Total Immersion Tests Research Articles

Analysis of wetability properties for kraft paper and corrugated cardboard

Corrugated cardboard and kraft paper are widely used in the packaging industry, providing versatility of use and protection for products. The analysis of the wettability properties of these materials is extremely important, as it allows us to understand how they react to humidity. This research aimed to study the wettability properties of corrugated paper (PO) and kraft paper in order to expand knowledge about the quality of packaging produced with them. The study was conducted in the laboratory using corrugated cardboard (PO) with waves of type "A", "B", "C" "E" and kraft paper obtained from coils with and without coating. The wettability tests performed were total immersion, absorption time and drop penetration method. The collected data was interpreted using descriptive and graphical analysis generated by the R program. The research concluded that for the total immersion test, both materials absorbed more water in the vertical position. In the droplet absorption and penetration time tests, cardboards with type “E” waves showed the highest results when compared to other materials, providing a superior barrier for products that will be transported in boxes of this type. Furthermore, the coated Kraft paper also demonstrated good performance for drop penetration testing, confirming the coating's effectiveness as a moisture barrier.

Development of anticorrosive self-adhesives from post-consumer poly(ethylene terephthalate) bottles for industrial applications

Corrosion is a spontaneous process that can result in both aesthetic and structural damage, incurring significant costs. One of the most commonly employed methods for mitigating the effects of corrosion is the application of organic coatings. However, no coating is precluded from potential damage, whether due to factors such as end-of-life degradation, inadequate application, poor quality, or impact-related incidents. Within this context, the primary objective of this study is to develop a novel and easy to apply anticorrosive adhesive for carbon steel surfaces from post-consumer poly(ethylene terephthalate) (PET) bottles as a temporary coating. PET films were produced by phase inversion technique, which involves the dissolution of PET bottles in a mixture of trifluoroacetic acid (TFA) and dichloromethane (DCM) solvents, followed by precipitation in a non-solvent bath. The resulting films were utilized as backing materials in the production of self-adhesive tapes with anticorrosive properties. Two different solvent proportions were selected to assess the feasibility of this technique, which are 70/30 and 50/50 (TFA/DCM v/v). For each condition, scanning electron microscopy, Fourier transform infrared spectroscopy, thermal analysis, immersion tests in NaCl aqueous solution 3.5 wt%, and electrochemical impedance spectroscopy were performed. Experimental results revealed that the utilization of a solvent system with a higher concentration of DCM produces a more cohesive and denser film, leading to improved outcomes in both total immersion and electrochemical impedance spectroscopy tests. The impedance modulus value obtained after 168 h of immersion in an aqueous solution of NaCl 3.5 wt% for 50/50 TFA/DCM film was 106 Ω·cm2, with no corrosion product observed on the protected area. Furthermore, thermal and infrared analyzes demonstrated that there is no change in PET chemical and thermal properties after inversion phase process.

Historical and Physicochemical Analysis of the Clinker Bricks in the Smart Memorial Gymnasium of the Tiancizhuang Campus at Soochow University, China

Clinker bricks were popular as a facade material in the United States between the 1890s and the 1930s. However, this material was unknown to Chinese builders and was seldom found in Chinese modern architecture from 1840 to 1949. The Smart Memorial Gymnasium built in the years 1934–1937 in the Tiancizhuang Campus of Soochow University (Suzhou, China) is one of the rare examples of a building featuring clinker bricks in modern China. Notably, those clinker bricks were not imported but locally manufactured. Despite the heritage significance of the Smart Memorial Gymnasium as part of a major historical and cultural site protected at the national level in China, the history and characteristics of those historical bricks have remained virtually unexplored. This study first provides a historical analysis of those bricks, giving insights into the general knowledge of this construction material around that time based on British and American historical sources from the 19th and 20th centuries, with a focus on historical treaties and documents. This analysis sheds light on the raw materials mixtures of clinker bricks, their manufacturing processes, and their architectural applications at the time. Moreover, this study presents a physicochemical analysis of the clinker bricks employed at Soochow University, focusing on the correlation between historical studies and physicochemical characteristics, as well as the materials’ characteristics that respond to the natural environment. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and total immersion tests were employed to investigate the physicochemical properties of the bricks at various locations of the Smart Memorial Gymnasium facades. Our findings deepen the knowledge and understanding of clinker bricks transferred from the West to China in the early 20th century. Additionally, our results reveal the chemical composition and physical characteristics of different types of clinker bricks used in the Smart Memorial Gymnasium, outlining practical implications and future research directions. Overall, this study lays a foundation for the heritage recognition and conservation of Chinese clinker bricks.

Accelerated ageing tests of sodium chloride for the evaluation of stones durability to salt crystallization: A comparative study of selected restoration lithotypes

This work presents the assessment of the susceptibility of five different lithotypes to salt crystallization decay, after the application of accelerated ageing tests of NaCl solution by total immersion, and duration of 60 days. Particularly, four different biocalcarenites (Rhodes Greece, Spain and Cyprus), and a calcitic sandstone (Achaia Greece) are investigated. Their durability to salt decay is evaluated by performing mass change measurements, total immersion tests, and the non-destructive techniques of Digital Microscopy, Ultrasound Pulse Velocity, and Colorimetry. It is demonstrated that the Cyprus biocalcarenite, followed by the calcitic sandstone, exhibit the lowest durability to NaCl crystallization decay among the investigated lithotypes. Finally, considering the results of this study with previously published data, it can be concluded that pore size distribution and in particularly the percentage of the pores with radii above 10 μm plays a key role in the susceptibility that the investigated lithotypes exhibit to NaCl crystallization damage.

Evaluating the Corrosion Behaviour of Borided Carbon Steel C35

In this work, an evaluation of corrosion resistance of boride layers formed on carbon steel C35 in different solutions of H2SO4, HCl, HNO3, NaCl and NaOH was carried out. Boriding treatment was applied on C35 carbon steel using Ekabor powder at 950 °C for 4 h. The corrosion behaviour was analyzed by the weight loss method after total immersion tests in different solutions at variable times from 24 hours to 6 months. The corrosion rate has been determined by electrochemical method using the polarization curves. Results obtained show that boriding treatment improved significantly the corrosion resistance of C35 steel in some acidic environments. The corrosion resistance of boride C35 steel is higher compared with that of untreated C35 steel, and the corrosion potentials Ecor of boride C35 steel are more electropositive than those of untreated C35 steel in some solutions.

Health risk assessment of dietary exposure to phthalates from plastic-coated paper among university students

Plastic-coated paper (PCP) is commonly used as a takeaway food container in Thailand. This study aimed to investigate the phthalate content in PCP and to evaluate the health risk of dietary exposure to phthalates. Determination of phthalates, namely, of benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), was carried out using a simple total immersion test followed by gas chromatography-mass spectrometry (GC-MS). Consumption data of 430 students in a university were collected by a questionnaire for health risk assessment. The results showed that DEHP was the most abundant compound detected in the PCP samples, followed by DBP and BBP, respectively. The hazard indexes (<1) showed that the health risk to all subjects was acceptable, but monitoring of phthalates in PCP on market shelves should be performed regularly to protect consumers’ health.

Corrosion Behavior of Super Austenitic Stainless Steel 904L Weldment in Sulfuric Acid Media Used for Leaching Application

This article reports the corrosion behavior of 904L weldment in sulfuric acid as a strong corrosive media. The corrosion behavior was studied by total immersion tests and potentidynamic polarization test. Total immersion test has been conducted at different acid concentrations typically: 1, 2, 4, 6, 8 and 18.4 M at 25°C. The effect of temperature (25- 100°C) on the weight loss measurements of the alloy samples was followed in the 4 M acid solution. On the other hand, potentiodynamic polarization tests were conducted in 2,5, 8 and 18.4 M H2SO4solution. The potentiodynamic polarization test was also conducted in the practically used leaching medium (2 M H2SO4+ 10% monazite).Results show that the weight loss increases with the increase of acid concentration and reaches its maximum at 4 M H2SO4and then gradually decreases. Meanwhile, the rise in temperatures results in the increase of weight loss. Potentiodynamic polarization tests indicate that the 5 M acid solution gives the highest corrosion rate of 0.6399 mm/Y. The leaching medium shows relatively higher corrosion rate (0.124 mm/y) than the corresponding 2 M H2SO4 without monazite (0.01712 mm/y).

The Effect of Fire on Building Materials: The Case-Study of the Varnakova Monastery Cells in Central Greece

The evaluation of the fire impact on building materials is of great scientific and socio-economic importance since fire can result in materials’ chemical and mechanical alterations, which leads to structural stability problems of historical and/or modern construction. This highly increases the cost of rehabilitation interventions. The case study of the Byzantine Monastery of Panagia (Virgin Mary) Varnakova is an example of the fire effect on both historical and newer stone masonries. The Varnakova Monastery is a typical 19th century monastic complex and, during its long history, it has undergone multiple reconstructions after major catastrophic events that have taken place due to its strategic geographical position and its financial and spiritual significance for the region. The last big-scale renovation of the Monastery was conducted between the years 1992 to 2014. However, in January 2017, a devastating fire destroyed the largest part of the monastic cells’ quarter. In this work, a diagnostic study of the different construction phases’ materials comprising the masonries of the monastery cells in their present state is presented. The examination of a series of samples through analytical techniques, such as optical microscopy, X-ray diffraction, thermal analysis, and total immersion tests, along with the use of non-destructive techniques in situ, such as Infra Red Thermography, Digital Microscopy, and Schmidt Hammer Rebound tests, shed light on the preservation state and on the decay of the diverse building materials. In addition, the impact of the fire on their properties was investigated. The results reveal the diversity of the materials used in the historical masonries throughout the centuries, while the combination of analytical and non-destructive techniques demonstrates the damages induced by the fire.

Enhancing the Corrosion Inhibition Behaviour of Epoxidized Natural Rubber-Polyaniline Dodecylbenzenesulfonate Blend via the Incorporation of WO3

Electrically-conductive (in the region of 10−3 S.cm−1) epoxidized natural rubber-polyaniline dodecylbenzenesulfonate [ENR-PAni.DBSA] blend was prepared, and the effect of incorporation of WO3 on its corrosion inhibition behaviour for carbon steel was assessed for the first time. It was found that the electrical conductivity of this blend could be enhanced by up to an order of magnitude for WO3 loadings of 20.0–22.5 wt.%. From both total immersion and electrochemical corrosion tests, ENR-PAni.DBSA blends with 20.0–22.5 wt.% of WO3 were found to be the best corrosion inhibitors for carbon steel, in both acid and artificial brine environments. However, a blend containing a higher WO3 content (i.e. 25.0 wt.%) showed a significant poorer corrosion inhibition behaviour for carbon steel due to its more severe phase separation and porosity between the ENR host matrix and WO3.

Corrosion resistance and molecular dynamics behavior of the MAO/SAM composite coatings on magnesium alloy

To improve corrosion resistance of magnesium alloy AZ91D, y-Mercaptopropyltrimethoxysilane (MPTS) was assembled on the surface of micro-arc oxidation (MAO) treated magnesium alloy by self-assembly membrane (SAM) technique. The surface morphology and chemical components of the MAO/SAM composite coatings were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The corrosion resistance of samples was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy and total immersion tests in a 3.5 wt % NaCl solution. The measured EIS data were simulated by an equivalent circuit. Also the molecular dynamic simulation was used to study the adsorption behavior at the molecular level. The results showed that the surface of magnesium alloy was well covered by the MAO/SAM composite coatings with a better corrosion resistance. Chemical adsorption was formed between the organic molecules and the surface of the MAO coating. The approach presented here afforded an effective alternative for surface modification of magnesium-based materials to meet the many aspects of the application requirements.

Investigating Pitting Corrosion of Stainless Steel and Aluminium Using Scanning Vibrating Electrode Techniques and Electrochemical Noise Measurement

In this study, the susceptibility of aluminium (Al) and steel SS304 to pitting corrosion in FeCl3 and NaCl solutions with varying pH values were investigated using electrochemical noise (ECN) measurement and Scanning Vibrating Electrode Technique (SVET). Preliminary surface drop test of SS304 in FeCl3 solution and total immersion test of Al in NaCl solution indicated higher pitting of samples at scratches simulated by scribe. Total immersion test on both SS304 and Al indicated that protecting a sample with epoxy-resin mold does not completely eliminate crevice attack. ECN tests results showed that Al suffered severe time-variant corrosion in FeCl3 solution unlike SS304. The results of SVET tests conducted after 24h immersion indicated that the early pits captured on Al samples were more intense than the later ones. Higher corrosion rates were obtained for samples in NaCl solution of pH 2.89 compared to pH 7.21, indicating that pitting increased with acidity. SVET maps obtained corroborated Scanning Electron Microscopy (SEM) images of the sampled surfaces. However, though SVET was unable to capture pitting of SS304 in the solutions, SEM image revealed pitting activity on the sample in FeCl3 solution.

CORROSION-INHIBITING BEHAVIOR OF EPOXIDIZED NATURAL RUBBER–POLYANILINE DODECYLBENZENESULFONATE (ENR-PANI.DBSA) BLENDS

ABSTRACT Electrically conductive (up to 10−1 S cm−1) ENR-PAni.DBSA blends were produced, and their corrosion-inhibiting behaviors for carbon steel were successfully investigated. As observed from both total immersion and electrochemical corrosion tests, ENR-PAni.DBSA blends consisted of very low and very high PAni.DBSA contents (i.e., ≤5.0 wt% and ≥40.0 wt%) and showed poor corrosion-inhibiting behavior for carbon steel, either in acid or artificial brine environment. Meanwhile, blends with 10.0 to 30.0 wt% of PAni.DBSA content exhibited the best corrosion-inhibiting behavior for carbon steel.

Evaluation of Vulcanized Elastomeric Composites after Ageing in Biodiesel

The incorporation of biodiesel in the worldwide energetic matrix has an increasing tendency to use in the world. However, there are many technological challenges to consolidate this biofuel as an alternative to fossil fuels. The evaluation of the materials compatibilities used in the automotive industry and biodiesel production chain has been configured as an important area of research in finding appropriate materials that comes into contact with diesel biodiesel/blends. The present work aims to evaluate the physical properties for elastomeric composites prepared with polymeric matrix of ethylene propylene diene monomer (EPDM), acrylonitrile-butadiene rubber (NBR), natural rubber (NR) and styrene-butadiene rubber (SBR). The composites were prepared under controlled conditions of mixing and vulcanization. The elastomeric composites were aged in a blend containing 95 vol% of diesel and 5 vol% of biodiesel (B5 blend). The static total immersion tests were carried out at controlled temperature (50°C) for 7, 14, 21 and 28 days, substituting the B5 blend every 7 days. The results showed that the properties of NBR are less affected than other elastomers. It showed better mechanical performance and less influence on the glass transition temperature, indicating less degradation of this rubber in contact with B5 blend used in immersion tests.

Examination of moisture sensitivity of aggregate–bitumen bonding strength using loose asphalt mixture and physico-chemical surface energy property tests

In this study, the moisture sensitivity of different kinds of aggregates and bituminous binders is examined by comparing the performance between five empirical test methods for loose mixtures – static immersion test, rolling bottle test (RBT), boiling water test (BWT), total water immersion test and the ultrasonic method – with more fundamental surface energy-based test data. The RBT and BWT results showed that limestone aggregates perform better than granite aggregates and that, for unmodified binders, stiffer binders provide better moisture resistance compared with softer binder. Both tests were sensitive to aggregate type, binder type and anti-stripping agent type. Ranking of the mixtures by RBT and BWT was in general agreement with the surface energy-based tests, especially for mixtures that performed worst or best in RBT and BWT. The magnitude of the work of debonding in the presence of water was found to be aggregate type dependent which suggests the physico-chemical properties of aggregates may play a fundamental and more significant role in the generation of moisture damage, than bitumen properties.

Is sheer thenardite attack impotent compared with cyclic conversion of thenardite–mirabilite mechanism in laboratory simulation tests?

The precipitation of mirabilite during the wetting stage of a cyclic total immersion test has widely been implicated as the main damage mechanism of sodium sulfate. We, however, hypothesized that the damage contribution from thenardite cannot be discounted in laboratory tests. To verify the supposition, a series of laboratory experiments was undertaken by subjecting three types of rocks to the sodium sulfate attack. To unambiguously demonstrate the potency of thenardite, in addition to cyclic total immersion tests, continuous partial immersion tests were also performed under different environmental conditions, which allowed either sheer thenardite precipitation or reversible thenardite–mirabilite conversion. Although rock breakdown occurred only during immersion, the results clearly indicated that thenardite alone could induce significant damage in both cyclic total immersion and continuous partial immersion tests. In most cases, tests that involved mirabilite precipitation, however, were more destructive than sheer thenardite tests, regardless of the type of salt supply technique. With the same duration and temperature of the immersion stage, the difference in drying temperature influenced the degree of damage, revealing the damage contribution from thenardite even in the tests with cyclic phase conversion. The reason why mirabilite is generally credited to be more destructive than thenardite and the effect of test duration on the damage potency of thenardite are also discussed.

Recycled Poly(Ethylene Terephthalate) Resins as Corrosion Protective Organic Coatings of Steel Pipelines

In this work, modification and application of Poly (ethylene terephthalate) (PET) waste as organic coating were reported. A potential application of PET coating is to provide protection against corrosion in automobile fuel tanks. PET powder was obtained from post-consumer beverage bottles. The corrosion resistance of the coating was evaluated by total and partial immersion tests in gasoline, diesel oil and alcohol. PET waste was depolymerized in the presence of glycols or ethanol amines and manganese acetate as a catalyst. The produced oligoesters were used to prepare epoxy, alkyd, vinyl ester and polyurethane organic coatings. The cured epoxy, alkyd, polyurethane and unsaturated polyester resins were evaluated as corrosion protective coating application of steel. The recent advances in manipulating patterned recycled PET arrays and patents are reviewed with a focus on the progress of the recycled products and applications. Keywords: Recycled PET, corrosion protection, organic coatings, epoxy resins, alkyd resins, flame spray coating, coating characteristics, terephthalic acid, ethylene glycol, alkaline hydrolysis, unsaturated polyesters, lead-tin-coated steel, Powder Coatings, solid polyesters, GLYCOLYZED PET

THE STABILITY, STAINING AND CORROSIVE PROPERTIES OF AN IODINE-NON-IONIC SURFACE-ACTIVE AGENT COMPLEX.

Abstract The stability of concentrated and dilute solutions of an iodine-cetomacrogol complex and the staining of fabrics and the corrosion of metals it produced, have been compared at the same available iodine concentration, with a system based on weak iodine solution B.P. The available iodine content of the complex decreased on storage, but this loss was associated with the production of an equivalent amount of hydrogen iodide, such that the total iodine content of the system remained constant. The reaction was accelerated by an increase in temperature, but was neither a photochemical nor an oxidative decomposition. The complex was not subject to the large losses of solvent which occurred with the potassium iodide-ethanol system, and in dilute solution was generally more stable; both systems being more stable in acid conditions. Dilute solutions of electrolytes, as found in hard waters, had little effect on the stability of either type of dilute solution except where they caused the pH to rise, but potassium salts produced a characteristic precipitation of the complex, which resulted in a loss of available iodine. The technique of testing the permanency of staining indicated that the complex often produced the less permanent stain, but it was not completely devoid of staining properties. The complex was less corrosive towards certain metals when tested by a static total immersion test, but when the attack was severe as with aluminium and copper, there was little difference between the two iodine systems in their corrosive action.

Factors affecting the amount of corroded iron converted into adherent rust in steels submitted to immersion tests

It is usually assumed that α∗, the amount of iron that is converted into adherent rust (AR), in steels exposed to immersion corrosion is a constant independent of time, pollutant concentration, and steel composition. In order to investigate these ideas, we have performed total immersion tests with varying chloride concentration and immersion time in carbon (CS) and weathering steels (WS). The corrosion products were weighted and characterized by XRD, and FT-IR, Raman and Mossbauer spectroscopies. We found that α∗ ranged between 0.30 and 0.72 for CS and between 0.20 and 0.60 for WS.

Study of patina formation on bronze specimens

In this study, bronze samples (94.059% Cu; 0.023% Zn; 0.077% Pb and 5.801% Sn, w/w) were exposed for 8 months to a marine atmosphere (splash zone) at Barra of Tijuca Beach, Rio de Janeiro. X-ray diffraction analysis (XRD) was used to identify the composition of the corrosion products formed on the samples. The electrochemical properties were analyzed using potential and electrochemical impedance measurements. These analyses and measurements were obtained from periodically removed samples, and compared to those exposed to laboratory tests (total and alternating immersion) in 10 −2 mol L −1 NaCl solution. The corrosion potential results, allied to XRD analysis, showed that the chemical nature of the films obtained on the surface of the field test samples was very similar to that obtained in the alternating immersion test. The main products identified were cuprite and atacamite. However, the film formed during the total immersion (TI) test was primarily composed of cuprite with nantokite traces, which was not observed in either the field or in alternating tests. The electrochemical impedance measurements obtained in laboratory and field test samples showed the formation of films with a porous structure. The thermodynamic evaluation was also consistent with the corrosion products formed.

Structural properties of iron phases formed on low alloy steels immersed in sodium chloride-rich solutions

Products of corrosion were obtained from low alloy steels submitted to total immersion tests in solutions containing sodium chloride at different concentrations, during seven days. In order to properly characterize the adherent (AR) and the non-adherent rusts (NAR), a methodology including room temperature Mossbauer spectrometry, diffuse reflectance infrared Fourier transform spectroscopy, Raman spectroscopy, scanning electron microscopy and X-ray diffraction was addressed. The techniques showed that the AR samples were composed of non-stoichiometric magnetite, goethite, akaganeite and lepidocrocite. The composition of the NAR samples was the same, but with very small amounts of magnetite. Different cell parameters and mean crystallite sizes were found for all phases presented in AR and the NAR samples. The corrosion rates were higher than 580 μm/y. The ratio of the abundances of goethite to the sum of lepidocrocite, akaganeite and magnetite were less than one.