Styrene Acrylate Research Articles

Effect of thermal history on scratch behavior of multi-phase styrenic-based copolymers

Effect of thermal history on scratch performance of acrylonitrile styrene acrylate (ASA) and acrylonitrile butadiene styrene (ABS) model systems was studied. ASAs with rubber particle sizes of 100nm and 1µm, respectively, and ABS with rubber particle size of 100nm were investigated. Linearly increasing normal load scratch tests were performed according to the ASTM-D7027/ISO-19252 standard. An improvement in scratch resistance is observed in ASAs when annealed at 140°C whereas a noticeable drop in scratch resistance is found in ABS under the same condition. Various microscopic analyses were conducted to determine the corresponding deformation mechanisms for the observed dependence of scratch performance on annealing. Implication of the present findings for design of scratch resistant rubber toughened polymers is discussed.

Application of A4F-MALS for the Characterization of Polymers Prepared by Emulsion Polymerization: Comparison of the Molecular Structure of Styrene-Acrylate and Methyl Methacrylate-Acrylate Copolymers

ABSTRACTIn this paper, organic asymmetric flow field flow fractionation coupled to a multi-angle light scattering detector is presented as a very efficient tool for the characterization of copolymers prepared by emulsion polymerization. The molar mass distribution and the extent of branching of styrene–acrylate copolymers have been compared with corresponding copolymers of methyl methacrylate. It has been found that the presence of acrylate monomer results in the increase of molar mass and formation of branched macromolecules due to intermolecular chain transfer to polymer similarly as in case of methyl methacrylate–acrylate copolymers. However, the effect is far less pronounced.

Heterocoagulation behavior of carbon black with surface encapsulation through emulsion polymerization

ABSTRACTNanocomposite microspheres containing styrene–acrylate resin, wax, and carbon black (CB) with desired CB dispersion were prepared through heterocoagulation. The CB surface was modified using conventional anionic emulsifier and anionic dispersants with different lengths of nonionic chains and reactivities or through polymer encapsulation via emulsion polymerization to regulate the dispersion and concentration of CB in the microspheres. Experimental results showed that anionic dispersants with long nonionic chains effectively dispersed and stabilized CB particles. Polystyrene (PS) was then encapsulated on the CB surface by using a reactive dispersant and a water‐soluble initiator of polymerization. The CB particles exhibited comparable pH stability with other heterocoagulation components. Overall, encapsulation through emulsion polymerization can be used to obtain not only high CB content but also improved CB distribution in the resulting microspheres. High coagulation efficiency can also be achieved using polystyrene‐encapsulated dispersed CB because of its high affinity to emulsifiers and reactive dispersants during dispersion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43516.

Synthesis of cationic styrene-acrylic acid ester copolymer emulsion for paper sizing

Surface sizing is an effective way to increase paper’s water-resistance and printability. The purpose of this study was to study synthesis process to develop an efficient cationic styrene-acrylic acid ester emulsion (SAE) for the surface sizing of paper. Dimethylaminoethyl methacrylate methyl chloride (DMC) was used as the cationic monomer, and cationic starch or native starch was used as the emulsion stabilizer to copolymerize with styrene and butyl acrylate. The results indicated that the SAE synthesized with cationic starch and DMC had a high cationic charge density and a high DMC conversion rate. Paper sized with the cationic SAE had higher surface strength and lower Cobb value than the paper sized with other surface sizing agents such as, anionic SAE, and cationic or oxidized starch. Scanning electron micrographs revealed that the paper sized with a combination of oxidized starch and cationic SAE had smoother surface morphology when compared to the paper sized with oxidized starch alone, or with oxidized starch and anionic SAE.

Multifunctional Nanocomposites between Different Carbon Nanostructures and Styrene Acrylic Latex

This work describes the preparation, characterization and properties study of multifunctional nanocomposites between poly(styrene-co -butyl acrylate) latex and different carbon nanostructures: iron-filled carbon nanotubes (CNT), graphene or graphene oxide. Different approaches were employed to prepare stable aqueous dispersions of these nanostructures, according to the specificity of each nanomaterial. The nanocomposites were characterized by Raman and Fourier transform infrared (FTIR) spectroscopy, as well as by scanning probe microscopy (SPM) at different modes, providing information regarding the nature of the interaction between the carbon nanostructures and the polymeric matrix. The synergistic effect between the components results in improved mechanical, electrical, thermal and chemical properties of the nanocomposites, when compared to the neat polymer. In addition, the iron species into CNT cavities provide an interesting and unusual magnetic property of the nanocomposites. Results show that the properties of the nanocomposites can be modulated aiming desired application by simply selecting the amount and/or the kind of carbon nanostructure. This work provides information on the features of the three systems used, showing the range of properties that can be covered by using the three nano-fillers.

Rheological Evaluation of Asphalt Cements Modified with ASA Polymer and Al2O3 Nanoparticles

This study aims to evaluate and characterize the properties of modified asphalt cements exposed to high temperature. The Acrylate Styrene Acrylonhrtilrei (ASA) polymer and nano aluminum oxide (Al2O3) nanoparticles were added to the base asphalt cement with concentrations of 3, 5 and 7% of the weight of asphalt. The storage stability, viscosity, frequency sweep and MSRC test were considered for evaluation. The results demonstrate that the addition of ASA polymer and Al2O3 nanoparticles content have a great influence on the rheological properties of the asphalt cement at high temperatures. Additionally, it is clear that the storage stability of modified asphalt cements with ASA polymer and Al2O3 nanoparticles has good compatibility among the asphalt cement and the modifiers. Moreover, the complex modulus (G*) improves as the concentration of both modifiers increases. The improvement was 63.70% for 5% ASA polymer, and 71.12% for 5% Al2O3 at 75°C. Moreover, the modified asphalt cements demonstrates great resistance to high temperatures rutting, as the enhancement was up to 80 and 59% for 5% concentration of ASA and Al2O3. The modification of asphalt cements provides increasing the creep recovery up to 69.23 and 62.53%. It was found that the usage of ASA polymer and Al2O3 nanoparticles is able to mitigate asphalt cement problems at high temperatures, and 5% is considered as the optimum content of both modifiers.

ASA/graphite/carbon black composites with improved EMI SE, conductivity and heat resistance properties

Composites, comprised of acrylonitrile styrene acrylate copolymer (ASA)/graphite (GR) with high electromagnetic interference shielding effectiveness (EMI SE), were fabricated by the introduction of carbon black (CB). The effects of CB on properties such as EMI SE, morphology, heat resistance, rheological and mechanical performance of the composites were characterized using a scanning electron microscope (SEM), rotational rheometer, electromagnetic shielding measuring instruments. The graphite and carbon black exhibited positive synergistic action, which promoted the complete formation of conductive networks in ASA matrix. The EMI SE and electrical conductivity of the ASA/GR/CB composites increased with higher CB loadings. In the frequency range of 30–3000 MHz, the maximum EMI SE of ASA composites with 50 % fillers reached 40 dB, but with 40 % fillers this property reached its maximum value of 50 dB. The flexural strength of ASA/GR/CB composites started to decline as CB loading exceeded 5 %. The heat resistance of the composites was improved due to the addition of CB. In this respect, the vicar softening temperature (VST) of the composites with 40 % fillers increased from 115.1 to 132.7 °C, and the VST of the composites with 50 % fillers was elevated from 125.4 to 138.9 °C.

Carbon‐fiber‐reinforced acrylonitrile–styrene–acrylate composites: Mechanical and rheological properties and electrical resistivity

ABSTRACTThe aim of this study was to improve the mechanical properties of an acrylonitrile–styrene–acrylate copolymer (ASA) with the help of carbon fibers (CFs). Additionally, the effects of the CFs on the morphology, rheological properties, dynamical mechanical properties, electrical resistivity, and heat resistance of the ASA composites were studied with scanning electron microscopy, rotational rheometry, and dynamic thermomechanical analysis (DMA). The mechanical properties of the ASA composites were enhanced largely by the CFs. The maximum tensile strength of the ASA/CF composites reached 107.2 MPa. The flexural strength and flexural modulus also reached 162.7 MPa and 12.4 GPa, respectively. These findings were better than those of neat ASA; this was attributed to the excellent interfacial adhesion between the CFs and ASA resin. Rheological experiments proved that the viscosity and storage modulus (G′) values of the ASA/CF composites did not increase until the CF content reached 20%. The DMA outcomes confirmed that the glass‐transition temperature of the ASA composites was elevated from 120.6 to 125°C. Importantly, the G′ values of the composites with 20 and 30% CFs showed a large increase during heating. In addition, the ASA/CF composites exhibited excellent conductivity and heat resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43252.

Morphological, Dynamic Mechanical, Creep and Weathering Behavior of Carbon Nanotube-Reinforced 50/50 ASA/Zn-Ionomer Blend

ABSTRACTThe nanocomposite of 50/50 acrylonitrile styrene acrylate/Zn-ionomer blend uses varying weight ratios (0.5–5.0%) of multiwalled carbon nanotubes. The morphological, thermal, thermomechanical, and creep behavior along with metal adhesion were evaluated. The phase-separated surface morphology of the blend formed non-uniform microscale nanotube dispersion and resulted in nanotube network formation at 1 wt%. Lowest creep compliance and increased complex modulus were found at 1 wt% nanotube loading. The presence of weather resistant acrylonitrile styrene acrylate and carbon nanotubes made the nanocomposite excellent weather resistant.

Bulk Copolymerization of Conjugated Linoleic Acid With Styrene and Butyl Acrylate: Reactivity Ratio Estimation

Free radical bulk copolymerizations of conjugated linoleic acid (CLA)/styrene (Sty) and CLA/butyl acrylate (BA) were performed at 80°C. Copolymers were characterized for composition, conversion, molecular weights and glass transition temperature (Tg). A pseudo-kinetic model was developed and validated with experimental data. Reactivity ratios estimations were performed and one impurity commonly found in CLA, oleic acid, influenced the reaction kinetics significantly. The Tg of CLA homopolymer was predicted to be 5°C.

The study of an energy efficient cool white roof coating based on styrene acrylate copolymer and cement for waterproofing purpose—Part II: Mechanical and water impermeability properties

The mechanical properties and water impermeability of the developed cool white roof coating based on styrene acrylic copolymer and cement are systematically investigated in the current paper. The coating has good tensile properties, adhesion strength and compliance at low temperature. In particular, the coating possesses excellent water impermeability. The good flexibility and compliance at low temperature result from the low glass transition temperature of the high elastic styrene acrylate copolymer emulsion. Compared with the untreated specimens, after thermal, alkali, water immersion and ultraviolet treatments, the tensile strength of the coating is increased, while its breaking elongation is decreased. In addition, the coating has good artificial accelerated weather resistance in terms of mechanical properties. The excellent water impermeability of the coating stem from the cross-linked nature of the high elastic styrene acrylate copolymer emulsion, the formation of interpenetrating network structures and the Ca2+ bridging effect.

The study of an energy efficient cool white roof coating based on styrene acrylate copolymer and cement for waterproofing purpose—Part I: Optical properties, estimated cooling effect and relevant properties after dirt and accelerated exposures

The composition and the preparation process of a bi-functional cool white roof coating based on styrene acrylate copolymer and cement that integrates both a good cooling effect and good mechanical properties and water impermeability are introduced. Its optical properties, cooling effect and relevant properties after dirt and accelerated exposures are systematically explored. Compared with the conventional polymer-modified cement-based waterproof coating, the cool white roof coating based on styrene acrylate copolymer and cement has a much higher solar reflectance due to the presence of the titanium dioxide rutile and Altiris 800, and it can significantly reduce the coating surface temperature. The sticky nature of the high elastic styrene acrylate copolymer emulsion makes it easy for the cool white roof coating based on styrene acrylate copolymer and cement to collect pollutants and thus endows the coating with moderate dirt resistance. Four hundred hours of artificial accelerated weathering decreases the solar reflectance of the cool white roof coating based on styrene acrylate copolymer and cement and the cooling effect of the coating. The artificial accelerated weather resistance of the cool white roof coating based on styrene acrylate copolymer and cement is qualitatively good.

Physical and rheological properties of acrylate–styrene–acrylonitrile modified asphalt cement

Polymer-modified asphalt cement (PMAC) has been used in the last few decades to mitigate several root causes of asphalt-cement failures. Furthermore, it has been proved that polymers used as asphalt-cement modifiers had significant influence on the properties of asphalt at low and high temperatures. The primary objective of this study was to investigate the rheological, mechanical, and physical properties of acrylate–styrene–acrylonitrile (ASA) PMAC. Three types of samples with different concentration of the additives were studied, namely asphalt cement with 3%, 5%, and 7% of ASA. The influence of the modifier on the rheological, mechanical, and physical properties was evaluated by conventional tests (penetration, softening point, and ductility), viscosity, X-ray diffraction (XRD), and measurements from a dynamic shear rheometer (DSR). From the results of this study, it is evident that the addition of ASA has a significant effect on the rheological properties of asphalt cement. The temperature susceptibility of modified asphalt cement (MAC) was reduced compared with unmodified asphalt cement. In addition, the storage-stability test confirmed that the ASA–MAC has good compatibility. Furthermore, XRD results revealed that the phase of ASA–MAC changed from amorphous to semi-crystalline, which indicates that these materials have good workability. Based on the results from the DSR measurements, ASA–MAC has reduced temperature susceptibility, and increased stiffness and elastic behavior in comparison to unmodified asphalt cement. Moreover, ASA–MAC shows improved rutting resistance at high temperatures and higher fatigue performance at low temperatures. As a result, ASA can be considered as a proper alternative additive to modify the properties of asphalt cement.

Thermal, dynamic mechanical, and creep behavior of carbon nanotube reinforced ASA/Na‐ionomer blend

The present manuscript is aimed at the development of the protective layer for metal components for outdoor applications such as telecommunication components. Multiwalled carbon nanotubes at varying weight (from 0.5% to 5.0% by weight) were incorporated into newly developed 50/50 blend of acrylonitrile styrene acrylate (ASA) and ethylene acrylic acid‐based Na‐ionomer blend. ASA has inherent weather‐resistant property whereas Na‐ionomer has high affinity to adhere metal components. Nanocomposites were prepared by melt blending technique and were evaluated for thermal properties (thermogravimetric analysis and differential scanning calorimetry), dynamic mechanical analysis, and creep as well as recovery properties. Up to 1% nanotube content, there were predominant polymer/nanotube interactions; further addition resulted in nanotube networks formation that reduced polymer/nanotube interactions. These interactions increased both the thermal stability and storage modulus till 1% nanotube concentration, and after that, decreasing trend is observed. The creep deformation, as well as recovery, shows the opposite trend. In addition, the nanotube/nanotube sliding above 1% nanotube content increased the creep deformation further. The higher temperature played an altogether different role during recovery of the nanocomposite. The different polymer chain parts of the “brush” type ASA/Na‐ionomer blend interacted differently with carbon nanotubes; the ionic aggregates peak position of Na‐ionomer in differential scanning calorimetry thermogram was influenced by multiwalled carbon nanotubes, but the endotherm peak due to polyethylene crystallites of Na‐ionomer was unaffected. Carbon nanotubes also affected the glass transition temperature of polystyrene acrylonitrile matrix of ASA. Copyright © 2015 John Wiley & Sons, Ltd.

Reactivity ratio determination of styrene and 2-ethylhexyl acrylate by least squares methods

The reactivity ratios of styrene (STY) and 2-ethylhexyl acrylate (EHA) synthesized by bulk copolymerization method, were determined by ordinary least square (OLS) and generalized least square (GLS) approaches according to Inverted Finemann - Ross (IFR), Yezrielev - Brokhina - Roskin (YBR), Kelen - Tudős (KT) methods. Composition results were summarized and the 95 % individual confidence limits were determined and compared with each other and Error - in - Variables - Model (EVM) approach. Based on the copolymer compositions, the calculated reactivity ratios of STY and EHA through the GLS approach show acceptable percentage deviation with the well-known EVM method, which proves GLS approach, is the best linear estimator program for determining the monomer reactivity ratios. The reactivity ratios of EHA and STY are equal to 0.292 and 0.980 in IFR technique through the generalized least squares (GLS) approach which is closer to the point estimated from Error-in-variables model (EVM) and also r EHA and r STY are equal to 0.292 and 0.979 in EVM method, respectively. The present paper shows an estimation integral method for investigating the reactivity ratios of styrene and 2-ethylhexyl acrylate in Eviews software and the estimated values are discussed in terms of two regression approaches and compared with EVM method.

Novel Pd-BTP/SiO2 as an Effective Heterogeneous Catalyst for Heck Reactions

A highly efficient and reusable catalyst, palladium (II) complex supported on functionalized silica, was prepared by anchoring palladium (II) onto 2,6-bis(5,6-dimethyl-1,2,4-triazine-3-yl)pyridine [BTP]-modified mesoporous silica (labeled as Pd-BTP/SiO2). The catalyst was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and Brunauer Emmett Teller (BET) analysis. Its catalytic performance was tested for the Heck coupling reactions between aryl halides with acrylic acid or styrene, and good to excellent results (higher conversions 87–96% and yields 66–78%) were obtained. The catalyst system was stable under the reaction conditions and could be successfully reused more than five times without the loss of catalytic activity.

Block Copolymer Composite Synthesis in a Mechanistic Approach

Carbon nanotubes-block copolymer composites were synthesized via reversible addition–fragmentation chain transfer living emulsion mechanism, based on zero–one and pseudo-bulk kinetics. In conjunction with multiwalled carbon nanotubes, ab initio reversible addition–fragmentation chain transfer homopolymerization of styrene and butyl acrylate, respectively, was carried out using xanthate-based reversible addition–fragmentation chain transfer agent through ultrasonified macroemulsion and miniemulsion. Then, the second and third monomer were applied at stage II and III, respectively, to produce multiwalled carbon nanotube diblock and triblock copolymer composites such as multiwalled carbon nanotube-b-poly(styrene)-co-polybutyl acrylate-co-polymethyl acrylate and multiwalled carbon nanotube-b-polybutyl acrylate-co-polymethyl acrylate-co-poly(styrene). As multiwalled carbon nanotube-homopolymer proceeds to diblock and triblock, thermal resistance of multiwalled carbon nanotube block composite products is enhanced. A mechanistic approach of reversible addition–fragmentation chain transfer living macroemulsion and miniemulsion polymerizations, with the purified multiwalled carbon nanotubes enables us to control the composite properties such as thermal degradation, mechanical strength, and glass transition temperature of multiwalled carbon nanotube-block copolymer composites, in conjunction with reaction conditions, monomer type, blocking sequence, particle size, and molecular weight.

Rapid fabrication of organic/organic photonic bandgap films with robust mechanical properties using blended polymer spheres

Photonic crystals were fabricated using self-assembled polystyrene (PS) submicrospheres with different content of nanospheres with different glass transition temperatures ( Tg: 100 to −54°C) and their opalescent and mechanical properties were investigated. PS spheres (185.4 nm) and nanospheres were prepared by soap-free emulsion polymerization. Nanospheres were prepared using one or two types of monomers, styrene, n-butyl methacrylate, and butyl acrylate with sodium p-styrenesulfonate. Surface morphology, particle size ( Dn), and wavelength ( λ) of photonic crystals were determined from scanning electron microscopy (SEM), effective refractive index equation, and modified Bragg’s law, respectively. The reflection wavelength ( λmax) was measured from ultraviolet-visible spectroscopy. SEM results showed that hard nanospheres were distributed around PS spheres in their photonic crystals. On the other hand, soft nanospheres were coated onto PS spheres in their photonic crystals. With increasing weight fraction of hard or soft nanospheres in the photonic crystals, Dn and λ were increased. The value of λmax corresponded to that of λ. The mechanical property of the photonic crystals was measured by the pencil hardness (PH) test. The result showed that by decreasing the Tg and increasing the weight fraction of nanospheres, PH was increased. The opal film prepared from PS spheres with 20% N-54 nanospheres had the highest PH (H).

Cationic styrene-butyl acrylate-quaternary ammonium copolymer nanospheres for surface modification of cotton fibers

Cationic copolymer nanospheres are important functional materials, for example, for fiber modification. Here, emulsifier-free ternary emulsion copolymerizations of styrene (St) and butyl acrylate (BA) with two different quaternary ammonium cationic monomers (QACMs), methacryloxyethyl trimethyl ammonium chloride (DMC) and trimethyl (vinylbenzyl) ammonium chloride (VBT), and 2,2’-azobis[2-methylpropionamidine] dihydrochloride (AIBA) as an initiator were conducted at 80 ×C, under agitation at 300 rpm. The differences between the two cationic comonomers strongly influenced the monomer conversion, diameter, morphology, and surface charge density of the nanospheres. In particular, a higher cationic comonomer content is found to produce more oligomer radicals and thus more primary particles in the polymerization process, which leads to higher monomer conversion, smaller particle diameter, and increased surface charge density. The cationic nanospheres could be adsorbed in either a monolayer or in multiple layers on the oppositely charged cotton fiber because of their fierce electrostatic attraction. Compared with poly(St-BA-VBT) nanospheres, the distribution of poly(St-BA-DMC) nanospheres was more nonuniform on fiber surfaces accompanied by agglomerates.

Synthesis and Characterization of Hydroxyl-Functionalized Polystyrene Microspheres With Monodispersity

Hydroxyl-functionalized polystyrene (HFPS) microspheres were prepared by the copolymerization of styrene (St) and hydroxyethyl acrylate (HEA) via dispersion polymerization in the absence of steric stabilizers. The copolymerization was conducted with V-50 as an initiator. The effect of initiator concentration, HEA amount, and medium composition on the average diameters and coefficient variations of HFPS microspheres were systematically investigated. The particle morphology, the average diameters, the surface N content, and the particle size distribution curves were measured by SEM, XPS, and laser particle size analyzer. The results indicated that monodisperse HFPS microspheres with diameter of 0.6–1.0 μm could be successfully generated by dispersion polymerization of St and HEA without steric stabilizers. Therefore, overall, the present manuscript provided a simple route to generate monodisperse hydroxyl-functionalized polymer microspheres.