Amount Of Superabsorbent Polymer Research Articles

Mechanical Properties of Recycled Concrete Incorporated with Super-Absorbent Polymer and Machine-Made Stone Powder under the Freeze-Thaw Cycle Environment.

Recycled concrete incorporating additional super-absorbent polymer (SAP) and machine-made stone powder (MSP) was prepared using a two-factor, four-level orthogonal test. To enhance the frost resistance of recycled concrete and improve its mechanical properties, such as compressive and flexural strength, the prepared concrete underwent 200 freeze-thaw cycles. Before freeze-thaw cycles, the amount of SAP has a predominant influence on the mechanical properties of recycled concrete in comparison with MSP. After 200 cycles of freeze-thaw, the influence of MSP became more significant than that of SAP. Typically, the compressive strength and flexural strength exhibited a trend of initially increasing and then decreasing as the contents of SAP and MSP increased. The optimized recycled concrete was identified as S16M6, containing 0.16% SAP and 6% MSP, as demonstrated by the minimal strength loss after freeze-thaw cycles. This study also proposed a linear regression model for predicting the mechanical properties which offered valuable guidance for the engineering application of recycled concrete mixed with SAP under the freeze-thaw cycle environment.

The Applicat ion of Super Absorbent Polymer in Self-Healing Morta r: The Effect on Mechanical Properties

Super Absorbent Polymer (SAP) were used in various application, including in mortar production. The ability of SAP to absorb a high amount of water made this material become a promising water reservoir in the mortar that can later mitigate micro-cracks in concrete. Besides SAP, a nutrient must be embedded into self-healing mortar to support metabolism in bacteria-based self-healing mortar. However, adding SAP and nutrient was reported to decrease the mechanical properties of the resulting self-healing mortar. Thus, in this research, the modification in the mix design of mortar containing SAP and nutrient were observed. The water to cement ratio was decreased up to 0.3. The amount of SAP and entrained water added is based on its swelling capacity. The swelling capacity of SAP, the workability of fresh mortar, and the compressive strength of mortar were examined. The results show that the swelling capacity of SAP was affected by the pH and the presence of calcium ions in the solution. The higher the pH and the calcium ion in the solution, the lower SAP’s swelling capacity. Applying the modified mortar mix design containing SAP and nutrient proofed to mitigate the reduction in workability and compressive strength of the resulting self-healing mortar.

Super absorbent polymers (SAP) in building materials: Application opportunities through physico-chemical and mechanical analysis

This paper shows the physicochemical and mechanical characterization of a new plaster material lightened with superabsorbent polymers (SAP) and reinforced with fibers. First, an experimental campaign has been conducted to determine the ideal quantity of sodium polyacrylate polymer (NaPA) to be added, analysing three water/plaster ratios and three different amounts of SAP. The aim is to achieve the maximum reduction in density and optimal mechanical resistance. Once this analysis was conducted, a 0.7 water/plaster ratio and 0.015 SAP/gypsum ratio were determined as the ideal mixture. With this, a complete characterization of the new material was conducted, also considering the incorporation of three different fibers. SAP addition led to a significant apparent density reduction in the new plaster compounds produced, reaching values up to 27 % lower than the reference samples. From those samples with fibers, kevlar and glass fiber got a better mechanical performance, always exceeding the limit values established by current regulations. In the same way, the incorporation of these superabsorbent polymers has managed to reduce the original plaster material thermal conductivity by up to 32 %, as porosity increased. Thus, it has been confirmed that the incorporation of superabsorbent polymers in the production of plaster compounds is a viable alternative to produce lightweight prefabricated elements within wide field of application for the design of new prefabricated elements.

Influence of Super-Absorbent Polymer on Growth and Productivity of Green Bean under Drought Conditions

The water-retaining and yield-increasing capacity of super-absorbent polymer (SAP) are essential for soil remediation in arid and semi-arid areas. Water availability is an increasing challenge to plant development and crop yield. During the growing seasons in 2021 and 2022, the present study was conducted to evaluate the effect of the addition of different amounts of SAP on the development and yield of green beans (Phaseolus vulgaris L. cv Bronco) under varying water deficit stresses, compared with the control treatment without SAP and water deficit stress. The results demonstrated that a 50% reduction in water requirement (WR) resulted in significant decreases in leaf fresh weight, specific leaf area, leaf total chlorophyll content, pod number, leaf free water content, pod fresh weight per plant, and yield. Decreases were also found in pod total chlorophyll content, carotenoids, dry matter and total protein, leaf proline content, and crude fiber content. Additionally, leaf water saturation deficit was significantly increased under the stress compared with the full irrigation at 100% WR. However, irrigation at 75% WR increased pod contents of ascorbic acid, total sugars, and leaf bound water. The current study also indicated that addition of SAP significantly enhanced the above-mentioned growth characteristics under irrigation at 50% and 75% WR. Treatment with SAP at 3 g/plant was the most effective in mitigating the adverse effects of water deficiency, especially at the irrigation rate of 75% WR. Pearson’s correlation analysis showed significantly positive correlations between the growth parameters, as well as pod yield, under water stress and SAP. This study provides a promising strategy for green bean cultivation by adding SAP to soil to alleviate water shortage stress.

Investigation of the effect of superabsorbent polymer application on soil moisture and plant growth

As climate change continues to affect the environment, drought management has become more critical in agri-food production. Farmers are now looking for alternative drought management methods that are easy to apply. In this sense, superabsorbent polymers (SAPs) were proposed as an alternative soil conditioning and drought management tool within this study. To test the efficiency of a developed SAP in terms of soil conditioning and plant growth promotion with different soil types and extreme drought conditions, long-term soil and greenhouse experiments were carried out in at least 4 replicates. The plant growth was monitored by 4 different growth indicators using wheat as a model plant. Plant growth indicators demonstrated that shoot dry matter, spike length, and grain yield were enhanced up to 24%, and 11.6% using different amounts of SAP at varying drought conditions. The study set forth and exemplary of superabsorbent polymer use in agriculture and useful in dose adjustment and understanding the drought-dose relationship in these types of polymers.

Effect of internal curing by superabsorbent polymers on the densification and microstructural development of cementitious materials exposed to different environmental conditions

Superabsorbent polymers (SAPs) are among the internal curing agents used in cementitious materials. This study aims to evaluate the influence of wider SAP dosages under different exposure environments on the microstructural densification of cementitious materials and the development of strength and durability based on this. With SAP incorporation, hydrate crystallization most easily occurs in the wet/dry condition through hydration with externally supplied water and by internal SAP curing, which leads to the formation of the densest microstructures. Microstructure densification further progresses as the SAP dosages increase. Despite the internal curing effect of SAPs, the ultrasonic pulse velocity and the compressive strength of S0.5 specimens compared with those of the REF specimens decrease due to SAP void presence. However, these mechanical properties of the S1.0 specimens are all recovered at later ages when exposed to the wet/dry condition, forming densest microstructures. As the SAP dosages increase, the sealing effect of SAPs improves the water permeability characteristics at early ages. The lowest water permeability coefficient is observed in the S1.0 specimen exposed to the wet/dry condition as the further hydration effect of SAPs is exerted with increasing ages. In conclusion, utilizing the appropriate amount of SAPs and environmental conditions can effectively densify the internal pore structures, thereby securing the mechanical and durable properties of concrete structures.

Effect of Cement Type and Water-to-Cement Ratio on Fresh Properties of Superabsorbent Polymer-Modified Cement Paste

Superabsorbent polymer (SAP) is a material with the ability to absorb liquid and desorb liquid from and to the environment, and it can ensure the internal curing of cementitious composites. Although the fresh state properties of SAP-modified mixtures (SAPCP) are affected and have been investigated nowadays, the rheological properties of SAPCP are still a virgin field and they are worth studying. Hence, the current study was aimed and conducted to observe what occurred if cements with different chemical compositions, various ratios of water/cement (w/c) and SAP were used together. Accordingly, CEM I 42.5R, CEM II/A-LL 42.5R and CEM IV/B (P) 32.5R were selected as binders in the mixtures, and w/c ratios were 0.40 and 0.50 for SAPCPs. In total, 24 mixtures were designed, produced and tested in the laboratory and spreading table tests, Vicate tests, viscosity tests and shear tests were conducted on the fresh state of the mixtures to observe the fresh behavior of SAPCPs. As a result, it was determined that the SAP, cement and w/c combinations considered in the article were effective on SAPCP fresh properties and rheology. However, it was determined that the use of high amounts of SAP in the mixture, high cement fineness and high oxide ratios in the cement (ratios of silicon dioxide/calcium oxide and aluminum oxide/calcium oxide) negatively affected not only the fresh state properties, but also the rheology. Moreover, the coexistence of the aforementioned negative conditions was the most unfavorable situation: high SAP ratio + high cement fineness + high oxide ratio in SAPCP. For these reasons, it was concluded that cement fineness and chemical composition should be taken into account in the rheology/workability-based design of SAPCPs. Then, the SAP content can be regulated for design purposes.

Investigation on Performances and Functions of Asphalt Mixtures Modified with Super Absorbent Polymer (SAP).

The super absorbent polymer (SAP) has been attracting extensive concerns due to its strong capacity in water absorption and retention. The amorphous hydrogels formed by the post-absorbent SAP have the potential of clogging the micro-cracks in asphalt materials and refraining the rainwater from infiltrating. This provides the possibility of applying SAP in asphalt pavements to seal or fill the cracks and relieve the distresses caused by rainwater infiltration in the underlying layers. Before exploring the cracking sealing mechanism of SAPs in asphalt pavements, a series of experiments were performed to evaluate the feasibility and influences of SAPs in asphalt mastics and asphalt mixtures on their mechanical performances and functionalities. Firstly, the basic properties of SAPs were analyzed, and then the rheological properties of the asphalt mastics using SAP replacing mineral powder (10%, 20%, 30%, and 40% by volume) were explored. The water stability and infiltration reduction effect of the asphalt mixtures incorporated with SAP were evaluated by the Marshall stability test, immersion Marshall stability test, freeze-thaw splitting strength test, Cantabro test, and permeability test. The test results indicated that SAPs could be used in the asphalt mixtures to partially substitute mineral powder with desirable mechanical performances. When less than 10% of the mineral powder was replaced by the SAP, the high-temperature performance and fatigue life of the asphalt mastics could be improved to some extent, but both declined after the content of the SAP was larger than 10%. Due to the hydrogels formed by SAPs after water absorption, the water stability of the asphalt mixtures deteriorated with the increased content of SAPs. Moreover, the results from the permeability tests implied that the SAP hydrogels could fill the seepage channels in the material, thus improving the migration and infiltration resistances of the asphalt mixtures. With the increased contents of SAPs, the permeability coefficients of the asphalt mixtures could be reduced up to 55%. Based on the research findings in this study, when an appropriate amount of SAP was added in the asphalt materials, desirable temperature stability, water stability, and fatigue resistance could be achieved regarding actual requirements from applications. At the same time, the addition of SAPs could effectively refrain the infiltration and migration of rainwater in asphalt pavements, thus potentially mitigating the effect of water erosion on the underlying layers.

Effect of Superabsorbent Polymers on the Self-Healing Properties of Pre-Damaged Concrete

Cracks in concrete structures reduce bearing capacity, durability, and safety. This paper reveals the effect of superabsorbent polymers (SAP) on the self-healing property of pre-damaged concrete based on mechanical properties tests, mercury intrusion porosimetry, scanning electron microscopy, and energy dispersive spectrometer. The experimental results show that SAP reduces the mechanical properties of the SAP-modified concrete under the same W/C ratio, but a small amount of SAP can improve the later strength under the 0.35 W/C ratio. The addition of SAP increased the volume of small capillary pores (<20 μm) and large capillary pores (>100 μm) and significantly reduced the former with an increase in age. The SEM-EDS analysis indicates that the water released by SAP promotes the formation of C-S-H gel. AFt in the cracks is the main reason for self-healing, and the addition of CO2 to produce calcium carbonate is another one. Furthermore, this study finds that SAP-modified concrete has the best self-healing effect and the densest structure when the W/C ratio is 0.35 and the SAP content is 0.25%. The self-healing performance makes the SAP-modified concrete have broad application prospects.

RETRACTED: Shrinkage and tensile properties of ultra-high-performance engineered cementitious composites (UHP-ECC) containing superabsorbent polymers (SAP) and united expansion agent (UEA)

Ultra-high performance engineered cementitious composites (UHP-ECC) had received extensive attention in recent years in material as well as the field of structural rehabilitation and strengthening due to its excellent mechanical properties, such as high strength and high ductility. However, the high shrinkage is one of the bottlenecks limiting widespread engineering application of UHP-ECC. In this paper, superabsorbent polymers (SAP) and United expansion agent (UEA) were introduced to mitigate UHP-ECC shrinkage. And the effect of different amounts of SAP with UEA on the shrinkage and tensile properties of UHP-ECC are investigate. Results indicate that the incorporation of SAP and UEA can effectively mitigate the autogenous shrinkage, and the autogenous shrinkage decreased with the increasing SAP dosage; however, drying shrinkage had the opposite trend. The incorporation of SAP and UEA improved the tensile ductility of UHP-ECC. The inclusion of SAP reduced the fracture toughness by increasing the matrix porosity, which produced more micro-cracking sources, thus improving the multiple cracking and strain-hardening behaviors of UHP-ECC. Conversely, the incorporation of SAP decreased the fiber/matrix interaction as well as decreasing the effective number of polyethylene (PE) fibers in the cross-section, thus reducing the tensile strength. Finally, pseudo strain hardening index of each specimen was conducted to analyze the effect of SAP with UEA on the tensile properties of UHP-ECC.

Evaluation of mix design strategies to optimize flow and strength of mortar internally cured with superabsorbent polymers

A straightforward mix design method was developed for proportioning mortars containing superabsorbent polymers (SAPs). When modified by introduction of a typical amount of SAP (i.e., 0.2% by weight of cement), the 0.42 w/c ordinary Portland cement (OPC) mortars required addition of extra water and/or high-range water reducing admixture (HRWRA) to achieve a minimum target percent flow in mortar flow table tests. At high w/c (≥0.49), SAP accelerated compressive and flexural strength development. In all mortars tested, the addition of SAP either preserved or increased compressive and flexural strength values relative to SAP-free mortar with the same w/c.

The Structural Formation of Cement Stone Modified by a Solution of Superabsorbent Polymer

With the development of 3D technologies in construction, the development of formulations that are indifferent to the influence of the environment is in demand. Conditions of intense water loss from cement systems arise during the layer-by-layer printing process. This leads to a decrease in density, high shrinkage, and a decrease in the strength and durability of the composite. The use of superabsorbent polymer (SAP) solutions, in contrast to granules, will provide hardening Portland cement with a water supply for internal care of hydration processes. The aim of the work is to study the effect of SAP solution on the processes of structure formation of cement stone, hardening in unfavorable conditions. In this paper, the features of the structure formation of cement systems in the presence of SAP are established. It is shown that the use of polymer in an amount of no more than 1.5% by the weight of Portland cement provides the formation of a more perfect crystalline structure of the cement stone, which allows for an increase in the degree of cement hydration. When the amount of SAP is ≥ 1.5% by the weight of Portland cement, a decrease in the intensity of the maxima corresponding to hydration products is observed.

Effect of Internal Pores Formed by a Superabsorbent Polymer on Durability and Drying Shrinkage of Concrete Specimens.

In this study, the effect of internal pores formed by a superabsorbent polymer (SAP) was analyzed by evaluating the compressive strength, chloride penetration depth, drying shrinkage, and pore size distribution of SAP-containing concrete, while securing workability using a water-reducing agent (WRA). The experimental results showed that the amount of WRA necessary increased as the amount of SAP added increased, and that the compressive strength was the highest when the SAP content was 1.5% of the concrete mix. Drying shrinkage tended to decrease as the SAP content increased, and it decreased by approximately 31–41% when the SAP content was 2.0% compared to that of the reference mix. The SAP expanded by approximately three times inside concrete, and it was distributed within the internal pores of air-entrained concrete. The optimal SAP content in concrete mix was 1.5%, and an SAP content of 2.0% or higher adversely affected the workability and compressive strength.

Effect of Cement Types and Superabsorbent Polymers on the Properties of Sustainable Ultra-High-Performance Paste.

This study focuses on the effects of superabsorbent polymers (SAP) and belite-rich Portland cement (BPC) on the compressive strength, autogenous shrinkage (AS), and micro- and macroscopic performance of sustainable, ultra-high-performance paste (SUHPP). Several experimental studies were conducted, including compressive strength, AS, isothermal calorimetry, X-ray diffraction (XRD), thermogravimetric analysis (TGA), attenuated total reflectance (ATR)–Fourier-transform infrared spectroscopy (FTIR), ultra-sonic pulse velocity (UPV), and electrical resistivity. The following conclusions can be made based on the experimental results: (1) a small amount of SAP has a strength promotion effect during the first 3 days, while BPC can significantly improve the strength over the following 28 days. (2) SAP slows down the internal relative humidity reduction and effectively reduces the development of AS. BPC specimens show a lower AS than other specimens. The AS shows a linear relationship with the internal relative humidity. (3) Specimens with SAP possess higher cumulative hydration heat than control specimens. The slow hydration rate in the BPC effectively reduces the exothermic heat. (4) With the increase in SAP, the calcium hydroxide (CH) and combined water content increases, and SAP thus improves the effect on cement hydration. The contents of CH and combined water in BPC specimens are lower than those in the ordinary Portland cement (OPC) specimen. (5) All samples display rapid hydration of the cement in the first 3 days, with a high rate of UPV development. Strength is an exponential function of UPVs. (6) The electrical resistivity is reduced due to the increase in porosity caused by the release of water from SAP. From 3 to 28 days, BPC specimens show a greater increment in electrical resistivity than other specimens.

The influence of superabsorbent polymers (SAPs) on autogenous shrinkage in cement paste, mortar and concrete

Due to the high amount of fines in combination with a low water-to-cement ratio (<0.35), high performance mortar and concrete are very prone to cracking as a result of autogenous shrinkage, resulting in a decreased durability, integrity and aesthetics of the structure. Superabsorbent polymers (SAPs) can be added as internal curing agents to reduce the autogenous shrinkage in cementitious materials. In this paper, the influence of SAP addition on mitigating autogenous shrinkage in cement paste, high performance mortar and high performance concrete is investigated. Two different types of SAPs were added in varying amounts: one sulfonate based SAP with specifically selected properties, and a commercially available poly-acrylate based SAP. To study the effect of the SAP addition on the mitigation of autogenous shrinkage, corrugated tube tests in case of cement paste and mortar, and restrained ring tests for concrete were performed. The poly-acrylate based SAPs reduced the autogenous shrinkage after 7 days in the mortar mixtures with 97% compared to the reference without SAPs, whereas in the cement paste, the autogenous shrinkage after 7 days was completely mitigated. Although the mixtures with sulfonate based SAPs did not show complete mitigation of the autogenous shrinkage, the shrinkage was significantly reduced for all cement pastes: increasing the amount of SAPs from 0.257 m% to 0.38 m% and 0.57 m% by weight of cement, lead to a reduction in the autogenous shrinkage after 7 days with 80%, 85% and 89% respectively. In mortar the reductions for the same amounts of SAPs were 19%, 20% and 70% respectively. Considering restrained shrinkage ring tests, the poly-acrylate based SAPs reduced the occurring strains significantly (-88%) compared to the reference and prevented the rings from cracking. For the sulfonate based SAPs, the moment of cracking was delayed and lower strains compared to the reference were observed.

Internal curing of blended cement pastes with ultra‐low water‐to‐cement ratio: Absorption/desorption kinetics of superabsorbent polymer

AbstractInternal curing by superabsorbent polymer (SAP) is an effective method to mitigate the autogenous shrinkage of cement‐based materials with low water‐to‐cement ratio (w/c). In this study, the water absorption/desorption kinetics of SAP were studied quantitatively in blended cement pastes with ultra‐low w/c. An absorption process at a rate of 0 to 6 g/(g h) was calculated at early ages. After that, SAPs showed mainly two distinct water desorption behaviors with a rate of 0 to 1.1 g/(g h), which was mainly governed by the osmotic pressure and capillary pressure triggered by the drop of internal relative humidity (IRH). The size and amount of SAP played a predominant role in controlling its absorption and desorption kinetics in the cement paste. Compared with ordinary Portland cement, a different desorption process with a higher release rate was noticed in binary and ternary cement pastes, primarily due to the changes in osmotic pressure resulting from the acceleration of cement hydration by silica fume at early ages. Overall, the mitigation of autogenous shrinkage is found to be highly dependent on SAP's absorption and desorption kinetics.

Early age shrinkage phenomena of 3D printed cementitious materials with superabsorbent polymers

3D printing of cementitious materials is a novel construction method, capable of producing complex geometries without the use of expensive formwork. However, due to the lack of molding, additional shrinkage will be induced and the risk of crack formation will increase. As cracks introduce ingress paths for chemical substances, it will harm the durability of the printed element. One potential way to tackle this disadvantage is by including superabsorbent polymers (SAPs) in the cementitious material. As these polymers are able to absorb part of the mixing water and to release it during hardening, they induce internal curing and can mitigate self-desiccation, plastic and autogenous shrinkage. Additionally, as drying shrinkage and the related early-age crack formation are major issues in printed structures, the mitigating effect of the SAPs on the latter is also investigated. Three different SAPs (bulk-polymerized monovalent salt polyacrylates with an irregular shape and different size) were used in this research to fabricate printed elements and their influence on the durability and the mechanical properties was correlated with the microstructural changes. First results showed that in general, the addition of superabsorbent polymers mitigates shrinkage in printed materials up to 200%. Inclusion of SAPs also reduced the nanoporosity in the pore size range of 100 nm–500 nm and increase the amount of voids with a diameter above 700 nm, resulting in less microcracks and a decreased amount of preferential ingress paths for chemical substances. On the other hand, the total air content increases with the addition of SAPs, proportional to the amount of SAPs and additional water added, due to the formation of macropores. The addition of SAPs did not seem to have a pronounced influence on the mechanical properties of the printed specimens with a reference water-to-cement ratio of 0.37.

Rheological study of Portland cement pastes modified with superabsorbent polymer and nanosilica

This paper addresses the use of rotational rheometry in determining the rheological parameters (viscosity and yield stress) of cement pastes over time. This study employed Portland cement pastes modified with superabsorbent polymer (SAP) and nanosilica (NS). Nine pastes were tested: one reference paste, two pastes with different amounts of SAP, two pastes with different amounts of NS, and four hybrid mixtures. Flow tests were performed using a parallel plate geometry in a rotational rheometer to determine the viscosity by graphical results and yield stress via the Herschel–Bulkley model. The results show that the flow test is satisfactory for determining the rheological properties, primarily the viscosity. Statistical analysis was performed to quantify the effect of each random variable and their interactions on the rheological properties, providing graphical tools for analyzing the tendencies of the viscosity and yield stress for both additives (SAP and NS). SAP exerted a weak effect on the rheological properties; in contrast, NS caused large changes in both rheological parameters (viscosity and yield stress) in the tested pastes. For pastes containing 2% NS, the presence of SAP caused slight reductions (less than 10%) in the rheological parameters, casting doubt on the absorption of SAP when in contact with mineral additives.

Effects of Super-Absorbent Polymer on Soil Remediation and Crop Growth in Arid and Semi-Arid Areas

The water-retaining and yield-increasing capacity of super-absorbent polymer (SAP) are essential for soil remediation in arid and semi-arid areas. Therefore, it is of great significance to investigate the influencing factors and mechanisms of SAP effects on soil environments and crop growth for the precise management of agricultural water-saving irrigation. In this study, we adopted SAP as a soil conditioner and monitored changes in soil temperature, photosynthetic rate, leaf transpiration rate, chlorophyll, crop growth indexes (plant height, stem diameter, leaf area index, dry matter accumulation), and yield under different SAP doses during the growth stage of maize, on the basis of which the improvement mechanism of SAP in arid and semi-arid soil was analyzed. The results demonstrated the following: (1) 45 kg/hm2 of SAP application could increase the temperature of the soil layer, effectively reduce the diurnal temperature variation of the soil surface, and promote the stable growth of maize; (2) when different SAP doses were applied, the leaf surface temperature of maize increased by 0.95 °C on average. In particular, when 135 kg/hm2 of SAP was applied, the leaf surface temperature increased by 1.55 °C; (3) SAP could promote the photosynthetic rate of maize. In addition, the plant height, leaf area index, and dry matter accumulation of maize gradually increased with an increasing amount of SAP; (4) the application of SAP not only increased the grain row number, ear row number, and average 100-seed weight, but also increased the crop yield by nearly 6%. The application of SAP demonstrated a comprehensive utility (redistribution of soil water and temperature, synergy between SAPs and plants), which suggests that the most basic goal, to ensure socio-economic and ecological sustainability in dryland systems, was obtained.

Multilayer Coatings Using Epoxy and Superabsorbent Polymer Composite Material with Self Healing Property

The property of superabsorbent polymer (SAP) was investigated as component of composite material for corrosion control application. The composite material is a multilayer coating consisting of SAP particles, epoxy and hardener. The absorption property of SAP at different concentrations of sodium chloride was measured. It included 3% NaCl concentration, which represent the concentration of salt in sea water, an environment which is corrosive to carbon steel. Results showed decreasing absorbency of SAP at increasing concentration of sodium chloride. Predetermined amount of SAP and epoxy were mixed to obtain a homogenous mixture after which the hardener was added and mixed homogenously to form the composite material’s main component. The composite material was studied for absorption properties in an HDPLE substrate and then later applied onto a carbon steel specimen of size 40 mm x 100 cm and thickness of 0.70 mm using paint brush forming a film on the carbon steel surface. After curing, the film was scratched with a definite length using a sharp knife. Immediately, the samples were exposed to cyclic immersion in 3% sodium chloride solution and subsequent drying to run the corrosion test. Results showed that the composite material was able to control corrosion on the surface of the carbon steel which could be attributed to its self-healing property.