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Zhu L, Gao W, Dikin DA, Percec S, Ren F. Anti-Ballistic Performance of PPTA/UHMWPE Laminates. Polymers (Basel) 2023; 15:polym15102281. [PMID: 37242856 DOI: 10.3390/polym15102281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/06/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Poly(p-phenylene terephthalamide) (PPTA) and ultra-high-molecular-weight polyethylene (UHMWPE) are high-performance polymer materials largely used for body armor applications. Although composite structures from a combination of PPTA and UHMWPE have been created and described in the literature, the manufacture of layered composites from PPTA fabrics and UHMWPE films with UHMWPE film as an adhesive layer has not been reported. Such a new design can provide the obvious advantage of simple manufacturing technology. In this study, for the first time, we prepared PPTA fabrics/UHMWPE films laminate panels using plasma treatment and hot-pressing and examined their ballistic performance. Ballistic testing results indicated that samples with moderate interlayer adhesion between PPTA and UHMWPE layers exhibited enhanced performance. A further increase in interlayer adhesion showed a reverse effect. This finding implies that optimization of interface adhesion is essential to achieve maximum impact energy absorption through the delamination process. In addition, it was found that the stacking sequence of the PPTA and UHMWPE layers affected ballistic performance. Samples with PPTA as the outermost layer performed better than those with UHMWPE as the outermost layer. Furthermore, microscopy of the tested laminate samples showed that PPTA fibers exhibited shear cutting failure on the entrance side and tensile failure on the exit side of the panel. UHMWPE films exhibited brittle failure and thermal damage at high compression strain rate on the entrance side and tensile fracture on the exit side. For the first time, findings from this study reported in-field bullet testing results of PPTA/UHMWPE composite panels, which can provide important insights for designing, fabricating, and failure analysis of such composite structures for body armors.
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Affiliation(s)
- Long Zhu
- Department of Mechanical Engineering, Temple University, Philadelphia, PA 19122, USA
| | - Weixiao Gao
- Department of Mechanical Engineering, Temple University, Philadelphia, PA 19122, USA
| | - Dmitriy A Dikin
- Department of Mechanical Engineering, Temple University, Philadelphia, PA 19122, USA
| | - Simona Percec
- Temple Materials Institute, Temple University, Philadelphia, PA 19122, USA
| | - Fei Ren
- Department of Mechanical Engineering, Temple University, Philadelphia, PA 19122, USA
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2
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Panneke N, Ehrmann A. Stab-Resistant Polymers-Recent Developments in Materials and Structures. Polymers (Basel) 2023; 15. [PMID: 36850264 DOI: 10.3390/polym15040983] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Stab-resistant garments have been used for centuries, utilizing metals, paper, or polymeric structures, often inspired by natural structures such as scales. Nowadays, stab-resistant vests or vest inserts are used by police and security personnel, but also by bus drivers, ambulance officers, and other people who are empirically often attacked on duty. Since stab protection garments are often heavy and thus uncomfortable and not well accepted, whether in the form of chain-mail or metal inserts in protective vests, researchers are striving to find lightweight, drapable alternatives, often based on polymeric materials. These research attempts have recently focused on textile fabrics, mostly with impregnation by shear-thickening fluids (STFs) or ceramic coatings, as well as on lightweight composites. The first studies on 3D printed polymeric objects with tailored shapes, as well as theoretical investigations of the stab-protective effect of different materials, have been published throughout the last years. Here, we discuss different measurement methods, including dynamic and quasistatic methods, and correlations of stab-resistance with other physical properties, before we give an overview of recent developments of stab-resistant polymers, using different materials/material combinations and structures.
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Wongmek A, Parry M, Scully S. Sternal Gap Syndrome Caused by Improperly Fitted Body Armor: A Preventable Military Injury. Med J (Ft Sam Houst Tex) 2022:82-84. [PMID: 34940973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Isolated atrophy of the pectoralis major muscle (PMM) secondary to traumatic lesion of the medial pectoral nerve is a known entity in the field of neuromuscular electrodiagnostics. Recent literature has begun describing a Pectoral Gap Phenomenon in which this atrophy occurs bilaterally as an overuse injury, leading to a marked concavity in the central chest wall musculature. While there is limited information in science journals on this topic, social media posts on weight lifting discuss the topic frequently. We report a case in which a soldier's body armor crushed the lateral medial and pectoral nerves against the anterior chest wall causing permanent upper body weakness. To optimize military medical readiness, awareness of this disorder and the pathophysiology causing it should spread so as to mitigate this potential for significant disability.
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Cronin DS, Bustamante MC, Barker J, Singh D, Rafaels KA, Bir C. Assessment of Thorax Finite Element Model Response for Behind Armor Blunt Trauma Impact Loading Using an Epidemiological Database. J Biomech Eng 2021; 143:1087628. [PMID: 33009546 DOI: 10.1115/1.4048644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Indexed: 11/08/2022]
Abstract
Nonperforating ballistic impacts on thoracic armor can cause blunt injuries, known as behind-armor blunt trauma (BABT). To evaluate the potential for this injury, the back face deformation (BFD) imprinted into a clay backing is measured; however, the link between BFD and potential for injury is uncertain. Computational human body models (HBMs) have the potential to provide an improved understanding of BABT injury risk to inform armor design but require assessment with relevant loading scenarios. In this study, a methodology was developed to apply BABT loading to a computational thorax model, enhanced with refined finite element mesh and high-deformation rate mechanical properties. The model was assessed using an epidemiological BABT survivor database. BABT impact boundary conditions for 10 cases from the database were recreated using experimentally measured deformation for specific armor/projectile combinations, and applied to the thorax model using a novel prescribed displacement methodology. The computational thorax model demonstrated numerical stability under BABT impact conditions. The predicted number of rib fractures, the magnitude of pulmonary contusion, and injury rank, increased with armor BFD, back face velocity, and input energy to the thorax. In three of the 10 cases, the model overpredicted the number of rib fractures, attributed to impact location positional sensitivity and limited details from the database. The integration of an HBM with the BABT loading method predicted rib fractures and injury ranks that were in good agreement with available medical records, providing a potential tool for future armor evaluation and injury assessment.
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Affiliation(s)
- D S Cronin
- Department of MME, University of Waterloo, 200 University Avenue West, Waterloo, ON N2 L 3G1, Canada
| | - M C Bustamante
- Department of MME, University of Waterloo, 200 University Avenue West, Waterloo, ON N2 L 3G1, Canada
| | - J Barker
- Department of MME, University of Waterloo, 200 University Avenue West, Waterloo, ON N2 L 3G1, Canada
| | - D Singh
- Department of MME, University of Waterloo, 200 University Avenue West, Waterloo, ON N2 L 3G1, Canada
| | - K A Rafaels
- Army Futures Command, CCDC Army Research Laboratory, Aberdeen Proving Ground, MD 21005
| | - C Bir
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202
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Denisov AV, Logatkin SM, Bozhchenko AP, Demchenko KN, Chipizubov NA, Tolmachyov IA. [Mechanism of formation and morphological features of a gunshot injury to the chest and abdomen arising from the use of body armor]. Sud Med Ekspert 2020; 63:8-12. [PMID: 32930527 DOI: 10.17116/sudmed2020630518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The features of a gunshot injury arising in the presence of body armor on the injured person are considered. The purpose of the work is to reveal the mechanisms of damage formation during non-penetration of an armored composition, during its penetration, as well as during external or internal rebound. The characteristic of damages arising with this is given. It was shown that injuries due to non-penetration of body armor are characterized mainly by local closed injuries, not only of integumentary soft tissues, but also of internal organs in the projection of impact of a wounding projectile. With through penetration of body armor, the severity and volume of gunshot damage increase due to the introduction of fragments of bullets, fragments of armored panels and pieces of equipment into the wound channel. Rebounding of elements of dismantled bullets from the outer or inner surface of the body armor can cause severe gunshot damage to both the wearer of body armor and other persons. Knowledge of the mechanisms of formation and morphological features of injuries that occur when using body armor are prerequisites for a full forensic medical assessment of the investigated incident.
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Affiliation(s)
- A V Denisov
- Military Medical Academy named after S.M. Kirov of Ministry of Defense of Russia, St. Petersburg, Russia
| | - S M Logatkin
- State Research Institute of Military medicine of Ministry of Defense of Russia, St. Petersburg, Russia
| | - A P Bozhchenko
- Military Medical Academy named after S.M. Kirov of Ministry of Defense of Russia, St. Petersburg, Russia
| | - K N Demchenko
- Military Medical Academy named after S.M. Kirov of Ministry of Defense of Russia, St. Petersburg, Russia
| | - N A Chipizubov
- Military Medical Academy named after S.M. Kirov of Ministry of Defense of Russia, St. Petersburg, Russia
| | - I A Tolmachyov
- Military Medical Academy named after S.M. Kirov of Ministry of Defense of Russia, St. Petersburg, Russia
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Wiley A, Joseph A, Orr R, Schram B, Kornhauser CL, Holmes RJ, Dawes JJ. The Impact of External Loads Carried by Police Officers on Vertical Jump Performance. Int J Exerc Sci 2020; 13:1179-1189. [PMID: 33042379 PMCID: PMC7523894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The purpose of this study was to examine the impact that external loads have on vertical jump height and peak anaerobic power output (PAPw) of police officers during a vertical jump (VJ) test. Retrospective data of 47 (mean age 38.79 ± 7.97 years) police officers from a US Law Enforcement Agency (LEA) were used for analysis. VJ heights and body mass were used in the Sayers Peak Power Equation to calculate PAPw. Power-to-weight (P:W) ratios were then calculated by dividing PAPw by the officer's body mass. VJ height significantly (p < .001) decreased with load (unloaded = 49.49 ± 8.46 cm: loaded = 43.62 ± 7.68 cm). A Pearson's correlation showed a significant (p < .01) low-moderate (r = .387) relationship between absolute load (9.57 ± .94 kg) and change in PAPw, and a significant (p < .01) strong (r = .794) correlation between relative load and changes in P:W. This study supports previous research that suggests that occupational load carriage has a negative impact on VJ performance in police officers and may influence job performance, and that training programs may mitigate these negative effects.
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Affiliation(s)
- Amy Wiley
- Bond Institute of Health and Sport, Bond University Gold Coast QLD 4229, AUSTRALIA
| | - Aaron Joseph
- Bond Institute of Health and Sport, Bond University Gold Coast QLD 4229, AUSTRALIA
| | - Robin Orr
- Bond Institute of Health and Sport, Bond University Gold Coast QLD 4229, AUSTRALIA
- Tactical Research Unit, Bond University, Gold Coast QLD 4229, AUSTRALIA
| | - Ben Schram
- Bond Institute of Health and Sport, Bond University Gold Coast QLD 4229, AUSTRALIA
- Tactical Research Unit, Bond University, Gold Coast QLD 4229, AUSTRALIA
| | | | - Ryan J Holmes
- Colorado State Patrol Training Academy, Golden, CO, USA
| | - J Jay Dawes
- Oklahoma State University, Oklahoma, UNITED STATES
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Kruppert S, Chu F, Stewart MC, Schmitz L, Summers AP. Ontogeny and potential function of poacher armor (Actinopterygii: Agonidae). J Morphol 2020; 281:1018-1028. [PMID: 32621639 DOI: 10.1002/jmor.21223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 11/11/2022]
Abstract
Many vertebrates are armored over all or part of their body. The armor may serve several functional roles including defense, offense, visual display, and signal of experience/capability. Different roles imply different tradeoffs; for example, defensive armor usually trades resistance to attack for maneuverability. The poachers (Agonidae), 47 species of scorpaeniform fishes, are a useful system for understanding the evolution and function of armor due to their variety and extent of armoring. Using publically available CT-scan data from 27 species in 16 of 21 genera of poachers we compared the armor to axial skeletal in the mid body region. The ratio of average armor density to average skeleton density ranged from 0.77 to 1.17. From a defensive point of view, the total investment in mineralization (volume * average density) is more interesting. There was 10 times the material invested in the armor as in the endoskeleton in some small, smooth plated species, like Aspidophoroides olrikii. At the low end, some visually arresting species like Percis japonica, had ratios as low as 2:1. We categorized the extent and type (impact vs. abrasion) in 34 Agonopsis vulsa across all 35+ plates in the eight rows along the body. The ventral rows show abrasive damage along the entire length of the fish that gets worse with age. Impact damage to head and tail plates gets more severe and occurs at higher rates with age. The observed damage rates and the large investment in mineralization of the armor suggest that it is not just for show, but is a functional defensive structure. We cannot say what the armor is defense against, but the abrasive damage on the ventrum implies their benthic lifestyle involves rubbing on the substrate. The impact damage could result from predatory attacks or from intraspecific combat.
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Affiliation(s)
- Sebastian Kruppert
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, USA
| | - Fabien Chu
- University of Washington, Seattle, Washington, USA
| | - Morgan C Stewart
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, USA.,W.M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont McKenna, California, USA
| | - Lars Schmitz
- W.M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont McKenna, California, USA
| | - Adam P Summers
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, USA
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Nguyen TTN, Meek G, Breeze J, Masouros SD. Gelatine Backing Affects the Performance of Single-Layer Ballistic-Resistant Materials Against Blast Fragments. Front Bioeng Biotechnol 2020; 8:744. [PMID: 32714916 PMCID: PMC7343711 DOI: 10.3389/fbioe.2020.00744] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 06/10/2020] [Indexed: 11/22/2022] Open
Abstract
Penetrating trauma by energized fragments is the most common injury from explosive devices, the main threat in the contemporary battlefield. Such devices produce projectiles dependent upon their design, including preformed fragments, casings, glass, or stones; these are subsequently energized to high velocities and cause serious injuries to the body. Current body armor focuses on the essential coverage, which is mainly the thoracic and abdominal area, and can be heavy and cumbersome. In addition, there may be coverage gaps that can benefit from the additional protection provided by one or more layers of lightweight ballistic fabrics. This study assessed the performance of single layers of commercially available ballistic protective fabrics such as Kevlar®, Twaron®, and Dyneema®, in both woven and knitted configurations. Experiments were carried out using a custom-built gas-gun system, with a 0.78-g cylindrical steel fragment simulating projectile (FSP) as the impactor, and ballistic gelatine as the backing material. FSP velocity at 50% risk of material perforation, gelatine penetration, and high-risk wounding to soft tissue, as well as the depth of penetration (DoP) against impact velocity and the normalized energy absorption were used as metrics to rank the performance of the materials tested. Additional tests were performed to investigate the effect of not including a soft-tissue simulant backing material on the performance of the fabrics. The results show that a thin layer of ballistic material may offer meaningful protection against the penetration of this FSP. Additionally, it is essential to ensure a biofidelic boundary condition as the protective efficacy of fabrics was markedly altered by a gelatine backing.
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Affiliation(s)
- Thuy-Tien N Nguyen
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - George Meek
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - John Breeze
- Department of Bioengineering, Imperial College London, London, United Kingdom.,Royal Centre for Defence Medicine, Queen Elizabeth Hospital Birmingham, Birmingham, United Kingdom
| | - Spyros D Masouros
- Department of Bioengineering, Imperial College London, London, United Kingdom
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Engelbrecht-Wiggans A, Burni F, Krishnamurthy A, Forster AL. Tensile Testing of Aged Flexible Unidirectional Composite Laminates for Body Armor. J Mater Sci 2020; 55:https://doi.org/10.1007/s10853-019-04063-w. [PMID: 33041370 PMCID: PMC7542579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Flexible Unidirectional (UD) composite laminates are commonly being used for ballistic-resistant body armor. These laminates comprise UD layers, each constructed by laminating thin layers of high-performance fibers held in place using very low modulus binder resins, with the fibers in each layer oriented parallel to each other. As these materials are used in body armor, it is important to investigate their long-term reliability, particularly with regards to exposure to temperature and humidity as these are known causes of degradation in other commonly used body armor materials. This work investigates the tensile behavior of a poly(p-phenylene terephthalamide), or PPTA flexible UD laminate aged for up to 150 d at accelerated conditions of 70 °C and 76 % relative humidity (RH). Tests were performed at three different crosshead displacement rates and three different gauge lengths. The effect of ageing on the mechanical properties of the material resulted in less than 10 % degradation in tensile strength, with a more significant reduction in longer specimens when tested at slower rates.
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Affiliation(s)
- Amy Engelbrecht-Wiggans
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Theiss Research, La Jolla, CA, USA
| | - Faraz Burni
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Chemical and Biomolecular Engineering Department, University of Maryland, College Park, MD, USA
| | - Ajay Krishnamurthy
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Theiss Research, La Jolla, CA, USA
| | - Amanda L. Forster
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
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Orr RM, Kukić F, Čvorović A, Koropanovski N, Janković R, Dawes J, Lockie R. Associations between Fitness Measures and Change of Direction Speeds with and without Occupational Loads in Female Police Officers. Int J Environ Res Public Health 2019; 16:E1947. [PMID: 31159364 PMCID: PMC6603879 DOI: 10.3390/ijerph16111947] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/26/2019] [Accepted: 05/28/2019] [Indexed: 11/19/2022]
Abstract
Female police officers may be required to pursue offenders on foot while wearing occupational loads. The aim of this study was to determine relationships between fitness measures and change of direction speed (CODS) in female police officers and the influence of their occupational loads. Retrospective data were provided for 27 female police officers (age = 32.19 ± 5.09 y, height = 162.78 ± 5.01 cm, and mass = 71.31 ± 13.42 kg) and included fitness measures of: lower-body power (standing long jump (SLJ)), upper-body and trunk muscle endurance (push-up (PU) and sit-up (SU)), aerobic power (estimated VO2max), and CODS (Illinois agility test). The CODS test was performed without and with occupational load (10 kg). Paired sample t-tests (between-load conditions) and Pearson's correlations (relationships between measures) were performed with linear regression analysis used to account for the contribution of measures to unloaded and loaded CODS performance. CODS was significantly slower when loaded (unloaded = ~23.17 s, loaded = ~24.14 s, p < 0.001) with a strong, significant relationship between load conditions (r = 0.956, p < 0.001). Moderate to strong, significant relationships were found between all fitness measures ranging from estimated VO2max (r = -0.448) to SU (r = -0.673) in the unloaded condition, with the strength of these relationships increasing in the loaded condition accounting for 61% to 67% of the variance, respectively. While unloaded agility test performance was strongly associated with loaded performance, female police officer CODS was significantly reduced when carrying occupational loads. A variety of fitness measures that influence officer CODS performances become increasingly important when occupational loads are carried.
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Affiliation(s)
- Robin M Orr
- Faculty of Health Sciences and Medicine, Bond Institute of Health and Sport, Bond University, Gold Coast QLD 4229, Australia.
- Tactical Research Unit, Bond University, Gold Coast QLD 4229, Australia.
| | - Filip Kukić
- Police Sports Education Center, Abu Dhabi Police 253, UAE.
| | | | - Nenad Koropanovski
- Specialized Physical Education at the department of Criminalistics, University of Criminal Investigation and Police Studies, 11080 Belgrade, Serbia.
| | - Radivoje Janković
- Specialized Physical Education at the department of Criminalistics, University of Criminal Investigation and Police Studies, 11080 Belgrade, Serbia.
| | - Jay Dawes
- Department of Helath and Human Performance, Oklahoma State University, Stillwater, OK 74074, USA.
| | - Robert Lockie
- Department of Kinesiology, California State Fullerton, Fullerton, CA 92831, USA.
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Abstract
This work demonstrates the synergy between the thermo-mechanical and humidity induced degradation as well as the oxidation reactions in the kink-banded areas of ultra-high molar mass polyethylene (UHMMPE) fiber-based laminates used in body armor. For aged materials, the energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) results reveal high concentrations of oxygen containing products, and the EPR results demonstrate the presence of the peroxyl radicals (RO2 • ) in the kink-banded areas. After one year of dark ambient storage, very long-lived RO2 • radicals were observed primarily in the samples exposed to ageing conditions of elevated temperatures, humidity, and mechanical stress. The total percentage of crystallinity, as measured by differential scanning calorimetry, of the kinkbanded fibers was unchanged, indicating that the degradation occurs primarily in the amorphous region, and may also involve recrystallization processes of the degraded chains. However, the most abundant orthorhombic crystalline phase decreases from 77 % to 70 %. This decrease in the orthorhombic structure leads to more diffusion of oxygen into the kink-banded region, enhancing the oxidation processes. No changes are observed in the monoclinic phase of the kinked fibers, which remained constant and constituted ~2 % of the total crystallinity.
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Affiliation(s)
- Zois Tsinas
- Materials Science and Engineering Department of University of Maryland, College Park, MD, USA
| | - Amanda L Forster
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Mohamad Al-Sheikhly
- Materials Science and Engineering Department of University of Maryland, College Park, MD, USA
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Affiliation(s)
- Peter F. Mahoney
- Defense Medical Service and Leonard Cheshire Centre, London, UK ,grid.83440.3b0000000121901201Royal Free and University College Medical School, London, UK ,Academic Division of Surgical Specialities, London, UK
| | - James M. Ryan
- grid.83440.3b0000000121901201Royal Free and University College Medical School, London, UK ,Academic Division of Surgical Specialities, London, UK ,grid.499383.c0000 0004 0505 7727Leonard Cheshire Centre, London, UK
| | - Adam J. Brooks
- grid.25879.310000000419368972Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA USA ,grid.411115.10000000404350884Division of Traumatology and Surgical Critical Care, Hospital University of Pennsylvania, Philadelphia, PA USA
| | - C. William Schwab
- grid.25879.310000000419368972Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA USA ,grid.411115.10000000404350884Division of Traumatology and Surgical Critical Care, Hospital University of Pennsylvania, Philadelphia, PA USA
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