Waste PP Research Articles

Manufacture and Characterization of Lightweight Sand-Plastic Composites Made of Plastic Waste and Sand: Effect of Sand Types

Over the past decade, many types of waste have been exploited as feedstocks in different industries. Recycled plastics are among the waste sought for several civil engineering applications. In this work, various plastic-bonded sand composites based on polypropylene waste and silica sand were produced to serve as building materials in many construction applications. Many tests and analysis were carried out in this investigation. First of all, two initial used compounds (waste PP and various silica sand) were analyzed by using ATR-FTIR, XRF, and grain size distribution. In the second time, the different plastic-bonded sand composites were analyzed by using ATR-FTIR to assess their composition. On the other hand, mechanical, and physical tests such as three-point flexural strength, compressive strength, water absorption, and optical observation were applied on different produced composite samples, then the results were examined and analyzed. The results showed that the developed composites exhibit commendable mechanical properties, especially flexural and compression resistance, and minimal water absorption. It is worth noting that the plastic-bonded sand containing Khobana sand showed the highest flexural and compressive strength at 11.56±0.36 and 26.19±0.27 MPa, respectively, along with the lowest water absorption rate of 0.46%. This study confirms its contribution to enhancing sustainability and promoting the principles of the circular economy.

Research on the co-pyrolysis kinetic and synergistic effect of waste PP and LDPE mixed plastics

Research on the co-pyrolysis kinetic and synergistic effect of waste PP and LDPE mixed plastics

Design a machine with technology to convert plastic waste into fuel renewable energy

Research has been carried out on the design of machines with technology to convert plastic waste into fuel renewable energy, the aim is to find out pyrolysis technology which is a technology in converting plastic waste into reusable gas and liquid phases that have the potential to be used as renewable energy. The machine consists of one pyrolysis reactor, 3 condensers, 3 storage tanks. The standard method used to test samples is ASTM D4052. This plastic waste converter machine uses Polypropylene and High-Density Polyethylene plastics. The results showed that the most pyrolysis oil from PP plastic waste was 0.52 kg and HDPE was obtained as much as 0.62 kg from each type of waste material as much as 3 kg. For PP plastic waste, the specific gravity of oil is 866.7 kg/m3 and 743.1 kg/m3 and HDPE plastic the specific gravity of oil is 842 kg/m3 and 737.7 kg/m3. The specific gravity of pyrolysis oil in waste PP plastic and HDPE plastic is close to the specific gravity of diesel fuel and gasoline. Data based on Directorate General of Oil and Gas Indonesia for specifications of diesel specific gravity 815-870 kg /m3, specifications of gasoline type 88 is 715-770 kg /m3.

Waste polypropylene filter induced synthesis of pure phase Fe3O4 and ZVI incorporated carbon composite for non-radical peroxymonosulfate activation dominated sulfamethoxazole degradation: Singlet oxygen versus electron transfer process

In this study, waste polyethylene (PP) obtained from obsoleting water purifier filter was mixed with ferric chloride hexahydrate (FeCl3·6H2O) to prepare a series of single crystal phased iron compound incorporated carbon composites (Fe/PP-C). The prepared Fe/PP-Cx catalysts were then utilized to degrade sulfamethoxazole (SMX) in water by activating peroxymonosulfate (PMS). The results showed that with the assistance of pyrolysis temperature regulation, waste PP filter could control the crystalline phase of the iron compound in the prepared Fe/PP-Cx through releasing distinct gaseous atmospheres at respective pyrolysis temperature. When the pyrolysis temperature was set at 600 °C and 900 °C, pure phase ferric oxide (Fe3O4) and zero-valent iron (ZVI) incorporated carbon catalysts were obtained, respectively. 0.2 g/L of Fe/PP-Cx could completely degrade 0.02 mM of SMX within 20 min, in which the toxicity of the reaction solution was also effectively reduced. In both Fe/PP-Cx/PMS systems, non-radical mechanisms dominated the SMX degradation, in which singlet oxygen played the dominant role in the Fe/PP-C600/PMS system, whereas electron transfer process was primarily responsible for SMX degradation in the Fe/PP-C900/PMS system. High-valent iron-oxo species was also involved in SMX degradation in the Fe/PP-C900/PMS system. Since Fe/PP-C600 and Fe/PP-C900 respectively activated PMS via heterogeneous and homogeneous routes, Fe/PP-C600 maintained higher longtime use stability. This study aims to present a simple approach to manipulate the nonradical organic pollutant degradation mechanisms in PMS activated system, which also provides a new strategy of utilizing waste polymer.

Sustainable Solution for Plastic Pollution: Upcycling Waste Polypropylene Masks for Effective Oil-Spill Management.

The use of Polypropylene PP in disposable items such as face masks, gloves, and personal protective equipment has increased exponentially during and after the COVID-19 pandemic, contributing significantly to microplastics and nanoplastics in the environment. Upcycling of waste PP provides a useful alternative to traditional thermal and mechanical recycling techniques. It transforms waste PP into useful products, minimizing its impact on the environment. Herein, we synthesized an oil-sorbent pouch using waste PP, which comprises superposed microporous and fibrous thin films of PP using spin coating. The pouch exhibited super-fast uptake kinetics and reached its saturation in fewer than five minutes with a high oil uptake value of 85 g/g. Moreover, it displayed high reusability and was found to be effective in absorbing oil up to seven times when mechanically squeezed between each cycle, demonstrating robust oil-sorption capabilities. This approach offers a potential solution for managing plastic waste while promoting a circular economy.

In situ nanofibrillation of polypropylene/polyethylene/poly(ethylene terephthalate) ternary system: A strategy of upgrade recycling

Upgrade recycling of multicomponent polymer blends remains a great challenge due to the inherent immiscibility of most polymer combinations. Herein, we report a new and efficient strategy potential for upgrade recycling of polypropylene/polyethylene/poly(ethylene terephthalate) (PP/PE/PET) ternary system, through in situ nanofibrillation of PET with the aid of extrusion-hot stretching and further annealing stretching. PET fibrils with high aspect ratios are achieved in the ternary blends by extrusion-hot stretching, and adding compatibilizer and further annealing stretching reduce the average diameter of PET fibrils down to as low as 240 nm. The PET nanofibrils suppress the relaxation of orientated structure during the hot stretching progress, which increases the orientation factor of PP from 0.08 to 0.30. During further annealing stretching, the PP molecular chains are highly oriented under the extensional flow field and PE grows epitaxially on the oriented PP substrate regardless of the presence of PET nanofibrils, promoting the interfacial adhesion between PP and PE. The high orientation of PP and PE, the epitaxial crystalline structure and PET nanofibrils impart remarkably enhanced tensile strength (up to 481.2 MPa), elasticity modulus (up to 4.85 GPa) and elongation at break (up to 1004.9%) to the PP/PE/PET ternary blends. This work could provide significant guidance for the high-performance processing and upcycling of waste PP, PE and PET materials.

Experimental and numerical investigation of mechanical strength characteristics of natural fiber retrofitted rammed earth walls

Unreinforced earthen houses offer manifold environmental and economic advantages. However, such houses are inadmissible in today's era due to their poor performance during earthquakes. Recent Jan 3, 2017 moderate Tripura earthquake (Mw=5.7) has evidenced a sizable stock of damages to non-engineered adobe/rammed earth houses which primarily act as the motivation behind the present study. In this context, the present study is an attempt to propose a novel seismic encasing retrofitting technique by providing natural and artificial fiber with a key focus on the economy, sustainability, and utilizing locally available material. In this regard, static mechanical strength characteristics (i.e., shear, compressive and flexural strength) of unreinforced and retrofitted rammed earth wall units are investigated through model-scale experiments in the laboratory considering parametric variations as well as numerical analysis of prototype wall. Further, multiple linear regression analysis is performed to develop empirical relationships for predicting shear and compressive strength of retrofitted rammed earth walls. The study highlights the significant improvement in mechanical strength of retrofitted rammed earth walls by treated natural fiber retrofitting strips as well as artificial waste PP strips. Besides, the sanctity of proposed regression-based empirical equations is well verified through a numerical case study on a prototype rammed earth wall.

Particle trajectory model for tribo-electrostatic separating mixed granular plastics

Tribo-Electrostatic Separation (TES) is suitable for recycling plastic from waste to avoid losing its virgin value. The separation model, which comprised of computing the electric field and the analysis of forces on the particles, was utilized to write a program by MATLAB language. The particle trajectory model based on TES is established. The model includes electric field computation and part of an analysis of forces on the particles. The electrode parameters and material parameters can be changed in the model. A photographic system including a high-speed camera (1000fps) was used to capture the plastic particle trajectories and to verify the model. Both waste PVC and waste PP particles were captured. The results computed by the model have a good agreement with the experimental results. The model can find suitable parameters for separating different waste plastics and help explore TES applications. • Establish a model to simulate the trajectory of plastic granules in TES. • Design the photographic system to capture the practical trajectories. • The model has a good agreement with the experimental results.

Preparation and Characterization of Recycled PP/Organo-Clay Filter for Dyeing Ability

Organo-modified clay was used to prepare waste polypropylene/clay composite by melt mixing method. Composites were then melt spun into linear filaments. Attention is given to how the organoclay influence the morphology and the dyeability of resultant waste PP filaments. Scanning electron microscopy was used to investigate the surface morphology and cross section of the filaments. Dyeing studies underlined the improvement of dye affinity of elaborated filaments to acid, basic, and disperse dyes. Moreover, we observed that waste PP and its composite monofilaments have the highest dyeability when using disperse dye. The prepared filaments were then used to fulfill a filter for the treatment of textile dye waste water. Thus, 3D geometrical design of the filter structure was realized by the SolidWorks mechanical design software.

Recycling of waste PP and crumb rubber together by use of self-healing ionomer as process compatibilizer

Recycling of mixed waste, including plastic and rubber, by the blending process is one of the promising sustainable routes. In this paper, the processing of crumb rubber with waste thermoplastic polypropylene is reported. The poly(ethylene-co-methacrylic acid) copolymer sodium ion was introduced as a compatibilizer. The waste materials were processed by injection molding to a property improved value-added plastic–rubber recyclate. There was an improvement of tensile strength and modulus of about 60 and 85%, respectively, by addition of 7 wt.% of ionomer as compatibilizer. Enhanced thermal stability was also observed as compared to that of neat blend. The change in morphological characteristics that influence the end properties was analyzed by field emission scanning electron microscope and atomic force microscope. Evaluation of dispersion of different phases and their stress transfer tendency was studied for both tensile fractured and molded samples. The changes in thermo-mechanical properties are correlated to morphological characteristics, and the efficacy of the compatibilization process was estimated.

A TG-FTIR investigation on the co-pyrolysis of the waste HDPE, PP, PS and PET under high heating conditions

The present study relates to the investigation of degradation of polymers such as HDPE, PP, PS and PET individually and in mixed forms. Eleven different mixture combinations were analyzed via TG Analysis to determine their degradation behavior individually and in mixed forms. FTIR analysis of the raw polymers was performed to investigate the presence of different functional groups in the sample. Online TG-FTIR analysis was performed to investigate the functional groups present in the volatiles fractions during single component pyrolysis and the interaction of polymers during co-pyrolysis was analyzed, compared and reported. Also, a real-world post consumer mixed waste was also analyzed and compared. During the co-pyrolysis of HDPE with PP and PS, the degradation of PP was delayed whereas PS reduced the degradation temperature of HDPE. In the case of degradation of PS with PP and PET, the increase in degradation temperature was reported whereas, in the case of PET and HDPE mixture, the degradation temperature of HDPE was reduced. During the interaction of PP and PET mixed degradation, PET degradation temperature was delayed. During the FTIR analysis a large amount of alkanes, alkenes, aromatics groups were observed during the degradation of HDPE, PP and PS whereas in case of PET the presence of oxygenated groups is observed. During the mixed degradation, the presence of PET in the sample caused the formation of oxygenated groups by reducing the absorption intensity of other groups or by disappearing the groups. Compounds such as benzoic acid, CO and CO2 was detected during the degradation of PET whereas in other polymers a large amount of methane or methylene group is observed. Overall during the degradation of mixed polymer mixture presence of PET played a vital role in the formation of light gas fractions. Even though a numerous investigation on co-pyrolysis of polymers were available, there is still not sufficient information of interaction of polymers with each other, especially with PET. This article attempts to fill this gap.

Deformation of virgin HD-PE, PP and waste PP Plastics into green fuel via a Pyrolysis-catalytic using a NiCO3 catalyst

ABSTRACTLiquid green fuel or petrochemicals from virgin polypropylene, high-density polyethylene and waste PP were produced via a pyrolysis-catalytic cracking. Recycling which is a capable way of PP and HD-PE changing into green fuel. Pyrolysis-catalytic cracking was conducted at the temperature range 23–370°C with a NiCO3 catalyst and it helps need of alternative fuel. Green fuel was analysed by triple quadrupole GC–MS–MS, FT-IR spectroscopy, Perkin-Elmer series-II CHNS/O 24000, ICP, TGA its result founding into five categories as paraffin, cyclic paraffin, alcohols, esters and acetates. Conversion rates of virgin PP, HD-PE and waste PP into liquid green fuels were 87%, 89%, 90%, light gases 12.28%, 10.45%, 9.51% and residues 0.72%, 0.55%, 0.49% recovered from overall production process.

Impact of Tunisian clay nanofillers on structure and properties of post-consumer polypropylene-based nanocomposites

This study investigates the influence of clay nanofiller on morphological, thermal, and mechanical behaviors of post-consumer polypropylene (PCPP)-based nanocomposites. Waste polypropylene was mixed with 1%, 3%, 5%, and 7% of Tunisian clay nanoparticles using twin-screw extruder. The structure and morphology of raw, purified, and organo-modified clays were characterized by Fourier-transform infrared spectroscopy and X-ray diffraction (XRD). The influence of clay nanoparticles content on the thermal behavior of waste polypropylene was studied by means of thermogravimetric analysis. The effect of nanoclay on morphology and properties of PCPP/clay nanocomposites was also studied. It was found from transmission electron microscopy and XRD analysis that clay nanoparticles are well dispersed into PCPP matrix and the addition of organo-modified Tunisian clay did not change the crystal structure of the PCPP polymer. Thus, organically modified Tunisian clay can be used for preparing organic–inorganic hybrids by melt processing with waste PP polymers. In dead, by varying the nanofiller loading, mechanical properties (Young’s modulus, tensile strength, and elongation at break) and thermal stability of filled PCPP showed an increase as compared to unfilled polymer. Optimal mechanical performances were obtained with 5% clay loading.

Catalytic cracking of heavy fractions from the pyrolysis of waste HDPE and PP

In the present paper, automotive waste plastics were considered as a potential source of fuels and chemicals. The feedstock in the experimental tests was represented by the heaviest fractions from the distillation of pyro-oil from the pyrolysis of high-density polyethylene (HDPE-wax) and polypropylene (PP-wax). Due to their very high viscosity both polymer-waxes were, prior to processing, diluted in atmospheric gas oil (GO). Mixtures with hydrotreated vacuum gas oil (HVGO) were also prepared and processed under simulated fluid catalytic cracking conditions via a MAT-test. The product distribution was similar to the one shown by the commercial FCC process: light gases (C1, C2), LPG, gasoline fraction, light and heavy cycle oil. To maintain optimal performance a commercial FCC equilibrium catalyst (FCC-ECAT) was used. When processing HDPE and PP waxes, high yields of profiling products – propylene and gasoline were obtained. In the case of the PP-wax feed without HVGO, the yield of gasoline was even higher than in case of pure HVGO. When cracking HDPE-wax feed mixtures the product distribution was oriented more towards the production of propylene. The composition of liquid products considering all types of feedstock consisted mainly of iso-alkanes and aromatics. The calculated values of microactivity for the HDPE-wax and PP-wax feedstock, with or without HVGO, were significantly higher than in the case of pure HVGO.

Thermal Behavior of Calcium Carbonate and Zinc Oxide Nanoparticles Filled Polypropylene by Melt Compounding

This study investigates the effect of Calcium Carbonate and Zinc Oxide nanoparticles on thermal behavior of virgin and waste polypropylene. CaCO3 nanoparticles at content of (3, 5, 7 and 10 wt. %) mixed with virgin and waste PP by using co-rotating twin screw extruder at 25 rpm and 190°C. Two techniques used to incorporate ZnO nanoparticles in waste PP in two steps: the first one ZnO nanoparticles mixed with acetone solvents by ultrasonic device and then using twin screw extruder to produce nanocomposite sheet. Fourier Transmitted Infraredspectroscopy (FTIR) test used to check the structure of polypropylene. X-Ray Diffraction is used to check the crystallinity of nanocomposite. Thermal conductivity of the modified composite was studies by using thermal coefficient meter model (YBF-3). The qualitative and quantitative temperatures distribution of the extruding polymer nanocomposite is tested by using FLIR thermal camera due to different melt flow rate. Strong relation between crystallinity, thermal conductivity and thermal gradient of nanocomposite is observed. The results show that an improvement in thermal conductivity for both virgin and waste PP with nanoparticles content increasing, thermal conductivity values of waste PP is higher than that of virgin PP and the effect of ZnO nanoparticles is higher than that of CaCO3naoparticles. The results of thermal image indicate that the uniform and smooth surface associate with Melt Flow Rate (MFR) at load 2.16 kg. The temperature gradient increases with MFR values decreasing for waste PP while decreasing for virgin PP.

Study on the Functionalization of Waste EPDM and PP Blend

Study on the Functionalization of Waste EPDM and PP Blend

초음파 처리와 분말 크기가 재생 폴리프로필렌/폐타이어 분말 복합체의 기계적 특성에 미치는 영향

본 연구에서는 초음파 처리기가 die에 장착된 일축 스크류식 압출기를 이용하여 다양한 크기의 폐타이어 분말을 탈황시켰고, 치합형 이축 스크류식 압출기를 이용하여 재생 폴리프로필렌/탈황된 폐타이어 분말 복합체를 제조하였다. 40, 80, 140 mesh 크기의 탈황되지 않은 폐타이어 분말과 탈황된 폐타이어 분말의 가교밀도와 탈황도를 계산하였고 각각의 기계적 특성을 비교하였다. 또한, 재생 폴리프로필렌과 탈황 전과 탈황 후의 폐타이어 분말 복합체에 대한 상용화제 SEBS-g-MA의 효과를 조사하였다. 가교밀도는 폐타이어 분말의 크기가 작아질수록 감소하였다. 반면에 탈황도는 작은 크기의 폐타이어 분말이 첨가될수록 증가하였다. 탈황된 폐타이어 분말이 첨가된 복합체의 인장강도, 충격강도, 신장률은 탈황되지 않은 폐타이어 분말이 첨가된 복합체보다 크게 증가했으며 첨가된 폐타이어 분말의 크기가 작을수록 복합체의 기계적 특성이 더욱 향상되었다. 재생 폴리프로필렌과 탈황 전과 탈황 후의 폐타이어 분말 복합체에 SEBS-g-MA를 첨가하였을 때 충격강도와 신장률이 큰 폭으로 증가하는 것이 관찰되었다. In this study, various sizes of waste ground rubber tire (WGRT) were devulcanized by a single screw extruder equipped with a sonicator in front of the die, and waste PP and devulcanized waste ground rubber tire (DWGRT) composites were prepared by an intermeshing co-rotating twin screw extruder. The crosslink density and percent devulcanization of WGRT and DWGRT for 40, 80 and 140 meshes were calculated. The mechanical properties of the composites were compared with each other. The effect of SEBS-g-MA as a compatibilizer was investigated on mechanical properties of both waste PP/WGRT and waste PP/DWGRT composites. The crosslink density was decreased with decreasing the WGRT size. On the other hand, the percent devulcanization was increased by adding the smaller size of WGRT. Also, tensile strength, impact strength and elongation at break of the composite with DWGRT were higher than those with WGRT. Especially, mechanical properties of the composites were significantly increased by adding the smaller size of WGRT and DWGRT. Addition of SEBS-g-MA into both waste PP/(D)WGRT composites exhibited better impact strength and elongation at break than the composites themselves.

Effects of a Crosslinking Agent and a Compatibilizer on the Mechanical and Rheological Properties of Waste PP and Waste Ground Rubber Tire Composites

In this study, we investigated the effects of a crosslinking agent and a compatibilizer on the mechanical and rheological properties of waste PP and waste ground rubber tire (WGRT) composites. In order to simulate a commercial TPV, the component of waste PP and WGRT was fixed at 30 and 70 wt%, respectively. With the simple addition of SEBS-g-MA into the waste PP/WGRT composites, the tensile strength of the composite was decreased, whereas both the elongation at break and impact strength were significantly increased because of rubbery characteristics of SEBS-g-MA. In order to further improve the properties of the composites, the waste PP/WGRT/SEBS-g-MA composites was revulcanized with dicumyl peroxide (DCP). As expected, mechanical properties of the revulcanized composites was generally improved. Especially, with 15 and 1 phr of SEBS-g-MA and DCP, elongation at break was highest value of about 183% because of the recross-linking of WGRT without chain scission of the main chain. It was found that complex viscosity of the revulcanized composite increased which might verify further vulcanization of the WGRT.

Study the Effect of CaCO<sub>3 </sub>Nanoparticles on the Mechanical Properties of Virgin and Waste Polypropylene

This paper study the effect of the calcium carbonate (CaCO3) nanoparticleson mechanical and physical properties of virgin and waste polypropylene (pp.). 3, 5, 7 and 10 (wt. %) of CaCO3nanoparticles are mixed with each of virgin and waste pp.These mixture are blended in co-rotating twin screw extruder at 190 °Cand different screw speed (25 and 50 rpm). Different mechanical and physical technique are used to evaluate the characteristics of polymer nanocomposites ex: Tensile strength , elastic modulus , impact strength , hardness and density. The results of virgin pp./(CaCO3) showed that The tensile strength decreasing with nano(CaCO3) concentration for virgin pp. , while for waste increasing at 5% and then decreasing gradually. The impact strength increasing with nanoCaCO3concentration increasing. The hardness and density increasing with the increasing of the nanoCaCO3concentration for two type of pp.Nearly all the mechanical properties were found to increase with the processing speed of 25 rpm. In this studies, it was seen that the highest processing speed of 50 rpm does not give the material performance enhancements due to higher shear intensity which causes defect points in the structure. Also the time is smaller at high screw speeds, so there is not enough time for good dispersion to occur.

Environmental ageing studies of impact modified waste polypropylene

Toughness of rigid thermoplastic is an important mechanical property in polymer technology. In the present study, toughening of waste polypropylene (WPP) with ethylene–propylene–diene monomer (EPDM) rubber at different loading levels was carried out by melt blending at 180 °C. The EPDM-toughened WPP samples were characterized for its thermo-mechanical properties. The effect of carbon black (5 wt%) as a functional filler in WPP/EPDM to impart UV protection was also studied. The test sheets were subjected to natural weathering in variable climatic conditions for a 4-month period of time and were taken out at regular intervals for characterization. The waste PP underwent excessive degradation as the mechanical strength properties such as tensile, flexural and impact strengths were reduced drastically. On the other hand, WPP containing varying proportions of EPDM and carbon black showed better retention of strength properties. The percentage degree of crystallinity has been unusually increased after the environmental degradation due to chemi-crystallization. The impact-modified WPP which contains carbon black retained the processability even after the environmental aging. After aging, the non-stabilized systems were shown extensive change, whereas the structural integrity has been well retained of the toughened WPP containing carbon black as was evident from SEM and optical photomicroscopy.