Emulsion Polymerization Of Butyl Acrylate Research Articles

Synthesis and Characterization of Colloidally Stable Self-crosslinking Water-based Anticorrosive Polymer at Room Temperature

The emulsion polymerization of butyl acrylate (BuA), styrene (St), and 3-isopropenyl-α,α-dimethylbenzyl isocyanate (IPMBI) is presented in this work. Obtain colloidally stable latexes for the poly (BuA/St/IPMBI) system during polymerization and storage for use in a water-based coating formulation. A series of semicontinuous polymerizations were also performed to investigate the effect of comonomer composition (w/w) in the feed (BuA/St) on conversion. The particle diameter (Dp), particle number (Np), hydrolysis of the IPMBI’s isocyanate groups, stability and storage properties. Films were created in which the effect of comonomer composition was also investigated, the glass transition temperature (Tg) was determined, the gel content was selected, and the mechanical properties and capacity as a barrier to water vapour and oxygen were assessed. Another series of reactions, on the other hand, was carried out in which the effect of the IPMBI content (1.5, 3.5, and 5.5%) was studied using a constant composition BuA/St=60/40. The studies conducted are the same as those mentioned for the effect of comonomer composition in feed. With increasing IPMBI percentage, slight differences in conversion, Dp, and Np were observed; the latices undergo hydrolysis during polymerization and storage. Colloidal stability, on the other hand, was preserved. The mechanical properties of the films improved as the percentage of IPMBI increased, while the boundary characteristics to moisture and oxygen improved when compared to the white film (0% of IPMBI). Finally, the formulation of a self-crosslinking water-based coating at room temperature using the previously obtained latex as a binder is reported; the coating demonstrated excellent adhesion, scratch hardness, and gloss regardless of the type of latex used.

Secondary nucleation of styrenated hydroxyl‐functionalized latexes

AbstractIn this study, secondary nucleation in emulsion polymerization of butyl acrylate (BA), styrene (St), and 2‐hydroxyethyl methacrylate (HEMA), was investigated. Different molar ratios of BA and St were used. Average particle size, particle size distribution (PSD), polymerization kinetics, glass transition temperature (Tg), and surface tension were monitored and compared. All synthetic latexes were prepared through seeded semi‐batch emulsion polymerization process. Three different BA to St ratios (1:1, 1:2, 2:1) were combined with eight different HEMA contents (0, 1, 3, 5, 10, 20, 30, 40 mol%) in monomer composition, respectively. In the case of high HEMA content (10–40 mol%) it is found that secondary nucleation is mainly affected by HEMA. Secondary nucleation at low HEMA content (1–5 mol%) is dependent on the BA to St monomer ratio, and consequently a reflection of z‐mer hydrophobicity.

The use of lignin in emulsion-based pressure-sensitive adhesives

Pressure sensitive adhesive (PSA) films were produced by in situ seeded semi-batch emulsion polymerization of butyl acrylate (BA) and methyl methacrylate (MMA) in the presence of varying amounts of lignin. Two types of Kraft lignin, water-soluble and non-water soluble, were used in this study. Lignin was modified using acrylation (methacryloyl chloride), maleation (maleic anhydride) and acetylation (acetyl bromide and acetic acid) to promote its miscibility with the BA and MMA monomers and encourage its incorporation into the polymer matrix. For the case of the maleated lignin, maximum incorporation of 10 wt% was achieved whereas, for the acrylated lignin case, a maximum of 5 wt% was attained. Lignin was shown to decrease latex viscosity in all cases. At a lignin loading of 1 wt% (relative to the amount of monomer) a tack and shear strength of the PSA films increased significantly while the peel strength remained constant. Thus, maleated lignin was shown to be an effective, renewable modifier for emulsion-based PSA properties.

Manipulation of chain transfer agent and cross-linker concentration to modify the performance of fluorinated acrylate latex pressure sensitive adhesive

n-Dodecyl mercaptan (DDM) chain transfer agent and 1,6-hexanediol diacrylate (HDDA) cross-linker were used to manipulate latex properties in a monomer-starved seeded semi-continuous emulsion polymerization of butyl acrylate (BA), fluorine monomer dodecafluoroheptyl methacrylate (DFMA) together with acrylic acid (AA) and 2-hydroxyethyl acrylate (HEA). The influences of both DDM and HDDA on the particle size of the latex, as well as on the gel content, thermostability (differential scanning calorimeter and thermal gravimetric analysis), surface properties (X-ray photoelectron spectra (XPS), contact angle analysis and atomic force microscopy), and viscoelasticity (N,N-dimethylacrylamide) of the polymer films were investigated. The results showed that the introduction of DDM and HDDA has no significant effects on the final particle size of the fluorinated pressure-sensitive adhesives (PSA) latexes. XPS analysis indicated that the fluoroalkyl groups had the tendency to enrich on the surface of the film. However, this enrichment of fluorine on the film surface was reduced after the introduction of HDDA, while increased with the addition of DDM. It was also found that the gel content, glass transition temperature (Tg), thermal stability, surface roughness, and modulus (G′, Gʺ) of the fluorinated latex PSA were all increased with the introduction of HDDA. Nevertheless, opposite trends were observed for the latex after the addition of DDM. Finally, the effects of DDM and HDDA on the adhesive properties (i.e. loop tack, peel strength and shear strength) of the fluorinated latex PSA were also evaluated.

Latex-state 13C-NMR spectroscopy for poly(butyl acrylate)

The resolution and the relaxation time of poly(butyl acrylate) in latex-state 13C-NMR spectroscopy are associated with local motions of the polymer in a dispersoid. Latexes were prepared by emulsion polymerization of butyl acrylate with ammonium persulfate. The latex-state 13C-NMR spectra were measured at 323–353 K with a spectrometer operating at 399.7 and 100.4 MHz for 1H and 13C, respectively. The half width of the latex-state 13C-NMR spectrum depends on the temperature. The half width and the spin-spin relaxation time, T2, are superimposed onto the master curve with a reference temperature, TX.

New Fluorescent Nanoparticles for Ultrasensitive Detection of Nucleic Acids by Optical Methods.

For decades the detection of nucleic acids and their interactions at low abundances has been a challenging task that has thus far been solved by enzymatic target amplification. In this work we aimed at developing efficient tools for amplification-free nucleic acid detection, which resulted in the synthesis of new fluorescent nanoparticles. Here, the fluorescent nanoparticles were made by simple and inexpensive radical emulsion polymerization of butyl acrylate in the presence of fluorescent dyes and additional functionalization reagents. This provided ultra-bright macrofluorophores of 9-84 nm mean diameter, modified with additional alkyne and amino groups for bioconjugation. By using click and NHS chemistries, the new nanoparticles were attached to target-specific DNA probes that were used in fluorimetry and fluorescence microscopy. Overall, these fluorescent nanoparticles and their oligonucleotide derivatives have higher photostability, brighter fluorescence and hence dramatically lower limits of target detection than the individual organic dyes. These properties make them useful in approaches directed towards ultrasensitive detection of nucleic acids, in particular for imaging and in vitro diagnostics of DNA.

Synthesis and characterization of fluorinated polyacrylate latex emulsified with novel surfactants

The fluorinated polyacrylate latex were successfully prepared with semi- continuous seeded emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) and hexafluorobutyl methacrylate (HFMA) which was initiated with potassium persulfate (KPS) initiator and emulsified with the novel mixed surfactants of sodium lauryl glutamate (SLG) and alkylphenol ethoxylates (OP-10). The structure of the resultant latex was confirmed by Fourier transform infrared spectroscopy (FTIR). The particle size of the latex was measured by Zetatrac dynamic light scattering detector. The film of latex was tested by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and contact angle (CA). The optimum conditions of preparing the novel fluorinated polyacrylate latex are optimized and the results are as follows: the amount of emulsifiers is 4.0%; mass ratio of SLG to OP-10 is 1:1, the amount of the initiator is 0.6%. The mass ratio of MMA to BA is 1:1 and the amount of HFMA is 7.0%. In this case, the conversion is high and the polymerization stability is good. In addition, the water resistance and thermal properties of the latex films were improved significantly in comparison with the film of the latex prepared without the fluorinated monomer.

Properties and characterization of novel cationic polyacrylate latex containing fluorine and silicon prepared with soap-free emulsion polymerization

ABSTRACTThe novel cationic polyacrylate latex containing fluorine silicon was successfully prepared via soap-free emulsion polymerization of butyl acrylate, methyl methacrylate, vinyltriethoxysilane and hexafluorobutylmethacrylate in water phase, which were initiated with water soluble azo initiator and emulsified with the mixed surfactants polymerizable emulsifier and OP-10. The films of the resultant latex were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA) determinator, respectively. In comparison with the conventional polyacrylate latex, the thermal stability and water resistance of novel latex film are improved. The conditions of preparing the novel cationic acrylate latexes were optimized. The optimum conditions of preparing the novel latex are as follows: the amount of emulsifiers and the initiator are 6.0% and0.3%, respectively; both the amount of VETS and amount of HFMA are 6.0%. In this case, the conversion is high and the polymerization stability is good.

Electrolytes on governing particle coagulation and size distribution in the emulsion polymerization of butyl acrylate

Poly (butyl acrylate) (PBA) latices with controllable particle size (90–350 nm) were synthesized via one-step batch emulsion polymerization in the presence of different species of electrolyte. The evolution of particle size and number as a function of monomer conversion were tracked in order to investigate the effect of electrolyte species on the particle stability. For electrolyte with different anions, the particle size of final latices decreased with increasing pH of the aqueous phase and the sequence was Na2CO3 < NaHCO3 < Na2C2O4 < NaCl, latices with Na2SO4 showed some particular performance and possessed of a particle size up to 347.4 nm; for electrolyte with different valences of counter ion, while achieving the similar particle size (Ca. 120 nm), an obvious variance in ionic strength was found (0.03, 0.016 and 0.0035 mol kg−1 for Na+, Mg2+ and Al3+). It indicate that electrolyte affects the particle stability by adjusting the pH of the aqueous phase and ionic strength, further controls the particle coagulation. As a result, latices with designated final particle size and distribution can be obtained by choosing the appropriate type and concentration of electrolyte.

Thermal degradation kinetics of poly(acrylate/α-methyl styrene) copolymers

The poly(acrylate/α-MeSt) copolymers were prepared by emulsion polymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2-EHA) and α-methyl styrene (α-MeSt). The contents of α-MeSt units combined into the copolymers were confirmed by 1H-NMR. In order to clarify the thermal degradation phenomenon of the copolymers differential scanning calorimetry (DSC) was used to monitor the initial decomposition of the copolymers at low temperatures without obvious weight loss, and gel permeation chromatography (GPC) was used to characterize the molecular weights of the copolymers and the thermally treated ones. The thermal degradation behavior of these copolymers was investigated by thermogravimetry (TGA), and the thermal degradation kinetics was systematically investigated by both Kissinger method, Flynn–Wall–Ozawa (FWO) method and Kissinger–Akahira–Sunose (KAS) method. The GPC and DSC measurements showed that bond breaking of the poly(acrylate/α-MeSt) copolymers occurred at a relatively low temperature compared with neat polyacrylates; the thermal degradation kinetics analysis verified that both the activation energy and pre-exponential factor increased with increasing the content of α-MeSt units in the copolymers; consequently, the decomposition reaction rate constant of the poly(acrylate/α-MeSt) copolymers increased with increasing the amount of combined α-MeSt units in the copolymers when the degradation temperature was higher than 320 °C. FWO method and KAS method revealed that the value of the degradation activation energy of the copolymer sample with higher content of α-MeSt units was higher than that of the copolymer sample with lower content of α-MeSt units at the same conversion.

A Population Balance Model for Butyl Acrylate Emulsion Polymerization

The goal of this work was to develop a population balance model with good predictive capabilities for the emulsion polymerization of butyl acrylate in a well-mixed and isothermal batch reactor. The model incorporated micellar nucleation and employed pseudo-bulk kinetics. The partial differential equations describing population balances were solved efficiently using orthogonal collocation. The model's reliability was demonstrated by successfully simulating the experimental data for a number of variables which included the number of particles formed at different emulsifier and initiator amounts, variation of particle diameter with time and the variation of conversion with time at one initiator amount and one emulsifier amount. Model predictions were in good agreement with the experimental data.

Synthesis and characterization of novel cross-linking poly(butyl acrylate-co-isobornyl methacrylate) colloids prepared via semi-continuous seeded emulsion polymerization

The novel cross-linking (butyl acrylate-co-isobornyl methacrylate) colloids are prepared via semi-continuous seeded emulsion polymerization of butyl acrylate, isobornyl methacrylate and N-methylol acrylamide in aqueous phase using mixture of polyethylene glycol mono(octylphenyl) ether and sodium dodecyl sulphate as emulsifier and potassium persulphate as initiator. The optimal composition for preparing the novel cross-linking colloid was determined, and the structure of the as-prepared colloid was confirmed with FTIR spectrum. The formation of colloidal polymer was also corroborated by a difference between glass transition temperatures of colloid film and corresponding homopolymers. Calorimetry measurements showed that the colloid is composed of random copolymer. The particle size distribution exhibits unimodal character, suggesting a high stability of the colloid polymer.

Characterization and Particle Size Control of Acrylic Polymer Latex Prepared with Green Surfactants

The application of green surfactants, which have low toxicity, excellent biodegradability in emulsion polymerization, has not been reported in the literature. In the present paper, alkyl polyglycosides (APG) and sodium alpha-olefin sulfonate (SAOS) were used as the nonionic emulsifier and anionic emulsifier, respectively to synthesize acrylic polymer latex. The acrylic polymer latex was prepared via semi-continuous seeded emulsion polymerization of butyl acrylate (BA) and methyl methacrylate (MMA) in water phase initiated with potassium persulfate (KPS) when nonylphenol ethoxylates (NPEOs) and sodium dodecyl-benzenesulfonate (SDBS) and are replaced with APG and SAOS, respectively. Both APG and SAOS have low toxicity, excellent biodegradability and outstanding properties. The structure of the acrylic polymer latex was confirmed with FTIR spectrum. Differential scanning calorimetry confirmed that the resultant latex is a kind of random copolymer. The unimodal distribution of particle size also confirmed that the acrylic polymer latex was prepared successfully. Factors, which have an influence on particle size of the resultant latex, were studied in detail. The optimum recipe of preparing the acrylic polymer latex with small particle size was obtained.

Preparation of hemicellulose-containing latex and its application as absorbent toward dyes

The removal of hazardous dyes from process water has become one of the most important tasks for water clarification. In this work, a novel type of latex, prepared by the emulsion polymerization of butyl acrylate (BA) and acrylamide (AM) in the presence of hemicellulose, was developed. Under the optimal polymerization conditions, the conversion of monomers reached as high as 97.6 %. The resulting hemicellulose-containing latex (HCL) was assessed as an absorbent toward dyes, methylene blue (MB) in particular. Much effort was made to revealing the impact of adsorption conditions of the dye removal induced by HCL. The maximum removal of the dye by HCL was about 93.8 %, much higher than that of the control sample. The dye adsorption isotherm was determined to further understand the adsorption mechanism. The adsorption data were found to fit Langmuir model well (R2=0.99904). The maximum adsorption capacity obtained at 25 °C was 42.7 mg g−1, suggesting that the HCL is promising as an excellent absorbent for the removal of dyes from effluents.

Characterisation and Properties of Fluorinated Acrylic Latex Prepared with Mixed Surfactants of Sds and Apg

The nonionic emulsifier of OP-10 is often used in preparing the latex. OP-10 belongs to a type of NPEOs. However, NPEOs are bioaccumulative and persistent in the environment while nonylphenol, the breakdown product of NPEs, is an endocrine disruptor. Therefore, the EU Commission has recommended implementing a risk reduction strategy, which foresees the ban of all applications leading to direct emissions to waste water and strict emission controls for all other technical processes using NPEOs as surfactants. The aim of the research is to study the possibility that OP-10 is replaced by APG to prepare the fluorinated acrylic latex. The fluorinated acrylic latex was prepared successfully via semicontinuous seeded emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) and hexafluorobutyl methacrylate(HFMA) in water phase initiated with potassium persulfate (KPS) and emulsified with the aid of mixed surfactants of sodium dodecyl sulfonate (SDS) and alkyl polyglucosides (APG). The structure of the resultant latex is confirmed by Fourier transform infrared spectroscopy (FTIR) spectrum. The influences of the amount of APG on the properties of the resultant latex and its film were investigated in detail. Results show that the particle size is decreased with the increase amount of APG. However, the calcium ion stability of the latex is increased with the increase of amount of APG.

Modification of poly (butylene terephthalate) with core-shell nanoparticles containing UV-absorber

A type of core-shell polymer nanoparticles capable of UV-stabilizing and toughening, was synthesized via the two-step emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) and glycidyl methacrylate (GMA), in the presence of 2-hydroxy-4-(3-methacryloxy-2-hydroxyl-proroxy) benzophenone (BPMA) as UV-stabilizing agent. Fourier transformed infrared (FTIR) analysis indicated that BPMA was successfully incorporated into the nanoparticles. The microstructures and microphases were investigated by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) and the results showed that the particles with an average diameter about 80 nm exhibited a core-shell structure and had a low glass transition temperature around −42 °C and a high glass transition temperature around 107 °C. UV–Vis absorption spectroscopy analysis revealed that poly (BA-MMA-BPMA-GMA) nanoparticles maintained almost the same UV-absorbing ability as 2, 4-Dihydroxybenzophenone (UV-0). Moreover, poly (BA-MMA-BPMA-GMA) was well dispersed in the poly (butylene terephthalate) (PBT) matrix as studied by scanning electron microscope (SEM). The mechanical properties before and after UV-irradiation illustrated that both of the UV-stability and toughness of PBT were remarkably improved by the core-shell nanoparticles simultaneously. In addition, thermogravimetry analysis (TGA) showed that PBT/poly (BA-MMA-BPMA-GMA) had better thermal stability than PBT/poly (BA-MMA-GMA)/UV-0 system and the UV-degradation degree of PBT was greatly retarded by poly (BA-MMA-BPMA-GMA).

Preparation of highly concentrated carboxyl-containing butyl acrylate based polymer dispersions by emulsion polymerization

A study of the influence exerted by the structure of oxyethylated and sulfooxyethylated alkylphenols on the features of emulsion polymerization of butyl acrylate with methacrylic acid showed that the use of mixtures of an ionic emulsifier with nonionic emulsifiers allows preparation of stable low-viscosity dispersions of butyl acrylate-methacrylic acid copolymers with no less than 65 wt % content of the main substance.

Emulsion Polymerization of Butyl Acrylate: Safe Optimization Using Topological Criteria

Fast and strongly exothermic emulsion polymerization processes are particularly difficult to optimize from both safety and productivity points of view because of the occurrence of a number of undesired side reactions (e.g., propagation of tertiary radicals, chain transfer to monomer, backbiting, termination by disproportionation, etc.) and the triggering of boiling phenomena with consequent stable foam formation under atmospheric pressure. Therefore, it would be useful to develop a suitable combined theoretical and experimental procedure able to detect both the optimum process dosing time and initial reactor temperature. In this work, it is discussed how an extended version of the topological criterion theory, originally developed for isoperibolic semibatch reactors, can be used to safely optimize an indirectly cooled isothermal semibatch reactor. Moreover, such a methodology is applied to a case study represented by the synthesis of poly(butyl acrylate) through the radical emulsion polymerization of butyl acrylate.

Ab initio RAFT emulsion polymerization of butyl acrylate mediated by poly(acrylic acid) trithiocarbonate

We describe a very simple and straightforward strategy towards self-stabilized poly(acrylic acid)-block-poly(butyl acrylate), PAA-b-PBA, block copolymer particles via an ab initio RAFT-controlled emulsion polymerization. Latexes were obtained at 23 wt% solids without the use of additional surfactants, thus avoiding any diffusion issues occurring during film formation. It was possible to reach in a controlled manner PAA-b-PBA diblock copolymers with high molar masses up to 100 kg mol−1. In contrast to previous studies, it was possible to reduce the weight percent of the hydrophilic polymer to 1.2 wt% (with respect to PBA). The block lengths of both PAA and PBA were varied in order to demonstrate the robustness of the system. Ammonium hydroxide was used as a volatile base to adjust the pH of the polymerization medium. Besides improving the polymerization control, ammonium hydroxide is particularly appealing for coating applications, as it can be easily removed during film formation by evaporation. Finally, using these latexes as seeds for the emulsion polymerization of styrene, it was possible to prepare novel nanostructured particles composed of PAA-b-PBA-b-PS triblock copolymers.

A Lumped Model for Butyl Acrylate Emulsion Polymerization

The goal of the present work was to develop a lumped model for butyl acrylate emulsion polymerization based on the monodispersed particle size distribution assumption (all particles having the same particle size at a given time). The polymerization system that the model simulates consists of an isothermal and well-mixed batch reactor with butyl acrylate (monomer), polybutyl acrylate (polymer), potassium persulphate (initiator), sodium dodecyl sulphate (emulsifier) and water as the dispersion medium. The model was validated against the experimental data for the number of particles formed at different emulsifier and initiator amounts, variation of particle diameter with time and the variation of conversion with time at one initiator amount and one emulsifier amount. The model predictions were in good agreement with the experimental data.