Styrene-butyl Acrylate Copolymers Research Articles

New approach for deacidification and consolidation of bone artifacts

AbstractAcidic conditions affect the archaeological bone in the burial and in uncontrolled display and storage environment or due to improper restoration processes. Accordingly, bones become weak and fragile. This study aims to evaluate nano calcium propionate and nano styrene butyl acrylate (used for the first time in the treatment of bones) at different concentrations for deacidification and consolidation of fragile bones. New bone samples were prepared. Artificial accelerated aging (acid and heat) was applied to prepare aged untreated samples. Deacidification and consolidation processes using the materials mentioned above were applied. The analytical techniques used were transmission electron microscope (TEM) and thermal gravimetric analysis (TGA) were used for morphological and thermal stability investigation for the prepared nano styrene butyl acrylate copolymer and its calcium propionate nonocomposites, a digital microscope and scanning electron microscope (SEM) for investigation of the surface morphology, pH value measurement, change of color measurement, attenuated total reflection—Fourier transform infrared spectroscopy (ATR/FTIR), contact angle (wettability), and X-ray diffraction analysis for measurement of bone crystallinity. The results proved that acid-heat aging affected bone properties such as changes in surface morphology and color, decrease in pH value, and contact angle. Bone samples became more crystalline, and the chemical composition of bone was also affected. The treatment of aged untreated bone samples with the materials used in this study improved their properties, such as increasing the pH value and contact angle. The surface morphology, color change, and crystallinity of bone improved and became more stable.

Effects of water-cement ratio and superplasticizer dosage on mechanical and microstructure formation of styrene-butyl acrylate copolymer concrete

The interaction between nanoparticles of Styrene-Butyl Acrylate latex and cement particles with various water-cement and superplasticizers-cement ratios during the hydration process has been investigated to achieve the best chemical combination of the materials for enhancing the mechanical properties and workability of the concrete. Analyses and experimental results have shown that the adhesive properties of Styrene Butyl Acrylate (SBA) copolymer latex along with an appropriate percentage of superplasticizers promote the performances of interlayer bonding of concrete. The compressive, splitting, and flexural strengths of specimens have been studied and the formations of the microstructures by the implementation of FESEM, EDX, XRD, FTIR, TEM, and DLS, have been analyzed. The obtained results show the considerable enhancement in the structural behavior of the copolymer-modified concrete in comparison with the control samples by creating cohesive microstructures in the presence of the copolymer. Appropriate water-cement ratio and superplasticizers were selected to study the efficient distribution of the copolymer nanoparticles throughout the cement matrix by the implementation of the FESEM and EDX analyses. The constructed polymer bridges and films between layers of Ca(OH)2 crystals have yielded to the formation of an internal cohesive strong microstructure. Also, XRD and FTIR results indicate that the stability and formation of ettringite have been enhanced by the development of calcium aluminate reaction with SBA copolymer. In the cement pore solution, the chemical interaction between nanoparticles, and Ca2+, the copolymer nanoparticles adsorption on cement paste were applied and the enhanced microstructure of the concrete was obtained.

Study of the anticorrosive properties of magnetic composites

Metal corrosion affects various sectors: construction, ships, pipes in the chemical industry, etc. Organic materials have been used as coatings to counteract it; recently improvements have been observed when magnetic polymers are used. These are materials formed by a polymeric matrix and a metal with magnetic properties, such as magnetic nanoparticles. The metal is sacrificed, preventing contact with the surface. Here we show the results of composites formed by magnetic nanoparticles of cobalt ferrite and magnetite obtained by coprecipitation, immersed in polystyrene, butyl polyacrylate and styrene-butyl acrylate copolymer matrices. The nanoparticles were incorporated by ultrasonic bath using different weights of nanoparticles (0.05%, 0.25%, 0.5% and 1%) using toluene as solvent. There is an acceptable dispersion of the nanoparticles in the polyacrylate and copolymer after 4 hours of cavitation, the styrene had acceptable dispersion after 5 hours. The composites were tested on a 316 Cal. 14 stainless steel film of 6 cm2 area, the specimens were dipped in acid to evaluate the corrosion protection with electrochemical techniques, having good results in the ferrite and magnetite composites where the protection capacity was better in the styrene-butyl acrylate copolymer.

Enhancing the dielectric properties of polymethyl methacrylate by using low loading graphene encapsulated styrene-butyl acrylate copolymer microspheres

With the rapid development of the electronics industry and electronic products, polymer nanocomposites with high dielectric constant and low dielectric loss will have great potential in various applications. In this work, a novel structure was obtained by absorbing reduced graphene oxide on the surfaces of styrene butyl-acrylate copolymer (rGO@SBA) microsphres through soap-free emulsion polymerization technique. Fourier-transform infrared spectrum characterization revealed the successful fabrication of rGO@SBA microspheres. SEM and TEM results indicated that rGO nanosheets were successfully loaded on the surface of SBA microspheres and the average diameter of rGO@SBA was increased to 650 nm. High dielectric permittivity rGO@SBA composites were obtained when the rGO loading was approximated to 2 wt%. The dielectric permittivity of rGO@SBA composites with 2 wt% rGO was 339 times higher than that of neat SBA. Furthermore, the electrical conductivity was also obviously enhanced. However, the dielectric loss of rGO@SBA composites was also inevitably increased. The rGO@SBA microspheres were further melt blended with polymethyl methacrylate (PMMA) matrix to obtain rGO@SBA/PMMA composites. The glass transition temperature of PMMA was increased with the content of rGO. The dielectric permittivity of rGO@SBA/PMMA composite with only 0.14 wt% rGO was increased to 15.5 at 1 kHz. On the other hand, the dielectric loss was controlled in a low level. SEM observation implied a segregated dispersion of rGO@SBA was realized in PMMA matrix. Our strategy provides a facile method to prepare high dielectric constant and low dielectric loss of rGO filled polymer composites through the fabrication of rGO encapsulated polymer microspheres.

Styrene-co-butyl acrylate copolymers with potential application as membranes in PEM fuel cell

Styrene-butyl acrylate (St-BuA) copolymers were obtained by mass free radical copolymerization reactions, using BPO as initiator. A 70:30 (St-BuA) comonomer composition was selected. Three different molar concentrations of sulfonating agent (50, 100 and 150%) were considered to obtain the sulfonated copolymer (sSt-BuA) and membranes were casted from sSt-BuA copolymers. Copolymers were characterized with FTIR, TGA and NMR 1H and mechanically by TMA. The sSt-BuA sulfonation degree (SD) effect on the ion-exchange capacity (IEC) was evaluated by titration and water uptake (WU) by gravimetry. Microstructure was also observed using scanning electron microscopy (SEM), and its electrochemical properties were evaluated by electrochemical impedance spectroscopy (EIS). The chemical composition of St-BuA copolymer was confirmed by proton nuclear magnetic resonance (NMR 1H) spectroscopy. Fourier transformed infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA) analysis also confirmed the existence of both comonomers and a successful sulfonation up to an actual 30% level, as well as a good thermal stability over 300 °C for the molecular structure and over 150 °C for sulfonated membranes. TMA indicate an increase in flexure modulus along degree of sulfonation. SEM images show a highly dense material with low pore size for the sulfonated copolymer. The IEC values obtained varied from 0.83 to 1.18 meq g−1, depending on sulfonation degree. The proton conductivity for St-BuA 50% membrane (9.77 × 10−5 S cm−1) was a two order of magnitude lower than the commercial Nafion membrane (4.53 × 10−3 S cm−1). Thermal, mechanical and electrochemical results demonstrate that these sSt:BuA copolymers are promising materials to be used as membranes in fuel cells applications.

An investigation on the effect of styrene-butyl acrylate copolymer latex to improve the properties of polymer modified concrete

The effect of adding styrene-butyl acrylate (SBA) nano copolymer latex on the mechanical properties of concrete is investigated via performing scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. For decreasing entrapped air content and increasing workability of the SBA modified concrete, silicone-based antifoam and superplasticizer were added to the mixture, respectively. Samples with different weigh proportions of SBA to cement, antifoam, and superplasticizer were fabricated to obtain proper ratios of these materials which had better effects on the mechanical properties of the concrete. Obtained results indicated that adding SBA along with antifoam and superplasticizer improved mechanical properties of the concrete significantly. On the other hand, the SEM analysis on the microstructure of the samples with the proper proportions showed that three-dimensional crystalline structures are forming in the structure of concrete and this can improve mechanical properties and durability of the sample.

Self-assembly of nanoencapsulated undecanoic acid on cotton fiber for thermoregulating textiles.

We herein report the preparation of phase change nanocapsules with undecanoic acid (UA) as the core and a styrene–butyl acrylate copolymer as the shell by miniemulsion polymerization using interfacial redox initiation. The morphology, particle size, thermal properties, and structure of the nanocapsules were characterized by transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. Further, the cotton fiber was dissolved in hydroxyl-functionalized ionic liquid 1-(3-chloro-2-hydroxypropyl)-3-methyl imidazolium chloride, and then the nanoencapsulated UA was immobilized on the cotton fiber by mixing the solution with the phase change nanocapsule emulsion. The desired thermoregulating fabrics were then recovered by vacuum suction filtration and drying, and their surface morphologies and thermoregulating properties were evaluated. The nanocapsules were found to be of a regular spherical shape with a diameter ranging from 90 to 110 nm, and they exhibit a phase change temperature of 29.3 °C. Finally, the prepared thermoregulating non-woven fabrics exhibited excellent thermal reliability, air permeability, and thermoregulating capability.

Tailoring of mechanical properties and printability of coated recycled papers

Coated papers have an excessive impact on the appearance and utility of printed materials with respect to the increase in mechanical strength, print gloss and print density. Styrene–butyl acrylate copolymers were synthesized utilizing different emulsifier systems and modified with acrylamide. These lattices were evaluated as paper coats in the presence of kaolin, calcium carbonate and a mixture of both as pigments. The evaluation aimed at employing these lattices on recycled white and brown paper substrates with respect to their mechanical properties and their printability. The tensile strength of coated papers was upgraded by ~ 20–30% in CD compared with that of uncoated papers. The improvement ratio was ~ 12–16% in bursting strength compared with that of the uncoated paper. The maximum gloss values (39 and 48) and the maximum print density values (2.51 and 2.44) were obtained for ground calcium carbonate “GCC” composites on white and brown bases, respectively. Formulas containing GCC had a uniform printed surface with high-quality ink distribution without any picking up of coated surface. This work is a promising one as efficient synthesized binders and a local pigment were employed besides achieving offset printing on recycled brown papers for the first time.

Study of structure and thermal properties of styrene-butylacrylate copolymer with OMMT nanocomposite emulsions

(St-co-BA) polymer through montmorillonite (MMT) nanocomposite emulsion is prepared by ‎in situ intercalative emulsion polymerization of styrene (St), butyl acrylate (BA) in the ‎presence of organic modified montmorillonite (OMMT) with different OMMT contents (0, ‎‎0.5, 1.0, 1.5, and 2.0 wt%). The synthetic compounds are characterized by FTIR, XRD. The ‎nanocomposite emulsions are characterized by applying FTIR, SEM, TEM, TGA and DSC ‎techniques in order to investigate the structure and the thermal properties of the coplymer. ‎The properties of the nanocomposite emulsions containing OMMT are better than styrene-‎acrylate emulsion. The study of monomer conversion versus time and different OMMT ‎contents indicates that the polymerization rate is decreased by increasing the concentration of ‎styrene and OMMT. Consequently the properties of the nanocomposite emulsion containing 1 ‎wt % OMMT are better than other contents. ‎

A Study of the Properties of Paper Sized with Styrene-Butyl Acrylate Copolymers

A Study of the Properties of Paper Sized with Styrene-Butyl Acrylate Copolymers

End group analysis of styrene-butyl acrylate copolymers initiated with benzoyl peroxide by stepwise chemolysis-pyrolysis gas chromatography

End groups in a series of styrene (St)-butyl acrylate (BA) copolymer samples (St:BA, 80:20 molar feed ratio) prepared through radical polymerization with various amounts (1.5–10wt%) of benzoyl peroxide (BPO) as an initiator were characterized. Two types of end groups originated from the BPO initiator—benzoyloxy and phenyl terminal groups—were individually determined by stepwise chemolysis-pyrolysis gas chromatography (Py-GC) using a double-shot furnace pyrolyzer. In the first (chemolysis) step, the copolymer sample was mixed with tetramethylammonium hydroxide and introduced into the pyrolyzer at 250°C for 10min. During this step, the benzoyloxy terminal groups were selectively and quantitatively decomposed into methyl benzoate through the thermally assisted hydrolysis and methylation of ester linkages, which was clearly observed in the pyrogram. In the second step, the residual polymer sample was analyzed by ordinary Py-GC at 600°C. In the observed pyrogram, benzene and C14H12 were separately detected as the key products reflecting the phenyl terminal groups among the various pyrolyzates of the polymer main chain. Based on the peak intensities of these characteristic products, the relative contents of both types of the end groups from BPO were estimated to be almost proportional to the feed amounts of BPO. Moreover, it was determined that the number of benzoyloxy end groups was roughly twice of that of the phenyl terminal groups.

Allylcyclohexylamine functionalized siloxane polymer and its phase separated blend as pervaporation membranes for 1,3-propanediol enrichment from binary aqueous mixtures

This work reports the synthesis of a novel allylcyclohexylamine functionalized siloxane and its phase separated blend with styrene-butyl acrylate copolymer and their application for pervaporative enrichment of 1,3-propanediol from dilute aqueous solutions. The phase separated blend allowed for the recovery of mechanical strength lost due to functionalization without loss in separation performance. Separation factors of 9–15 were achieved with functionalization levels of 50–90%, while 1,3-propanediol flux was 1.5×10−3–1.6×10−3 g/m2-s (5.5–5.8 g/m2-h). Separation efficiency increased with functionalization and decreased with increasing temperature and feed concentration. Solution diffusion model was used to compute the overall mass transfer coefficients, concentration polarization and intrinsic material mass transport properties. The overall mass transfer coefficient for 1,3-propanediol was between 1.0×10−7–1.4×10−7m/s while the boundary layer mass transfer coefficient ranged from 5×10−7m/s to 18×10−7m/s indicating the dominance of the membrane on the transport resistance. A computation of Hansens solubility parameters by a group contribution method was carried out to underscore the results. The membrane, with its good cost/performance tradeoff and excellent mechanical integrity, offers the possibility of fabrication into modules and scale up.

Styrene-butyl acrylate copolymers latexes prepared with different functional monomers and their application as anti-icing coatings

Four polymer latexes, including Base latex synthesized using styrene and butyl acrylate as the main monomers, Latex Si prepared with 4.0 wt% of vinyl triethoxysilane, Latex F with 4.0 wt% of dodecafluoroheptyl methacrylate and Latex D4 with 8.5 wt% of octamethyl cyclotetrasiloxane (D4), were prepared through a semi-continuous emulsion polymerization. Characterization of the latex films revealed that water absorption of the films of Latex D4 and the Base latex were lower than those of Latexes F and Si; whereas their contact angle with water were also smaller than those of the other two latex films. The latexes were applied as coating onto steel and Al metals of different forms to evaluate their performance in corrosion and anti-icing tests. Coated on steel plates for water resistance test, it was found that Latex D4 and Base latex showed poorer performance; whereas the films made from Latex F and Latex Si showed better performance. In anti-icing tests, with the coating applied either on Al circular helix coils followed by refrigeration after water spray, or on Al stranded power line followed by anti-icing test in an IWT (ice wind tunnel), Latex D4 showed the best anti-icing performance, Base latex with the lowest performance, and the other two, Latex F and Latex Si, located in between. The test in IWT was also conducted with the latexes coated on stainless steel rods used in Al stranded power line with reinforced steel core. The anti-icing effectiveness was quite similar to those observed on Al coils or stranded power transmission lines: Latex D4 showed the highest performance and Base latex the lowest, although the differences of the magnitude in their performance were obviously different in different tests.

Influence of main ingredients on properties of latex and latex film in polysiloxane modification of styrene-butyl acrylate copolymers

Water borne latexes of styrene (St) and butyl acrylate (BA) copolymer, modified with octamethylcyclotetrasiloxane (D4) were prepared through a semi-continuous emulsion polymerization with dodecylbenzene sulfonic acid (DBSA) as the catalyst for D4 ring-opening and ammonium persulfate (APS) as the initiator for St-BA polymerization. To enhance the compatibility of the silicone with St-BA copolymer by establishing chemical bonds between the two components, 3-(methacryloxy) propyl trimethoxysilane (MPTS) or hydroxyethyl acrylate (HEA) was employed as the coupling agents. The effect of DBSA location at start of emulsion polymerization was studied. It was found that more stable latex was obtained when DBSA was initially added in the reactor in comparison with its addition to the preemulsion followed by slow feeding to the reactor. HEA was also an effective coupling agent to improve the properties of the latex and the latex film. In addition, the influences of the amounts of APS, the catalyst DBSA, and D4 on the latex properties were studied. The process was optimized with regard to the ingredients used in the polymerization. To achieve stable latex with good latex film properties, APS amount should be kept between 0.18 and 0.28 wt.%, D4 monomer no more than 8 wt.% relative to the mass of all vinyl monomers, and the molar ratio of MPTS/D4 is recommended to be 1/4. With HEA as the coupling agent, its amount should be 6.6 wt.% relative to the mass of D4. The mechanical property of the latex film and its water absorption were also characterized.

Thermal properties of a novel nanoencapsulated phase change material for thermal energy storage

A novel nanoencapsulation of a paraffine type phase change material, RT80, in a styrene–butyl acrylate copolymer shell using the miniemulsion polymerization process was carried out. General characteristics of the RT80 nanoparticles in terms of thermal properties, morphology, chemical composition and particle size distribution were characterized by Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Dynamic Light Scattering (DLS). The influence of different monomers (styrene, butyl acrylate) and the surfactant/paraffin mass ratios on nanoparticles properties such as thermal capacity, particle size and morphology were systematically investigated. In all cases studied, encapsulation efficiency was close to 80wt% with a particle size distribution between 52 and 112nm and regular spherical shape and uniform structure. The amount of encapsulated paraffin achieved was comprised between 8 and 20%. Melting and crystallization heats were found to be approximately 5–25Jg−1, mainly depending on surfactant/paraffin mass ratio. Melting temperature of RT80 nanoparticles slightly decreased (1–7°C) respect to the raw RT80. In addition, the encapsulated RT80 nanoparticles show thermal stability even after 200 thermal (heat-cooling) cycles.

Fabrication and characterization of nanocapsules containing n-dodecanol by miniemulsion polymerization using interfacial redox initiation

Phase change material nanocapsules with n-dodecanol as the core and styrene-butyl acrylate copolymer as the shell were prepared by miniemulsion polymerization using interfacial redox initiation. The morphology, particle size, polydispersity index, thermal properties, and structure of the nanocapsules were characterized by TEM, laser particle diameter analyzer, DSC, TGA, and FT-IR. When the monomers/n-dodecanol mass ratio of 1:1 was used, the phase change enthalpy and encapsulation efficiency of the nanocapsules reached to 109.2 J/g and 98.4%, respectively. The thermal decomposition temperature of the nanocapsules was about 195 °C. Spherical nanocapsules with a mean diameter of 100 nm and a phase change temperature of 18.4 °C were obtained, which have good energy storage potential.

Microstructure of Latex Dispersion by Small-Angle X-ray Scattering

The microstructures of two samples of latex dispersion system and the influence of their blending on the crystallization behavior were investigated by means of synchrotron small-angle X-ray scattering(SAXS) technique.The experimental results confirmed that the latex dispersion at a volume fraction of 50% composed of styrene-butylacrylate copolymer did not show up crystalline structures at room temperature.By virtue of fitting the scattering intensity distribution curve,the average radius of the latex particle was 76 nm,which is smaller than the value determined by dynamic light scattering(80 nm).However,the crystalline structure can be probed in the latex dispersion of styrene-butadiene copolymer with a solid content of 50%.Each Bragg peak in the scattering profile can be assigned to one or several crystal indices by assuming diffraction from a face-centered-cubic crystalline structure with a lattice constant of 212 nm.The diffraction peaks can be detected after mixing the two latex dispersion samples,implying that the partial crystallites in the original latex solution are still stable in the blending process.

Influence of rheological additives on char formation and fire resistance of intumescent coatings

Styrene–butyl acrylate copolymer based fire retardant coatings were prepared using intumescent flame-retardant additives and mineral clay type rheological additives. Three different widely used nanoclays, organic-modified montmorillonite, palygorskite and sepiolite were applied in order to determine their effect on the flame retardancy. Significant differences were found when their heat-shielding activities were evaluated. It was observed that the addition of different clay particles in amount of 0.25 w% changes the char formation process; the height, the morphology, the structure and also the mechanical resistance of the protecting shield. The different geometry and composition of the additives induced different changes in fire performance. In case of palygorskite the catalytic effect of Fe accelerated mainly the thermal decomposition, therefore the fire resistance decreased. The plate-like montmorillonite reduced the extent of the intumescent char, whereas also improved the mechanical and sustained heat resistance of the fire protecting shield. The fibrous sepiolite of low Fe content assisted the development of efficient protecting shield, which exhibited optimal cell structure, suitable thickness, and thus ensured better heat-insulating performance. Consequently, fire retardant effect of sepiolite was found to be better than the other studied clay types.

Effect of the synthetic methodology on molecular architecture: from statistical to gradient copolymers.

Styrene-butyl acrylate (S-BuA) copolymers were synthesized by nitroxide-mediated controlled radical polymerization using an alkoxyamine as an initiator. Using different synthetic methodologies, statistical copolymers were be obtained by batch nitroxide mediated polymerization while the gradient composition was a forced gradient by continuous addition of S during BuA polymerization (semi-batch process). These gradient copolymers have been studied by H NMR and size exclusion chromatography to characterize the gradient composition molecular structure. The evolution of the composition was correlated with the glass transition temperature () of the copolymers. The gradient copolymers exhibit one with a value in between the of polystyrene and poly(butyl acrylate), indicating that the materials did not present well defined microphase separation. Specific organization at the air-polymer interface of such copolymers has also been demonstrated by comparison between classical and attenuated total reflection (ATR) Fourier transform infra-red spectra. This bulk soft matter assembly was confirmed by AFM analysis, which showed a different morphology at the surface and in the bulk following removal of the top layer. Moreover, for the most well defined gradient composition, a specific nano-structuring was demonstrated by small angle neutron scattering. The preliminary rheological properties of these gradient copolymers were studied and are discussed in relation with their molecular structure.

High-throughput screening of the chemical composition distribution of random styrene-butyl acrylate copolymers

AbstractThe development of high-throughput liquid chromatographic techniques for the analysis of styrene-butyl acrylate (SBA) copolymers is discussed. The analysis time in size-exclusion chromatography (SEC) can be reduced to about 3 min per sample when high-throughput SEC columns and high flow rates are used. In gradient HPLC, small columns with improved separation efficiencies can be applied. The time requirements can be decreased to less than 2 min per sample. Using the high-throughput HPLC technique, the chemical composition distribution of high-conversion SBA copolymers can be analyzed in a fast and efficient way. The calibration of HPLC separation is conducted by coupling the HPLC system with FTIR through the LC-transform interface. A comparison of the chemical compositions of the copolymers obtained by 1H NMR, off-line FTIR and coupled HPLCFTIR verifies the accuracy of the high-throughput copolymer analysis approach.