorinated acrylate microemulsion

Fluorinated acrylate microemulsion was prepared via co-polymerising methyl methacrylate, butyl acrylate and dodecafluoroheptyl methacrylate that were stabilised by polyethylene glycol mono-p-nonyl phenyl ether and sodium dodecyl benzene sulphonate and initiated by potassium persulphate. Many factors, which had an influence on the particle size and its distribution, had been investigated. It was possible to produce nanoparticles <100 nm and with narrower size distributions using the semicontinuous seeded emulsion polymerisation. Fourier transform infrared spectroscopy confirmed the structure of the microemulsion. The appearance of the microemulsion was translucent and accompanied with blue fluorescence. The stability of the microemulsion was very high. The solid content of the microemulsion was 38·65%. The contact angle of the film was not very high.

Synthesis of core‐shell fluoroacrylate copolymer latex via emulsion polymerization and its application in ink‐jet ink

AbstractCore‐shell fluoroacrylate copolymer latex was synthesized via semicontinuous seed emulsion polymerization, in which ethyl acrylate was utilized to prepare core, and methyl methacrylate, butyl acrylate, methacrylate acid, and hexafluorobutyl methacrylate were employed to constitute the shell. So the yielded latex particles had the soft core and hard shell. Multifunction and low viscosity of the latex had been applied as the binder of latex inks. The ζ potential showed that the latex particles had high thermodynamic stability. The latex and latex inks exhibited viscosity plateau of Newtonian fluid behaviors. Rheological tests revealed that viscous behaviors dominated in the latex and latex inks. However, there was some interaction among the latex and pigment particles. The hydrophobicity of the cast films of the latex increased with the amount of the fluoroacrylate monomer. Fluorine tended to migrate to the interface between the cast film and air. Therefore, the hydrophobicity was derived from the fluorine enrichment phenomena on the top side of the cast films. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Properties of polyacrylate latex prepared under different emulsified systems

The polyacrylate latexes were synthesized via pre-emulsified and semi-continuous seeded emulsion polymerization technology when conventional surfactant or polymerizable surfactant was used as emulsifiers. The resultant latexes and their films were characterized with the contact angle determinator and rheometer. Effect of the polymerizable surfactant on water resistance, stability and rheology of the latex was studied. Results show that the water resistance of film is increased first then decreased with the increase of the amount of the polymerizable surfactant. There exists the optimum value of the amount of the polymerizable surfactant for the water resistance of the film. In comparison with the latex prepared with the conventional surfactant, both the mechanical stability and the freezing-thaw stability of the latex are improved when the polymerizable surfactant is used during the course of the emulsion polymerization. The resultant latex has rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

Synthesis and Characterization of Polyacrylate Latex Containing Fluorine and Silicon

Polyacrylate latex containing fluorine and silicon was successfully synthesized by semi-continuous seed emulsion polymerization, using organic silicon(OSi) monomer, fluorocarbon(FC), methacrylic acid(MAA), and butyl acrylate(BA) as raw materials. Transmission electron microscope(TEM) characterization indicated that the latex particles were form uniform analogous core-shell structure. Dynamic light scattering(DLS) show a narrow size distribution. The results of X-ray photoelectron spectroscopy(XPS) revealed the fluorine and silicon transfer to the film-air interface. The reaction was evaluated using fourier transform infrared(FT-IR) spectrum. The thermal stability of the latex films which analysed by thermogravimetric(TG) was improved due to the join of OSi and FC.

Nanometre fluorinated acrylate latex prepared with gemini surfactant

The nanometre fluorinated acrylate latex was prepared via semi-continuous seeded emulsion polymerisation of butyl acrylate, methyl methacrylate and hexafluorobutyl acrylate in water phase when gemini surfactant and 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride are used to be emulsifier and initiator, respectively. The resultant latex is characterised by Fourier transform infrared (FTIR) spectrometry, contact angle measurements, dynamic light scattering and differential scanning calorimetry (DSC). FTIR spectrum identifies the formation of terpolymer. DSC confirms that the latex is a kind of random terpolymer and the consistency among the chain segment is fairly good. The average particle size of latex is decreased with the increase of the amount of gemini surfactant. The particle size of resultant latex is 22.4 nm and is further confirmed by transmission electron microscope when the amount of gemini surfactant is 3%. However, the viscosity of latex is increased with the increase of the amount of gemini surfactant. In comparison with the nanometre fluorinated acrylate latex, the hydrophobic property of the resultant latex is improved.

Alkali-Thickening Characteristics of Vinyl Acetate and Vinyl Ester Versatic Acid Copolymer Latex Using Carboxylic Monomers

VAc/Veova10/MAA copolymer latex containing carboxyl groups was synthesized by the semi-continuous seed emulsion polymerization with vinyl acetate (VAc), vinyl ester of versatic acid (Veova10) and methacrylic acid (MAA). Alkali-thickening characteristics of VAc/Veova10/MAA copolymer latex containing carboxyl groups, adjusted from pH 5.5 to 6.4, 8.9, 9.8 with NaOH aq., were investigated by DSC. The results showed that the viscosities of VAc/Veova10/MAA copolymer latex were increased with the inceasing of pH, The frozen temperature peaks were observed to increase with the increasing of pH, the thawed temperature peaks were shifted to lower temperature, and the state of water in latexes were different. The partial morphologies of latexes were irregular and latexes were pseudoplastic fluid. And water absorption of films were increased with the increasing of pH in latexes and dry and wet shear strengths were also decreased.

Effect of different surfactants on colloidal and polymer properties of fluorinated acrylate latex

Fluorinated acrylate latex was successfully prepared by semi-continuous seeded emulsion polymerization of dodecafluoroheptyl methacrylate (DFMA) with butyl acrylate (BA), methyl methacrylate (MMA) initiated by potassium persulfate in the water. The resultant latexes and their films are characterized with Fourier transform infrared (FTIR) spectrometry, contact angle determinator, dynamic light scattering detector and surface tension determinator. Effect of different surfactants on colloidal and polymer properties of fluorinated acrylate latex was studied. Results show that the latex prepared with sodium dodecyl benzene sulfonate surfactant has the smallest particle size and contact angle but the moderate surface tension. The latex prepared with perfluorooctanesulfonic acid potassium surfactant has the smallest surface tension, moderate particle size but the biggest contact angle. The latex prepared with sodium 2-hydroxy-3-(methacryloyloxy) prop- ane-1-sulfonate surfactant has the biggest particle size and surface tension but moderate contact angle. In addition, the latex prepared with sodium 2-hydroxy-3-(methacryloyloxy) prop- ane-1-sulfonate has higher electrolyte stability.

Preparation and characterization of pure polyacrylate polymer colloid through emulsion polymerization using a novel initiator

A series of acrylic polymer colloids were prepared via semi-continuous seeded emulsion polymerization of BA and MMA in water phase when OP-10 and AIBI is used to be emulsifier and initiator, respectively. FTIR spectrum identifies the formation of copolymers of P (MMA-co-BA). DSC confirms that the colloid is a kind of random copolymer and the consistency among the chain segment is fairly good. The emulsion polymerization conditions of preparing acrylic polymer colloid are optimized. Results show that the conversion rate is high and the coagulum is low and the particle size of the acrylic polymer colloids is small when the amount of AIBI is 0.75 g. The polymerization temperature is 70 °C, which is lower than the one that the emulsion polymerization is initiated with the persulfate.

Preparation of High Solid Content Emulsion with Core-Shell Structure

Core-shell copolymer emulsion of P(St + AA)/P(MMA + BA +DMAM) with solids content up to 60% was synthesized by the semi-continuous seed emulsion polymerization in which the pre-emulsified monomers were added dropwise. The effects of polymerization technique, the contents of seed emulsion, the amounts of emulsifier, the concentration of initiator, solid content, and polymerization temperature on emulsion particle size and its distribution were investigated. The emulsion particle morphology was characterized by transmission electron microscopy (TEM). The results indicated that the average particle size was within 200–600 nm and the particle size distribution index within 1.2–1.4. The particle size displays multidispersity.

Influence of the Reactive Emulsifier-HPMA on the Properties of the Acrylate Emulsion

The acrylate emulsion was prepared via pre-emulsified and semicontinuous seeded emulsion polymerization technology when nonreactive emulsifiers such as sodium dodecyl-benzenesulfonate (DSB) are replaced with reactive emulsifiers such as sodium2-hydroxy-3-(methacryloyloxy)propane-1-sulfonate (HPMAS). Influence of HPMAS on the particle size, water resistance, viscosity, rheology, and stability of the emulsion was studied. Results show that the particle size and the viscosity of the emulsion are increased with the added amount of HPMAS. However, water resistance of film first is increased and then decreased with the increase of the added amount of HPMAS. The water resistance of the film is best when the added amount of HPMAS is 2.0%. The viscosity of the emulsion is increased with the increase of the added amount of HPMAS. Both the mechanical stability and the freezing-thaw stability of the emulsion are improved when DSB is replaced with HPMAS during the course of the emulsion polymerization. The emulsion is of rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

Stability of Emulsion Polymerization of New Fluorinated Acrylate Emulsion and Its Characterization

The new fluorinated acrylate emulsion was synthesized by using the intermediate perfluorous nonene and 2-hydroxyethyl methacrylate as the staring reactants via semi-continuous seeded emulsion polymerization. The structures, glass transition temperature, thermal property and water repellency of the fluorinated acrylate emulsion were characterized with FTIR, differential scanning calorimetry, thermal analysis, and contact angle meter. Influences of many factors such as the theoretical solid content, the temperature of the emulsion polymerization on the stability of the emulsion polymerization, the added amount of emulsifiers and the added amount of the initiator were studied. Results show that the stability of the emulsion polymerization is fairly good when the theoretical solid content is below 30% and the reaction temperature is 80°C and the added amount of emulsifiers and the initiator are 6.0–8.0% and 2.0% respectively. In comparison with the acylate emulsion, the thermal stability of the fluorinated acrylate emulsion is decreased but the water repellency of the fluorinated acrylate emulsion is greatly increased.

Study on the double fluorinated modification of the acrylate latex

Double fluorinated acrylate latex (DFAL) has been successfully prepared by macromolecule reaction between m-trifluoromethylphenylamine (m-TFMPA) and the single fluorinated acrylate latex (SFAL), which is prepared by semi-continuous seeded emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) 2-(perfluoro-(1,1-bis-isopropyl)-2-propenyl)oxyethyl methacrylate (POMA) and glycidyl methacrylate (GMA). The resultant DFAL is characterized by Fourier transform infrared (FTIR) spectrometry, contact angle determinator, dynamic light scattering detector and thermo-gravimetric analysis (TGA). Results show that the contact angle of DFAL film is improved in comparison with that of SFAL film. The surface properties especially the contact angle of the film with annealing have been improved greatly because more fluorine atom is introduced into the molecule of acrylate latex and moves to the surface of the film. However, the thermal stability of the DFAL film is not improved.

Influence of carboxyl groups on the particle size and rheological properties of polyacrylate latices

The PAL was synthesized with BA, MMA and some monomers containing carboxyl groups (for example, acrylic acid (AA) and methacrylic acid (MAA)) as co-monomers by semi-continuous seeded emulsion polymerization technique. The influences of alkalinization temperature, the feeding manner of AA or MAA on the particles size Rheological properties and carboxyl distribution of the latex were discussed, and the rheological mechanism was analyzed. The experimental results show that the PAL system has preferable viscosity and particle size when the alkalinization temperature is 50 °C. Different distribution of carboxyl group in the particles and different resultant rheological properties are obtained by different feeding manner of AA or MAA into the system. The TEM images show that the particle is a smooth globe with carboxyl group concentrating on the surface and stabilized with electric double layer and nonionic adsorbed layer. The concentration of carboxyl functional group on the surface of particles can be achieved by the specific polymerization technique. The rheologyical properties are determined by accretion of particle volume and variation of the two phase volume ratio resulted from the carboxyl group spreading layer.