Manufacturing and Testing of Polymer Composites

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Processing and Engineering".

Deadline for manuscript submissions: closed (30 April 2022) | Viewed by 26793

Special Issue Editors


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Guest Editor
Department of Chemical, Materials and Industrial Production Engineering, University of Naples Federico II, 80125 Naples, Italy
Interests: composite; polymers; NDT; mechanical characterization; low velocity impact; FDM
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Institute for Polymer, Composites and biomaterials, National Research Council, Piazzale Enrico Fermi, 1, 80055 Portici, Italy
Interests: composite materials; natural Fibres; impact properties; fire properties

Special Issue Information

Dear Colleagues,

The growing interest in innovative and performing materials has made composite materials an object of interest for research due to their excellent strength/weight ratio and the variety of fields of application (aerospace, automotive, sports, construction). Many studies concern the research of new techniques for the realization of composites with polymer matrix and fiber reinforcements, from pultrusion to filament winding. However, these conventional techniques require the use of molds, and this inevitably raises costs. Other studies, on the other hand, concern the optimization of processes for existing techniques, to obtain high-performance and at the same time light materials. The present Special Issue aims to focus on research related to innovative technologies, manufacturing processes, and composite materials for high-performance components. Contributions may be related to conventional or unconventional processes, highlighting novel aspects of processing and manufacturing methods, coating technology, and fiber treatments and materials that can be used to obtain high-performance components.

Dr. Ilaria Papa
Dr. Maria Rosaria Ricciardi
Guest Editors

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Keywords

  • Innovative manufacturing
  • Composite materials
  • Optimization
  • Mechanical
  • Material characterization
  • NDT
  • Treatment surface

Published Papers (10 papers)

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Research

7 pages, 1158 KiB  
Communication
New Technology for Production of Dicyclopentadiene and Methyl-Dicyklopentadiene
by Tomáš Herink, Petr Fulín, Jiří Krupka and Josef Pašek
Polymers 2022, 14(4), 667; https://doi.org/10.3390/polym14040667 - 10 Feb 2022
Cited by 6 | Viewed by 2582
Abstract
ORLEN Unipetrol’s Steam Cracking unit processes a wide range of hydrocarbons from gases to heavy oils produced in refinery processes. Due to the heavy feedstock, the Steam Cracking unit can produce very valuable hydrocarbons such as cyclopentadiene and dicyclopentadiene in addition to ethylene, [...] Read more.
ORLEN Unipetrol’s Steam Cracking unit processes a wide range of hydrocarbons from gases to heavy oils produced in refinery processes. Due to the heavy feedstock, the Steam Cracking unit can produce very valuable hydrocarbons such as cyclopentadiene and dicyclopentadiene in addition to ethylene, propylene and benzene. These hydrocarbons can be obtained and used as very profitable monomers for many other chemical applications. ORLEN Unipetrpol, in cooperation with the University of Chemistry and Technology in Prague, has developed a technology for the isolation of technical dicyclopentadiene of both medium purity grades and high purity grades. Making DCPD grades will add considerable value to the raw C5 by-product stream from the Steam Cracker pyrolysis gasoline. The capacity of the new existing DCPD unit is expected to be in the range of 20–26 thousand metric tons per year, depending on the derivative product portfolio and purity of the DCPD. The construction of the unit started in September 2020, and production is expected to be launched in the second half of 2022. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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9 pages, 2507 KiB  
Article
Color Changes and Mechanical Properties of Glass Fiber Reinforced Polycarbonate Composites after Thermal Aging
by Zhenbo Lan, Jiangang Deng, You Song, Zhuolin Xu, Yu Nie, Yanming Chen and Ye Ma
Polymers 2022, 14(2), 222; https://doi.org/10.3390/polym14020222 - 06 Jan 2022
Cited by 4 | Viewed by 1924
Abstract
Thermal aging of polymer matrix composites exert significant influence on their properties and applications. This paper studied the color changes and mechanical properties of glass fiber reinforced polycarbonate (GF-PC) composites after aging at different temperatures, and the correlation between the trend of color [...] Read more.
Thermal aging of polymer matrix composites exert significant influence on their properties and applications. This paper studied the color changes and mechanical properties of glass fiber reinforced polycarbonate (GF-PC) composites after aging at different temperatures, and the correlation between the trend of color changes and mechanical properties after aging was discussed. The GF-PC composites were aged at 85 °C, 100 °C, 115 °C, 130 °C and 145 °C, respectively. Thereafter, CIELAB colors were used to characterize the color changes of the composites after aging. Tensile and three-point bending tests were carried out to determine the mechanical properties of the composites. According to the values of CIELAB color, the color changes and the color difference (ΔE) of the GF-PC composites after aging were calculated, which showed that color of the GF-PC composite aged at 100 °C changed the most. The color changes of the composites after aging mainly comes from the change of brightness (L value), which was 25.067 for the Raw GF-PC composite. When the aging temperature increased from 85 °C to 100 °C, the brightness of the composites also increased, but decreased when the aging temperature is above 100 °C and continues to rise. Coincidentally, the trend of the mechanical properties of GF-PC composites is closely associated with color changes in the aging temperature range of 85 °C to 145 °C. The tensile and flexural strength of the composites reached the maximum value 72 MPa and 131 MPa, respectively, after aged at 100 °C. It can be speculated that the brightness of the GF-PC composites correlates with trends observed in its tensile strength and bending strength. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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10 pages, 3219 KiB  
Article
Effect of Thermal Aging on Mechanical Properties and Color Difference of Glass Fiber/Polyetherimide (GF/PEI) Composites
by You Song, Jiangang Deng, Zhuolin Xu, Yu Nie and Zhenbo Lan
Polymers 2022, 14(1), 67; https://doi.org/10.3390/polym14010067 - 24 Dec 2021
Cited by 8 | Viewed by 3578
Abstract
This research study is aimed at evaluating the mechanical characteristics in terms of tensile strength and flexural strength of glass fiber reinforced Polyetherimide (GF/PEI) under different thermal aging. Tensile testing and bending testing were performed on the thermally aged polyetherimide composites. The mechanical [...] Read more.
This research study is aimed at evaluating the mechanical characteristics in terms of tensile strength and flexural strength of glass fiber reinforced Polyetherimide (GF/PEI) under different thermal aging. Tensile testing and bending testing were performed on the thermally aged polyetherimide composites. The mechanical properties of the thermally aged samples were also correlated with their color difference. The experimental results showed that both the tensile strength and flexural strength of the GF/PEI composite samples decreased with increasing aging temperature. However, the elastic modulus of the composite samples is nearly independent on the thermal aging. The thermally aged samples exhibited brittle fracture, resulting in low strength and low ductility. The loss in strength after thermal aging could be also linked to the change of their color difference, which can indirectly reflect the change of the strength for the composites after thermal aging. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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11 pages, 2052 KiB  
Article
Fabrication, Tensile Properties, and Photodecomposition of Basalt Fiber-Reinforced Cellulose Acetate Matrix Composites
by Yuxi Shen, Alia Gallet-Pandellé, Hiroki Kurita and Fumio Narita
Polymers 2021, 13(22), 3944; https://doi.org/10.3390/polym13223944 - 15 Nov 2021
Cited by 3 | Viewed by 2113
Abstract
Cellulose acetate (CA) is widely used as an alternative to conventional plastics because of the minor environmental impact of its decomposition cycle. This study synthesized five-layer environmentally friendly composites from CA bioplastic and basalt fibers (BFs) to produce a high-strength marine-biodegradable polymer. Maleic [...] Read more.
Cellulose acetate (CA) is widely used as an alternative to conventional plastics because of the minor environmental impact of its decomposition cycle. This study synthesized five-layer environmentally friendly composites from CA bioplastic and basalt fibers (BFs) to produce a high-strength marine-biodegradable polymer. Maleic anhydride-grafted polypropylene (PP-g-MAH) was mixed with CA as a surface-active agent (SAA) to understand the effect of surface treatment on the mechanical properties of the composite. Tensile tests and scanning electron microscopy were conducted to observe the fracture surfaces. The ultimate tensile strength (UTS) of the BF/CA composite increased by approximately a factor of 4 after adding 11 vol.% unidirectional BF. When the SAA was added, the UTS of the composite with 11 vol.% BF was multiplied by a factor of about 7, which indicates that the surface treatment has a significant positive effect on the mechanical properties. However, the improvement is not apparent when the added BFs are in a plain weave with a vertical orientation. A photodecomposition experiment was then conducted by adding TiO2. Observing the UTS changes of the CA and BF/CA composites, the effect of the photocatalyst on the decomposition of the materials was explored. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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17 pages, 5196 KiB  
Article
Enhanced Low-Velocity Impact Properties for Resin Film Infusion-Manufactured Composites by Flow-Control Approach
by Juan-Antonio Almazán-Lázaro, Elías López-Alba, Sebastian Schmeer and Francisco-Alberto Díaz-Garrido
Polymers 2021, 13(19), 3431; https://doi.org/10.3390/polym13193431 - 06 Oct 2021
Cited by 3 | Viewed by 2064
Abstract
The optimization of the mechanical properties of composite materials has been a challenge since these materials were first used, especially in aeronautics. Reduced energy consumption, safety and reliability are mandatory to achieve a sustainable use of composite materials. The mechanical properties of composites [...] Read more.
The optimization of the mechanical properties of composite materials has been a challenge since these materials were first used, especially in aeronautics. Reduced energy consumption, safety and reliability are mandatory to achieve a sustainable use of composite materials. The mechanical properties of composites are closely related to the amount of defects in the materials. Voids are known as one of the most important defect sources in resin film infusion (RFI)-manufactured composites. Minimizing the defect content leads to maximized mechanical properties and lightweight design. In this paper, a novel methodology based on computer vision is applied to control the impregnation velocity, reduce the void content and enhance the impact properties. Optimized drop-impact properties were found once the impregnation velocity was analyzed and optimized. Its application in both conventional and stitching-reinforced composites concludes with an improvement in the damage threshold load, peak force and damaged area. Although stitching tends to generate additional voids and reduces in-plane properties, the reduction in the damaged area means a positive balance in the mechanical properties. At the same time, the novel methodology provides the RFI process with a noticeable level of automation and control. Consequently, the industrial interest and the range of applications of this process are enhanced. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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25 pages, 17775 KiB  
Article
Enhancing Impact Energy Absorption, Flexural and Crash Performance Properties of Automotive Composite Laminates by Adjusting the Stacking Sequences Layup
by Hassan Alshahrani and Azzam Ahmed
Polymers 2021, 13(19), 3404; https://doi.org/10.3390/polym13193404 - 03 Oct 2021
Cited by 6 | Viewed by 2024
Abstract
In response to the high demand for light automotive, manufacturers are showing a vital interest in replacing heavy metallic components with composite materials that exhibit unparalleled strength-to-weight ratios and excellent properties. Unidirectional carbon/epoxy prepreg was suitable for automotive applications such as the front [...] Read more.
In response to the high demand for light automotive, manufacturers are showing a vital interest in replacing heavy metallic components with composite materials that exhibit unparalleled strength-to-weight ratios and excellent properties. Unidirectional carbon/epoxy prepreg was suitable for automotive applications such as the front part of the vehicle (hood) due to its excellent crash performance. In this study, UD carbon/epoxy prepreg with 70% and 30% volume fraction of reinforcement and resin, respectively, was used to fabricate the composite laminates. The responses of different three stacking sequences of automotive composite laminates to low-velocity impact damage and flexural and crash performance properties were investigated. Three-point bending and drop-weight impact tests were carried out to determine the flexural modulus, strength, and impact damage behavior of selected materials. Optical microscopy analysis was used to identify the failure modes in the composites. Scanning electron microscopy (SEM) and C-scan non-destructive methods were utilized to explore the fractures in the composites after impact tests. Moreover, the performance index and absorbed energy of the tested structures were studied. The results showed that the flexural strength and modulus of automotive composite laminates strongly depended on the stacking sequence. The highest crash resistance was noticed in the laminate with a stacking sequence of [[0, 90, 45, −45]2, 0, 90]S. Therefore, the fabrication of a composite laminate structure enhanced by selected stacking sequences is an excellent way to improve the crash performance properties of automotive composite structures. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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13 pages, 3175 KiB  
Article
Effect of Fibre Orientation on Novel Continuous 3D-Printed Fibre-Reinforced Composites
by Ilaria Papa, Alessia Teresa Silvestri, Maria Rosaria Ricciardi, Valentina Lopresto and Antonino Squillace
Polymers 2021, 13(15), 2524; https://doi.org/10.3390/polym13152524 - 30 Jul 2021
Cited by 34 | Viewed by 3241
Abstract
Among the several additive manufacturing techniques, fused filament fabrication (FFF) is a 3D printing technique that is fast, handy, and low cost, used to produce complex-shaped parts easily and quickly. FFF adds material layer by layer, saving energy, costs, raw material costs, and [...] Read more.
Among the several additive manufacturing techniques, fused filament fabrication (FFF) is a 3D printing technique that is fast, handy, and low cost, used to produce complex-shaped parts easily and quickly. FFF adds material layer by layer, saving energy, costs, raw material costs, and waste. Nevertheless, the mechanical properties of the thermoplastic materials involved are low compared to traditional engineering materials. This paper deals with the manufacturing of composite material laminates obtained by the Markforged continuous filament fabrication (CFF) technique, using an innovative matrix infilled by carbon nanofibre (Onyx), a high-strength thermoplastic material with an excellent surface finish and high resistance to chemical agents. Three macro-categories of samples were manufactured using Onyx and continuous carbon fibre to evaluate the effect of the fibre on mechanical features of the novel composites and their influence on surface finishes. SEM (Scanning Electron Microscopy) analysis and acquisition of roughness profile by a confocal lens were conducted. Tensile and compression tests, thermogravimetric analysis and calorimetric analysis using a DSC (differential scanning calorimeter) were carried out on all specimen types to evaluate the influence of the process parameters and layup configurations on the quality and mechanical behaviour of the 3D-printed samples. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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12 pages, 5765 KiB  
Article
Effect of Oxidation Time on the Properties of Cellulose Nanocrystals Prepared from Balsa and Kapok Fibers Using Ammonium Persulfate
by Marwanto Marwanto, Muhammad Iqbal Maulana, Fauzi Febrianto, Nyoman Jaya Wistara, Siti Nikmatin, Nanang Masruchin, Lukmanul Hakim Zaini, Seung-Hwan Lee and Nam-Hun Kim
Polymers 2021, 13(11), 1894; https://doi.org/10.3390/polym13111894 - 07 Jun 2021
Cited by 15 | Viewed by 3238
Abstract
This study aimed to evaluate the effect of ammonium persulfate’s (APS) oxidation time on the characteristics of the cellulose nanocrystals (CNCs) of balsa and kapok fibers after delignification pretreatment with sodium chlorite/acetic acid. This two-step method is important for increasing the zeta potential [...] Read more.
This study aimed to evaluate the effect of ammonium persulfate’s (APS) oxidation time on the characteristics of the cellulose nanocrystals (CNCs) of balsa and kapok fibers after delignification pretreatment with sodium chlorite/acetic acid. This two-step method is important for increasing the zeta potential value and achieving higher thermal stability. The fibers were partially delignified using acidified sodium chlorite for four cycles, followed by APS oxidation at 60 °C for 8, 12, and 16 h. The isolated CNCs with a rod-like structure showed an average diameter in the range of 5.5–12.6 nm and an aspect ratio of 14.7–28.2. Increasing the reaction time resulted in a gradual reduction in the CNC dimensions. The higher surface charge of the balsa and kapok CNCs was observed at a longer oxidation time. The CNCs prepared from kapok had the highest colloid stability after oxidation for 16 h (−62.27 mV). The CNCs with higher crystallinity had longer oxidation times. Thermogravimetric analysis revealed that the CNCs with a higher thermal stability had longer oxidation times. All of the parameters were influenced by the oxidation time. This study indicates that APS oxidation for 8–16 h can produce CNCs from delignified balsa and kapok with satisfactory zeta potential values and thermal stabilities. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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10 pages, 18127 KiB  
Article
Effect of Plasma Treatment on the Impact Behavior of Epoxy/Basalt Fiber-Reinforced Composites: A Preliminary Study
by Maria Rosaria Ricciardi, Ilaria Papa, Giuseppe Coppola, Valentina Lopresto, Lucia Sansone and Vincenza Antonucci
Polymers 2021, 13(8), 1293; https://doi.org/10.3390/polym13081293 - 15 Apr 2021
Cited by 22 | Viewed by 2052
Abstract
Hydrophobic surfaces are highly desired for several applications due to their exceptional properties such as self-cleaning, anti-icing, anti-friction and others. Such surfaces can be prepared via numerous methods including plasma technology, a dry technique with low environmental impact. In this paper, the effect [...] Read more.
Hydrophobic surfaces are highly desired for several applications due to their exceptional properties such as self-cleaning, anti-icing, anti-friction and others. Such surfaces can be prepared via numerous methods including plasma technology, a dry technique with low environmental impact. In this paper, the effect of a one-step sulfur hexafluoride (SF6) plasma treatment upon the low velocity impact behavior of basalt/epoxy composites has been investigated by using several characterization techniques. A capacitive coupled radiofrequency plasma system was used for the plasma surface treatment of basalt/epoxy composites, and suitable surface treatment conditions were experimentally investigated with respect to gas flow rate, chamber pressure, power intensity, and surface treatment time by measuring the water droplet contact angle of treated specimens. The contact angle measurements showed that treating with SF6 plasma would increase the hydrophobicity of basalt/epoxy composites; moreover, the impact results obtained on reinforced epoxy basalt fiber showed damage in a confined area and higher impact resistance for plasma-treated basalt systems. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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15 pages, 4656 KiB  
Article
New Method for Optimization of Polymer Powder Plasma Treatment for Composite Materials
by Zuzana Weberová, Hana Šourková, Jakub Antoň, Taťána Vacková and Petr Špatenka
Polymers 2021, 13(6), 965; https://doi.org/10.3390/polym13060965 - 22 Mar 2021
Cited by 4 | Viewed by 2434
Abstract
This paper describes a newly developed testing method for determination of the adhesivity of a film sintered from thermoplastic powder. This method is based on the modified EN 15337 standard. Application of this method enables an effective development of thermoplastic composites with enhanced [...] Read more.
This paper describes a newly developed testing method for determination of the adhesivity of a film sintered from thermoplastic powder. This method is based on the modified EN 15337 standard. Application of this method enables an effective development of thermoplastic composites with enhanced adhesion between reinforcement and matrix and/or high-quality joints between plastics and dissimilar materials. The proposed method was successfully tested on a series of polyethylene powders treated in the oxygen atmosphere for 0–1200 s. Adhesion to metal and glass substrates in dependence on treatment conditions is described along with powder wettability and X-ray photoelectron spectroscopy analysis. The results show an increase in adhesion to metal by 580% and to glass by 1670% for the longest treatment time, compared to a nontreated powder. Sintering of treated powders revealed a strong influence of treatment time on the melting process. The XPS analysis confirmed the formation of new oxygen groups (C–O, C=O, O–C=O). The method reveals a specific behavior of powders based on treatment conditions, which is crucial for the optimization of plasma treatment for the improved adhesion, applicability of polymer powders, and a development of composite materials. Full article
(This article belongs to the Special Issue Manufacturing and Testing of Polymer Composites)
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