Effect Of Ethylene Vinyl Acetate Research Articles

Effect of Ethylene-Vinyl Acetate on the properties of Polybutylene Terephthalate/ Ethylene-Vinyl Acetate polymer blends

This research study analyzes the influence of Ethylene-Vinyl Acetate (EVA) resin on the properties of Polybutylene Terephthalate (PBT)/EVA blends produced by injection molding technique. It is based on the fact that a way to recycle PBT from toothbrush bristles is needed. Mechanical samples were made by mixing EVA into PBT with 0, 5, 10, 15, 20, and 25% contents. The samples were tested for flexural strength, impact strength, and hardness according to the standards of ASTM D790, ASTM D256, and ASTM D2240, respectively. The results show that when increasing the EVA content in the PBT/EVA blends, the flexural strength tends to decrease; the hardness fluctuates along a decreasing trend; however, the decrease is not significant. Interestingly, the measured impact resistance results are very positive, especially at the highest increase point, increasing by 40.7% compared to neat PBT. The microstructure results showed a good dispersion of EVA on the PBT substrate, but there was no compatibility between these two polymers. The results of XRD analysis showed that when EVA was mixed, it increased the crystallinity and improved the crystal growth of the blends.

Isolated and combined effects of EVA and TPU custom foot orthoses on constant speed, treadmill running kinematics

Introduction: We investigated the isolated and combined (HYB) effects of ethylene-vinyl acetate (EVA) and expanded thermoplastic polyurethane (TPU) custom foot orthoses (CFOs), compared to a control condition (CON; shoes only), on constant speed, treadmill running kinematics.Methods: Twenty (10 male and 10 female subjects) well-trained runners performed four 6-min bouts at the same individualized speed for each bout on a treadmill under four footwear conditions (EVA, TPU, HYB, and CON). Twenty markers and four clusters (four markers each) were placed on lower limbs and the pelvis. Lower limb and pelvis movements were tracked using a three-dimensional motion capture system with 11 cameras (Vicon MX System, Oxford, United Kingdom). Lower limb joint angles and angular velocity were normalized to 100% of the stance phase.Results: Peak ankle eversion (p < 0.001, η2 = 0.72), peak ankle eversion angular velocity (AV) (p < 0.001, η2 = 0.64), peak ankle inversion AV (p < 0.001, η2 = 0.60), and peak ankle internal rotation AV (p < 0.001, η2 = 0.49) demonstrated the largest differences between conditions. Statistical non-parametric mapping analysis revealed that HYB exhibited the largest proportions of change during the total stance phase compared to the CON.Discussion: All CFO materials caused significant reductions in peak angles and peak AVs at the ankle in the frontal plane, with more pronounced effects for harder (EVA) than softer (TPU) materials. These significant reductions occurred during large portions of the total stance phase for the angles and for the AVs. Although some effects could be found in more proximal joints such as the knee and hip, most significant effects were found at the ankle joint. Overall, combining hard EVA material in the heel and soft TPU in the forefoot (HYB) resulted in significant, more favorable changes compared to the CON that lasted for the largest proportion of stance phase when compared to wearing shoes only.

Laboratory performance evaluation of waste tire rubber (WTR) and ethylene-vinyl acetate (EVA)-modified asphalt mixtures

ABSTRACT This paper aims to explore the performance and economy of asphalt mixture with waste tire rubber (WTR)/ethylene-vinyl acetate (EVA) compound-modified asphalt. In this paper, five kinds of WTR/EVA asphalt mixture were selected as research targets, 70# base asphalt mixture and 5% styrene–butadiene–styrene (SBS) asphalt mixture were compared. Laboratory test results showed that WTR and EVA could significantly improve the performance of the asphalt mixture. The rutting resistance and anti-ageing ability of 15%WTR + 4%EVA asphalt mixture were superior to the 5% SBS asphalt mixture, and the anti-cracking ability and water stability were extremely close between them. Furthermore, the analysis of variance results revealed that WTR and EVA had a significant effect on asphalt mixture performance, the effect of EVA was more obvious than WTR. According to the economy analysis, the application of WTR/EVA-modified asphalt could significantly reduce construction costs, the material cost of 15%WTR + 4%EVA asphalt mixture was about 9.3% lower than 5% SBS asphalt mixture. As summarised above, WTR/EVA compound-modified asphalt mixture was an economical and environmentally pavement construction material due to its superior performance and lower cost, and 15%WTR + 4%EVA was the optimal combination dosage for asphalt mixture.

Effect of ethylene vinyl acetate on cement mortar – A review

Mortar is a mixture of sand, a binder and water. It is used as a paste, which hardens and fuses the masonry components used in the construction, such as stones, bricks or concrete. Polymers have been incorporated in Portland cement as property enhancers for a while. Since then, polymers have been used to improve the water retention, permeability, adhesive strength, workability and deformability of mortars and concretes. Cement concrete structures’ bearing capacity and durability are adversely affected by the brittleness of the cement material, which makes it simple to break under the influence of an external force. Various mechanical and physical properties of cement-based materials can be improved by using polymers, which have good elastic deformation capabilities, acid and alkali corrosion resistance, flexibility and compatibility with cement materials. Ethylene and vinyl acetate are copolymerized to form EVA or ethylene vinyl acetate. Excellent flex-crack and puncture resistance, a wide range of polar and nonporous substrate adhesion, and good hot-tack performance are just a few of the appealing qualities of EVA. The majority of research has demonstrated a beneficial effect of EVA on mortar performance. Foam rubber or Expanded rubber are the other popular names of EVA. EVA copolymers are adhesives that are utilised in packaging, bookbinding, and textile, for bonding plastic films, coated paper, and metal surfaces. The effectiveness of the EVA-modified mortar is examined in this paper. According to studies, the EVA-modified mortar's interface performance significantly increased as EVA was added to the mortar. While Scanning electron microscope studies were conducted for analysing the internal structure of EVA-added mortar, it was discovered that the EVA-cement composite had a three-dimensional net structure. Consequently, the mortar's cohesive strength rose. Also, Samples incorporated with EVA polymer waste had shown the ability of noise insulation. Incorporating EVA with CaO showed a positive effect on mortar performance. The risk of cracking was reduced in EVA-incorporated mortar. Thus, reviewing all the research papers it was found that the addition of EVA can considerably enhance the mortar’s physical as well as mechanical properties.

Investigation on effect of EVA on properties of desert sand-based permeable materials

This paper aims at studying the effect of adding ethylene vinyl acetate (EVA) emulsion on the properties of desert sand-based permeable materials and explore the modification effect and mechanism of polymers. EVA emulsion can improve the fluidity of the slurry, and significantly improve the compressive strength, water permeability and freezing resistance at 10 % content. The EVA emulsion cured film is adsorbed on the surface of anhydrous cement particles. At the same time, the ester group in emulsion reacts with Ca2+ following hydrolysis, which inhibits the early hydration process of cement and reduces the early heat release. However, it has a non-significant impact on the later-age hydration and ensures the strength development of cement at the later stage. The emulsion can affect the pore structure of the material and can significantly increase the micropores content at 10 % content. The physical and chemical actions of polymer together influence the hydration process of cement and improve the bonding between desert sand and cement paste.

Effect of EVA Polymer and PVA Fiber on the Mechanical Properties of Ultra-High Performance Engineered Cementitious Composites

In order to study the mechanical properties of ultra-high performance engineered cementitious composites (UHP-ECC) used for cable channel repair, orthogonal tests were carried out with four influencing factors, water binder ratio, silica fume, fly ash and mortar ratio, to obtain the optimum mix ratio of the cement paste. On this basis, the effects of ethylene-vinyl acetate (EVA) polymer and polyvinyl alcohol (PVA) fiber on the fluidity, flexural strength and compressive strength of UHP-ECC were studied, and the micromechanism was analyzed with SEM. The results show that the fluidity of UHP-ECC material prepared was 170-200 mm, which meets the requirements of working performance. The average compressive strength at 28 days reached 85.3 MPa, and the average flexural strength at 28 days reached 22.3 MPa. EVA polymer has a fast film forming rate in an alkaline environment. The formed polymer film wraps the fiber, enhances the bridging role between the fiber and the matrix and increases the viscosity of the material. Therefore, the early flexural strength is significantly improved. The 1-d flexural strength of UHP-ECC material mixed with 9-mm fiber is increased by 18%, and the 1-d flexural strength of 3-mm fiber is increased by 15%. Due to PVA fiber's high elastic modulus and tensile strength, it improved the flexural and tensile properties of the material after incorporation, especially in the later stages; the 28-d flexural strength of UHP-ECC material mixed with 9-mm fiber increased by 12%, and the 28-d flexural strength of 3-mm fiber increased by 7%. It was concluded that the effect of 9-mm PVA fiber is better than that of 3 mm PVA fiber.

STUDY OF THE CYTOTOXIC EFFECT OF ORTHOPEDIC MATERIALS BASED ON ETHYLENE-VINYL ACETATE ON CELL CULTURES

Measuring the potentially adverse effects of materials on the human body is vital and essential for their use, including medical applications. One of the properties that need to be known is the cytotoxic effect of the materials to avoid local and systemic adverse effects. It is very important that scientists and medical professionals are aware of the effects of materials on the human body. This study also summarizes the data on the morphology, chemical composition, and the effect of ethylene-vinyl acetate (EVA) orthopaedic materials on cytotoxicity. Qualitative and quantitative cytotoxicity analysis was performed using fluorescent microscopy and metabolic cell toxicity assay. The results of the studies demonstrated low in vitro cytotoxicity and high biocompatibility. These results may serve as the basis for a toxicological study of orthopaedic materials to prevent severe side effects.

Estimate of the Effect of Ethylene Vinyl Acetate on Technological and Deformation Properties of Silane-Based Cross-Linked Polyethylene

Estimate of the Effect of Ethylene Vinyl Acetate on Technological and Deformation Properties of Silane-Based Cross-Linked Polyethylene

Insights into Flow Improving for Waxy Crude Oil Doped with EVA/SiO2 Nanohybrids.

Nanohybrid materials can significantly inhibit wax deposition and improve the fluidity of crude oil. However, the mechanisms behind wax resolving, crystal modification, and flow improving are still unclear owing to the complexity of crude oil. Here, we compared the effect of ethylene vinyl acetate (EVA) and nanohybrids composed of EVA and SiO2 nanoparticles on wax crystallization and rheological behavior of Shengli waxy oil. Differential scanning calorimetry results indicate that SiO2 nanoparticles boost the efficiency of EVA for reducing the wax appearance temperature of waxy crude oil. Thermo X-ray diffraction characterization demonstrates that EVA/SiO2 nanohybrids cut down the crystal index of waxes, with the grain size of crystal cells decreased in (006) and (200) but increased in (110) cross sections. Polarized optical microscopy imaging reveals that EVA can modify the morphology of wax crystals to suppress the formation of wax gel, and nanohybrids serve as nucleuses to adsorb asphaltenes and resins, restraining the appearance of wax crystals. The rheological test shows that nanohybrids outperform EVA in decreasing the viscosity, inflection point, and yield stress of waxy crude oil. These findings help the understanding of flow improving by nanohybrid materials and offer guidelines for designing the new generation of wax inhibitors for safe transportation and flow assurance of waxy crude oil.

Experimental and theoretical behavior of cementitious plates containing ethylene vinyl acetate reinforced with glass woven fabric under impact load

Abstract The paper is an analysis of the experimental and theoretical behavior of cementitious plate containing waste ethylene vinyl acetate (EVA) with and without reinforcement with glass fiber woven fabric (GFRP) under low-velocity impact load effect. Cementitious plates of 150 mm × 150 mm size and three different thicknesses (15 mm, 30 mm, 50 mm) are produced by replacing the cement mixture aggregate with EVA at 0%, 18%, 32%, 45%, and 56% by volume of aggregate. Then, the cementitious plates are coated with GFRP using vacuum infusion method. The effect of EVA and GRFP coatings on the dynamic impact behavior of cementitious plates is investigated by applying a low-velocity impact test on the produced cementitious plates with an impactor of 18 mm diameter, 10.50 kg weight, and 500 mm height. The data obtained from the experimental results are analyzed based on the mass-plate theory, lightweight (LWC) and normal weight (NWC) concrete, and the consistency of the theoretical results with the experimental results is compared. It has been determined that the use of NWC is more suitable for cementitious plates with an EVA replacement rate in the range of 0–32%, while the use of LWC offers more optimum results if the EVA ratio is in the range of 32–56%. Especially when the EVA displacement exceeds 32%, it causes excessive void formation in the structure, resulting in a reduction in the dynamic impact loads of cementitious plates. GFRP coating with vacuum infusion method is not recommended for cementitious plate structures when the EVA replacement rate exceeds 32% by volume of aggregate.

Study on Effect of inhibitor on wax precipitation in Iranian oil fields by using differential scanning calorimetry and microscopy

In this study, effect of ethylene vinyl acetate (EVA) as an inhibitor on wax appearance temperature (WAT) of crude oil in the Iranian oil field has been investigated using differential scanning calorimetry (DSC) method. The effect of EVA on the morphology of crude oil wax crystals has been investigated using a system designed to be equipped with an ocular microscope. The EVA inhibitor has a very good performance in reducing the Wax appearance temperature of crude oil and by adsorbing on the growing wax crystals, it prevents the crystallization process and also their connection to each other to form a network structure. By 800 ppm of the EVA inhibitor, the largest decrease occurred in the WAT of crude oil (at the rate of 26.13 ° C) and also smaller crystals and weaker structures were formed at this concentration. Therefore, 800 ppm of EVA inhibitor was selected as an optimal value

Effect of EVA copolymer containing different VA content on the thermal and rheological properties of bio-based high-density polyethylene/ethylene vinyl acetate blends

The effect of ethylene vinyl acetate (EVA) concentration and vinyl acetate (VA) content of EVA on the mechanical, morphological, and rheological properties of bio-based high-density polyethylene (BioPE)/EVA blends was investigated. The blends were characterized by X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and rheological measurements under oscillatory shear flow. The degree of crystallinity of BioPE decreased with the increase in the EVA concentration and was unaffected with the increase in the VA content. DMTA results showed a decrease in the storage modulus (E′) with the increase in EVA content and that the BioPE/EVA19 blends showed higher E′ values than BioPE/EVA28 blend. The impact strength substantially increased with the addition of EVA concentration above 5 mass% and was higher for the blends containing the highest VA content. The blends containing a higher content of VA exhibited the higher EVA dispersed phase domain size, which increased with the increase in EVA concentration. The complex viscosity increased with the increase in the EVA content, being higher for the BioPE/EVA blends containing higher VA content. The storage modulus increased, at low frequencies, with the increase in the EVA content and can be ascribed to the increase in the EVA dispersed phase domain size.

Effect of Ethylene-Vinyl Acetate Copolymer/Amino-Functionalized Polymethylsilsesquioxane Composite Wax Inhibitor on the Rheological and Wax Depositing Characteristics of Waxy Crude Oil

In this paper, a novel ethylene-vinyl acetate copolymer (EVA)/amino-functionalized polymethylsilsesquioxane (PAMSQ) composite wax inhibitor (WI) was prepared through melt blending, and the rheological and wax depositing properties of the doped crude oil were studied. The EVA/PAMSQ composite can strongly crystallize with wax molecules and trigger the formation of compact wax flocs, which greatly improve the rheological properties of crude: compared to the pure EVA at the same dosage, the composite can further decrease the gel point and apparent viscosity (25 °C) by 14.6 °C and 92.0%, respectively. The wax deposition can also be inhibited by adding the composite: adding EVA inhibits the mass of the wax deposit at 24 h by 62.3%, and this number is suppressed by 77.9% after adding the EVA/PAMSQ composite, but the wax molecule diffusion is accelerated and the wax content in the wax deposit rises because of the improved crude oil rheological characteristics. Here, we develop the gel structure theory to consider the wax deposition process affected by the WI. Adding the WI contributes little to the wax precipitation temperature but decreases the gel structural strength of the oil a lot, and thus, the oil near the pipe wall can only form the wax deposit with a higher wax content to resist the pipe wall shearing. Therefore, the crude oil added EVA/PAMSQ composite possesses not only the lowest wax deposit rate and the highest aging rate but also the highest wax content in the wax deposit.

Rheological and Spectroscopic Properties of Ethylene Vinyl Acetate–Modified Rubberized Asphalt

AbstractThe effect of ethylene vinyl acetate (EVA) on the aging properties and rheological properties of rubberized asphalt was measured in this paper to identify the optimum proportion of EVA comb...

Performance of Subgrade Soil Blended with Cement and Ethylene Vinyl Acetate

To improve the essential properties of soil, stabilization proved to be more significant in overcoming the limitations of the desired soil. The improvement of soil properties will not only enhance the mechanical properties rather it will help in preventing dust and erosion formation. In this study, a set of tests are carried out to examine the strength characteristics of subgrade soil blended with ethylene vinyl acetate (EVA) and cement. EVA contributes almost 14% mass to the global waste, requiring bigger lands for its disposal; therefore, in order to promote a green environment and to bring an economical waste management system, an investigation of using EVA in the soil stabilization techniques is attempted. Soil specimens are investigated with and without the inclusion of EVA and cement. For this purpose, EVA was mixed with soil at a percentage level of 3, 6, and 9% whereas the cement was mixed at a percentage level of 4, 6, and 8%. To examine the combined effects of EVA and cement, the specimens were tested for compaction, direct shear, unconfined compression, triaxial, XRD, porosity, and permeability tests. All the soil samples were cured at 7, 14, and 28 days followed by the standard testing procedure. When cement was added to soil up to 4, 6, and 8% at a constant level of EVA (9%), cohesion was increased by 37, 42, and 46% while the unconfined compressive strength (UCS) was increased by 76, 81, and 84% for the same mixes. From the statistics, it clearly evident that the percentage increase caused by the addition of even 3% EVA to the cemented and uncemented soil specimens is very significant regarding cohesion and compressive strength. Porosity and permeability of soil containing both EVA (9%) and cement (8%) were decreased by 37% and 77%, respectively.

Influences of EVA and methylcellulose on mechanical properties of Portland cement-calcium aluminate cement-gypsum ternary repair mortar

Portland cement–calcium aluminate cement–gypsum ternary repair mortar has the problems of poor toughness, low flexural strength and later strength retrogression in the process of road repair. The effects of ethylene-vinyl acetate (EVA) copolymer and methylcellulose on the mechanical properties of Portland cement–calcium aluminate cement–gypsum ternary repair mortar were investigated. The flexural strength of mortar increases with increasing content of EVA powder by less than 1.5% and the modified mortar with 1.5% EVA has better toughness but the late strength did not grow or was even lower than early strength. The combination of EVA and methylcellulose can effectively improve the flexural and compressive strengths and ensure the development of late strength. The acetic group of EVA copolymer consumes calcium hydroxide to produce calcium acetate under the basic condition, thus forming fine ettringite (AFt) crystal, which can improve the flexural strength with the filling effect of EVA particles. The methylcellulose has good water retention ability, which improves the stability of AFt and thus ensures the late strength. The combined addition of EVA and methylcellulose into the ternary system can improve the stability of AFt, optimize the crystal morphology of AFt, and increase the compressive strength and flexural strength, so as to ensure the development of strength in the later stage.

Investigation of Fresh and Hardened Characteristics of Self-Compacting Concrete with the Incorporation of Ethylene Vinyl Acetate and Steel-Making Slag

Advancement in the construction industry causes decline in the availability of natural resources, and this decline can be overcome by utilization of the available raw materials. This study is focused on the combined effects of ethylene vinyl acetate (EVA) and ladle furnace slag (LFS) on fresh and hardened characteristics of self-compacting concrete (SCC) by replacing some fraction of cement and sand. The characteristics of SCC in its fresh state are investigated by workability, while hardened characteristics are investigated by elastic modulus and compressive, tensile, and flexural strength. The findings showed that the workability is enhanced by the incorporation of EVA, while decreased with LFS. Furthermore, all the strength properties were enhanced at all the replacement levels of EVA and LFS except for the splitting tensile strength. The utmost gain in elastic modulus and compressive, tensile, and flexural strength was up to 18, 20, 10, and 15% more by increasing the dosage of LFS while keeping EVA constant.

Rheology, Mechanical Properties and Morphology of Poly(lactic acid)/Ethylene Vinyl Acetate Blends

In this work, the effect of ethylene vinyl acetate (EVA) content on the rheology, mechanical properties, and morphology of poly (lactic acid) (PLA)/EVA blends was investigated. Differential Scanning Calorimetry (DSC) showed that the addition of EVA to PLA decreased the degree of crystallinity of PLA. Dynamic Mechanical Thermal Analysis (DMTA) results showed that the presence of EVA copolymer increased the cold crystallization temperature (Tcc) of PLA. The addition of 10% of EVA to PLA substantially increased the impact strength. Morphology analysis by Scanning Electron Microscopy (SEM) indicated the immiscibility between PLA and EVA phases and an in increase the EVA average dispersed phase domains size with the increase in EVA content. Rheological measurements under oscillatory shear flow showed that storage modulus (G′) increased with the increase in the EVA content at low frequencies and is related to the increase in the EVA dispersed phase domains size, as also observed by relaxation spectrum analysis. Cole–Cole plots of imaginary viscosity (η″) versus real viscosity (η′) and Han plots of storage modulus (G′) versus loss modulus (G″) indicated that PLA and EVA phases are immiscible, as also observed by SEM.

Influences of ethylene-vinyl acetate and methylcellulose on the properties of calcium sulfoaluminate cement

Calcium sulfoaluminate (CSA) cement is widely used in architecture engineering and emergency repairs. However, it still exhibits several disadvantages, such as low flexural strength and strength regression during the late curing age. Ethylene-vinyl acetate (EVA) copolymer is useful in improving the flexural strength of Portland cement. Methylcellulose can improve the water retention properties of cement-based materials to ensure homogeneity during hydration and to improve the stability of hydration products. The effects of EVA and methylcellulose on the setting time, strength, and pore structure of CSA cement mortar were investigated in this study. Both polymers evidently prolong setting time and enhance flexural strength, but decrease compressive strength. The regression of strength after 7 days of curing was well controlled using methylcellulose. The hydrates and mechanism of the polymer-modified CSA cement were investigated via X-ray diffraction analysis and scanning electron microscopy.

Effect of Ethylene Vinyl Acetate (EVA) on the Setting Time of Cement at Different Temperatures as well as on the Mechanical Strength of Concrete

This study presents the effect of ethylene vinyl acetate (EVA) on the setting time of cement at different temperatures as well as on the compressive, flexural and tensile strength of concrete. Setting time tests were conducted at various percentages of EVA at different temperatures (i-e 22, 35 and $$50\,^{\circ }\hbox {C}$$ ). It was found that the setting time was increasing with an increase in the EVA percentage. Moreover, for strength evaluation, samples of EVA-modified concrete were prepared with various percentages of EVA by weight of cement and then tested for compressive, flexural and tensile strength at the curing age of 3, 7 and 28 days. The results revealed that the compressive and flexural strength of EVA-modified concrete tended to increase at a rapid rate by incorporating EVA up to 16%, but beyond this percentage the rate of strength development become slow at all the ages, but in case of split tensile strength, it was maximum at 4% EVA and got decreased with further increase in EVA percentage.