Development of lightweight human prosthetic vinyl based composite material using porous biocarbon, low density luffa fibre and recycled waste polyethylene terephthalate (PET) foam

Polyethylene terephthalate (PET) foam is a possible replacement option for polyurethane (PUR) foam as insulation material in district heating pipes. In this study, the diffusion coefficients and activation energies of cell gases in carbon dioxide blown PET foam (densities 148–157 kg·m −3 ) were determined at temperatures between 23 °C and 90 °C. The foam thermal ageing due to the mass transport of air into and carbon dioxide out of the foam was about ten times slower in PET foam than in PUR foam. The thermal conductivities of the PET foam boards were determined in a heat flow meter apparatus. The contribution to the foam thermal conductivity due to conduction in the solid polymer and radiation within the cell voids was determined to 17 mW·m −1 ·K −1 at 20 °C. This is higher than the value estimated for PUR foam in district heating pipes, 12 mW·m −1 ·K −1 . This contribution can probably be reduced by developing low density PET foam and reducing the cell size.

Polyethylene terephthalate (PET) foam sandwich structure is widely used in the fields of construction, aerospace and shipbuilding. We have conducted research on its hygroscopic phenomenon. Take different sizes of GFRP panels, PET foam and PET foam sandwich structure for moisture absorption tests, analyze the data on the basis of the classic Fick’s law of diffusion to obtain the moisture absorption curves of each sample. And get the diffusion coefficient of the specimen. Then, we use the multi-physics software COMSOL to model and analyze the moisture absorption properties of the specified samples. The moisture absorption curve obtained by theoretical calculation was compared with the experimental moisture absorption curve, and the results showed that the two Good agreement. Tests have proved that the moisture absorption performance of PET foam is much greater than that of GFRP panel material, and the relative moisture absorption is related to the specific surface area of the sample. In the PET foam sandwich structure, the GFRP panel can effectively inhibit the hygroscopicity of the PET foam and has an excellent protective effect on the PET foam.

Effect of fiber orientation on mechanical behavior of glass fiber reinforced polyethylene terephthalate foam sandwich composite

Effects of elevated temperature on the shear response of PET and PUR foams used in composite sandwich panels

Mechanical behaviour in shear and compression at elevated temperature of polyethylene terephthalate (PET) foam

The polyethylene terephthalate (PET) foam sandwich structure is widely used for ships and for studying the influence of the seawater environment on its mechanical properties as an important way to evaluate its safety performance. To study the effect of the seawater environment on the mechanical properties of the PET foam sandwich structure, this paper mainly studies the static properties, interlayer cracking properties, and fatigue failure properties of the PET foam sandwich structure under the simulated seawater environment at a constant temperature of 40°C. The compressive properties test, tensile properties test, three-point bending properties test, double cantilever beam test, and four-point test were carried out on PET foam specimens, glass fiber reinforced plastic (GFRP) panel specimens, and PET foam sandwich structure specimens with different immersion times. The multiphysics software COMSOL was used to model and analyze the mode I interlayer cracking properties of the PET foam sandwich structure. The comparative analysis of the experimental results shows that the seawater environment has an effect on the compression properties of PET foam, the tensile and flexural properties of GFRP panels, and the interlayer cracking properties of the PET foam sandwich structure, and as the immersion time is extended, the effect is more obvious. Seawater immersion can also lead to a reduction in the fatigue life and ultimate fatigue of the PET foam sandwich structure.

Static crushing of aluminium tubes filled with PET foam and a GFRP skeleton. Numerical modelling and multiobjective optimization

An investigation was conducted on the foaming formula and production technique of polyethylene terephthalate (PET) using orthogonal design analysis and Box–Behnken response surface analysis. PET was combined with polyolefin elastomer (POE) and filled with surface‐treated mica, quartz, and graphene oxide (GO). POE served as a carrier and modifier for the foaming agent, as well as a toughening agent. The addition of fillers can improve the thermal properties of PET foaming material. To do this, the blending process includes using a microsphere foaming agent on an open mill at a low temperature of 50°C for 5–6 min. After this, dicumyl peroxide (DCP) and antioxidant are added for 1 min before the specimens are removed from the open mill and flattened. The next step involves placing the specimens in a plate vulcanizing machine at 265°C and 10 MPa for 10 min to initiate the foaming process. The PET foam obtained has a density of 0.4–0.5 g/cm3, a tensile strength of 5–6.8 MPa, an elongation at break of 64–276%, and a tear strength of 5.1–14.5 N/m. Scanning electron microscope (SEM) images reveal that the PET foam contains micron‐sized cells, with measurements ranging from about 107 to 273 μm. The tested samples showed that the PET foam with 50 phr of POE, 7 phr of foaming agent, and 5 phr of mica exhibited relatively good mechanical properties, including tensile strength, elongation at break, and tear strength. The thermogravimetric analysis (TGA) indicated that the thermal properties of PET foam are better than those of pure PET. The modified PET foam has many applications due to its low density and excellent properties. This study introduces a new and uncomplicated method for producing PET foam, which differs from the commonly used extrusion foaming process that involves supercritical carbon dioxide or other media.

Polyethylene terephthalate (PET) foams have the characteristics of being lightweight and high strength, as well as offering good heat resistance, minimal water absorption, etc., and they have been widely used in the wind power field. In addition, they are being promisingly applied in automotive, rail, marine, construction, and other related fields. Therefore, the flame retardancy(FR) of PET foams is an issue that requires investigation. The addition of flame retardants would affect the chain extension reaction, viscoelasticity, and foamability of PET. In this study, zinc diethyl hypophosphite (ZDP) and decabromodiphenylethane (DBDPE) were used to form a synergistic FR system, in which ZDP is an acid source and DBDPE is a gas source, and both of them synergistically produced an expanded carbon layer to improve the flame retardancy of PET foams. The ratio of ZDP and DBDPE is crucial for the carbon yield and the expansion and thermal stability of the char layers. At the ZDP/DBDPE ratios of 9/3 and 7/5, the thickness of the char layers is about 3-4 mm, the limiting oxygen index (LOI) values of FR modified PET are 32.7% and 33.6%, respectively, and the vertical combustion tests both reached the V-0 level. As for the extruded phosphorous/bromine synergism FR PET foams, ZDP/DBDPE ratios of 3:1 and 2:1 were applied. As a result, the vertical combustion grade of foamed specimens could still reach V-0 grade, and the LOI values are all over 27%, reaching the refractory grade.

The primary aim of this research work was to develop a lightweight vinyl ester based prosthetic composite with silane treated Polyethylene terephthalate (PET) foam and areca fiber and how the silane surface treatment process influence the laminar adhesion against to accelerated aging conditions. Both the foam (3 mm) and fiber is silane‐treated via aqueous solution method and the composites were subjected to accelerate aging via temperature (40 and 50°C) as well as sea and rain water. The developed composites were evaluated based on American society of testing of materials (ASTM) standards and the results revealed a consistent stability in tensile strength for post‐silane treated composites on both aging conditions. Particularly, the interlaminar shear strength (ILSS) test emphasized that the silane treated reinforcements has high resistance against delamination. Similarly, flammability test demonstrated sustained fire‐resistant properties in both horizontal and vertical orientations, with negligible variations in flame propagation speed. Thermal conductivity test revealed the intricate interplay of PET core and areca fiber on heat transfer. Thus, from results it is evident that the silane surface treatment helped to maintain the laminates adhere with matrix in spite of the accelerated aging conditions such as prolonged heat exposition as well as water immersion. These findings contribute valuable insights into the load bearing performance of the lightweight composite materials in human prosthetic applications where prolonged heat and water aging happened frequently.Highlights Lightweight polymer foam‐areca fiber prosthetic composites prepared and tested for accelerated weather conditions PET foam and areca fiber is silane surface treated using amino‐silane Treated foam and fiber maintained mechanical properties under aged condition Treated foam and fiber maintained flammability properties under aged condition Silane treated foam and fiber maintained good thermal conductivity under aged condition

In this study, polymer composites comprised of shavings of SBS paperboard coated with polyethylene terephthalate (PET) and recycled low-density polyethylene (LDPE) were obtained. The tensile properties, flexural strength, impact resistance and water absorption were determined according to the standards published by the American Society for Testing and Materials (ASTM). The results show that the composites with the highest concentration of LDPE were more resistant to absorption when exposed to water and humidity. As regards density, a 19.5% increase of this property was verified for the 30% cellulosic fiber reinforced composite relative to the pure LDPE density. In relation to the mechanical properties, these samples were found to be very flexible in the elasticity test. The extrusion method provided adequate adhesion between the interfaces of the matrix with the fiber. The composite showed a tensile strength of approximately 55% larger than that originated by pressing. However, the values for the tensile, flexural and impact strength were lower than expected due to the lack of homogeneity of the SBS paperboard shavings. Keywords: packaging residue, mechanical properties and polymers.

This paper discusses the study of mechanical properties of glass fibre-vinyl ester composites and the effect of fillers namely Silicon Carbide and Boron carbide. Mechanical properties including tensile strength, tensile modulus and elongation at break, flexural strength, impact strength and surface hardness are investigated in accordance with ASTM (American Society for Testing and Materials) standards. Reinforced plastics were fabricated with vinyl ester resin as matrix system and woven glass fabric as reinforcement with boron carbide particulate fillers. Each fabrication carries the filler content varied from 3% -9% with incremental steps of 3%. Mechanical tests were carried out on specimens from each laminate, comparison between boron carbide and silicon carbide filled composite was done and it is observed that boron carbide filler enhances the mechanical properties of glass fiber reinforced vinyl ester composites.

The role of PTFE in-situ fibrillation on PET microcellular foaming

Shape memory properties of PET (polyethylene-terephthalate) foams have been evaluated for two different foam densities. Samples were subjected to multiple memory-recovery cycles along three different directions to measure the effect of foam anisotropy on static mechanical and shape memory properties. The memory cycle was performed by uniaxial compression tests at room temperature. Despite these severe conditions, PET foams demonstrated very good shape memory behavior with shape recovery always higher than 90%. Due to cycling, the mechanical performance of foam samples is partially reduced, mainly along the extrusion direction of the foam panels. Despite this loss of static performance, shape memory properties are only partially affected by thermo-mechanical cycles. The maximum reduction is 10% for shape fixity and 3% for shape recovery. The experimental results are particularly interesting considering that compression tests were undertaken at room temperature. Indeed, PET foams seem to be optimal candidates for self-repairing structures.

In this work, fire-retardant systems consisting of graphene nanoplatelets (GNPs) and dispersant agents were designed and applied on polyethylene terephthalate (PET) foam. Manual deposition from three different liquid solutions was performed in order to create a protective coating on the specimen’s surface. A very low amount of coating, between 1.5 and 3.5 wt%, was chosen for the preparation of coated samples. Flammability, flame penetration, and combustion tests demonstrated the improvement provided to the foam via coating. In particular, specimens with PSS/GNPs coating, compared to neat foam, were able to interrupt the flame during horizontal and vertical flammability tests and led to longer endurance times during the flame penetration test. Furthermore, during cone calorimetry tests, the time to ignition (TTI) increased and the peak of heat release rate (pHRR) was drastically reduced by up to 60% compared to that of the uncoated PET foam. Finally, ageing for 48 and 115 h at 160 °C was performed on coated specimens to evaluate the effect on flammability and combustion behavior. Scanning electron microscopy (SEM) images proved the morphological effect of the heat treatment on the surface, showing that the coating was uniformly distributed. In this case, fire-retardant properties were enhanced, even if fewer GNPs were used.