Thyssenmarsh5909

r for hydrogen peroxide is demonstrated.A new approach to produce nanocellular polymers combining small cell sizes with low relative densities is presented herein. This production method, based on gas dissolution foaming, consists of performing a double saturation and foaming cycle. Thus, nanocellular polymethylmethacrylate (PMMA) has been produced through a first saturation at different saturation conditions (6, 10, and 20 MPa and -32 °C), at constant foaming conditions (60 °C for 1 min). 3-Amino-9-ethylcarbazole Then, the nanocellular PMMAs obtained from the previous step were again saturated at different saturation conditions, 10 MPa 24 °C, 31 MPa 24 °C, 35 MPa 22 °C, and 6 MPa -15 °C and foamed at different temperatures (40, 80 and 100 °C) for 1 min. This new approach allows the cells created in the first saturation and foaming cycle to further grow in the second cycle. This fact permits producing nanocellular polymethylmethacrylate sheets combining, for the first time in the literature, cell sizes of 24 nm with relative densities of 0.3.This research deals with the development of knitted hollow composites from recycled cotton fibers (RCF) and glass fibers (GF). These knitted hollow composites can be used for packaging of heavy weight products and components in aircrafts, marine crafts, automobiles, civil infrastructure, etc. They can also be used in medical prosthesis or in sports equipment. Glass fiber-based hollow composites can be used as an alternative to steel or wooden construction materials for interior applications. Developed composite samples were subjected to hardness, compression, flexural, and impact testing. Recycled cotton fiber, which is a waste material from industrial processes, was chosen as an ecofriendly alternative to cardboard-based packaging material. The desired mechanical performance of knitted hollow composites was achieved by changing the tube diameter and/or thickness. Glass fiber-reinforced knitted hollow composites were compared with RC fiber composites. They exhibited substantially higher compression strength ad cotton fiber-reinforced hollow composites. The use of recycled fibers is a positive step in the direction of ecofriendly materials and waste utilization. Their performance is compared with commercial packaging material for a possible replacement and reducing burden on the environment.The recent identification of a finite shear elasticity in mesoscopic fluids has motivated the search of other solid-like properties of liquids. We present an innovative thermal approach of liquids. We identify a dynamic thermo-elastic mesoscopic behavior by building the thermal image produced by different liquids upon applying a low frequency mechanical shear field. We selected three fluids a low molecular weight polybutylacrylate (PBuA), polypropyleneglycol (PPG), and glycerol. We demonstrate that a part of the energy of the shear strain is converted in cold and hot shear bands varying synchronously with the applied shear field. This thermodynamic change suggests a coupling to shear elastic modes in agreement with the low frequency shear elasticity theoretically foreseen and experimentally demonstrated.Oleic acid (OA)-modified Fe3O4 nanoparticles were successfully covered with polyanilines (PANIs) via inverse suspension polymerization in accordance with SEM and TEM micrographs. The obtained nanoparticles were able to develop into a ferrite (α-Fe) and α″-Fe16N2 mixture with a superparamagnetic property and high saturated magnetization (SM) of 245 emu g-1 at 950 °C calcination under the protection of carbonization materials (calcined PANI) and other iron-compounds (α″-Fe16N2). The SM of the calcined iron-composites slightly decreases to 232 emu g-1 after staying in the open air for 3 months. The calcined mixture composite can be ground into homogeneous powders without the segregation of the iron and carbon phases in the mortar without significantly losing magnetic activities.In this paper, creep measurements were carried out on poly(lactic acid) (PLA) and its blends with poly(butylene succinate-adipate) (PBSA) to investigate the specific micromechanical behavior of these materials, which are promising for replacing fossil-based plastics in several applications. Two different PBSA contents at 15 and 20 wt.% were investigated, and the binary blends were named 85-15 and 80-20, respectively. Measurements of the volume strain, using an optical extensometer, were carried out with a universal testing machine in creep configuration to determine, accompanied by SEM images, the deformation processes occurring in a biopolymeric blend. With the aim of correlating the creep and the dilatation variation, analytical models were applied for the first time in biopolymeric binary blends. By using an Eyring plot, a significant change in the curves was found, and it coincided with the onset of the cavitation/debonding mechanism. Furthermore, starting from the data of the pure PLA matrix, using the Eyring relationship, an apparent stress concentration factor was calculated for PLA-PBSA systems. From this study, it emerged that the introduction of PBSA particles causes an increment in the apparent stress intensity factor, and this can be ascribed to the lower adhesion between the two biopolymers. Furthermore, as also confirmed by SEM analysis, it was found that debonding was the main micromechanical mechanism responsible for the volume variation under creep configuration; it was found that debonding starts earlier (at a lower stress level) for the 85-15 blend.The bond fluctuation model was employed to characterize the approach to the mesophase separation transition of pure linear AB copolymers and symmetric miktoarms, also called Janus, star polymers, Af/2Bf/2 , where f = 6 or 12 is the total number of arms, in a common good solvent. We consider a concentration sufficiently high to mimic the melting behavior and also a lower concentration. The segregation between A and B units is represented by a repulsive interaction parameter, . Different total numbers of units are also considered. Results for different properties, such as the molecular size, the asphericity and orientational correlation of blocks, or arms, of different compositions are obtained as a function of the segregation parameter. We also calculate scattering structure factors. The initial effect of segregation on the scattering with opposite contrast factors between the A and B blocks can be explained with a common description based on the random phase approximation for both the linear copolymers and the f = 6 miktoarms, once the numerical form factors of the different molecules in their particular systems are considered. However, the results for f = 12 clearly deviate from this description probably due to some degree of ordering in the position of highly armed molecules.Graphene is an excellent 2D material that has extraordinary properties such as high surface area, electron mobility, conductivity, and high light transmission. Polymer composites are used in many applications in place of polymers. In recent years, the development of stable graphene dispersions with high graphene concentrations has attracted great attention due to their applications in energy, bio-fields, and so forth. Thus, this review essentially discusses the preparation of stable graphene-polymer composites/dispersions. Discussion on existing methods of preparing graphene is included with their merits and demerits. Among existing methods, mechanical exfoliation is widely used for the preparation of stable graphene dispersion, the theoretical background of this method is discussed briefly. Solvents, surfactants, and polymers that are used for dispersing graphene and the factors to be considered while preparing stable graphene dispersions are discussed in detail. Further, the direct applications of stable graphene dispersions are discussed briefly. Finally, a summary and prospects for the development of stable graphene dispersions are proposed.In this study, for the first time, Brazil nut seed oil was chemically modified with maleic anhydride to obtain maleinized Brazil nut seed oil (MBNO). The same process was developed to obtain maleinized hemp seed oil (MHO). The use of MBNO and MHO was studied as bio-based plasticizers by incorporating them with different contents ranging from 0 to 10 phr in a polylactic acid (PLA) matrix. By means of mechanical, thermal and thermomechanical characterization techniques, the properties of the different formulations were studied to evaluate the plasticizing effect of the MBNO and MHO. With the addition of both plasticizers, a significant increase in ductile properties was observed, reaching an increase in elongation at break of 643% with 7.5 phr MBNO and 771% with 10 phr MHO compared to neat PLA. In addition, it has been observed that the mechanical resistant properties do not decrease, since the oils enhance the crystallization of PLA by increasing the free volume between its chains and counteracting the effect. Finally, a disintegration test was carried out under thermophilic conditions at 58 °C for 27 days, demonstrating that the incorporation of MHO and MBNO does not significantly affect the biodegradability of neat PLA.Polycyclic aromatic hydrocarbons (PAHs) are a class of naturally occurring chemicals resulting from the insufficient combustion of fossil fuels. Among the PAHs, phenanthrene is one of the most studied compounds in the marine ecosystems. The damaging effects of phenanthrene on the environment are increasing day by day globally. To lessen its effect on the environment, it is essential to remove phenanthrene from the water resources in particular and the environment in general through advanced treatment methods such as photocatalytic degradation with high-performance characteristics and low cost. Therefore, the combination of metals or amalgamation of bimetallic oxides as an efficient photocatalyst demonstrated its propitiousness for the degradation of phenanthrene from aqueous solutions. Here, we reviewed the different nanocomposite materials as a photocatalyst, the mechanism and reactions to the treatment of phenanthrene, as well as the influence of other variables on the rate of phenanthrene degradation.Polyethylene films are one of the most frequently used packaging materials in our society, due to their combination of strength and flexibility. An unintended consequence of this high use has been the ever-increasing accumulation of polyethylene films in the natural environment. Previous attempts to understand their deterioration have either focused on their durability using polymer analysis; or they have focused on changes occurring during outdoor exposure. Herein, this study combines those strategies into one, by studying the chemical and physical changes in the polyethylene structure in a laboratory using molecular weight and IR spectroscopic mapping analysis, combined with temperate UV-accelerated weathering cycles. This approach has been correlated to real-world outdoor exposure timeframes by parallel testing of the sample polyethylene films in Florida and France. The formation of polyethylene microparticles or polyethylene waxes is elucidated through comparison of drop point testing and molecular weight analysis.