An Analysis of the Properties of Recycled PET Fiber-Gypsum Composites (original) (raw)
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Influence of polycarbonate waste on gypsum composites: Mechanical and environmental study
Journal of Cleaner Production, 2019
This work analyzes the influence of added plastic polycarbonate waste from recycled compact discs (CDs) and digital optical disc (DVDs) on the mechanical and environmental properties of composites with a gypsum matrix. Fifteen mixtures were produced including different percentages by weight of plastic aggregate with two different granulometries. In each case, the strength properties (flexural and compressive) and density of the new composites were tested. In addition, scanning electron microscopy (SEM) and X-ray computed tomography (XCT) were performed in order to know the internal structure and porosity of the new composites. Finally, a simplified environmental study was conducted using the Life Cycle Assessment (LCA) method. The results show that lighter and more eco-efficient materials can be obtained that have, in some cases, better mechanical properties than the reference material (gypsum). A density reduction of a 9.89% was achieved for mixtures with 60% of plastic waste, having also an environmental improvement of 35% compared to the reference sample. In all the cases, the minimum values for mechanical properties required by the standard were obtained. These properties make the composites suitable for use in new products and in construction works.
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Due to the economic importance of polypropylene (PP) and polyethylene terephthalate (PET), and the large amount of composites made with PP matrix and recycled PET as reinforcing material; an investigation was performed regarding the mechanical and thermal behavior of PP composites containing recycled polyethylene terephthalate fibers (rPET). Interfacial adhesion between the two materials was achieved by adding a compatibilizer, maleic anhydride grafted polypropylene, PP-g-MA. Mechanical behavior was assessed by tensile, flexural, impact and fatigue tests, and thermal behavior by HDT (Heat Deflection Temperature). Fractured surfaces and fiber were investigated by scanning electron microscopy. Multiple regression statistical analysis was performed to interpret interaction effects of the variables. Tensile strength, tensile modulus, flexural strength, flexural modulus and HDT increased after rPET fiber incorporation while strain at break, impact strength and fatigue life decreased. Addition of compatibilizer increased tensile strength, flexural strength and flexural modulus, fatigue life and HDT while tensile modulus, strain at break and impact strength decreased. However, at low fiber content, the impact strength increased, probably due to nucleation effects on PP.
Physical and mechanical properties of polymer-gypsum composite
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E3S Web of Conferences
Recycling and reuse of plastic waste by blending with virgin polymer has been affirmed to be the best way of managing the waste. Equally, agro-waste are best recycled than being burnt off. In the development of stronger and cheaper ecoefficient recycled PET composite for food packaging, this study focused on reinforcement of the blend of 20 wt. % recycled PET (rPET) and 80 wt. % virgin PET (vPET) with snail shell particulate and kenaf fiber via compression moulding process. The process parameters are fiber dosage, particulate dosage, moulding pressure and temperature. Box-Behnken design was engaged in the design of experiment and the samples were produced according to the experimental runs. Result of analysis of variance pinpointed the process factors as significant contributors to the flexural strength response. The model developed was validated to be significant and statistically fit. Interactions between the process variables as revealed by the response surface plots indicated th...
Journal of Materials Processing Technology, 2005
The interfacial adhesion and mechanical properties of injection-molded recycled poly(ethylene terephthalate) with glass fibre has been studied as a function of two variables involved in the extrusion process: screw speed and screw torque. The composites properties studied included DMTA, flexural strength, Young's modulus and impact strength. The Young's modulus and impact resistance of the composites increased with the addition of glass fibre in recycled PET matrix. A factorial experimental design (FED), based on the screw speed and torque of the double screw extruder used, was done to get the best thermo-mechanical properties versus processing conditions. Screw speed at the high level (200 rpm) was significant to increase Young's modulus. It was shown that "screw torque" on its high level (60%) was the significant factor to increase Impact strength of these composites. The results of these preliminary studies showed clearly the positive effect on the interfacial adhesion between matrix-fibre for some processing condition and also showed the best mechanical properties.
Materials Research-ibero-american Journal of Materials, 2008
The use of waste fibers for the reinforcement of brittle matrices is considered opportune for the sustainable management of urban solid residues. This paper examines the microstructure and mechanical properties of a composite material made of gypsum reinforced with cellulose fibers from discarded Kraft cement bag. Two different kinds of gypsum were used, natural gypsum (NG) and recycled gypsum (RG), both with an addition of 10% by mass of limestone. For the production of samples, slurry vacuum de-watering technique followed by pressing was evaluated revealing to be an efficient and innovative solution for the composites under evaluation. The composite was analyzed based on flexural strength tests, scanning electron microscopy (SEM) imaging, secondary electron (SE) detection, and pseudo-adiabatic calorimetry. The morphology of the fractured surfaces of flexural test samples revealed large gypsum crystals double the original size surrounding the fibers, but with the same overall aspect ratio. Natural fibers absorb large amounts of water, causing the water/gypsum ratio of the paste to increase. The predominance of fiber pullout, damaged or removed secondary layers and incrusted crystals are indicative of the good bonding of the fiber to the gypsum matrix and of the high mechanical resistance of composites. This material is a technically better substitute for the brittle gypsum board, and it stands out particularly for its characteristics of high impact strength and high modulus of rupture.
Enhanced Impact Strength of Recycled PET/Glass Fiber Composites
Polymers, 2021
In this paper, we report a study on the effects of different ethylene copolymers in improving the impact strength of a fiber-reinforced composite based on a recycled poly(ethylene terephthalate) (rPET) from post-consumer bottles. Different ethylene copolymers have been selected in order to evaluate the effects of the polar co-monomer chemical structure and content. The composite mixtures were prepared via melt extrusion, and the samples were manufactured by injection molding. Impact strength was evaluated using Izod tests, and a morphological study (FESEM) was performed. As a result, a composite with substantially improved impact properties was designed. This study demonstrates that a post-consumer PET from the municipal waste collection of plastic bottles can be successfully used as a matrix of high-performance, injection-molded composites, suitable for use in the automotive sector, among others, with no compromise in terms of mechanical requirements or thermal stability.
Recycling of Low-Density Polyethylene Waste to Produce Eco-Friendly Gypsum Composites
WIT Transactions on Ecology and the Environment
Over 367 million metric tons of plastic were produced worldwide in 2020. Within the most consumed standard plastics, low-density polyethylene (LDPE) is the second resin most demanded in Europe. Far from reducing its consumption, this continues to grow despite environmental impact. Due to the low recycling rate of LDPE waste (~35%), coming mainly from post-consumer packaging and lightweight bags, most parts of this waste end up in the environment. As an alternative to restrained governmental steps, i.e. extra taxes to reduce single-use plastic consumption, new solutions for the recycling and reuse of plastic waste are being developing from different economic sectors. Because of the worldwide significance of the construction sector, which has a large consumption of natural resources and production of waste, this sector plays a critical role within the new models of circular economy. In light of this, and committed to the sustainable development goals adopted by the United Nations, the present work intends to determine the feasibility of using LDPE waste sourced from plastic bags to produce eco-friendly gypsum-based composites. Four replacement levels of plastic waste were chosen for analysis-0.25%, 0.5%, 1%, 5% by weight of gypsum. The experimental campaign consisted of analysing the resulting compounds based on density, mechanical behaviour (flexural and compressive strength), as well as evaluating their water absorption by capillary action and adsorption by exposing them to continuous moisture. Comparing this to the control material, lighter composites with a decrease of mechanical strength were obtained. However, all the values of flexural and compressive strength exceeded the minimums established by standard. Also, the LDPE-containing composites presented lower water absorption and adsorption capacity (up to ~50% when compared to the control material). So it could be inferred that the waste material can be considered as a viable partial substitute to the current commercial gypsum for the manufacturing of gypsum products, i.e. plasterboards.
International Journal of Polymer Science, 2021
After primary uses of the plastic product, most developing countries like Ethiopia are facing a shortage of postconsumer disposal waste sites and it became a very serious problem on environmental pollution due to its nonbiodegradable nature. For this reason, regenerating and using the waste product as resources and reducing environmental pollutions are a great opportunity. This research is aimed at the manufacturing of composite materials from waste poly(ethylene terephthalate) (PET) bottles reinforced with glass fibers and filled with waste glass powder for floor tile applications. The tile composites were prepared by the melt-mixing method followed by compression molding. The effect of filler, fiber, and PET matrix loading on the composite was investigated using their tensile, compression, and flexural strength tests. The sample was characterized using a universal testing machine. PerkinElmer FTIR instrument was also used. For this, eleven samples prepared by varying the glass fiber weight % from 0 to 10, PET matrix weight % from 70 to 85, and glass powder filler weight % from 5 to 20. The measurement results of the composite were maximum tensile strength (81.625 MPa) and flexural strength (1067.59 MPa) recorded at 10%weight of glass fiber, 85% weight of PET matrix, and 5%weight of window glass filler. The maximum compressive strength is 1876.14 MPa at 10% weight glass fiber, 70 wt% PET matrix, and 20 wt% window glass filler. Based on this, the tensile strength and flexural strength increased with increased weight % of glass fiber and decreased with increased window glass filler. The FTIR spectrum shows some of the groups that have been removed from the recycled PET; this explains the brittleness of the recycled PET as compared to the waste bottle PET. The microstructure was uniformly distributed, and the material became opaque, probably because the decrease in chain length improves chain packing, increasing the crystallinity degree and crystal size.
Polymers
This paper presents an investigation of the tensile properties of two composites made from recycled polyethylene tetraphthalate, cement–concrete mix and standard polymer-based adhesive mixes, used in the construction industry. To describe tensile behavior, experimental measurements of each component of the resulting composite materials were processed in detail. It presents the possibilities of modifying materials suitable for building structures and at the same time provides an opportunity to get rid of polyethylene tetraphthalate (PET), which has already been recycled several times. Because the resulting composite contains a majority of the composite composition on a fragile basis, its use in practice depends on its simple thrust properties. In this paper, a study of the most important mechanical properties of a previously unused composite is presented. These properties were obtained experimentally using an innovative tensile test method.