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José Eduardo Galve,Daniel Elduque,Carmelo Pina,Carlos Javierre 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.3
Plastics recycling is becoming a common action to reduce our products and processes’ environmental impact, and it is of the utmost importance to introduce circular economy strategies. However, for most of the different types of thermoplastics, recycling is not currently its usual end of life due to the technical difficulties in the sorting and recycling processes. This paper presents the complete life cycle assessment of an industrial component made with three different thermoplastics; two virgin thermoplastics typically used for similar parts in the market as Polyamide 6 and Polypropylene, and an alternative source of 100% recycled Polypropylene. All life cycle stages are included in the study. After carrying out the life cycle inventory, calculations of the environmental impact of each life cycle steps have been performed with ReCiPe 2016 EndPoint (H/A) v1.03/World and with IPCC 2013 GWP 100a v1.03 methodologies, comparing all three materials under the same conditions. A sensibility assessment has also been performed, calculating a worst-case scenario of the recycled material, and considering higher material acquisition distances. This study shows that recycled Polypropylene contributes to reducing the overall environmental impact of the component life cycle by 29.8% under ReCiPe, and by 42.8% under Carbon Footprint when compared to virgin Polypropylene. For the worst-case scenario, these reductions in the environmental impact of the component life cycle are also significant: 23.2% and 36.4%, respectively, showing that the use of recycled polymers is a key approach to reduce the environmental impact of plastic components
Effects of Multiple Recycling on the Structure and Morphology of SEBS/PP Composites
김정근,김청현,박명환 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.6
A study of the chemical, mechanical, rheological, and morphological properties of recycled styrene–ethylene–butylene–styrene/polypropylene (SEBS/PP) composites was performed to investigate the viability of the application of these materials as recyclable halogen-free alternatives to plasticized poly(vinyl chloride). The SEBS and PP were initially compounded in a ratio of 3:7 and repeatedly recycled. After over ten rounds of recycling, the SEBS/PP composites exhibited no significant changes either in tensile strength or in tensile elongation. However, a reduction in hardness, decrease in the temperature of the onset of thermal decomposition, and significant increase in their melt flow index (MFI) values were observed. Notably, X-ray scattering measurement and transmission electron microscopy experiments of the SEBS/PP composites indicated that these changes in hardness and MFI originated from morphological changes of the SEBS/PP composites resulting from thermal degradation of the SEBS triblock copolymers that occurred over multiple rounds of recycling.
Zhang, Shu Ling,Zhang, Zhen Xiu,Xin, Zhen Xiang,Pal, Kaushik,Kim, Jin Kuk Elsevier 2010 Materials & Design Vol.31 No.4
<P><B>Abstract</B></P><P>Polypropylene (PP)/waste ground rubber tire powder (WGRT) composites were studied with respect to the effect of bitumen and maleic anhydride-grafted styrene–ethylene–butylene–styrene (SEBS-g-MA) content by using the design of experiments (DOE) approach, whereby the effect of the four polymers content on the final mechanical properties were predicted. Uniform design method was especially adopted for its advantages. Optimization was done using hybrid artificial neural network–genetic algorithm (ANN–GA) technique. The results indicated that the composites showed fairly good ductibility provided that it had a relatively higher concentration of bitumen and SEBS-g-MA under the studied condition. A quantitative relationship was presented between the material concentration and the mechanical properties as a set of contour plots, which were confirmed experimentally by testing the optimum ratio.</P>
Preparation and Physical Properties of Wood Flour/Recycled Polypropylene Composites
( Seong Ho Ahn ),( Dae Su Kim ) 충북대학교 산업과학기술연구소 2020 산업과학기술연구 논문집 Vol.34 No.2
Wood plastic composites (WPCs) are environmentally friendly because they can be manufactured using waste woody materials and recycled plastics. However, studies performed on using recycled plastics to produce WPCs are still limited. Therefore, in this study, WPCs were prepared by melt-blending followed by compression molding using two kinds of commercially available post-industrial recycled polypropylenes (PPs) and six kinds of coupling agents, and their physical properties were investigated to find a reasonable solution to recycle the recycled PPs. Mechanical properties of the WPCs were investigated by UTM and izod impact tester. Water absorption characteristics of the WPCs were also tested. The WPC with the recycled PP from PP car bumpers and the maleic anhydride PP copolymer with relatively higher maleic anhydride content and higher melting temperature showed most reasonable, commercially applicable physical properties, though its physical properties were slightly lower than those of the WPC with the virgin PP.
Fangfang Wei,Liping Li,Yu Zhu,Youzheng Zhao 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.7
Recycled concrete reinforced by polypropylene fibers boosts an alternative sustainable solution to address the need of reusing waste concrete. This paper reports experimental and analytical studies of static and dynamic comprehensive behavior on recycled concrete specimens reinforced with different contents of polypropylene fiber (PPF). Electro-hydraulic pressure testing was used to obtain static compressive strength, whereas 74 mm diameter Split HopkinsonPressure Bar (SHPB) was applied for dynamic impact compression tests at four strain rates. In addition, the reinforcing mechanism of polypropylene fiber on recycled concrete was analyzed of the micro-structure through Scanning Electron Microscope (SEM). Finally, ANSYS/LS-DYNA was applied for the simulation of the SHPB test, which was validated by good agreements of the stress waveform and failure modes of the fiber-reinforced recycled concrete specimen during the impact test. It appears that polypropylene fiber can optimize the microscopic pore structure inside the concrete, thus effectively improving the mechanical properties of recycled concrete which were originally defected by recycled aggregate. Also, higher strain rates significantly increase dynamic compressive strength as well as impact toughness. This study shows that the optimal content of polypropylene fiber in recycled concrete is 0.1% − 0.2%. The numerical simulation by ANSYS/LS-DYNA further proved that the HOLMQUIST-JOHNSON-COOK (HJC) constitutive model can better reflect the dynamic performance of concrete.
재활용 횟수에 따른 폴리프로필렌 및 탄소섬유 강화 PP 복합재료의 물성 변화 관찰
권동준 ( Dong Jun Kwon ),왕작가 ( Zuo Jia Wang ),이태웅 ( Tea Ung Lee ),박종만 ( Joung Man Park ) 한국복합재료학회 2013 Composites research Vol.26 No.5
탄소섬유(CF) 강화 폴리프로필렌(PP) 복합재료의 수요는 증가되고 있다. 본 연구에서는 재활용 횟수에 따라 변화되는 복합재료의 물성 변화를 관찰하였다. CF 함량을 20% 함량으로 조성한 복합재료에 대해서 재활용 횟수에 따른 기계적 물성 평가를 진행하였다. 인장, 굴곡, Izod 동적 피로 실험에 따른 영향을 확인하였다. CF/PP 복합재료의 계면 물성을 평가하기 위해 젖음성 평가와 파단면을 FE-SEM으로 확인하였다. 재활용 횟수에 따라 섬유와 기지는 변화된다. CF/PP 복합재료는 재활용 할수록 섬유와 기지간의 계면에 열 데미지와 분쇄 과정에 의한 결합력 감소가 확인하였다. Carbon fiber (CF) reinforced polypropylene (PP) compositeis was increased to amount consumed. In this study, recycle of composites by recycle times. CF was containing 20%. Mechanical and interfacial propertis of CF/PP was evaluation for number of recycle time. Mechanical assessment of CF/PP was tension, bending, fatigue tension test and izod test method. Interfacial assessment of CF/PP was wettability test and FE-SEM of fracture surface method. Fiber and matrix was changed to recycle time. The more recycle of CF/PP, the more interfacial bonding was decreased. Because fiber and matrix was damaged to thermal damage. And then reinforced CF was shorter than original shape.
Reinforced fibrous recycled aggregate concrete element subjected to uniaxial tensile loading
Hameed, R.,Hasnain, K.,Riaz, M. Rizwan,Khan, Qasim S.,Siddiqi, Zahid A. Techno-Press 2020 Advances in concrete construction Vol.9 No.2
In this study, effect of recycled aggregates and polypropylene fibers on the response of conventionally reinforced concrete element subjected to tensile loading in terms of tension stiffening and strain development was experimentally investigated. For this purpose, concrete prisms of 100 × 100 mm cross section and 500 mm length having one central deformed steel re-bar were cast using fibrous and non-fibrous Recycled Aggregate Concrete (RAC) with varying percentages of recycled aggregates (0%, 25%, 50%, 75% and 100%) and tested under uniaxial tensile load. For all fibrous RAC mixes, polypropylene fibers were used at constant dosage of 3.15 kg/㎥. Effect of recycled aggregates and fibers on the compressive strength of concrete was also explored in this study. Through studying tensile load versus global axial deformation of composite and strain development in concrete and steel, it was found that replacement of natural aggregates with recycled aggregates in concrete negatively affected the cracking load, tension stiffening and strain development, and this negative effect was observed to be increased with increasing contents of recycled aggregates in concrete. The results of this study showed that it was possible to minimize the negative effect of recycled aggregates in concrete by the addition of polypropylene fibers. Reinforced concrete element constructed using concrete containing 50% recycled aggregates and polypropylene fibers exhibited cracking behavior, tension stiffening and strain development response almost similar to that of concrete element constructed using natural aggregate concrete without fiber.
Weiwei Su,Zongping Chen,Haoyu Liao,Dingyuan Liu,Xingyu Zhou Techno-Press 2023 Advances in concrete construction Vol.16 No.3
In this study, the steel fiber and the polypropylene fiber were used to enhance the mechanical properties of fully recycled coarse aggregate concrete. Natural crushed stone was replaced with recycled coarse aggregate at 100% by volume. The steel fiber and polypropylene fiber were used as additive material by incorporating into the mixture. In this test two parameters were considered: (a) steel fiber volume ratio (i.e., 0%, 1%, 1.5%, 2%), (b) polypropylene fiber volume ratio (i.e., 0%, 0.1%, 0.15%, 0.2%). The results showed that compared with no fiber, the integrity of cubes or cylinders mixed with fibers after failure was better. When the volume ratio of steel fiber was 1~2%, the width of mid-span crack after flexural failure was 5~8 mm. In addition, when the volume ratio of polypropylene fiber was 0.15%, with the increase of steel fiber content, the static elastic modulus and toughness of axial compression first increased and then decreased, and the flexural strength increased, with a range of 6.5%~20.3%. Besides, when the volume ratio of steel fiber was 1.5%, with the increase of polypropylene fiber content, the static elastic modulus decreased, with a range of 7.0%~10.5%. The ratio of axial compression toughness first increased and then decreased, with a range of 2.2%~8.7%. The flexural strength decreased, with a range of 2.7%~12.6%. On the other hand, the calculation formula of static elastic modulus and cube compressive strength of fully recycled coarse aggregate with steel-polypropylene fiber was fitted, and the optimal fiber content within the scope of the test were put forward.