Semi-continuous Seeded Emulsion Polymerization Research Articles

Preparation and characterization of long carbon chain based polyacrylate latexes and their pressure sensitive adhesive application

Aqueous emulsion homo- and co-polymerization of lauryl methacrylate (LMA), a strong hydrophobic monomer with long carbon chain, is quite challenging. In this study, a long carbon chain emulsifier N-390 was used as the primary emulsifier to facilitate the emulsion copolymerization of LMA with other acrylate monomers through the mutual hydrophobic interaction between N-390 and LMA, and ultimately polyacrylate latex pressure sensitive adhesives modified by LMA via pre-emulsified semi-continuous seeded emulsion polymerization process were synthesized. The effects of LMA on the resulting latex and PSA properties was comprehensively examined. Both FTIR and 1H NMR spectra indicated that LMA has been successfully introduced into copolymer chain with the aid of long carbon chain emulsifier N-390. The results also showed that the introduction of LMA will contribute to decrease in particle size and zeta potential, while increase viscosity and gel content of the acrylate PSA latex. Moreover, as the LMA content increased, the latex PSA films demonstrated gradual improvements in both water resistance and thermal stability. Finally, for the long carbon chains adhesive film, the shear strength was improved greatly while at the sacrifice of loop tack and peel strength, when compared to counterparts without LMA.

Research on Nano-ZnO/fluorine Polyacrylate Linen Fabric Finishing Agent

ABSTRACT With nano-ZnO, methyl methacrylate (MMA), ethyl acrylate (EA), and dodecafluoroheptyl methacrylate (DFMA) as reaction monomers, potassium persulfate as initiator, nano-ZnO/fluorine polyacrylate linen fabric finishing agent was prepared by semi-continuous seed emulsion polymerization to improve the hydrophobicity and anti-fouling performance of linen fabric. The structure and properties of the film and the finished fabric were characterized and analyzed by1HNMR, FT-IR, and TG. The results showed that the nano-ZnO/fluorine emulsion was successfully prepared with a particle size of about 46 nm, which was combined with linen. The contact angle of the finished linen fabric to water was 130.33°, which indicated that the finished linen fabric had good hydrophobicity. Meanwhile, the anti-fouling performance of the finished linen fabric was also improved. The introduction of nano-ZnO and organic fluorine in turn made linen fabric had the properties of the heat-resistant stability, UV resistance, antibacterial properties, and yellowing resistance.

Chemical, thermal and film properties of metal cross-linking fluorinated polyacrylate colloid prepared via semi-continuous seeded emulsion polymerization

The metal cross-linking fluorinated polyacrylate colloid has a high cross-linking density, high transparency, high heat resistance and hydrophobicity. In this paper, the metal cross-linking fluorinated polyacrylate colloid is synthesized via the semi-continuous seeded emulsion polymerization technology, which uses the self-made magnesium acrylate, calcium acrylate and zinc acrylate as metal crosslinker and dodecafluoroheptyl methacrylate as a fluorine monomer. In this study, the ablation effect of the metal ions is weakened by the increased amount of environmentally friendly and polymerizable anion emulsifier DNS-86. The demulsification phenomenon of emulsion is successfully overcome through destroying the double layer structure of micelles or colloid particles by polyvalent metal ions. The colloidal particle size is smaller and the particle size distribution of the colloid is more uniform. Colloidal film has a good hydrophobicity and the glass transition temperature and the thermal decomposition temperature are high.

CaCO3-TiO2 IMPREGNATED AlOE VERA-ALLYL METHACRYLATE ANTIMICROBIAL NANOEMULSION FOR COATING

The present work aims to utilize AMA/MMA/BA/Aloe Vera (AMBA) nanoemulsion for the preparation of sustainable antimicrobial coating materials. The AMBA was synthesized using a semi-continuous seeded emulsion polymerization methodology. The developed coating material has been synthesized by SEM, DSC, TGA/DTA, XRD, and FT-IR spectroscopy. Some properties such as viscosity, hot box stability gloss retention, solid content, freezethaw stability, scrub resistance, electrolytic stability, weather resistance, solvent resistance, and opacity of the coating material were also investigated. It has been found that the coating developed with a 70:30 monomer ratio shows the best results the with highest antimicrobial activity.

Fabrication of Novel Crosslinking Carboxylic Styrene-Acrylate Latices as Binders for Exterior Flexible Facing Tiles.

To overcome the shortcomings of the temperature sensitivity of exterior flexible facing tiles (EFFIs), a series of crosslinking carboxylic styrene-acrylate (SA) latices were prepared via the semicontinuous seed emulsion polymerization of glycidyl methacrylate (GMA), methacrylic acid (MAA), acrylic acid (AA), butyl acrylate (BA), and styrene (St), and were applied as binders to fabricate EFFTs with mineral powder. The obtained latices exhibited Bragg diffraction because of the narrow particle size distribution. Owing to the low dosage of emulsifiers and the crosslinking reaction between the epoxy group and the carboxyl group, the latex films displayed excellent water resistance, with water adsorption as low as 7.1%. The tensile test, differential scanning calorimeter (DSC) test, and dynamic mechanical analysis (DMA) indicated that at a GMA dosage of 4-6% the latex films had high mechanical strengths, which remained relatively stable in the temperature range of 10 to 40 °C. The optimal AA dosage was found in the range of 2 to 3%, at which the wet mixture exhibited good processability, conducive to forming an EFFT with a compact microstructure. Using the optimal SA latex, the obtained EFFT displayed a series of improved performances, including low water absorption, high mechanical strength, and stable self-supporting ability over a wide temperature range, exhibiting the application potential in the decoration and construction industries.

Preparation and Characterization of Self-crosslinked Acrylate Emulsified with Environmentally Friendly Surfactants

The self-crosslinking polyacrylate latex was prepared via the semi-continuous seed emulsion polymerization technology that methyl methacrylate(MMA) and butyl acrylate (BA)were used as the main monomers and hexafluorobutyl methacrylate (HFMA) and monobutylitaconate (MBI) were used as the modified monomers and glycidyl methacrylate (GMA) was used as the crosslinked monomer which were emulsified with the environmentally friendly mixed surfactant of the isomeric triethylene (9) ether (E-1309) and the lauryl polyoxyethylene ether sulfosuccinate disodium salt (MES-30). The resultant latex and its film is characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), laser particle sizer, contact angle determinator. The comparison of thermal stability between the resultant latex and conventional latex is carried out via the thermogravimetric analyzer (TGA). Factors, which have an influence on the properties of the resultant latex and the emulsion polymerization, are studied in detail. Results indicate that the thermal decomposition temperature of the latex film was increased from 336.9 °C to 370.1 °C The contact angle of the latex film is 82.9 ° owing to the introduction of GMA and MBI.

Fluorinated acrylic monomer modified core-shell polyacrylate latex particles: Preparation, properties and characterizations

The core-shell acrylic emulsion was synthesized by a semicontinuous seeded emulsion polymerization with acrylate monomers as the main materials and octafluoropentyl methacrylate (OFPMA) as modified monomers. The influences of OFPMA on the hydrophobicity, thermal stability and mechanical properties of acrylic latex film were investigated. Fourier transform infrared spectroscopy (FTIR) analysis and X-ray photoelectron spectroscopy (XPS) indicated that the OFPMA was successfully incorporated into the acrylic resin chain. Transmission electron microscope (TEM) image showed a core-shell structure of the emulsion particles. The addition of OFPMA reduced the water absorption ratio (3.2 wt%) of the latex film and improved its water resistance. Contact angle of coating film surface increased from 80.7° to 90.7°. Moreover, TGA curves showed that the addition of OFPMA increased the initial decomposition temperature of the polymer from 355 to 370 °C. Additionally, with the addition of OFPMA, the tensile strength of modified polymers was also improved to 7.77 MPa compared to pure acrylic resin. The application of the core-shell structure can reduce the amount of fluorine-containing acrylic monomers and environmental pollution, and improve economic benefits. This study provides a new kind of environmentally friendly waterborne acrylic resin and a simple method for optimizing the performance of waterborne resins. • The core-shell acrylic emulsion modified by octafluoropentyl methacrylate was synthesized via a semicontinuous seeded emulsion polymerization. • The core-shell acrylic emulsion exhibited excellent water resistance and thermal stability. • The core-shell structure reduces the amount of fluorine-containing acrylic monomers.

Synthesis of tertiary amine functionalized Multi-Stimuli-Responsive latex nanoparticles by semicontinuous emulsion Polymerization: Investigation of responsivities and antimicrobial activity

Stimuli-responsive core–shell nanoparticles (CSNPs) are an important class of smart polymers, which their physical and chemical properties could be changed in response to induced external stimuli. In this study, the amphiphilic CSNPs were synthesized via semi-continuous seeded emulsion polymerization using dimethylamino ethyl methacrylate (DMAEMA) as a hydrophilic monomer, and styrene as a hydrophobic monomer. Developed CSNPs were obtained in two series, poly(N, N-dimethylamino ethyl methacrylate) (PDMAEMA)-polystyrene (PS) core–shell particles and PS-PDMAEMA core–shell particles. The PDMAEMA chains exhibited different responsivities towards temperature rising, pH change, and CO2-gas, which their smart behaviors were investigated by dynamic light scattering (DLS) analysis. The temperature-responsivity of CSNPs was confirmed by observed particle size variation in the case of PDMAEMA-PS (increase) and PS-PDMAEMA (decrease) core–shell latex particles, when temperature increased to 70 °C, above the lower critical solution temperature (LCST) of PDMAEMA. Protonation of tertiary amine functional groups in the presence of CO2 bubbling led to an increase in the size of CSNPs as a result of water swelling of PDMAEMA chains. On the other hand, the size of CSNPs was changed in acidic (pH = 4) and basic (pH = 10) media by swelling and deswelling of PDMAEMA located in the core or shell. Obtained results indicated that maximum antimicrobial activity was observed for PS-PDMAEMA CSNPs compared to PDMAEMA-PS, which is probably due to presence of the PDMAEMA on the surface and increase of positive charge related to amine groups in this sample. The developed antimicrobial latexes have potential applications for using as antibacterial additives in water-based coatings and adhesives.

Chitosan strengthened and multiple hydrogen bonds crosslinked styrene-acrylate coatings as conductive substrate with excellent mechanical performance

In this work, styrene-acrylate (SA) coatings were strengthened with renewable natural polymers (carboxymethyl chitosan, CMCS) and crosslinked by multiple hydrogen bonds, which improved the mechanical performance and endowed the self-healing properties. SA latex was synthesized by styrene (St), butyl acrylate (BA), glycidyl methacrylate (GMA) and acrylamide (AM) with semi continuous seed emulsion polymerization. SA coatings were obtained after drying the mixture of SA latex and CMCS. The rigid skeleton of CMCS and hydrogen bonds cross-linked network improved the mechanical properties of SA coatings. The stress and strain improved from 12.3 to 17.9 MPa and 1765% to 2148%. The reversible hydrogen bonding interactions between SA and CMCS made the films had a self-healing efficiency of 68.7%. Moreover, the hardness of SA coatings reached 80.6. Combined with the spraying technique, SA conductive coatings were prepared by spraying carbon nanotubes aqueous dispersions (CNTs) on the surface. The conductivity and sensing ability of the SA conductive coatings were examined by an electrochemical workstation. The results demonstrated that SA conductive coatings had the signal sensing ability for tiny movements, which was of potential applications in the field of sensors.

SUSTAINABLE ANTIMICROBIAL COPOLYMER NANOEMULSION OF Aloe Vera AND ALLYL ALCOHOL: AN In-situ APPROACH

The current study describes the formation of a new sustainable Aloe Vera and allyl alcohol nanoemulsion with outstanding antimicrobial efficacy against Gram (+ive) and Gram (-ive) bacteria. The sustainable nanoemulsion of allyl alcohol/butyl acrylate/methyl methacrylate/ Aloe Vera with surfactant initiated by potassium persulphate was synthesized using a semi-continuous seeded emulsion polymerization technique. Several techniques like 1H, 13C NMR, XRD, SEM with EDX, DSC, TGA, DTA, FTIR spectroscopy, and physicochemical properties were utilized for the characterization of the synthesized sustainable nanoemulsion. A comparative study was done with different sets of organic-aqueous ratios for the determination of the ratio effect on the various properties of nanoemulsion. The results revealed tremendous improvement in the physicochemical characteristics and antimicrobial activity of nanoemulsions with a 50:50 organic-aqueous phase ratio.

Preparation and properties of a self-crosslinking styrene acrylic emulsion using amino-functional graphene oxide as a crosslinking agent and anti-corrosion filler

In this paper, we prepared a self-crosslinking amino-functional graphene oxide/styrene acrylic hybrid emulsion (AGO/SA). The styrene acrylic emulsion (SA) was synthesized with acetoacetoxyethyl methacrylate (AAEM) by semicontinuous seeded emulsion polymerization. Then, amino-functionalized graphene oxide (AGO) was prepared via the modification of graphene oxide (GO) with 3-aminopropyltriethoxysilane (APTES) and reacted with the SA emulsion as a crosslinking agent by in situ polymerization. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravity analysis (TGA), and transmission electron microscopy (TEM) were applied to explore the chemical structures and morphologies of the samples. The anti-corrosion performance of the AGO/SA coatings was evaluated by Tafel polarization and electrochemical impedance spectroscopy (EIS). Along with the crosslink between AGO and SA, the micropores in the matrix were reduced, the coating expressed improved corrosion resistance due to the graphene barrier, and the hybrid emulsion with 0.7 wt.% AGO exhibited the best anti-corrosion properties. These results indicate that AGO can act as both a crosslinking agent and an anti-corrosion agent in self-crosslinking hybrid emulsions, which have great potential in the field of environmentally friendly emulsions.

Preparation and characterization of self-crosslinking acrylic emulsion with different fluorocarbon chain lengths

PurposeFluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare self-crosslinking fluorocarbon polyacrylate latexes containing different fluorocarbon chain lengths by semi-continuous seeded emulsion polymerization technology.Design/methodology/approachMethyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and fluorine-containing monomers were used as main monomers. The fluorine-containing monomers included hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and trifluorooctyl methacrylate (TFMA). Potassium persulfate (KPS) was used as thermal decomposition initiator, non-ionic surfactant alkyl alcohol polyoxyethylene (25) ether (DNS-2500) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS) as mixed emulsifier.FindingsThrough optimizing the reaction conditions, the uniform and stable latex is gained. The polymer of structure was characterized by Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA) were tested on latex films. The particle size and distribution range of emulsion were tested with nano particle size analyzer. After comprehensively comparing the latexes and films prepared by HFMA, DFMA and TFMA, the performance of DFMA monomer modified is better.Originality/valueThe self-crosslinking acrylic emulsion is prepared via semi-continuous seeded emulsion polymerization, which methyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and fluorine-containing monomers were used as main monomers. The fluorine-containing monomers were composed of hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and trifluorooctyl methacrylate (TFMA). Potassium persulfate (KPS) was used as thermal decomposition initiator, non-ionic surfactant alkyl alcohol polyoxyethylene (25) ether (DNS-2500) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS) as mixed emulsifier. There are two main innovations. One is that the self-crosslinking acrylic emulsion is prepared successfully. The other is that the effects of monomers containing different fluorocarbon chain lengths on polyacrylate, such as monomer conversion rate, coagulation rate, mechanical stability, chemical stability, emulsion particle size and storage stability, are studied in detail.

Core/shell colloidal nanoparticles based multifunctional and robust photonic paper via drop-casting self-assembly for reversible mechanochromic and writing

Photonic crystals film that possesses periodic dielectric structure have shown great prospect in developing environmentally friendly paper alternatives due to the unique properties of dye free and non-photobleaching, but their practical application is limited by the weak interaction between colloidal particles. Although some progress has been obtained, it is still a challenge to develop photonic paper with the desired mechanical and optical properties. Herein, multifunctional hard core/soft shell nanoparticles with controlled size are fabricated by semi-continuous seed emulsion polymerization method. Compared with convention colloidal particles, these core/shell nanoparticles can facile self-assemble into large-scale dense ordered structure film via dried at room temperature due to the relatively low glass transition temperature (Tg) of the shell layers. The facile fabrication route enables the continuous high-through put production of the photonic papers. The as-formed papers not only possess the capacity to solvent (water/ethanol) rewritable and multicolor painting, but also can rapidly reversible mechanochromic. Moreover, due to the good compatibility of core/shell interface, these photonic films possess excellent mechanical properties, demonstrating that this multifunctional film makes the fabrication of novel robust rewritable papers possible and enables visual monitoring of deformation degree.

Styrene-Acrylic Emulsion with "Transition Layer" for Damping Coating: Synthesis and Characterization.

In order to study the dynamic mechanical properties of styrene–acrylic latex with a core/shell structure, a variety of latexes were synthesized by semi-continuous seeded emulsion polymerization based on “particle design” with the same material. The latexes were characterized by rotary viscosimeter, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), dynamic mechanical analysis (DMA), and universal testing machine. The effects of difference at the glass transition temperature (Tg) of core and shell and the introduction of the “transition layer” on the damping and mechanical properties of latex film were studied. The results indicate that as the Tg of core and shell gets closer, the better the compatibility of core and shell, from phase separation to phase continuity. Furthermore, the introduction of the “transition layer” can effectively improve the tensile strength and tan δ (max) of the latex film. The tensile strength and maximum loss factor (f = 1 Hz) of latex with the “transition layer” increased by 36.73% and 29.11% respectively compared with the latex without the “transition layer”. This work provides a reference for the design of emulsion for damping coating.

Effect of Poly (aniline-co-o-toluidine) loaded on emulsion paints with different pigments on corrosion inhibition of mild steel

Three groups of plastic emulsion paints were formulated using three different types of pigments. TiO2 was applied in the first group of paint (T-series) as a neutral pigment. Zn3(PO4)2 and Fe2O3 were added in the two other paint groups (Z-series and F-series, respectively) as anticorrosive pigments. Styrene/butyl acrylate latex was prepared by semicontinuous seeded emulsion polymerization and used as a binder in the paint formulations. Poly (ani-co-o-toluidine) (PAOT) was introduced to the painting series as an inhibitor in proportions of 0%, 1%, 2%, 3%, and 4%. PAOT inhibitor was prepared by oxidative emulsion polymerization with an equimolar amount of aniline and o-toluidine monomers. The binder and the inhibitor were tested for their particle size and chemical structure by DLS and FTIR analysis. The properties of the paint formulations were estimated physically, mechanically, and thermally. The protection efficiency of the paint coatings on steel was estimated against corrosion using an immersion test and electrochemical measurements. The DLS curves of the binder latex and the inhibitor showed a unimodal distribution of sizes 151 nm and 42 nm, respectively. However, a mix of the two emulsions exhibited a bimodal distribution of both sizes. The potentiodynamic polarization measurements showed a decrease in the corrosion current density of TiO2 coating paint from 26.4×10-7 A/cm2 to 12.3×10-7 A/cm2 in Fe2O3 coating paint. The least corrosion current density was obtained from Zn3(PO4)2 coating paint of 7.50×10-7 A/cm2. PAOT inhibitor enhanced the protection efficiency of the paint coatings with the optimum of 3%. Zn3(PO4)2 coating paint loaded with 3% PAOT inhibitor demonstrated the highest protection efficiency of 99.96%.

Preparation and characterization of self-cross-linking long fluorocarbon polyacrylate latex modified by silane cross-linker

PurposeSilane cross-linkers have been used to strengthen the mechanical stabilities and friction resistance of plastic products. Therefore, the effect of silane cross-linkers on latex has been studied through preparing modified self-cross-linking long fluorocarbon polyacrylate latex. In this paper, nonionic surfactant alcohol ether glycoside (AEG1000) and anionic polymerizable surfactant 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (DNS-86) acted as mixed emulsifier and 3-(methacryloyloxy) propyltrimethoxysilane (KH-570) and bis (2-ethylhexyl) maleate (DOM) were used as functional monomers.Design/methodology/approachThe modified acrylate polymer latex was synthesized through the semi-continuous seeded emulsion polymerization with methyl methacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA) and hydroxypropyl methacrylate (HPMA) as main monomers. Potassium persulfate (KPS) was applied to initiate polymerization reaction, nonionic surfactant AEG1000 and DNS-86 acted as emulsifier, KH-570 and DOM were used as functional monomers, respectively.FindingsThe optimum conditions of synthesizing the modified latex were the following. The mass ratio of monomers containing MMA, BA, DFMA, HPMA, KH-570 and DOM was 13.58:13.58:0.90:1.20:0.15:0.60, the usage of initiator KPS was 0.5% of the total weight of monomers and the amount of emulsifier was 7% of all monomers with AEG1000:DNS-86 = 1:1. The results indicated that the conversion of monomer was 99% and the coagulation was about 2.0%.Originality/valueThe resultant latex was modified silane cross-linker KH-570 and DOM, which positively affected the comprehensive properties of latex and its film. Apart from this, the novel mixed emulsifier was used to improve the size and distribution of latex particles and reduce environmental problems caused by the use of emulsifiers.

Preparation and characterization of modified self-crosslinking fluorocarbon acrylate latex

The modified self-crosslinking fluorocarbon acrylate (MSFA) latex has been successfully synthesized via semi-continuous seeded emulsion polymerization. Methyl methylacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA), and hydroxypropyl methacrylate (HPMA) were chosen as main monomers, vinyl triethoxysilane (VTES), and benzyl methacrylate (BZMA) served as functional monomers. Latex was emulsified by mixed emulsifier containing nonionic surfactant alcohol ether glycoside (AEG1000) and anionic surfactant fatty alcohol polyoxyethylene ether sulfate (AES), and the reaction process was initiated by potassium persulfate (KPS). The optimal conditions were studied and obtained. The results indicated that the monomer conversion was up to 99.36%, and the coagulation was lowered to 0.60% under the optimal conditions. At the same time, the outward appearance of resultant latex presented blue white which confirmed the latex was a successful preparation. The latex was tested through Fourier-transform infrared spectroscopy (FTIR). The mechanical stability and chemical stability of latex were measured. Thermogravimeter (TGA) results demonstrated that the introduction of functional monomers has extensively augmented the thermal stability of prepared film. The glass transform temperature (Tg) was detected by differential scanning calorimetry (DSC) and the water resistance of film was evaluated through water contact angle (WCA). The average particle size of latex was 62.99 nm and PDI was 0.069.

Study on Influence of Monobutyl Itaconate and N,N-diethylacrylamide on Acrylic Latex

Polyacrylate latex contained monobutyl itaconate (MBI) and N,N-diethylacrylamide (DEA) was successfully prepared by semi-continuous seeded emulsion polymerization with a green mixed emulsifier of sodium dodecyl benzene sulfonate (SDBS) anion surfactant and tetradecyl hydroxypropyl decyl betaine (THDB) amphoteric emulsifier, the mixed monomers of methyl methacrylate (MMA), butyl acrylate (BA) were modified by MBI and DEA, which were initiated with potassium persulfate (KPS). The structure was characterized by Fourier transform infrared spectroscopy (FTIR). The film of latex was measured by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA). The particle size of the latex was tested by Zetatrac dynamic light scattering detector. The optimal conditions are as follows: the amount of mixed emulsifiers is 6.0%; the optimum mass ratio of SDBS to THDB is 1 : 1; the amount of initiator is 0.7%; the mass rate of main monomers of MMA : BA = 1 : 1; the amount of DEA is 5.0% and MBI is 2%. In this paper, the polyarcylate emulsion shows excellent thermal stability and hydrophobicity.

Preparation and characterization of fluorine-containing soap-free acrylic emulsion

Purpose Fluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare fluorine-containing soap-free acrylic emulsion, which sodium allyoxypropyl hydroxypropyl sulfonate (COPS-1) and anionic emulsifier sodium a-alkenyl sulfonate (a-AOS) were combined as polymerizable emulsifier, and undecylenic acid (UA) and dodecafluoroheptyl methacrylate(DFMA) were introduced as functional monomer. Design/methodology/approach The fluorinated polyacrylate emulsion was successfully prepared by semi-continuous seed emulsion polymerization, wherein the main monomers were methyl methacrylate (MMA) and butyl methacrylate (BA), and the initiator was potassium persulfate (KPS). Sodium alloxypropyl sulfonate (COPS-1) and an anionic emulsifier sodium a-alkenyl sulfonate (a-AOS) were compounded as a polymerizable emulsifier. Besides, undecylenic acid (UA) and dodecafluoroheptyl methacrylate (DFMA) were introduced as the functional monomers. Findings The optimum recipe of preparing the modified latex is as follows: the amount of emulsifier was 4%, the ratio of emulsifier (COPS-1: AOS) was 3: 1, and the content of initiator was 0.6%. In this case, the conversion rate of acrylic polymer emulsion was high and the polymerization stability was good. When the amount of monomer UA was 2% and the amount of DFMA was 4%, the overall performance of the emulsion was the best. Originality/value The fluorine-containing soap-free acrylic emulsion is prepared via semi-continuous seeded emulsion polymerisation, which sodium allyoxypropyl hydroxypropyl sulfonate (COPS-1) and anionic emulsifier sodium a-alkenyl sulfonate (a-AOS) were combined as polymerizable emulsifier, and undecylenic acid (UA) and dodecafluoroheptyl methacrylate (DFMA) were introduced as functional monomer. There are two main innovations. One is that the fluorine-containing soap-free acrylic emulsion is prepared successfully. The other is that the undecylenic acid is introduced as functional monomer.

Preparation and Properties of Nano-ZnO/ Organic Fluorine Modified Polyacrylate Finishing Agent

A nano-ZnO/organic fluorine-modified polyacrylate leather finishing agent was prepared using a mixture of a Silyl-modified nano-ZnO, dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA) and butyl acrylate (BA) as raw materials. A semi-continuous seeded emulsion polymerization followed. The overall research objective was to improve the bacteriostatic, hydrophobicity and anti-aging properties of leather articles. The structure of the composite emulsion and its film were characterized and analyzed by FT-IR, TEM and XPS. The results showed that the latex particles had an obvious core-shell structure, a smooth surface and were monodisperse. The particle size of the emulsion ranged between 30 and 50 nm. The average value of Zeta potential was -40.1 mV which signified a good emulsion stability. The composite emulsion and its film had good UV resistance and water resistance. When the content of organic fluorine in the film was a maximum 20 %, the contact angle of a water drop on the finished leather, tensile strength and tear strength were 133.48°, 620 N and 61 N, respectively. When the content of nano-ZnO in the film was 1.0%, the average width of antibacterial band of finished leather was 2.1 mm. The finished leather also demonstrated a good anti-aging property.