Loss Of Tensile Strength Research Articles

Nutritional and sensory evaluation of Moringa oleifera fortified pasta

Present study was undertaken to evaluate the quality of pasta supplemented with different proportion of Moringa powder. Three treatment (T1, T2 and T3) of Pasta were prepared by using rice flour and different proportion of Moringa powder. Control sample containing only 100% Maida. All the treatment was evaluated for the nutritional and sensory quality. In India pasta is used as a fast food and if the nutritional properties of the pasta will be enhanced then it can be easily useful as a regular food. Pasta with ideal sensory and physical quality is characterized by elasticity and strength of the dough, high tensile strength and minimum cooking losses. India is largest producer of Drumsticks with an annual production of 1.1 to 1.3 million tons of tender fruits from an area of 380km 2. Drumsticks are a store house of important and anti-nutrients. All the parts of this tree are useful for Nutritional, Medicinal and Allied purpose. Drumsticks can be an extremely valuable source of various nutrients for people of all ages. Drumsticks is the richest source of Iron, beta carotene, providing micronutrient including protein, vitamin c, folic acid, Zinc and also calcium and potassium (Gopalan, 2000) Drumsticks leaves also contain good amount of Folates, Thiamine, Pyridoxine and Niacin, Antioxidants such as Flavonoids. Drumsticks are full of essential disease preventing nutrients. In India tradition maintains that the nearing tree can cure 300 diseases. The investigation was carried out in the Food Science and Nutrition Department, College of Home Science, CSA U & T, Kanpur. For this study Drumsticks powder has been prepare by sun drying method. Pasta (extruded product) has been prepared from the Drumsticks powder. Each product has three treatments and one control along with three different replications. Prepared product evaluated with sensory evaluation. According to Sensory Evaluation T1 (7.47) were Best in the product of Pasta among the three treatment that is ‘’liked moderately and liked slightly’’. So, the study suggests that drumstick can be used for prepared fortified food products because of its high acceptability and nutritional and medicinal quality.

Decolorization of dark-colored waste cotton fabric using redox decoloring agents.

A huge quantity of dark-colored waste cotton fabrics with a high content of dye powder is dumped in landfills and incinerated, which is a waste of resources and pollutes the land and atmosphere. Also, it is meaningful to effectively strip the color from these dark-colored waste cotton fabrics with minimal damage to the strength of the textiles. In this study, a dark-colored waste cotton fabric dyed with reactive dyes was subjected to chemical treatment with redox decoloring agents. The effects of various treatments on the coloration and mechanical properties of the fabric were compared. This work developed an effective Na2S2O4–H2O2 system for decolorizing waste cotton fabric, with numerous advantages over conventional physicochemical approaches including achieving a CIE whiteness index of 74.1, tensile strength loss of 24.0%, weight loss of 1.2%, decoloration rate of 97.8%, and a degree of polymerization of 735.3. Furthermore, a mechanism was proposed to explain the two-step synergistic decolorization process.

Carbon Source Starvation of a Sulfate-Reducing Bacterium–Elevated MIC Deterioration of Tensile Strength and Strain of X80 Pipeline Steel

It is known that starved sulfate-reducing bacterial biofilms corrode carbon steel more aggressively because they use electrons from elemental iron oxidation as an alternative source of energy. This work used carbon source starvation to vary MIC (microbiologically influenced corrosion) severity for studying subsequent MIC impacts on the degradation of X80 carbon steel mechanical properties. X80 square coupons and dogbone coupons were immersed in ATCC 1249 culture medium (200 ml in 450-ml anaerobic bottles) inoculated with Desulfovibrio vulgaris for 3-day pre-growth and then for an additional 14 days in fresh media with adjusted carbon source levels for starvation testing. After the starvation test, the sessile cell counts (cells/cm2) on the dogbone coupons in the bottles with carbon source levels of 0, 10, 50, and 100% (vs that in the full-strength medium) were 8.1 × 106, 3.2 × 107, 8.3 × 107, and 1.3 × 108, respectively. The pit depths from the X80 dogbone coupons were 1.9 μm (0%), 4.9 μm (10%), 9.1 μm (50%), and 6.4 μm (100%). The corresponding weight losses (mg/cm2) from the square coupons were 1.9 (0%), 3.3 (10%), 4.4 (50%), and 3.7 (100%). The 50% carbon source level had the combination of carbon starvation without suffering too much sessile cell loss. Thus, both its pit depth and weight loss were the highest. The electrochemical tests corroborated the pit depth and weight loss trends. The tensile tests of the dogbone coupons after the starvation incubation indicated that sulfate-reducing bacteria (SRB) made X80 more brittle and weaker. Compared with the fresh (no-SRB-exposure) X80 dogbone coupon’s ultimate tensile strain of 13.6% and ultimate tensile stress of 860 MPa, the 50% carbon source level led to the lowest ultimate tensile strain of 10.3% (24% loss when compared with the fresh dogbone) and ultimate tensile stress of 672 MPa (22% loss). The 100% carbon source level had a smaller loss in ultimate tensile strain than the 50% carbon source level, followed by 10% and then 0%. Moreover, the 100% carbon source level had a smaller loss in ultimate tensile strength than the 50%, followed by 10% and 0% in a tie. This outcome shows that even in the 17-day short-term test, significant degradation of the mechanical properties occurred and more severe MIC pitting caused more severe degradation.

Recycling and reinforcement potential for the fly ash and sisal fiber reinforced hybrid polypropylene composite

AbstractThe investigation explores mechanical, thermal and thermomechanical behavior of hybrid composites post‐recycling, and subsequent, 5 wt.% additional reinforcement to the recyclate of sisal (SSL) fiber fly ash (FA)/polypropylene (PP) hybrid composite. Impact of recycling and 5 wt.% of SSL fiber reinforcement of the recyclate on mechanical properties of hybrid composites made of 15–30 wt.% SSL and 5–15 wt.% FA were investigated. Noticeably, after recycling, a minimal loss of 2.39% only in tensile and 2.20% in flexural strength were recorded for the hybrid composites fabricated with 15 wt.% each of FA and SSL. The highest loss in tensile (10.32%) and flexural (4.22%) strength were reported for only 30 wt.% SSL fiber reinforced PP indicating that hybridization with FA has a benign effect on reducing property degradation. These lost properties were regained by reinforcing recycled composites with 5 wt.% of SSL fiber. Mechanical studies showed that the composite with 30 wt.% SSL fibers recycled and reinforced with additional 5 wt.% fibers showed a substantial improvement of ~10% and ~4% in the tensile and flexural strength while keeping the impact strength stable. FE‐SEM images confirmed a reduction (~67%) in aspect ratio of the SSL fiber due to reprocessing. DMA demonstrated a decrease of ~11% in storage modulus of the composites after first recycling. TGA confirmed an insignificant change in the degradation temperature of the recycled and re‐reinforced recycled composites versus fresh composites. The study paves the way for potential future recycling applications of waste natural fiber reinforced PP.

Behavior of Metakaolin-Based geopolymer concrete at ambient and elevated temperatures

Geopolymer or alkali-activated binders are emerging as a potential green sustainable alternative for ordinary Portland cement (OPC). In addition to the environmental benefits of geopolymers, it possesses excellent mechanical properties, including good resistance to elevated temperatures. Although many studies were conducted on the thermal performance of metakaolin-based geopolymer mortar and pastes, the performance of metakaolin-based geopolymer concrete under elevated temperature has been rarely studied. Therefore, the present study investigates the behavior of MK-based geopolymer concrete under ambient and elevated temperatures of 200 °C, 400 °C, and 600 °C. The experimental program of this study comprised five mixes with different formulations to primarily investigate the influence of varying Na2O/Al2O3 and SiO2/Al2O3 molar ratios. The results are discussed in terms of the visual observations for the fresh and hardened specimens, compressive strength development, stress–strain behavior, splitting tensile strength, water absorption, and weight loss percentage due to exposure to elevated temperatures. The residual compressive strength varied from 56% to 63%, 38% to 51% and 28% to 34% after exposure to 200 °C, 400 °C, and 600 °C, respectively. The rate of degradation in the modulus of elasticity with the increase in the exposure temperature is much higher than the compressive strength. Models are proposed for predicting the residual compressive strength and modulus of elasticity of geopolymer concrete after exposure to elevated temperature, which show good correlations with experiments. The SEM-EDS analysis confirms the formation of dense homogeneous geopolymerization gel and corroborate the trends of strength degradation after exposure to elevated temperature.

Prediction of the Tensile Strength of Normal and Steel Fiber Reinforced Concrete Exposed to High Temperatures

The tensile strength of concrete has a great impact on the performance of concrete structures, especially for members exposed to high temperatures. The inclusion of steel fibers in concrete is one of the measures to retrieve the loss of tensile strength. The previous equations for the prediction of the tensile strength, are valid for conventional concrete and can predict the tensile strength after high-temperature exposure. Therefore, they are unsatisfactory for forecasting the tensile strength of plain and steel fiber reinforced concrete under high-temperature exposure. To establish a model that can effectively simulate the tensile strength of plain concrete, specimens with compressive strengths of 20–80 MPa are tested. Then by performing tensile strength tests on the specimens containing various content of steel fiber, an equation for prediction of the tensile strength at the ambient temperature is proposed. Meanwhile, the tensile strength tests are conducted at temperatures of 100–800 °C to develop a model for high-temperature exposure. The results indicate that an increase of compressive strength from 20 to 84 improves the tensile strength by 169.4%, and the incorporation of 0.25 and 0.5% of steel fibers can improve the tensile strength of normal concrete by 58.48 and 80.29% on average at the tested temperatures, respectively. Moreover, the proposed model is able to predict the tensile strength of normal and steel fiber reinforced concrete exposed to high temperatures accurately. This equation would help a wider application of the steel fibers in the construction industry with the risk of a fire accident.

Physical Properties of Fabrics: Chemical Compositions of Selected Detergents on Colourfastness of GTP Wax Print and ATL Wax Print (Indigo) in Ghana

The study sought to investigate the Physical Properties of Fabrics: Chemical Compositions of Selected Detergents on Colourfastness of GTP Wax Print and ATL Wax Print (Indigo) in Ghana. A 3×2×2 factorial experiment which includes three washing cycles, the two detergents and two fabrics types were used or the study. A total of 146 specimens were cut randomly from along the warp and weft grain directions of ATL and GTP wax prints and subjected to washing and breaking at the laboratory using standard equipment. The data was analysed using Microsoft Excel 2007 version and the results were presented using means and percentage tables. One-way analysis of variance (Anova) was used to test the hypotheses formulated. The study revealed that there was no significant difference in the tensile strength between GTP and ATL wax prints after undergoing three washing cycles with Omo multiactive and Ariel enzymax. The degrading effect in terms of loss of tensile strength of Ariel enzymax on both wax prints was greater than that of Omo multiactive. There was no significant difference in the colour fastness between ATL and GTP wax prints after undergoing three washing cycles each with Ariel enzymax and Omo multiactive. It is recommended that both GTP and ATL fabric manufacturers should pay particular attention to the physical properties (such as thread count, fabric weight and weave type) when purchasing grey goods for further processing of their products. It is also recommended that, Ghana Standards Authority should make it compulsory for the manufacturers of washing detergents to indicate the correct chemical composition of their products on the packages.

Laboratory Evaluation of Rice Husk and Sawdust on the Performance of Asphalt Binders and Mixtures. (Dept. C)

Although waste materials have negative effects on the environment, they can be utilized in civil engineering applications, particularly in pavement construction. This research investigates the feasibility of using agricultural waste and byproduct materials i.e., Rice Husk (RH) and Sawdust (SD) as modifiers to asphalt binders and mixtures. A mechanical mixer was used at 1400 rpm speed, and temperature of 140°C±5°C to blend the byproduct material with a typical 60/70 penetration grade asphalt for 60 minutes. Three different contents of 10, 15, and 20% by total weight of asphalt binder) were employed for modifying asphalt binders. Scanning Electron Microscopy (SEM) and, Fourier Transform Infrared Spectroscopy (FTIR) were used for the microstructural and chemical characterization of the modified asphalts. The neat and modified asphalts were tested against conventional properties. Modified asphalt mixtures were prepared and designed by Marshall method utilizing an optimum content of 15% by the total weight of asphalt binder for each of the byproduct materials. The moisture sensitivity was characterized in the laboratory for the control and modified mixes using the Tensile Strength Ratio (TSR) and loss of stability. Results showed that with the increase in the content of the waste/byproduct material, penetration value decreased, softening point temperature increased, and viscosity increased. Marshall stability of the prepared hot asphalt mixture containing RH-modified asphalt binder was the highest but with higher loss of stability compared with other asphalt mixes. The TSR of the control mix was the highest compared with other mixes.

Degradation of Polyfurfuryl Alcohol-Based Biopolymer by Soil-Burial and Photo-Degradation Methods

Recently, polyfurfuryl alcohol (PFA) based material has been gaining attention. Despite its use as an intermediate in various industries, the degradation process of PFA has rarely been reported. In this study, neat PFA (PF) and polylactic acid (PLA) incorporated PFA (PF-PL) based thermoset biopolymers were prepared by casting method. The degradation of the prepared biopolymer specimens was carried out under environmental conditions via soil-burial test and photo-degradation method for 21-months. The extent of degradation of PF and PF-PL was assessed by evaluating weight loss, variation in mechanical properties and change in complex viscosity. Structural and morphological changes of degraded PF and PF-PL samples were evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Weight loss percentage in case of photo-degraded samples was found to be much higher compared to soil buried specimens. SEM micrographs showed a blistered surface and visible cracks on the surface of soil buried and photo-degraded samples, respectively. FTIR spectra of photo-degraded samples showed a new peak at 673 cm−1 indicating the furan ring opening during the degradation process. Significant variation in mechanical properties of PF and PF-PL specimens after soil-burial test also indicated biodegradable nature of the biopolymers. Approximately 45% and 63% of loss in tensile strength was obtained in PF and PF-PL soil buried specimens, respectively. Complex viscosity was lowest for PF and PF-PL samples after 21 months of degradation compared to undegraded specimens thus indirectly indicating the decrease in molecular weight after degradation. All the obtained data revealed the fragmentation of biopolymers, hence supporting the biodegradable nature of PFA-based biopolymer.

Hiatal hernia, lower esophageal sphincter and their combined effect on the natural history of gastroesophageal reflux disease: implications for surgical therapy

: The modern surgical therapy of gastroesophageal reflux disease (GERD) is based upon the concept that the antireflux barrier has two components that form a “double-sphincter” and work synergistically to protect from reflux of gastroduodenal contents: the lower esophageal sphincter (LES) and the crural diaphragm. Factors implicated in the pathogenesis of hiatal hernia (HH) are the thoraco-abdominal pressure gradient, the esophageal shortening secondary to reflux-induced fibrosis, and the hiatal enlargement due to peri-esophageal tissue deterioration. Genetic and biologic factors can predispose to HH formation through alterations in extracellular matrix protein metabolism, and through structural changes of the muscular crura, central tendon, and phreno-esophageal ligament. This will eventually result in loss of tensile strength and/or loss of recoil ability of elastic fibers. Failure of LES or the crural diaphragm or both contribute to progression of GERD and development of complications such as Barrett’s esophagus and esophageal adenocarcinoma. Patients’ selection for antireflux surgery is critical for optimal outcomes. While laparoscopic cruroplasty and Toupet or Nissen fundoplication remain the current gold standard in antireflux surgery, the high rates of anatomical and clinical recurrence in patients with large hiatus hernia still represent a matter of concern. To reduce recurrence rates after surgical repair, it is clear that both axial and radial tension at the esophago-gastric junction (EGJ) must be minimized. This has led to an increasing interest for the use of prosthetic mesh to reinforce the esophageal hiatus. Recognition of anatomical and functional abnormalities at an early disease-stage is critical to prevent complications and to provide the most appropriate surgical therapy and the best clinical outcomes.

Evaluation of Strength and Water Susceptibility Performance of Polypropylene Fiber–Reinforced and Silica Fume–Modified Hot Mix Asphalt

Abstract The use of industrial recycled waste material has exponentially increased in past decades for green and sustainable construction practices. Numerous industrial wastes are being effectively used to replace the conventional construction material with paved structure construction. The use of industrial waste ash to replace the mineral filler and plastic waste as reinforcement has shown tremendous scope for use in hot mix asphalt (HMA). This research aims to explore the effect of alternative mineral filler and fiber reinforcement in HMA. In the present study, an extremely fine nanocrystalline polymorph of silica fume (SF) and polypropylene (PP) fiber was used as mineral filler and reinforcement. The varying percentages of SF (i.e., 4.0 %, 6.0 %, and 8.0 %) and PP fiber (0.25 %, 0.5 %, 0.75 %, and 1.0 %) by volume of total mix were used. The strength and durability of the HMA were evaluated using Marshall Stability, indirect tensile strength, mean Marshall Stability ratio, index of retained strength, water sensitivity, indirect tensile fatigue test, and rut depth tests. The statistical significance analysis has been carried out using the analysis of covariance. The loss of indirect tensile strength was observed between 16–18 % at the optimum limits of the SF and PP fiber; this signifies the higher durability of PP-fiber-reinforced HMA modified with SF. Ministry of Road Transport & Highways (MoRTH), 2013. The results also show the use of PP fiber and SF significantly improves the strength and durability of HMA.

Durability performance of reinforced waste-based geopolymer foam concrete under exposure to various corrosive environments

The construction of conventional concrete structures produces a significant quantity of CO2 released into the environment which can directly impact human health and contribute to global warming. Geopolymer foam concrete is a low carbon eco-friendly concrete in which CO2 releasing cement is replaced with industrial waste materials. However, the durability of geopolymer foam concrete under needs to be investigated over a range of corrosive environments to enable application as a construction material. Therefore, determining the influence of these corrosive factors on the reinforcing steel in geopolymer foam concrete is the objective of the current research. A detailed multi-variable experimental programme was conducted, and models were derived to quantifying the factors influencing the corrosion and mechanical behaviour of reinforced geopolymer foam concrete (RGFC) under exposure to varying chloride, temperature and humidity. Specimens were cast with three chloride percentages, i.e., 1%, 3% and 5% for accelerated corrosion, and exposed to temperatures of 35 and 24 Celsius, and humidity levels of 50% and 90%, respectively. Gravimetric weight loss measurements of the corroded reinforcing steel were undertaken at three designated time intervals. Following corrosion monitoring, the corroded reinforcing steel was tested under tension to observe the influence of the environmental exposure on their mechanical properties, specifically ductility and strength. Utilizing the test results, analytical expression and Multilayer Perception (MLP) neural network computations were executed to accurately quantify the influence of the various environmental exposure conditions on corrosion in RGFC. The findings of the modelling suggested temperature as the most dominant factor in inducing corrosion followed by humidity. Furthermore, the relationships for the prediction of loss of ductility and tensile strength of the reinforcing steel in RGFC as the function of chloride, temperature and humidity were derived. Finally, to conclude, the outcomes of the current research enhance the knowledge on the durability of GFC as a construction material and practically contribute to its service life determination.

Effects of high heat flux exposures on tensile strength of firefighters' protective clothing

SummaryThe effects of thermal aging on tensile strength of three Kevlar/PBI blends used in the outer shell layer of firefighters' protective clothing were examined using cone calorimeter exposures of 10‐70 kW/m2 for 30‐300 seconds. Lower heat flux exposures of 10‐15 kW/m2 did not result in significant change in the tensile strength of the fabrics, but significant losses of tensile strength were first observed as the heat fluxes increased to 20‐30 kW/m2 for two ripstop fabrics, and 45 kW/m2 for the third fabric. Further decreases in tensile strength were observed with increasing heat flux until there was almost a total loss of original tensile strength following exposure to 70 kW/m2. Decreases in tensile strength were explained by comparing fabric temperature measurements made using an infrared thermometer, key temperatures in thermal gravimetric analysis test results, and the appearance of the three fabrics after the exposures. While duration of exposure had little effect on tensile strength after exposures to 10 kW/m2, tensile strength decreased with duration of exposure for heat fluxes of 20‐40 kW/m2. The effect of duration was greatest for a heat flux of 20 kW/m2. These results indicate that one must consider not only the maximum temperature that the fabric reaches, but the complete temperature‐time trace, including the time at which the fabric remains at the maximum temperature, when examining the effects of thermal aging on tensile strength.

Fatigue characterization of porous asphalt mixture complicated with moisture damage

This study investigated the fatigue behavior of a porous asphalt mixture (PAM) considering the effect of moisture damage. The PAM was designed with a high-viscosity asphalt and target air void of 20%. Moisture damage was induced through freeze–thaw (F-T) conditioning with 1, 3, 5, 10, and 15 cycles, and was quantified in terms of loss in the indirect tensile (IDT) strength. The IDT fatigue test with the single- and two-stage loading patterns was employed. Results indicated that the strength decreased with the number of F-T cycles following an exponential decay function. Moisture damage rendered the PAM more susceptible to fatigue loading, and at higher stress levels the material exhibited higher fatigue dependence on moisture damage. In the S-N relationships established from the single-stage fatigue characterization, the role of moisture damage was incorporated into the intercept and slope as exponential functions. The two-stage characterization resulted in the Miner’s sum M < 1 for the high-to-low loading sequence, and M > 1 for the low-to-high sequence. The power-law nonlinear damage rule was adopted, in which the dependence of the exponent on moisture damage was found to follow an exponential decay function. In the predictive models developed for both loading patterns, the effects of moisture damage and loading level were mathematically described in uncoupled forms, as a result of no moisture damage progression during fatigue loading.

A novel strength behavior prediction model of self‐compacting concrete with foundry sand and hybrid fibers

AbstractIn this paper, an Improved FireFly Optimization Algorithm (IFFOA)‐based optimal Self‐Organizing Polynomial Neural Network (SOPNN) is proposed to analyze the compressive strength, tensile strength, and flexural strength of the self‐compacting concrete (SCC) with the inclusion of hybrid fibers whenever exposed to high temperature. The SCC mixture is formed by the materials taken in this study along with the hybrid fibers. The preparation of SCC is made by adding water to powder with a proportion of 3:10 and hybrid fibers content is about 2 kg/m3. The samples are heated to a temperature of 210, 320, 530, and 790° at the duration of 7 and 28 days. Experiments are performed to analyze the loss in compressive strength, tensile strength, and flexural strength. The proposed method is used to analyze the loss functions based on the amount of cement, aggregates, temperature, additives along with the inclusion, and exclusion of hybrid fibers. Further, it is found the proposed method analyzes the loss in compressive strength, tensile strength, and flexural strength of SCC more accurately than the other methods.

Impact of elevated temperatures on the behavior and microstructure of reactive powder concrete

Reactive Powder Concrete (RPC) is a composite material that will permit the concrete industry to improve material use, generate economic benefits, durable and sensitive to environment. At high temperature due to extremely dense microstructure of RPC shows poor performance owing to the development of high pore pressure that causes the deterioration of the material. By using fiber reinforcement, elevated temperature compression strength and when it is collaborate with the steel the tension strength is increased, as noted by many researchers.This study was aimed to investigate the effect of elevated temperatures on the mechanical and physical characteristics of RPC, containing varying percentages of waste materials as cement replacement. The superplasticizer dosages at the ratios of 1.8% and 2.7% of cement weight were used. The specimens were prepared with 23% silica fume, 23% quartz, 15% granulated slag and two percentages of steel fibers (0.17% and 0.23% by vol.), exposed to two different curing conditions and were subjected to five temperatures, i.e., 20, 200, 400, 500, 600 and 800 °C. Later, the specimens were tested for compressive strength test, flexural tensile strength and mass loss test at all temperature ranges. Finally, the degradation of the RPC exposed to high temperatures was estimated by means of the scanning electron microscopy.Experimental results showed that using 0.23% volume fraction of steel fibers, flexural strength of RPC was completely improved. The compressive strength formulated with 15% slag, 23 % quartz powder showed the maximum best mechanical performance at both elevated and normal temperatures.Due to exposed to high temperature, mechanical properties of RPC gradually improves by increasing temperature up to 200° C. The compressive, flexural and tensile strength, decreased at a higher rate of temperatures higher than 200 °C. For an exposure temperature of 400 °C, results show that the reduction on mechanical properties with deference to the one obtained for room. Furthermore, this mechanical strength exhibited a clear diminution within the temperature range 600–800 °C. Using steel fibers in RPC was resisted deterioration, and the amount decrease failure due to high temperatures.

Investigations on the Effects of Styrene Butadiene Styrene in Asphalt Mixture Design

This study aims to determine the effect of using a styrene butadiene styrene modifier with basalt aggregate as coarse particles and using limestone as mineral filler. In general, several modified hot mix asphalt specimens at 4% air voids have been prepared to study the influence of different percentages of SBS (0%, 3%, 4%, 5%, 6%) with various portions of asphalt content (4.5%, 5%, 5.5%, 6%, 6.5%) using Marshall Method and Super-Pave Method. The investigations have shown that using limestone as mineral filler improves the bond strength between the basalt aggregate and the asphalt cement. Moreover, the optimum asphalt content using the Marshall method has been 5% at different percentages of Styrene Butadiene Styrene. On the other hand, super-Pave tests have showed that the best ratio of SBS in the MR test has been 3%, while, in the creep test, it has been 4% and 6% in the loss of indirect tensile strength and fatigue tests. In general, the best asphalt mixture performance is referred to as binder asphalt with 6% SBS.

Surface Protection of Wood with Metal Acetylacetonates

Metal acetylacetonates are coordination complexes of metal ions and the acetylacetonate anion with diverse uses including catalysts, cross-linking agents and adhesion promotors. Some metal acetylacetonates can photostabilize polymers whereas others are photocatalysts. We hypothesize that the ability of metal acetylacetonates to photostabilize wood will vary depending on the metal in the coordination complex. We test this hypothesis by treating yellow cedar veneers with different acetylacetonates (Co, Cr, Fe, Mn, Ni, and Ti), exposing veneers to natural weathering in Australia, and measuring changes in properties of treated veneers. The most effective treatments were also tested on yellow cedar panels exposed to the weather in Vancouver, Canada. Nickel, manganese, and titanium acetylacetonates were able to restrict weight and tensile strength losses and delignification of wood veneers during natural weathering. Titanium acetylacetonate was as effective as a reactive UV absorber at reducing the greying of panels exposed to 6 months of natural weathering, and both titanium and manganese acetylacetonates reduced the photo-discoloration of panels finished with a polyurethane coating. We conclude that the effectiveness of metal acetylacetonates at photostabilizing wood varies depending on the metal in the coordination complex, and titanium and manganese acetylacetonate show promise as photoprotective primers for wood.

Exploration of polyvinylidene difluoride (PVDF) for improvement of weathering resistance of textile substrates

Coated and laminated fabrics intended for out-door application suffer from property degradation due to hazardous environmental factors, which results in poor durability and limited shelf-life. In this study, polyvinylidene difluoride (PVDF) film having completely ultraviolet (UV) blocking property was developed by solution casting method with optimizing different process parameters. UV blocking property was achieved by pigmentation of pristine PVDF films using titanium dioxide (TiO2). Various characterizations and tests were carried out to determine mechanical, thermal, EDX, FTIR and light transmission properties etc. in case of pristine and pigmented films and the results obtained were analyzed to judge the stability, structure and suitability of the developed films. Pigmented film was then laminated with light sensitive textile substrate by adhesion bonding method. The laminated fabric was subjected to natural and artificial weathering conditions for assessment of efficacy of developed film. The obtained results indicated that film laminated sample exhibited excellent weathering protection compared to control sample (without film) which was evaluated in terms of tensile strength loss after exposure.

Reactive processing of PA6/EPDM‐MA blends as modifier for application and development of high‐performance polypropylene

AbstractIn this work, PA6/EPDM‐MA was added as an impact modifier for high‐performance polypropylene (PP) production. PA6/EPDM‐MA compounds were processed in an internal mixer, aiming at chemical reaction between maleic anhydride of EPDM‐MA and the amine terminal groups of PA6. Afterward, PP/(PA6/EPDM‐MA) blends were processed by extrusion and injection molding. Rheological properties were evaluated using torque rheometry; additionally, Fourier transform infrared spectroscopy, Molau test, impact and tensile strengths, Shore D hardness, thermal deflection temperature, X‐ray diffraction, differential scanning calorimetry, thermogravimetry, water absorption, contact angle, and scanning electron microscopy tests were performed in injected specimens. PP/(PA6/EPDM‐MA) with 70/(15/15)% displayed quite high increase in impact and elongation at break, with gains of 850% and 265%, compared to neat PP. There were no drastic losses in tensile strength, elastic modulus, and Shore D hardness, due to PA6 addition. A significant increase was seen in the thermal stability of PP/(PA6/EPDM‐MA), corroborating the increase in structural stability seen in HDT. SEM images showed high interfacial adhesion between PP and PA6/EPDM‐MA corroborating higher mechanical properties. Summing up, PA6/EPDM‐MA premix acted as an efficient impact modifier for PP. Acquired data show that P6/EPDM‐MA system was effective in developing high‐performance PP with potential for application in the automotive and electronics industries.