Styrene-acrylic Emulsion Research Articles

Heat storage and release performance of solar greenhouses made of composite phase change material comprising methyl palmitate and hexadecanol in cold climate

Solar greenhouses play a crucial role in winter crop cultivation in the cold regions of China. However, adverse weather conditions such as low temperatures can negatively affect their production. Therefore, improving the greenhouse thermal environment and energy utilisation is crucial for optimising greenhouse productivity. One effective method of storing energy is phase change technology. In this study, melt blending was used to prepare composite phase change materials (CPCMs), with methyl palmitate and hexadecanol as raw materials. In addition, ceramsite was encapsulated with a styrene-acrylic emulsion to form a shape composite phase change material (SCPCM). The results showed that the latent heat of phase change of the CPCMs was 221 J/g, with an initial phase change temperature of 23.48 ℃. The encapsulation of the SCPCM with a styrene-acrylic emulsion significantly reduced leakage. Phase-change ceramsite concrete slabs were developed by integrating the SCPCM into concrete. These slabs were used to construct phase-change and non-phase-change greenhouses. A temperature-testing system was installed in the greenhouses to examine the temperature variations and distributions under typical sunny and cloudy conditions. Results revealed that compared with the control greenhouse, the phase-change greenhouse exhibited a decrease of 3.0 ℃ in the maximum indoor temperature during sunny days and an increase of 3.2 ℃ in the minimum indoor temperature at night. This study highlights the effective temperature control capabilities of phase-change ceramsite concrete slabs for improving energy utilisation and provides valuable theoretical and technical insights for the future utilisation and widespread adoption of phase-change greenhouses.

Effect of gamma radiation on the crack pattern of a styrene-acrylic emulsion dry droplet

We present findings on the influence of gamma radiation on the crack pattern of dried drops of an aqueous styrene-acrylic emulsion. An increase in the dose of gamma radiation reduces the number of cracks and expands the edge of the dried droplet. Furthermore, gamma radiation induces a reduction in the branching of the crack pattern and an increase in the frequency of cracks, with a magnitude comparable to the width of the edge of the dried droplet. The results of the infrared analysis indicated that the micelles surrounding the styrene-acrylic copolymer in the emulsion exerted a protective effect, preventing indirect damage caused by radicals formed due to water radiolysis. The results of the zeta potential and particle size measurements demonstrated that gamma radiation caused an increase in the average size of the micelles, a widening of the size distribution, and a redistribution of surface charges. Doses above 100 kGy induce a loss of emulsion stability. The effects of gamma radiation on the crack patterns were interpreted by considering the dynamics of micelle deposition at the edge of the drop during drying and the appearance of mechanical instabilities in the deposit that lead to cracks. The larger micelles produced due to gamma radiation on the emulsion modify the microstructure formation at the edge of the dried drop, thereby alleviating the formation of mechanical stresses that result in the appearance of cracks.

Effect of modifiers on the properties of bamboo scraps/magnesium oxychloride composites under dry-wet cycling environments

Bamboo scraps/magnesium oxychloride composites (BS/MOC) is a new low-carbon and eco-friendly building material, which is composed of magnesium oxychloride cement (MOC) as the matrix and bamboo scraps as the reinforcing materials. However, the poor strength and durability of BS/MOC under special environmental conditions seriously restrict its application range. To solve the above problems, citric acid (CA), D-gluconic acid sodium salt (GS), and styrene-acrylate emulsion (SAE) were used as modifiers to improve BS/MOC properties. The effect of modifier addition on the mechanical strength and durability of BS/MOC was investigated under dry-wet cycling environments. The phase composition, microstructure, pore structure, and Clˉ concentration of BS/MOC were characterized by XRD, TGA, SEM, MIP, and ICS-600. The results showed that CA and GS improved the interface adhesion between bamboo scraps and MOC matrix, and both inhibited the hydration reaction of the residual MgO and the hydrolysis of phase 5 crystals, resulting in good mechanical properties and microstructural stability of BS/MOC under dry-wet cycles. GS outperformed CA in refining pore structure, improving mechanical properties and durability of BS/MOC under identical dry-wet cycles. Conversely, the addition of SAE increased initial defects and interfacial transition zones in the BS/MOC matrix, and increased the total porosity and the harmful pores content, which negatively affected the mechanical properties and durability of BS/MOC.

Smoke Suppression Properties of Fe2O3 on Intumescent Fire-Retardant Coatings of Styrene–Acrylic Emulsion

The intumescent flame-retardant coatings were prepared using ammonium polyphosphate (APP), pentaerythritol (PER), melamine (MEL), styrene–acrylic emulsion, and iron oxide yellow (FeOOH) as the base material. A cone calorimeter (CCT), smoke density meter (SDA), and scanning electron microscope (SEM) were employed to investigate the smoke suppression and flame retardancy of FeOOH in intumescent fire-retardant coatings. The thermal degradation performance of intumescent fireproofing coatings with varying FeOOH content was investigated through thermogravimetric analysis (TGA). The structure of the carbon slag in the CCT test was analyzed using a scanning electron microscope (SEM). The results of the cone calorimeter (CCT) experiments demonstrated that FeOOH significantly reduced the heat release rate (HRR), total heat release rate (THR), smoke production rate (SPR), and total smoke release rate (TSR) of the coating, while simultaneously increasing the carbon residue rate of the coating. The smoke density analysis (SDA) results demonstrate that adding FeOOH can effectively reduce smoke generation, regardless of whether a pilot flame is used. TGA results demonstrate that FeOOH can enhance the weight of coke residue at elevated temperatures. SEM results indicate that incorporating FeOOH resulted in a more compact coke residue. According to these findings, among all the samples, those containing 2 wt% FeOOH showed low levels of HRR, THR, SPR, and TSR and high levels of SOD, which proves that FeOOH can be used as a smoke inhibitor in flame-retardant coatings.

IMPACT OF FREEZE-THAW CYCLES ON BACTERIAL VIABILITY IN CONCRETE

Calcium carbonate precipitating bacteria can improve mechanical and physical properties of building materials. Most commonly, bacteria are used for the crack repair, production of self-healing concrete, or as a cementitious agent for low-strength materials. The favorable effect of bacterial metabolism can only be achieved if the sufficient number of cells remain viable in the structural material. Besides the limited amount of oxygen, extremely high pH level and mechanical pressure on cell walls, bacteria must survive the repetitive freezing and thawing in concrete-type materials. Freezing water may generate additional internal pressure damaging the bacterial cells and suppressing the bacterial activity. In present study, the viability two of bacteria strains (Bacillus pseudofirmus and Bacillus cohnii), was studied under repeated freezing and thawing conditions. It was shown that concrete-embedded bacteria may survive fluctuations of low temperatures and freeze-thaw cycles, compromising approximately 50% of viable spores. This survivability may only be achieved if bacterial spores are protected from the concrete environment itself, for example, spores could be injected to the expanded clay particles and coated with the styrene-acrylate emulsion. These findings confirm that Bacillus pseudofirmus and Bacillus cohnii bacteria could be used in cold climatic regions, retaining viable bacteria spores within the concrete.

IMPACT OF FREEZE-THAW CYCLES ON BACTERIAL VIABILITY IN CONCRETE

Calcium carbonate precipitating bacteria can improve mechanical and physical properties of building materials. Most commonly, bacteria are used for the crack repair, production of self-healing concrete, or as a cementitious agent for low-strength materials. The favorable effect of bacterial metabolism can only be achieved if the sufficient number of cells remain viable in the structural material. Besides the limited amount of oxygen, extremely high pH level and mechanical pressure on cell walls, bacteria must survive the repetitive freezing and thawing in concrete-type materials. Freezing water may generate additional internal pressure damaging the bacterial cells and suppressing the bacterial activity. In present study, the viability two of bacteria strains (Bacillus pseudofirmus and Bacillus cohnii), was studied under repeated freezing and thawing conditions. It was shown that concrete-embedded bacteria may survive fluctuations of low temperatures and freeze-thaw cycles, compromising approximately 50% of viable spores. This survivability may only be achieved if bacterial spores are protected from the concrete environment itself, for example, spores could be injected to the expanded clay particles and coated with the styrene-acrylate emulsion. These findings confirm that Bacillus pseudofirmus and Bacillus cohnii bacteria could be used in cold climatic regions, retaining viable bacteria spores within the concrete.

Repairing Performance of Polymer-Modified Cement-Based Thin Spray-On Liners on Pre-Cracked Rock-like Specimens

With the development of coal mining and the increase in excavation depth, the stress on roadway surrounding rock is also increasing. This creates conditions for crack development in the roadway, so it is urgent to develop rock repair materials with excellent performance. The ability of thin spray-on liner (TSL) to repair rock and concrete opens up the possibility of reusing abandoned roadways. The ability of TSL to support the surrounding rock is also important in preventing the generation of roadway waste. In this paper, styrene–acrylic emulsion (SAE), vinyl acetate–ethylene copolymer emulsion (VAE), and polyvinyl alcohol powder (PVA) were used to prepare three TSLs. Rock-like materials were configured using cement mortar according to similar principles. Three types of TSLs were tested for basic properties such as viscosity and mechanical strength, which provided data to support the explanation of the repair performance of TSLs. Three TSLs were used to repair pre-cracked rock-like specimens (PR). The number of brushing times and the angle of PR’s cracks were regarded as test variables. Changes in the mechanical strength of repaired PRs were tested by compressive and flexural tests. TSL repair performance was evaluated with the help of mechanical strength changes. Results show that polyvinyl alcohol powder modified cement-based thin spray-on liner is most suitable for repairing rock cracks; as the thickness of the brush slurry increases, its repair performance continues to improve. This paper can provide experience and a theoretical basis for the research of other rock repair materials, and it is also instructive for repairing shotcrete in the roadway.

Effects of styrene–acrylic emulsion on bond performance and interface microstructure of repair mortar of ternary cementitious system

AbstractThis study investigates the effects of styrene–acrylic emulsion (SAE) as a modifier and interfacial agent on the interfacial bond performance of ordinary Portland cement–aluminate cement–gypsum (PAG) repair mortar. The hydration products and interfacial microstructure are analyzed via x‐ray diffraction (XRD), x‐ray photoelectron spectroscopy (XPS), Fourier‐transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The results demonstrate that the addition of SAE can effectively enhance the tensile bond strength and flexural bond strength of the PAG repair mortar, and the optimal addition amount of SAE is 10 wt%. The tensile and flexural bond strengths of the PAG repair mortar with SAE interfacial agent at 40% concentration are 1.38 and 1.34 times than those of the mortar without the interfacial agent, respectively. XPS and FTIR analyses reveal that the carboxyl groups in SAE and Ca2+ generated from cement hydration form Ca2+–carboxyl complexes. The SEM and XRD analyses indicate that SAE can alter the distribution and size of crystals at the bond interface and considerably reduce the thickness of the bond interface; however, SAE cannot change the type of hydration products at the bond interface.

Water Consolidation Performance of Acrylic-Polymer-Modified Materials and Their Concrete Impermeability Repair Characteristics.

Acrylic materials exhibit favorable grouting repair performance. However, their curing products are easily inclined to drying shrinkage, and their concrete impermeability repair characteristics have seldom been investigated. To improve material properties, reveal the impermeability repair mechanism, and address drying shrinkage, this study proposed the addition of styrene-acrylate copolymer emulsion (styrene-acrylic emulsion) to the grouting material to prepare two-component acrylate grouting materials. Using orthogonal and single-factor tests combined with physical and mechanical properties, the mechanical properties and impermeability repair performance (physical and mechanical properties combined) of grouting materials were analyzed and studied, and the optimal ratio of each component of acrylate grouting materials was determined. Results show that (1) the hydrogel produced by the reaction of sodium methacrylate with hydroxyethyl acrylate has good physical and mechanical properties. (2) With the increase in the accelerator dosage, the setting time of slurry initially decreases and then increases; as the initiator dosage increases, the setting time of slurry decreases, which is negatively correlated with the initiator dosage. (3) Talcum powder can improve the physical and chemical properties of gel and enhance the reliability and durability of acrylate grouting materials, and the comprehensive performance is the best at a dosage of 3%. (4) Styrene-acrylic emulsion can increase the solid content and reduce the volume drying shrinkage when added to grouting materials. The fractured impermeable specimens were repaired by grouting with prepared acrylate grouting materials and cured for 24 h for the impermeability test, and the water pressure for the 24 h impermeability repair was 1.0 MPa. This study's results provide important reference and basis for revealing the impermeability principle of acrylate grouting materials and evaluating their impermeability.

Synthesis of styrene–acrylate emulsion by glow discharge electrolysis plasma and its application for the conservation of simulated disrupting murals in Dunhuang Mogao grottoes

AbstractIn this work, a styrene (ST)–acrylate emulsion was synthesized via glow discharge electrolysis (GDE) plasma technique. A possible forming mechanism was proposed. Moreover, the adhesion property of the emulsion was evaluated for the conservation of simulated disrupting murals. The results showed that under optimum conditions, the solid content, emulsion conversion, and gel rate are 29.0%, 85.6%, and 1.04%, respectively. The obtained ST–acrylate emulsion is spherical in shape, with a particle size of about 100 nm. The property of ST–acrylate emulsion prepared by GDE is superior to that of the commercial ST–acrylate emulsion for the conservation of simulated disrupting murals. Compared with other methods, GDE has the advantages of simple steps, controllable reaction, environmental friendliness, no chemical initiator, and no N2 atmosphere.

UHPC-XPS insulation composite board reinforced by glass fiber mesh: Effect of structural design on the heat transfer, mechanical properties and impact resistance

Extruded foamed polystyrene (XPS) and ultra-high performance concrete (UHPC) are the ideal insulation and structural materials for preparing sandwich composite boards, respectively. However, how to design the multilayer structure of composite board to maximize thermal insulation, mechanical properties and impact resistance has not been clarified yet. In this study, styrene-acrylic emulsion was coated on the surface of XPS to improve its wettability, and glass fiber mesh-reinforced bonding mortar with vac-ethylene copolymer emulsion was used to improve the adhesive properties between UHPC and XPS layers. Then the contribution of each layer in heat-transfer, load-bearing, and impact resistance were investigated and simulated by finite element analysis. By separating XPS and UHPC into serval layers, the midspan displacement at peak load and fracture energy of composite boards increased by 689.4% and 39.1% respectively, then roles of each layer in composite board were discussed. The results provide an effective method to prepare high performance composite board by multilayer structural design, and then promote energy-saving and emission-reduction of prefabricated wall system and even building industrialization.

Investigation of the effects of styrene acrylate emulsion and vinyl acetate ethylene copolymer emulsion on the performance and microstructure of mortar

Investigation of the effects of styrene acrylate emulsion and vinyl acetate ethylene copolymer emulsion on the performance and microstructure of mortar

Influence of styrene-acrylic emulsion additions on the electrical and self-sensing properties of CNT cementitious composites

Carbon nanotube (CNT) cementitious composite sensors are considered as an effective method for monitoring the health of building structures owing to their good self-sensing properties. However, previous studies have shown that the high electrical conductivity imparted by CNTs to cement-based materials can increase the risk of steel corrosion. To overcome this drawback and further enhance the piezoresistive performance of the material, a new method has been proposed in this study to improve the self-sensing properties of CNT-cement composites by incorporating styrene-acrylic emulsion (SAE) in them. The results show that the electrical resistivity of CNT-cement composites increases significantly with the addition of SAE, which is attributed to the polymer film hindering the mutual contact of the CNTs and ion migration. In addition, the piezoresistive properties of the composite sensor are significantly improved owing to the CNT/SAE three- dimensional network structure of the conductive system established in the cement matrix. The CNT-cement composite sensor containing 10 wt% SAE exhibits the best self-sensing properties and can reach a stress sensitivity of 22.1 × 10–3 MPa−1. The utilization of polymers as reinforcement for CNT-cementitious materials presents an economical and efficient approach for fabricating piezoresistive stress sensors intended for SHM applications.

Sodium Oleate and Styrene-Acrylate Copolymer Emulsion-Modified Cement Mortar: Functional Combination of Physical Barrier and Hydrophobicity

Styrene-acrylic emulsion (SAE)-modified mortar is typically used as an impermeable cement-based material. Although high-volume SAE-modified mortar shows excellent penetration resistance performance, this property can also cause compressive strength loss. In this work, sodium oleate (SO) is used as a hydrophobic agent to enhance the antipermeability of mortar with low SAE content. The influence of the incorporation of hydrophobic agent on the mechanical properties, hydration characteristics, water absorption, and impermeable and hydrophobic properties of low content polymer emulsion-modified cement mortars was investigated. The results show that the mortar with 5% SAE and 1% SO has better impermeability, hydrophobicity, and compressive strength than a mortar with 15% SAE only, which is attributed to the physical barrier of SAE and the hydrophobicity of SO. SO works well with 5% SAE-modified mortar, and the improvements in all aspects of the performance are greater than that of the high content SAE-SO–modified mortars. However, increasing the amount of SO will not bring continuous improvement in antipermeability, as the air-entraining effects of SO increase the porosity of the matrix.

Enhanced Flame Retardancy of Styrene-Acrylic Emulsion Based Damping Composites Based on an APP/EG Flame-Retardant System.

Developing flame-retarded styrene-acrylic emulsion (SAE) based damping composites is a challenging task because of their very high flammability. A promising approach is the synergistic combination of expandable graphite (EG) and ammonium polyphosphate (APP). In this study, the surface modification of APP was modified by commercial titanate coupling agent ndz-201 through ball milling, and the SAE-based composite material was prepared with SAE and different ratios of modified ammonium polyphosphate (MAPP) and EG. The surface of MAPP was successfully chemically modified by NDZ-201 through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Energy Dispersion Spectroscopy (EDS), and contact angle. The effects of different ratios of MAPP and EG on the dynamic and static mechanical properties and flame retardancy of composite materials were explored. The results showed that when MAPP:EG = 1:4, the limiting oxygen index (LOI) of the composite material was 52.5%, and the vertical burning test (UL-94) was at the V0 level. Its LOI increased by 141.9% compared to the composite materials without flame retardant. The optimized formulation of MAPP and EG in SAE-based damping composite materials showed a significant synergistic effect on the flame retardancy of the composite material.

Evaluation of the aminosilane and colloidal silica treated red iron oxide pigment effects in styrene acrylic and polyurethane dispersion

PurposeThis study aims to perform the surface treatment of synthetic α-Fe2O3 red iron oxide pigment with hydrolysate 3-aminopropyl silane (A) and colloidal silica (CS) and investigate the effects of surface-treated pigment on the styrene acrylic (SA) emulsion and polyurethane (PU) dispersion.Design/methodology/approachFor this purpose, firstly red iron oxide particles were modified with A and CS separately in an aqueous medium. After isolation of the modified iron oxide were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Moreover, the degree of the dispersion stability of the modified pigment in coatings with SA emulsion and PU dispersion was investigated by using an oscillation rheometer. Loss (G''), storage (G') modulus, loss factor [tan(δ)] and yield stress (τ0) values were determined by performing amplitude and frequency sweep tests.FindingsThe τ0 in SA coatings decreases with the amount of used A and increases with the amount of used CS. The τ0 decreases as the amount of used A and CS in PU coatings increases. The use of CS on red iron oxide pigments causes storage modulus to increase in SA coatings at low angular frequencies, while it causes a decrease in PU coatings.Originality/valueTo the best of the authors’ knowledge, for the first time, the suspended state of the iron oxide hybrid pigment formed with CS in the coating was investigated rheologically in this study.

Fabrication of Graphene-Modified Styrene–Acrylic Emulsion by In Situ Aqueous Polymerization

With the aim of developing green coatings, styrene–acrylic emulsion has been widely used in architectural coatings due to its excellent environmental protection and energy conservation. Nevertheless, the lack of water and oxygen resistance of water-based styrofoam coatings has promoted various nanomaterials being studied for modification. To improve the performance of waterborne styrofoam coating, we introduced the graphene nanopowder and expected to enable it with the function of electromagnetic interference (EMI) shielding to reduce the damage of electromagnetic radiation. In this paper, the problem of poor interface compatibility between graphene and polymer resin was successfully addressed by in situ polymerization. In the process of pre-polymerization of styrene–acrylic emulsion monomer, graphene-modified styrene–acrylic emulsion was obtained by introducing graphene aqueous dispersion. The results showed that the styrene–acrylic emulsion with 4 wt% aqueous graphene dispersions exhibited the best dispersion stability, improved water and oxygen resistance, and the conductivity reached 1.89 × 10−2 S/cm. Then, the graphene-modified coating for building was prepared by using graphene-modified styrofoam emulsion. All the performance indexes of the coating are in line with the industry standards, and it still showed benign EMI shielding effect even when the graphene content was low. It is demonstrated that in situ polymerization technology and the application of graphene in resin coatings modification will promote the development of green coatings.

For the improvement of toughness and volume stability of alkali-activated slag with styrene-acrylic emulsion

Alkali-activated slag (AAS) is a green and environmentally friendly cementitious material, but its poor toughness and volume stability limit the practical application. Due to the flexibility and weathering resistance, SAE is widely used to promote the toughness of cementitious materials. Thus, SAE could be a potential additive in AAS system to improve the toughness and volume stability. In this work, different dosages of SAE were used to improve toughness and volume stability of AAS system. The toughness of AAS was evaluated by mechanical F/C ratio and fracture energy. The volume stability was characterized by one-dimensional drying shrinkage test and two-dimensional plate cracking test. The results indicated that the addition of 10 wt% SAE could enhance the F/C ratio (by 120.0%) and the fracture energy (by 242.3%) of AAS at 28 days, and this promotion of toughness could be attributed to physical adhesion and chemical bonding between SAE and hydration products. 5 wt% SAE could also reduce the drying shrinkage rate (by 10.3%) and crack area (by 99.4%) at 28 days, and the improvement of volume stability was due to the refinement effect of SAE on pore structure of AAS. This study provides a reference for the systematic evaluation method for the toughness and volume stability of AAS, and offers guidance for the application of SAE in AAS.

Synthesis of Nano-ZnO Composite Polystyrene Acrylic Emulsion and Its Application in Chinese Painting Pigments

With the continuous development of coating technology and environmental protection concepts, coating has become an indispensable item in the field of architecture and industry. Styrene acrylic emulsion as a new type of waterborne paint has attracted much attention since its emergence. Its functional modification is the focus of research, but the research results have not been ideal. To further improve the performance of styrene acrylic emulsion, nano-ZnO composite polystyrene emulsion was synthesized by emulsion polymerization, and its properties were analyzed. Aiming at the problem that nanopigments are prone to agglomeration, corresponding solutions are proposed, and the stability of nano-coatings is preliminarily studied. The inherent culture and essence of traditional culture and art is the wealth of realizing the unique nationalization and internationalization of design works. There is a lot of artistic quintessence in traditional Chinese painting art that can be used for reference to visual communication design. Through in-depth understanding and learning of Chinese painting theory and techniques, designers’ aesthetic abilities and innovation abilities can be qualitatively improved. First of all, the emulsion polymerization was carried out by semicontinuous method. The composite polystyrene emulsion containing different content of nano-ZnO was successfully prepared, which was recorded as N, Z, Z15, Z25, and Z35, respectively. The properties of the emulsion were determined, and the solid content, monomer conversion, viscosity, water absorption, and bacteriostatic effect of the emulsion were determined. The experimental results show that the solid content of emulsion Z15 (nano-ZnO content is 15%) reaches the highest value of 43.5%. The content of monomer in the emulsion affects the solid content, but the higher the monomer content, the better the solid content. The highest monomer conversion of Z15 was 86.4% at 80°C. The monomer conversion increased with the increase of polymerization temperature and tended to be stable after reaching the highest value. In the absence of nano-ZnO, the viscosity of the emulsion is the highest, and the viscosity of the emulsion decreases with the increase of the content of nano-ZnO monomer. Z35 (when the content of nano-ZnO is 35%) is the highest, which is 18.91%. The water absorption increases with the increase of nano-ZnO content. The content of nano-ZnO in the emulsion increased, the MIC value became smaller, and the bacteriostatic effect became better and better. This indicates that nano-ZnO composite polystyrene emulsion has good monomer conversion, super water resistance, and bacteriostatic effect, but its viscosity is relatively poor.

Preparation and properties of antibacterial styrene-acrylic emulsion containing thiazole structure and its application as coating

Preparation and properties of antibacterial styrene-acrylic emulsion containing thiazole structure and its application as coating