Effect Of Nanoclay Research Articles

Engineering properties of geopolymer concrete incorporating hybrid nano-materials

Geopolymer concrete is considered to be a sustainable alternative to Portland cement in construction industry. The incorporation of nano materials into geopolymer matrix contributes to enhance the mechanical and durability properties of concrete. Carbon nanotubes (CNTs) are characterized by high tensile strength and good durability properties. However, CNTs particles have significant large specific surface area that leads to encounter adhesion and dispersion difficulties in geopolymer matrix. Nano clay (NC) is utilized to increase pozzolanic activity and decrease the adhesion problems in geopolymer concrete. This research aims to investigate the hybrid effect of NC and CNTs on the resulting performances of hybrid fly ash/slag geopolymer concrete. In this study, geopolymer mixes were produced using fly ash/slag as an aluminosilicate source. The utilized alkaline activator was composed of both; sodium silicate (Na 2 SiO 3 ) and sodium hydroxide (NaOH) solutions. Mechanical properties of the mixes were determined based on compressive and flexural strengths tests. Also the impacts of the inclusion of NC and CNTs on the air content, chloride resistance and water penetration depth on hybrid fly ash/slag geopolymer concrete were demonstrated. It was observed that the superior compressive strength for geopolymer mix was found to be in the mix incorporated by (2.5%) NC blended with (0.01%) CNTs. The engineering properties were significantly improved by using hybrid nanoparticles. The high pozzolanic effect of NC led to improve the compressive strength, as long as the nanotubes were used to reinforce the geopolymer concrete and hence enhance the durability properties.

The effect of nanoclay on the nonlinear viscoelastic behavior of high‐density polyethylene

AbstractThe study's main motivation is to determine the creep behavior of high‐density polyethylene (HDPE)‐based nanocomposites in unexpected situations where short‐term constant loading may occur. On this basis, the short‐term creep behavior of 1 wt.%, 3 wt.%, and 5 wt.% nanoclay reinforced HDPE nanocomposites were investigated at room temperature (23 ± 1°C) and strain rate of 1E‐4 1/s under 8, 12, and 16 MPa stress levels. As the nanoclay reinforcement ratio by weight increased, the creep resistance and modulus of neat HDPE increased at 8 MPa stress level, but they decreased at 12 and 16 MPa stress levels. The absorbed energy that corresponds to the area under the stress–strain curve increase as the stress level increase from 8 to 16 MPa. However, absorbed energy decreases as nanoclay reinforcement increases for 8 MPa. The curves produced from the four‐element Burger's model and Findley's power law models were compared with the creep curves obtained from the experiments. The four‐element Burger model was found to fit the creep curves better than Findley's power‐law model. Also, some regression curves were given for interpolations to give intermediate values of the maximum creep strain values at different stress levels. The presented models can be used to evaluate creep strain, considering the usage fields of parts or semi‐products produced from nanoclay/HDPE nanocomposites.

The effects of nanosilver and nanoclay nanocomposites on shrimp (Penaeus semisulcatus) samples inoculated to food pathogens

Today, antibacterial packaging plays a major role in enhancing shelf life of food products. Application of nanoclay and nanosilver as antimicrobial agents has been glorified recently in the food industry due to their ability to enhance mechanical properties of food packaging. As vibrio parahaemolyticus, Staphylococcus aureus and Escherichia Coli are among of the most usual bacteria affecting fisheries, the aim of this study was to evaluate effects of nanoclay and nanosilver packaging on the growth of pathogens within 6 days of shrimp shelf life at 4 °C. Silver and clay nanoparticles (NPs) were analyzed using AFM, SEM, FESEM, EDX, FTIR, DLS and TEM as well. The size of clay and silver nanoparticles were 15 nm and 35 nm respectively. 21 packaging samples containing 1 to 7 percent of NPs were produced using melt mixing method. Shrimps samples were inoculated with pathogens using a 0.5 McFarland standard and hot sealed using nanopackaging treatments. Result showed that nanopackaging could decrease colony counts more than one logarithmic cycle which was a significant reduction (P < 0.05). Also, a synergistic effect was observed for packaging containing both nanoclay and nanosilver particles. Results of the current study shows that application of silver and clay NPs in nanocomposites could be a promising method to reduce microbial load and increasing shelf life of perishable food products.

Effect of nanoclay and burnt limestone powder on fresh and hardened properties of self-compacting concrete

The growing rate of cement production and construction waste due to rapid urbanization is producing environmental threat. Therefore, it is necessary to replace fully or partially with reinforcement material. Thus, in this research work, sulfate resistance cement (SRC) was replaced with different weight percentages of nanoclay (NC) (2, 4 and 6%) and burnt limestone powder (BLP) (50, 75 and 100 kg) to produce self-compacting concrete (SCC) for investigating the fresh and hardened properties. The local Iraqi natural Kaolin clay was calcinated at 700 °C for 2 h and milled for 40 h through ball milling to produce NC. Further, the limestone powder was burnt at 700 °C for 2 h and partially replaced with SRC. The ball milling successfully reduced clay to a particle size of < 75 nm sized for NC. Moreover, the inclusion of NC and BLP significantly affected the fresh properties of SCC. For hardened properties, the inclusion of both mixtures gradually increased hardened properties; however, the NC-incorporating SCC specimens have higher hardened properties than reference SCC (SCC0), whereas the lower weight percentages of BLP provided insignificant hardened properties. Additionally, as based on results, both mixture material (NC and BLP) can be utilized for producing SCC.

Effect of Nano clay on the fatigue of epoxy and glass fiber composites

This study describes the experimental results of the fatigue behavior manifested by fatigue strength, fatigue life, and fatigue limit composites for epoxy resin and its E-glass fiber (2,4,6) laminates, nano clay prepared in laboratory reinforced in with (2%, 4%, 6%) weight fraction. The evaluation of (S-N) curves of the tested specimens was depending according to the type of E-glass fibers, laminates number, and addition nano clays small granular volume which prepared in laboratory to a polymer. The fatigue tests showed high resistance to all samples after being immersed in water. Adding the nano clay reduced the brittle nature of the Epoxy resin as it is improved drastically.

Triaxial Mechanical Properties and Micromechanism of Calcareous Sand Modified by Nanoclay and Cement

Calcareous sand is developed by the fracture of marine biological skeleton under the impact of seawater. Calcareous sand is not transported in the process of deposition. Therefore, calcareous sand retains the characteristics of marine biological skeleton, low strength, and porous. In order to study the effect of nanoclay and cement on the modification of calcareous sand, a series of tests were carried out on the modified cement calcareous sand (CCS) with different content of nanoclay. In this study, the triaxial mechanical properties and failure modes of nanoclay and cement composite modified calcareous sand (NCCS) were studied through the triaxial UU test. Then, SEM tests were carried out on CCS and NCCS samples, and the micromechanism of nanoclay and cement composite modified Nanhai calcareous sand was analyzed. The results showed that (1) the shear properties of CCS could be improved by adding nanoclay. The optimum admixture ratio of nanoclay was 8%, and its peak stress was 23%-39% higher than that of CCS. (2) The peak stress and strain of NCCS showed a linear correlation. (3) Compared with CCS, the internal friction angle and cohesion of NCCS were increased by 5.2% and 52%, respectively. (4) Nanoclay could improve the compactness and structure of cement calcareous sand, and the macroscopic performance is the improvement of peak stress and cohesion.

Effect of Nanoclay in the Mechanical and Thermal Behaviour of Glass Fibre Reinforced Epoxy

This work investigates the effect of nanoclay in the mechanical and thermal characteristics of GFRP laminates. The Cloisite 15A nanoclay has added to the matrix with proportion of 1%, 2% and 3% by weight. The processed nanocomposites are characterized with X-Ray Diffraction to identify the inter layer spacing of clay in the matrix. The filler added epoxy, reinforced with the unidirectional glass fibre by hand layup technique and the specimens are tested for tension, hardness, flexural and fracture loadings. Dynamical mechanical analysis and thermo gravimetric tests are also conducted to understand the visco-elastic and thermal behaviour of the material. The addition of clay in the matrix generally increases the mechanical properties up to our consideration that is 3% clay loading. Thermal and visco-elastic behaviour found consistent up to 1% clay loading and reduces the performance after that in overall sense.

Experimentally Investigation of Nano Clay Effects on Leaching and Self-healing Process of Cracked Clayey Soils

Compacted clay layers are known as one of the common low impermeable layers used in geotechnical structures. Due to geotechnical properties, these layers damaged through cracks in their lifespan. This research has attempted to improve the workability by using self-healing features of clays. By conducting numerous experimental tests, it has been shown that, by increasing the plasticity index of clays, the pace of crack healing process will be enhanced. Experiments have shown that percentages of Montmorillonite Nano Clay (MNC) are quite effective and reduce the flow rate in the samples, which is a sign of self-healing of the cracks by an NC additive. On this basis, NC can be perfectly used to repairing cracks in clayey soils. The results of this study show that in the sample with 1 mm crack, about 500 milliliters of water pass through the crack in 60 minutes under no pressuring conditions. While, if the sample contains 2 and 5 percent NC, the amount of water passing through the cracks within 60 minutes, will be 40 and 5 ml, respectively. This dramatic reduction for passing water reflects the positive effect of Nano sized grains on the closure of the created cracks. Therefore, it can be concluded that the self-healing process occurs earlier in smaller cracks, because the NC and soil particles can easily touch each other after swelling. Five percent of MNC can insure the cracks closure at 100% density. I

Effects of Nanoclay on Mechanical and Dynamic Mechanical Properties of Bamboo/Kenaf Reinforced Epoxy Hybrid Composites.

Current work aims to study the mechanical and dynamical mechanical properties of non-woven bamboo (B)/woven kenaf (K)/epoxy (E) hybrid composites filled with nanoclay. The nanoclay-filled BK/E hybrid composites were prepared by dispersing 1 wt.% nanoclay (organically-modified montmorillonite (MMT; OMMT), montmorillonite (MMT), and halloysite nanotube (HNT)) with high shear speed homogenizer followed by hand lay-up fabrication technique. The effect of adding nanoclay on the tensile, flexural, and impact properties of the hybrid nanocomposites were studied. Fractography of tensile-fractured sample of hybrid composites was studied by field emission scanning electron microscope. The dynamic mechanical analyzer was used to study the viscoelastic properties of the hybrid nanocomposites. BK/E-OMMT exhibit enhanced mechanical properties compared to the other hybrid nanocomposites, with tensile, flexural, and impact strength values of 55.82 MPa, 105 MPa, and 65.68 J/m, respectively. Statistical analysis and grouping information were performed by one-way ANOVA (analysis of variance) and Tukey method, and it corroborates that the mechanical properties of the nanoclay-filled hybrid nanocomposites are statistically significant. The storage modulus of the hybrid nanocomposites was improved by 98.4%, 41.5%, and 21.7% with the addition of OMMT, MMT, and HNT, respectively. Morphology of the tensile fracture BK/E-OMMT composites shows that lesser voids, microcracks and fibers pull out due to strong fiber–matrix adhesion compared to other hybrid composites. Hence, the OMMT-filled BK/E hybrid nanocomposites can be utilized for load-bearing structure applications, such as floor panels and seatbacks, whereby lightweight and high strength are the main requirements.

Effect of Nanoclay on Physical and Rheological Properties of Waste Cooking Oil–Modified Asphalt Binder

The use of waste cooking oil (WCO) and nanoclay (NC) in the modification of asphalt binder can produce sustainable material for paving applications. This study evaluated the change in physical and rheological properties attained by modification of a conventional asphalt binder using varying percentages of WCO and NC; 0%, 2.5%, and 5% WCO was used to modify a VG 30 binder, followed by reinforcement using four different dosages of montmorillonite NC (0%, 2%, 4%, and 6%). A total of 12 combinations of asphalt binders were produced (VG30, 2NC, 4NC, 6NC, 2.5WCO, 5WCO, 2.5WCO2NC, 2.5WCO4NC, 2.5WCO6NC, 5WCO2NC, 5WCO4NC, and 5WCO6NC) and subjected to physical (penetration, softening point, viscosity, and temperature susceptibility) and rheological [high-temperature performance grading (PG), multiple stress creep and recovery (MSCR), and linear amplitude sweep test (LAS)] measurements. The physical and rheological measurements showed that the use of NC in WCO-modified asphalt binder could reverse the softening effect caused by the inclusion of WCO in VG 30. At 50°C and 60°C, 2.5WCO with 4% and 6% NC had higher values of percentage recovery (R) compared with VG 30. It was found that the use of NC insignificantly increased the strain susceptibility of the asphalt binders at intermediate temperatures for all WCO levels. Statistical analysis revealed that the effect of modification on unrecoverable creep compliance is less significant than the change in R for a temperature range of 40°C–70°C. The significance of modification at intermediate temperatures was not consistent and clear. A simple cost–benefit analysis was proposed, which indicated that 2.5WCO6NC is the optimum combined blend for obtaining higher benefits relative to the cost of modification.

Effects of nanoclay addition on the permeability and mechanical properties of ultra high toughness cementitious composites

Tuning microstructures by adding nanoparticles is a promising way of improving the performance of cementitious composites. In this study, nanoclay was introduced to polyvinyl alcohol (PVA) fiber reinforced ultra high toughness cementitious composites (UHTCCs). The mechanical properties, crack patterns, water permeation resistance, and microstructures of UHTCCs with different dosages of nanoclay were studied. The addition of a proper dosage of nanoclay shows few effects on the compressive strength of UHTCCs, however, the compressive strength is decreased when an excessive amount of nanoclay is added. The flexural deformation capacity of UHTCCs is independent of nanoclay dosage, whereas the flexural strength generally decreases with an increasing dosage of nanoclay. Different cracking patterns were observed in the ultra high toughness cementitious composites containing nanoclay (NC-UHTCC) specimens subject to bending tests. A UHTCC with 1% (in weight) nanoclay shows the best water permeation resistance and the lowest water permeability. Variations in the mechanical properties and the water permeation resistance of UHTCCs containing different dosages of nanoclay could be ascribed to the synthetic effects of filling and heterogeneous nucleation of nanoclay at low dosages and the agglomeration effect of nanoclay at high dosages. This study is to optimize the water permeation resistance of UHTCCs, paving a path for the future application of UHTCCs in the fields of construction, decoration, and repair.

Effect of nanoclay on the properties of rosin derivative cross‐linked green composite based on chicken feather fiber and modified vegetable oil

AbstractFully biodegradable composites based on waste chicken feather fiber (CF), functionalized epoxidized soybean oil (ESO), rosin derivative and various nanoclay percentages were prepared via compression molding. Rosin derivative was synthesized as a substitute of styrene/divinylbenzene. Nuclear magnetic resonance and Fourier transform infrared spectroscopy confirmed the synthesized rosin derivatives structures. Delamination and distribution of silicate layers were studied by X‐ray diffraction and transmission electron microscopy. Scanning electron microscopy was used to analyse compatibility among modified ESO and rosin. FTIR study revealed the interaction between resin, CF, rosin derivative, and nanoclay. The nanoclay loaded composites showed better mechanical properties than the nanoclay free composite. The thermal stability of nanoclay loaded composites were also found to be enhanced. Composites loaded with nanoclay (3 wt%) revealed the least chemical resistance, volumetric swelling and water vapor uptake capacity.

Effect of nanoclay on relaxation and breakup of polyamide 6 threads in polystyrene matrix

AbstractIn this work, we investigate the compatibilizing mechanism of nanoclay in binary polymer blends by measuring the interfacial tension of polystyrene/polyamide 6, PS/PA6, as a typical system, in the presence of nanoclay. The interfacial tension of PA6 nanocomposites and PS are determined with the breaking thread method by employing the Tomotika theory. The interfacial tension is reduced when organoclay is incorporated in the PA6 phase. To investigate the effect of the localization of nanoclay, nanoclay is intentionally located at the interface of PA6 and PS. Microscopic observations show that PA6 fiber remain unchanged and does not go through break‐up process; therefore, one can deduce that the apparent interfacial tension of the system reduces significantly when nanoclay particles saturate the interface.

Artificial Neural Network and NLR techniques to predict the rheological properties and compression strength of cement past modified with nanoclay

One of the most important industries and building operations that cause carbon dioxide emissions is the cement and concrete-related industries that consume about 6 million Btus per metric ton and release about 1 metric ton CO2. Reducing cement consumption while using nanomaterials as cement replacement is favored for environmental protection reasons. In this study, the effect of nanoclay (NC) as an additive to the cement paste was evaluated and quantified. Scanning Electronic Microscope (SEM), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), and Raman Spectroscopy analysis were used to identify the cement and nanoclay. Experimental tests and modeling were conducted to predict the cement paste's flow properties like yield stress, shear strength (shear stress limit), viscosity, and stress at the failure stress of cement paste. The cement paste modified with nanoclay was tested at a water-to-cement ratio (w/c) of 0.35 and 0.45 and temperatures ranging from 25⁰C to 75⁰C. The addition of NC increased the ultimate shear strength (τmax) and the yield stress (τo) from 22.5% to 54.4% and from 26.3% to 203%, respectively based on the NC content, w/c, and temperature. TGA tests showed that the 1% nanoclay additive reduces the weight loss of the cement at 800⁰C by 74% due to the interaction with the nanoclay with the cement paste. The nonlinear regressions model (NLR), and Artificial Neural Network (ANN) technical approaches were used for the qualifications of the flow of slurry and stress at the failure of the cement paste modified with nanoclay. Based on the static analysis assessments, the rheological properties and compressive strength of cement paste modified with nanoclay can be well predicted in terms of w/c, nanoclay content, temperature, and curing time using two different simulation techniques. Among the used approaches and based on the experimental data set, the model made based on the NLR models is the most reliable model to predict rheological properties and compression strength of the cement and it is performing better than the ANN model. The coefficient of the correlation (R), mean absolute error (MAE), and root mean square error (RMSE) concluded that the nanoclay content is the most important parameter for rheological estimation and compression strength of cement paste.

Investigating the High Velocity Impact Behavior of the Laminated Composites of Aluminum/Jute Fibers- Epoxy Containing Nanoclay Particles

In this research work, the effect of adding nanoclay on the high velocity impact behavior of fibers metal laminates (FMLs) of aluminum- Jute fibers/epoxy was investigated. To do so, the nanoclay particles with different percentages (0, 1, 3 and 5 wt.%) were firstly added into the epoxy matrix. In the following, the FMLs with the configuration of 0/90/0/90/0 were made by hand lay-up method. After that, the fabricated samples were tested by high velocity impact test. In order to investigate the effect of nanoparticles on the impact properties, the field emission scanning electron microscope (FESEM) was used. The obtained results showed that the samples with 0, 1, 3 and 5 wt.% had the limit velocity of 81.9, 83.7, 87.4 and 85.4 m/s, respectively. The limit velocity increment in these samples by adding nanoclay were 2.2, 6.7 and 4.3 %, respectively. Also, the obtained results showed that by adding the 1, 3 and 5 wt.% nanoclay, the absorbed energy was improved about 4.5, 14 and 8.8 %, respectively. The sample with 3 wt.% nanoclay had minimum delamination length between aluminum shell and composite core, which was due to the effect of nanoclay in the interface adhesion of core-shell. The microscopically analysis showed that the nanoclay increased the fibrillation of Jute fibers as one of the absorbed energy mechanisms in the Jute fibers. Also, the agglomeration phenomenon in the sample with the 5 wt.% nanoclay was illustrated, which was the decreasing factor of its impact properties, as comparison with sample with 3 wt.% nanoclay.

A Theoretical and Experimental Analysis of the Effect of Nanoclay on Gas Perm‐Selectivity of Biodegradable PLA/EVA Blends in the Presence and Absence of Compatibilizer

AbstractPoly (lactic acid) (PLA)‐based compounds are widely used in thin‐film and food packaging industries. Herein, PLA/ethylene vinyl acetate copolymer (EVA)/nanoclay nanocomposites are prepared in various compositions by melt blending. The gas permeability against N2, CO2, and O2 gases is determined as a function of composition and morphology of the nanocomposites. Inclusion of high aspect ratio of platelet‐like nanoclay to the blend reduces the gas diffusion. The best barrier properties against all gases is observed on introducing 5 wt% poly(ethylene/n‐butyl acrylate glycidyl methacrylate) copolymer as compatibilizer to the PLA/EVA/nanoclay (75/25/5) system. The scanning and transmission electron microscopic analyses and wide‐angle X‐ray scattering studies reveal that inclusion of compatibilizer to the filled‐blends improves the blend morphology, dispersion state, and intercalation level of clay platelets which are preferably localized at the interface of the blend. Analysis of selectivity parameter (α) shows the lowest O2 permeability and the highest αCO2/N2 and αO2/N2 values for the compatibilized filled‐blend (75/25/5/5). In situ aspect ratio of clay and the degree of intercalation are theoretically evaluated based on the permeability data using various empirical models. It is found that the compatibilized filled‐blend has the highest aspect ratio and intercalation level that are responsible for the optimum perm‐selectivity performance.

Synergistic effects of double-walled carbon nanotubes and nanoclays on mechanical, electrical and piezoresistive properties of epoxy based nanocomposites

Many studies performed on multifunctional properties of epoxy based nanocomposites reinforced with carbon nanotubes (CNTs) and nanoclay (NC) whereas their synergetic effects on piezoresistive behaviour of ternary state nanocomposites still remains unaddressed. Therefore, the hybrid effects of double-walled CNTs (DWCNTs) and NC on the mechanical, electrical and piezoresistive performances of the epoxy were addressed in this study. Nanocomposites were prepared in two different states, i.e. the binary state (DWCNTs/epoxy) and the ternary states (DWCNTs-NC/epoxy). SEM, FESEM, and XRD were used for the microstructural analysis of the materials while tensile and mode I fracture tests were performed for mechanical and piezoresistive characterizations. The addition of NC to CNTs doped epoxy resulted in a better CNT dispersion, hindering CNT re-agglomeration. A significant increase in KIC (94%) and GIC (254%) compared to the neat epoxy was obtained for the hybrid nanocomposites loaded at 1 wt% NC due to crack bridging and crack deflection. The electrical conductivity of the ternary state materials increased by 700% and 400% with respect to the binary nanocomposite, for 0.5 wt% and 1 wt% NC loadings, respectively. The hybrid nanocomposites also manifested higher piezoresistivity and a more robust signal in tensile and fracture tests, respectively.

Effect of nanoclay on mechanical and morphological properties of poly(lactide) acid (PLA) and polypropylene (PP) blends

The aim of this study is to blend the poly(lactide) acid (PLA) and polypropylene (PP) with a fixed ratio of PLA to PP, 75 to 25% by weight using the twin screw extruder. A 3 wt% MAgPP was added into the polymer blends as a compatibilizer. Organo-nanoclay of montmorillonite (OMMT), were added in the amounts of 1, 3, 5 and 7 wt% in polymer blends to improve the mechanical, thermal and morphological properties of the nanocomposites. The resulting polymer nanocomposites were evaluated by using universal testing machine, Izod impact test, thermogravimetric analyzer (TGA) and scanning electron microscope (SEM). The nanocomposites with 1 wt% nanoclay showed the highest tensile strength results which is 49.53 MPa. The Izod impact strength was increased up to 39.2% for 3 wt% of nanoclay. The tensile strain increased about 9.4% after addition of 1 wt% of nanoclay as compared with PLA/PP blend without nanoclay. Overall tensile strain results show that there were slightly changes was observed as increasing the nanoclay content from 3 to 5 and 7 wt%. TGA results showed that the degradation temperature was improved by the addition of 5 wt% of nanoclay in PLA/PP blend. The brittle fractured surface was observed under SEM analysis when 5 wt% nanoclay used. In general, mechanical properties reduced as the nanoclay content increased.

Journal Vol – 15 No -7, July 2020 Journal &gt; Journal &gt; Journal Vol – 15 No -7, July 2020 &gt; Page 6 PERFORMANCE AND EMISSION CHARACTERISTICS OF GASOLINE-ETHANOL BLENDS ON PFI-SI ENGINE Authors: D.Vinay Kumar ,G.Samhita Priyadarsini,V.Jagadeesh Babu,Y.Sai Varun Teja, DOI NO: https://doi.org/10.26782/jmcms.2020.07.00051 admin July 26, 2020 Abstract: Alcohol based fuels can be produced from renewable energy sources and

Journal Vol – 15 No -7, July 2020 Journal &gt; Journal &gt; Journal Vol – 15 No -7, July 2020 &gt; Page 6 PERFORMANCE AND EMISSION CHARACTERISTICS OF GASOLINE-ETHANOL BLENDS ON PFI-SI ENGINE Authors: D.Vinay Kumar ,G.Samhita Priyadarsini,V.Jagadeesh Babu,Y.Sai Varun Teja, DOI NO: https://doi.org/10.26782/jmcms.2020.07.00051 admin July 26, 2020 Abstract: Alcohol based fuels can be produced from renewable energy sources and

Influence of polypropylene and nanoclay on thermal and thermo-oxidative degradation of poly(lactide acid): TG-FTIR, TG-DSC studies and kinetic analysis

Compatibilized poly(lactic acid)/polypropylene (PLA/PP) blends with a drop-matrix morphology containing 25 wt.% PP, 5 wt.% ethylene/n-butyl acrylate/glycidyl methacrylate terpolymer (PTW) as compatibilizer, and 5 wt.% nanoclay were prepared by one-step mixing process in a twin-screw extruder. TEM analysis revealed that the clay particles were mainly localized in the PLA matrix phase in the absence of PTW; by contrast, the addition of compatibilizer changed the location to the blend interface. Multiple rate thermogravimetric analysis revealed two-stage and single-stage weight losses under neutral and air atmospheres, respectively. To reveal the influence of blending, nanoclay inclusion and compatibilization process on the PLA degradation process, a systematic quantitative evaluation of degradation processes was carried out based on kinetic parameters derived from model-free and model-fitting analyses. The results revealed that the activation energy of the thermo-oxidative process, being significantly lower than that of the thermal pyrolysis, greatly increases in the presence of nanoclay, indicating the accelerating role of oxygen in the degradation process and the barrier effect of nanoclay against oxygen diffusion. The combined TG-DSC analysis in the nitrogen environment confirmed the appearance of endothermic signals being proportional to the sample weight loss, which is characteristic of thermal pyrolysis. Subsequently, in an oxygen-containing environment, initial exothermic peaks were formed, which was attributed to the oxidative degradation of the sample. As the reaction progressed, secondary peaks were observed due to the degradation of residuals formed in the first stage of the degradation process. Also, for chemical analysis of volatiles, simultaneous TG-FTIR analysis was employed in a neutral atmosphere at the maximum degradation temperature. Lactide, acetaldehyde, carbon dioxide (CO2) and carbon monoxide (CO) were the products obtained from the degradation process of the PLA phase.