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An Approach to the Impact Simulation on Foamed Injection Molded Polypropylene Parts: An Example of Application in the Automotive Industry. Polymers (Basel) 2023; 15:polym15040936. [PMID: 36850220 PMCID: PMC9961383 DOI: 10.3390/polym15040936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
An approach to the simulation of foamed injection molded Polypropylene parts subjected to impact loading is presented in this paper. The proposed method, which considers strain-rate-dependent material properties and the possible occurrence of fracture, is, in particular, suitable for parts manufactured with core-back technology. The method was developed to be used within the functionality of a commercial Finite Element solver using a shell-type element mesh. The material model is based on a three-layer structure, with two compact skin layers and a foamed core layer made of expanded material. The properties of the foamed material are assumed as those of the compact grade scaled by a suitable factor, which is identified via inverse engineering on a set of bending tests executed on specimens having different foam densities. The fracture of the material is then predicted using a damage model which considers the effects of triaxiality. The approach is then validated on industrial parts from the automotive sector, subjected to impact in a component test. Despite the simplicity of the presented approach, which makes this method suitable for industrial applications and especially for early-stage design, the validation shows a sufficiently accurate simulation of part behavior under the impact, with a reasonable prediction of damage and fracture.
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Fontana D, Recupido F, Lama GC, Liu J, Boggioni L, Silvano S, Lavorgna M, Verdolotti L. Effect of Different Methods to Synthesize Polyol-Grafted-Cellulose Nanocrystals as Inter-Active Filler in Bio-Based Polyurethane Foams. Polymers (Basel) 2023; 15:polym15040923. [PMID: 36850207 PMCID: PMC9962898 DOI: 10.3390/polym15040923] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/02/2023] [Accepted: 02/08/2023] [Indexed: 02/15/2023] Open
Abstract
Currently, the scientific community has spent a lot of effort in developing "green" and environmentally friendly processes and products, due the contemporary problems connected to pollution and climate change. Cellulose nanocrystals (CNCs) are at the forefront of current research due to their multifunctional characteristics of biocompatibility, high mechanical properties, specific surface area, tunable surface chemistry and renewability. However, despite these many advantages, their inherent hydrophilicity poses a substantial challenge for the application of CNCs as a reinforcing filler in polymers, as it complicates their dispersion in hydrophobic polymeric matrices, such as polyurethane foams, often resulting in aggregate structures that compromise their properties. The manipulation and fine-tuning of the interfacial properties of CNCs is a crucial step to exploit their full potential in the development of new materials. In this respect, starting from an aqueous dispersion of CNCs, two different strategies were used to properly functionalize fillers: (i) freeze drying, solubilization in DMA/LiCl media and subsequent grafting with bio-based polyols; (ii) solvent exchange and subsequent grafting with bio-based polyols. The influence of the two functionalization methods on the chemical and thermal properties of CNCs was examined. In both cases, the role of the two bio-based polyols on filler functionalization was elucidated. Afterwards, the functionalized CNCs were used at 5 wt% to produce bio-based composite polyurethane foams and their effect on the morphological, thermal and mechanical properties was examined. It was found that CNCs modified through freeze drying, solubilization and bio-polyols grafting exhibited remarkably higher thermal stability (i.e., degradation stages > 100 °C) with respect to the unmodified freeze dried-CNCs. In addition, the use of the two grafting bio-polyols influenced the functionalization process, corresponding to different amount of grafted-silane-polyol and leading to different chemico-physical characteristics of the obtained CNCs. This was translated to higher thermal stability as well as improved functional and mechanical performances of the produced bio-based composite PUR foams with respect of the unmodified CNCs-composite ones (the best case attained compressive strength values three times more). Solvent exchange route slightly improved the thermal stability of the obtained CNCs; however; the so-obtained CNCs could not be properly dispersed within the polyurethane matrix, due to filler aggregation.
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Affiliation(s)
- Dario Fontana
- Chemistry Department, University of Pavia, Via Torquato Taramelli 12, 27100 Pavia, Italy
- Institute for Chemical Science and Technologies, CNR, Via Alfonso Corti 12, 20133 Milan, Italy
| | - Federica Recupido
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), P.zzale Enrico Fermi 1, 80055 Portici, Italy
| | - Giuseppe Cesare Lama
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), P.zzale Enrico Fermi 1, 80055 Portici, Italy
- Correspondence: (G.C.L.); (L.B.); Tel.: +39-081-775-8839 (G.C.L.)
| | - Jize Liu
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), P.zzale Enrico Fermi 1, 80055 Portici, Italy
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China
| | - Laura Boggioni
- Institute for Chemical Science and Technologies, CNR, Via Alfonso Corti 12, 20133 Milan, Italy
- Correspondence: (G.C.L.); (L.B.); Tel.: +39-081-775-8839 (G.C.L.)
| | - Selena Silvano
- Institute for Chemical Science and Technologies, CNR, Via Alfonso Corti 12, 20133 Milan, Italy
| | - Marino Lavorgna
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), P.zzale Enrico Fermi 1, 80055 Portici, Italy
| | - Letizia Verdolotti
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), P.zzale Enrico Fermi 1, 80055 Portici, Italy
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Pongmuksuwan P, Salayong K, Lertwiriyaprapa T, Kitisatorn W. Electromagnetic Absorption and Mechanical Properties of Natural Rubber Composites Based on Conductive Carbon Black and Fe 3O 4. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15196532. [PMID: 36233900 PMCID: PMC9571088 DOI: 10.3390/ma15196532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/11/2022] [Accepted: 09/13/2022] [Indexed: 05/27/2023]
Abstract
In contemporary civilization, the electromagnetic radiation from electronic devices and communication systems has become a substantial pollutant. High-performance electromagnetic absorbers have become a solution for absorbing unwanted electromagnetic waves. This research proposed a lightweight and flexible electromagnetic absorber produced from natural rubber filled with conductive carbon black (CCB) and Fe3O4. The effect of CCB, Fe3O4, and a combination of CCB and Fe3O4 as a hybrid filler on foam morpholog, electromagnetic reflectivity, tensile strength, and compression set properties were investigated. In addition, the effect of the alternating layered structure of CCB and Fe3O4 on electromagnetic absorption was investigated. The results indicated that the composite foam exhibited an interconnected network structure that enhanced the electromagnetic attenuation in the absorber. CCB increased the electromagnetic absorption of the foam, whereas Fe3O4 had less of an effect. The foam filled with the hybrid filler at the CCB/Fe3O4 ratio of 8/2 exhibited excellent electromagnetic absorption. The composite foam had a higher tensile modulus and higher strength compared to neat foam. The addition of CCB decreased the compression set; however, the compression set was improved by the incorporation of Fe3O4. Composite foams filled with hybrid filler can serve as highly efficient electromagnetic absorbing materials.
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Affiliation(s)
- Pornlada Pongmuksuwan
- Department of Materials and Production Technology Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok, 1518, Pracharat 1 Road, Wongsawang, Bangsue, Bangkok 10800, Thailand
| | - Kiadtisak Salayong
- Research Center of Innovation Digital and Electromagnetic Technology (iDEMT), Department of Teacher Training in Electrical Engineering, Faculty of Technical Education, King Mongkut’s University of Technology North Bangkok, 1518, Pracharat 1 Road, Wongsawang, Bangsue, Bangkok 10800, Thailand
| | - Titipong Lertwiriyaprapa
- Research Center of Innovation Digital and Electromagnetic Technology (iDEMT), Department of Teacher Training in Electrical Engineering, Faculty of Technical Education, King Mongkut’s University of Technology North Bangkok, 1518, Pracharat 1 Road, Wongsawang, Bangsue, Bangkok 10800, Thailand
| | - Wanlop Kitisatorn
- Department of Materials and Production Technology Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok, 1518, Pracharat 1 Road, Wongsawang, Bangsue, Bangkok 10800, Thailand
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Żukowska W, Kosmela P, Wojtasz P, Szczepański M, Piasecki A, Barczewski R, Barczewski M, Hejna A. Comprehensive Enhancement of Prepolymer-Based Flexible Polyurethane Foams' Performance by Introduction of Cost-Effective Waste-Based Ground Tire Rubber Particles. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15165728. [PMID: 36013863 PMCID: PMC9412428 DOI: 10.3390/ma15165728] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/13/2022] [Accepted: 08/18/2022] [Indexed: 05/11/2023]
Abstract
Material innovations in polyurethane (PU) foams should ideally combine performance enhancement, environmental impact limitation, and cost reduction. These goals can be achieved by applying recycled or waste-based materials without broader industrial applications, implicating their low price. Herein, from 5 to 20 parts by weight of ground tire rubber (GTR) particles originated from the recycling of postconsumer car tires were incorporated into a flexible foamed PU matrix as a cost-effective waste-based filler. A two-step prepolymer method of foams manufacturing was applied to maximize the potential of applied formulation changes. The impact of the GTR content on the foams' processing, chemical, and cellular structure, as well as static and dynamic mechanical properties, thermal stability, sound suppression ability, and thermal insulation performance, was investigated. The introduction of GTR caused a beneficial reduction in the average cell diameter, from 263.1 µm to 144.8-188.5 µm, implicating a 1.0-4.3% decrease in the thermal conductivity coefficient. Moreover, due to the excellent mechanical performance of the car tires-the primary application of GTR-the tensile performance of the foams was enhanced despite the disruption of the cellular structure resulting from the competitiveness between the hydroxyl groups of the applied polyols and on the surface of the GTR particles. The tensile strength and elongation at break were increased by 10 and 8% for 20 parts by weight GTR addition. Generally, the presented work indicates that GTR can be efficiently applied as a filler for flexible PU foams, which could simultaneously enhance their performance, reduce costs, and limit environmental impacts due to the application of waste-based material.
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Affiliation(s)
- Wiktoria Żukowska
- Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Paulina Kosmela
- Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Paweł Wojtasz
- Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Mariusz Szczepański
- Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Adam Piasecki
- Institute of Materials Engineering, Poznan University of Technology, Jana Pawła II 24, 60-965 Poznan, Poland
| | - Roman Barczewski
- Institute of Applied Mechanics, Poznan University of Technology, Jana Pawła II 24, 60-965 Poznan, Poland
| | - Mateusz Barczewski
- Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland
| | - Aleksander Hejna
- Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
- Correspondence:
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Effects of grafting and long-chain branching structures on rheological behavior, crystallization properties, foaming performance, and mechanical properties of polyamide 6. E-POLYMERS 2022. [DOI: 10.1515/epoly-2022-0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Polyamide 6 (PA6) was modified with ethylene maleic anhydride syndiotactic copolymer resin (ZeMac), and triglycidyl isocyanurate (TGIC) as modifiers to prepare a grafting structure and a long-chain branching structure, respectively. The effects of two modifiers on the rheological behavior, crystallization properties, foaming performance, and mechanical properties of PA6 were systematically studied by rotating rheometry, differential scanning calorimetry and scanning electron microscopy. The results showed that there were differences in crystallization properties between the two modification methods, but they significantly improved the rheological, foaming performance, and mechanical properties of PA6. In particular, PA6 with long-chain branching structure through TGIC modification showed better performance in various physicochemical characterizations. The introduction of ZeMac reduced the average diameter of bubbles in pure PA6 from 146.32 to 88.12 µm, and the density of bubbles increased from 1.69 × 105 to 5.35 × 105 cells·cm−3. The introduction of TGIC reduced the average diameter of bubbles in pure PA6 from 146.32 to 64.36 µm, and the density of bubbles increased to 1.31 × 106 cells·cm−3. Moreover, the mechanical properties of both nonfoamed and foamed samples were improved after modification.
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Yakushin V, Cabulis U, Fridrihsone V, Kravchenko S, Pauliks R. Properties of polyurethane foam with fourth-generation blowing agent. E-POLYMERS 2021. [DOI: 10.1515/epoly-2021-0081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Climate change makes it imperative to use materials with minimum global warming potential. The fourth-generation blowing agent HCFO-1233zd-E is one of them. The use of HCFO allows the production of polyurethane foam with low thermal conductivity. Thermal conductivity, like other foam properties, depends not only on the density but also on the cellular structure of the foam. The cellular structure, in turn, depends on the technological parameters of foam production. A comparison of pouring and spray foams of the same low density has shown that the cellular structure of spray foam consists of cells with much less sizes than pouring foam. Due to the small size of cells, spray foam has a lower radiative constituent in the foam conductivity and, as a result, a lower overall thermal conductivity than pouring foam. The water absorption of spray foam, due to the fine cellular structure, also is lower than that of pouring foam. Pouring foam with bigger cells has higher compressive strength and modulus of elasticity in the foam rise direction. On the contrary, spray foam with a fine cellular structure has higher strength and modulus in the perpendicular direction. The effect of foam aging on thermal conductivity was also studied.
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Affiliation(s)
- Vladimir Yakushin
- Latvian State Institute of Wood Chemistry, Polymer Laboratory , Riga , LV-1006 , Latvia
| | - Ugis Cabulis
- Latvian State Institute of Wood Chemistry, Polymer Laboratory , Riga , LV-1006 , Latvia
| | - Velta Fridrihsone
- Latvian State Institute of Wood Chemistry, Polymer Laboratory , Riga , LV-1006 , Latvia
| | | | - Romass Pauliks
- Ventspils University of Applied Sciences, Ventspils International Radio Astronomy Centre , Ventspils , LV-3601 , Latvia
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