{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T02:21:11Z","timestamp":1791339671248,"version":"4.3.1"},"reference-count":76,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,20]],"date-time":"2021-12-20T00:00:00Z","timestamp":1639958400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010790","name":"Erasmus+","doi-asserted-by":"publisher","award":["2019-1-PL01-KA202-064936"],"award-info":[{"award-number":["2019-1-PL01-KA202-064936"]}],"id":[{"id":"10.13039\/501100010790","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>In the context of the COVID-19 pandemic, shortwave ultraviolet radiation with wavelengths between 200 nm and 280 nm (UV-C) is seeing increased usage in the sterilization of medical equipment, appliances, and spaces due to its antimicrobial effect. During the first weeks of the pandemic, healthcare facilities experienced a shortage of personal protective equipment. This led to hospital technicians, private companies, and even members of the public to resort to 3D printing in order to produce fast, on-demand resources. This paper analyzes the effect of accelerated aging through prolonged exposure to UV-C on mechanical properties of parts 3D printed by material extrusion (MEX) from common polymers, such as polylactic acid (PLA) and polyethylene terephthalate-glycol (PETG). Samples 3D printed from these materials went through a 24-h UV-C exposure aging cycle and were then tested versus a control group for changes in mechanical properties. Both tensile and compressive strength were determined, as well as changes in material creep properties. Prolonged UV-C exposure reduced the mechanical properties of PLA by 6\u20138% and of PETG by over 30%. These findings are of practical importance for those interested in producing functional MEX parts intended to be sterilized using UV-C. Scanning electron microscopy (SEM) was performed in order to assess any changes in material structure.<\/jats:p>","DOI":"10.3390\/polym13244467","type":"journal-article","created":{"date-parts":[[2021,12,20]],"date-time":"2021-12-20T08:43:32Z","timestamp":1639989812000},"page":"4467","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":54,"title":["Aging of 3D Printed Polymers under Sterilizing UV-C Radiation"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6621-5034","authenticated-orcid":false,"given":"Catalin Gheorghe","family":"Amza","sequence":"first","affiliation":[{"name":"Department of Quality Engineering and Industrial Technologies, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5948-8536","authenticated-orcid":false,"given":"Aurelian","family":"Zapciu","sequence":"additional","affiliation":[{"name":"Department of Robotics and Production Systems, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0574-6149","authenticated-orcid":false,"given":"Florin","family":"Baciu","sequence":"additional","affiliation":[{"name":"Department of Strength Materials, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mihai Ion","family":"Vasile","sequence":"additional","affiliation":[{"name":"Department of Quality Engineering and Industrial Technologies, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8859-6923","authenticated-orcid":false,"given":"Diana","family":"Popescu","sequence":"additional","affiliation":[{"name":"Department of Robotics and Production Systems, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,20]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2021, November 05). News Release: Shortage of Personal Protective Equipment Endangering Health Workers Worldwide. Available online: https:\/\/www.who.int\/news\/item\/03-03-2020-shortage-of-personal-protective-equipment-endangering-health-workers-worldwide."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e41","DOI":"10.1056\/NEJMp2006141","article-title":"Critical Supply Shortages\u2014The Need for Ventilators and Personal Protective Equipment during the COVID-19 Pandemic","volume":"382","author":"Ranney","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"106263","DOI":"10.1016\/j.ypmed.2020.106263","article-title":"Contributing factors to personal protective equipment shortages during the COVID-19 pandemic","volume":"141","author":"Cohen","year":"2020","journal-title":"Prev. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1002\/bjs.11750","article-title":"Personal protective equipment for surgeons during COVID-19 pandemic: Systematic review of availability, usage and rationing","volume":"107","author":"Jessop","year":"2020","journal-title":"Br. J. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.1001\/jama.2020.4770","article-title":"Conserving Supply of Personal Protective Equipment\u2014A Call for Ideas","volume":"323","author":"Bauchner","year":"2020","journal-title":"JAMA"},{"key":"ref_6","unstructured":"World Health Organization (2021, November 05). Interim Guidance, Rational Use of Personal Protective Equipment for Coro-Navirus Disease (COVID-19) and Considerations during Severe Shortages. Reference Number WHO\/2019-nCoV\/IPC_PPE_use\/2020.4. Available online: https:\/\/www.who.int\/publications\/i\/item\/rational-use-of-personal-protective-equipment-for-coronavirus-disease-(covid-19)-and-considerations-during-severe-shortages."},{"key":"ref_7","first-page":"5","article-title":"Additive manufacturing (\u201c3D printing\u201d) and the future of organizational design: Some early notes from the field","volume":"8","author":"Jordan","year":"2019","journal-title":"J. Org. Des."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1177\/0008125617695284","article-title":"Decentralization and Localization of Production: The Organizational and Economic Consequences of Additive Manufacturing (3D Printing)","volume":"59","author":"Siemsen","year":"2017","journal-title":"Calif. Manag. Rev."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Hagen, A., Chisling, M., House, K., Katz, T., Abelseth, L., Fraser, I., Bradley, S., Kirsch, R., Morris, J., and Giles, J.W. (2021). 3D Printing for Medical Applications: Current State of the Art and Perspectives during the COVID-19 Crisis. Surgeries, 2.","DOI":"10.3390\/surgeries2030025"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1007\/s40964-020-00159-x","article-title":"The role of 3D printing during COVID-19 pandemic: A review","volume":"6","author":"Longhitano","year":"2021","journal-title":"Prog. Addit. Manuf."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1186\/s41205-020-00076-3","article-title":"A 3D-printed nasopharyngeal swab for COVID-19 diagnostic testing","volume":"6","author":"Ford","year":"2020","journal-title":"3D Print. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1361","DOI":"10.1016\/j.matpr.2020.11.505","article-title":"3D printing of nasopharyngeal swabs for COVID-19 diagnose: Past and current trends","volume":"44","author":"Manoj","year":"2021","journal-title":"Mater. Today Proc."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wesemann, C., Pieralli, S., Fretwurst, T., Nold, J., Nelson, K., Schmelzeisen, R., Hellwig, E., and Spies, B.C. (2020). 3-D Printed Protective Equipment during COVID-19 Pandemic. Materials, 13.","DOI":"10.3390\/ma13081997"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1108\/EOR-01-2023-0005","article-title":"A quantitative analysis of 3D printed face shields and masks during COVID-19","volume":"2","author":"Novak","year":"2020","journal-title":"Emerald Open Res."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Marinescu, R., Popescu, D., and Laptoiu, D. (2020). A Review on 3D-Printed Templates for Precontouring Fixation Plates in Orthopedic Surgery. J. Clin. Med., 9.","DOI":"10.3390\/jcm9092908"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1093\/annhyg\/meq085","article-title":"Effect of Fit Testing on the Protection Offered by N95 Filtering Facepiece Respirators against Fine Particles in a Laboratory Setting","volume":"55","author":"Reponen","year":"2011","journal-title":"Ann. Occup. Hyg."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"O\u2019Kelly, E., Arora, A., Pirog, S., Ward, J., and Clarkson, P.J. (2021). Comparing the fit of N95, KN95, surgical, and cloth face masks and assessing the accuracy of fit checking. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0245688"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1612","DOI":"10.1001\/jamainternmed.2020.4218","article-title":"Filtration Efficiency, Effectiveness, and Availability of N95 Face Masks for COVID-19 Prevention","volume":"180","author":"Dugdale","year":"2020","journal-title":"JAMA Intern. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1016\/j.acra.2020.11.005","article-title":"Quantitative Fit Tested N95 Respirator-Alternatives Generated with CT Imaging and 3D Printing: A Response to Potential Shortages during the COVID-19 Pandemic","volume":"28","author":"Ballard","year":"2021","journal-title":"Acad. Radiol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"McAvoy, M., Bui, A.-T.N., Hansen, C., Plana, D., Said, J.T., Yu, Z., Yang, H., Freake, J., Van, C., and Krikorian, D. (2021). 3D Printed frames to enable reuse and improve the fit of N95 and KN95 respirators. BMC Biomed. Eng., 3.","DOI":"10.1186\/s42490-021-00055-7"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"455","DOI":"10.1016\/j.ijpharm.2017.12.003","article-title":"Sterilization of implantable polymer-based medical devices: A review","volume":"544","author":"Tipnis","year":"2018","journal-title":"Int. J. Pharm."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"015017","DOI":"10.1088\/1748-605X\/aa51d5","article-title":"Effects of different sterilization methods on the physico-chemical and bioresponsive properties of plasma-treated polycaprolactone films","volume":"12","author":"Ghobeira","year":"2017","journal-title":"Biomed. Mater."},{"key":"ref_23","unstructured":"Walker, J. (2020). 20\u2014An overview of current surgical instrument and other medical device decontamination practices. Woodhead Publishing Series in Biomaterials, Decontamination in Hospitals and Healthcare, Woodhead Publishing. [2nd ed.]."},{"key":"ref_24","unstructured":"Shanmugam, P.S.T., Chokkalingam, L., and Bakthavachalam, P. (2020). 10\u2014Overview of medical device processing. Trends in Development of Medical Devices, Academic Press."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1403","DOI":"10.1111\/jam.14412","article-title":"Terminal sterilization of medical devices using vaporized hydrogen peroxide: A review of current methods and emerging opportunities","volume":"127","author":"McEvoy","year":"2019","journal-title":"J. Appl. Microbiol."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Grzelak, K., \u0141aszcz, J., Polkowski, J., Mastalski, P., Kluczy\u0144ski, J., \u0141uszczek, J., Torzewski, J., Szachog\u0142uchowicz, I., and Szymaniuk, R. (2021). Additive Manufacturing of Plastics Used for Protection against COVID-19\u2014The Influence of Chemical Disinfection by Alcohol on the Properties of ABS and PETG Polymers. Materials, 14.","DOI":"10.3390\/ma14174823"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"103423","DOI":"10.1016\/j.mechmat.2020.103423","article-title":"Effects of multiple sterilizations and natural aging on the mechanical behavior of 3D-printed ABS","volume":"148","author":"Popescu","year":"2020","journal-title":"Mech. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"P\u00e9rez Davila, S., Gonz\u00e1lez Rodr\u00edguez, L., Chiussi, S., Serra, J., and Gonz\u00e1lez, P. (2021). How to Sterilize Polylactic Acid Based Medical Devices?. Polymers, 13.","DOI":"10.3390\/polym13132115"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1080\/15459624.2015.1018518","article-title":"Effects of Ultraviolet Germicidal Irradiation (UVG) on N95 Respirator Filtration Performance and Structural Integrity","volume":"12","author":"Lindsley","year":"2015","journal-title":"J. Occup. Environ. Hyg."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1564","DOI":"10.1056\/NEJMc2004973","article-title":"Letter to the Editor: Aerosol and Surface Stability of HCoV-19 (SARS-CoV-2) Compared to SARS-CoV-1","volume":"382","author":"Bushmaker","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"126017","DOI":"10.6028\/jres.126.017","article-title":"Comparison of Reflective Properties of Materials Exposed to Ultraviolet-C Radiation","volume":"126","author":"Stojalowski","year":"2021","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"126016","DOI":"10.6028\/jres.126.016","article-title":"Methods and Mechanisms of Photonic Disinfection","volume":"126","author":"Spicer","year":"2021","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_33","unstructured":"Standard ISO 4892-3:2016 (2021, November 06). Plastics\u2014Methods of Exposure to Laboratory Light Sources\u2014Part 3: Fluorescent UV Lamps. Available online: https:\/\/www.iso.org\/standard\/67793.html."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"26298","DOI":"10.1039\/D0RA00274G","article-title":"Study on the biodegradability of modified starch\/polylactic acid (PLA) composite materials","volume":"10","author":"Yu","year":"2020","journal-title":"RSC Adv."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"59","DOI":"10.4028\/www.scientific.net\/AMM.804.59","article-title":"Influence of Multifunctional Monomers on Gamma Irradiated Polylactic Acid","volume":"804","author":"Chaochanchaikul","year":"2015","journal-title":"Appl. Mech. Mater."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.polymdegradstab.2010.10.016","article-title":"Electron-beam treatment of poly(lactic acid) to control degradation profiles","volume":"96","author":"Cairns","year":"2011","journal-title":"Polym. Degrad. Stab."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/S0141-3910(01)00030-1","article-title":"Degradation of poly(l-lactic acid) by \u03b3-irradiation","volume":"72","author":"Nugroho","year":"2001","journal-title":"Polym. Degrad. Stab."},{"key":"ref_38","unstructured":"The National Institute of Standards and Technology (2021, November 05). Summary of Event and Post-Workshop Activities, Available online: https:\/\/www.nist.gov\/news-events\/events\/2020\/01\/workshop-ultraviolet-disinfection-technologies-healthcare-associated-4."},{"key":"ref_39","unstructured":"International Ultraviolet Association (IUVA) (2021, November 05). Fact Sheet on UV Disinfection for COVID-19. Available online: https:\/\/www.iuva.org\/IUVA-Fact-Sheet-on-UV-Disinfection-for-COVID-19."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"126014","DOI":"10.6028\/jres.126.014","article-title":"Ultraviolet Radiation Technologies and Healthcare Associated Infections: Standards and Metrology Needs","volume":"126","author":"Poster","year":"2021","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"126015","DOI":"10.6028\/jres.126.015","article-title":"Perspectives and Recommendations Regarding Standards for Ultraviolet-C Whole-Room Disinfection in Healthcare","volume":"126","author":"Kreitenberg","year":"2021","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.polymdegradstab.2016.09.006","article-title":"A comparison study of the degradative effects and safety implications of UVC and 405 nm germicidal light sources for endoscope storage","volume":"133","author":"Irving","year":"2016","journal-title":"Polym. Degrad. Stab."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"126020","DOI":"10.6028\/jres.126.020","article-title":"Best Practices for Germicidal Ultraviolet-C Dose Measurement for N95 Respirator Decontamination","volume":"126","author":"Geldert","year":"2021","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"763","DOI":"10.1016\/j.chemosphere.2003.11.038","article-title":"Effects of ultraviolet light (315 nm), temperature and relative humidity on the degradation of polylactic acid plastic films","volume":"55","author":"Copinet","year":"2004","journal-title":"Chemosphere"},{"key":"ref_45","first-page":"1","article-title":"The Effect of UV Treatment on the Degradation of Compostable Polylactic Acid","volume":"1","author":"Zhang","year":"2013","journal-title":"J. Emerg. Investig."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"48198","DOI":"10.1002\/app.48198","article-title":"Influence of UV stabilizers on the weathering of PETG and PCTT films","volume":"136","author":"Arangdad","year":"2019","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"313","DOI":"10.3139\/217.1826","article-title":"Predicting the Long-Term Creep Behavior of Plastics Using the Short-Term Creep Test","volume":"19","author":"Lim","year":"2004","journal-title":"Int. Polym. Process."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Morreale, M., Mistretta, M.C., and Fiore, V. (2017). Creep Behavior of Poly(lactic acid) Based Biocomposites. Materials, 10.","DOI":"10.3390\/ma10040395"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"768","DOI":"10.1016\/j.proeng.2015.08.024","article-title":"Creep and Stress Relaxation Behaviour of PLA-PCL Fibres\u2014A Linear Modelling Approach","volume":"114","author":"Martins","year":"2015","journal-title":"Proc. Eng."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1177\/0731684412464586","article-title":"Structure and properties of flax\/polylactide\/alumina nanocomposites","volume":"32","author":"Siengchin","year":"2013","journal-title":"J. Reinf. Plast. Compos."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1007\/s10965-021-02707-7","article-title":"Effect of accelerated weathering on the creep behaviour of additively manufactured Polyethylene Terephthalate Glycol (PETG)","volume":"28","author":"Romeijn","year":"2021","journal-title":"J. Polym. Res."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"123013","DOI":"10.1016\/j.polymer.2020.123013","article-title":"Thermomechanical deformation of polyethylene-terephthalate artificial muscles","volume":"210","author":"Chou","year":"2020","journal-title":"Polymer"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"47564","DOI":"10.1002\/app.47564","article-title":"Effects of the printing parameters on short-term creep behaviors of three-dimensional printed polymers","volume":"136","author":"Tezel","year":"2019","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"1225","DOI":"10.1007\/s00170-018-2539-z","article-title":"Creep behavior analysis of additively manufactured fiber-reinforced components","volume":"99","author":"Mohammadizadeh","year":"2018","journal-title":"Int. J. Adv. Manuf."},{"key":"ref_55","unstructured":"Business and Institutional Furniture Manufacturers Association (BIFMA) (2014). Health Care Furniture Design\u2014Guidelines for Cleanability, BIFMA. Available online: https:\/\/www.ahe.org\/system\/files\/media\/file\/2019\/05\/BIFMACleanGuide6Oct14.pdf."},{"key":"ref_56","unstructured":"Standard ISO 4892-1:2016 (2021, November 05). Plastics\u2014Methods of Exposure to Laboratory Light Sources\u2014Part 1: General Guidance. Available online: https:\/\/www.iso.org\/standard\/60048.html."},{"key":"ref_57","unstructured":"Standard ISO 4582:2017 (2021, November 05). Plastics\u2014Determination of Changes in Colour and Variations in Properties after Exposure to Glass-Filtered Solar Radiation, Natural Weathering or Laboratory Radiation Sources. Available online: https:\/\/www.iso.org\/standard\/67791.html."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Podsiad\u0142y, B., Skalski, A., Rozpi\u00f3rski, W., and S\u0142oma, M. (2021). Are We Able to Print Components as Strong as Injection Molded?\u2014Comparing the Properties of 3D Printed and Injection Molded Components Made from ABS Thermoplastic. Appl. Sci., 11.","DOI":"10.3390\/app11156946"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"012033","DOI":"10.1088\/1757-899X\/227\/1\/012033","article-title":"The influence of printing parameters on selected mechanical properties of FDM\/FFF 3D-printed parts","volume":"227","author":"Grabowik","year":"2017","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_60","unstructured":"Standard ASTM D638-14 (2021, November 05). Standard Test Method for Tensile Properties of Plastics. Available online: https:\/\/www.astm.org\/Standards\/D638."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.polymertesting.2018.04.029","article-title":"Anisotropic mechanical property variance between ASTM D638-14 type i and type iv fused filament fabricated specimens","volume":"68","author":"Laureto","year":"2018","journal-title":"Polym. Test."},{"key":"ref_62","unstructured":"Standard ASTM D2990-01 (2021, November 05). Standard Test Methods for Tensile, Compressive, and Flexural Creep and Creep-Rupture of Plastics. Available online: https:\/\/www.astm.org\/Standards\/D2990.htm."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"506","DOI":"10.1016\/j.compositesb.2016.06.009","article-title":"Isotropic and anisotropic elasticity and yielding of 3D printed material","volume":"99","author":"Zou","year":"2016","journal-title":"Compos. B Eng."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1080\/17452759.2014.984042","article-title":"Thermal conditions affecting heat transfer in FDM\/FFE: A contribution towards the numerical modelling of the process","volume":"10","author":"Costa","year":"2015","journal-title":"Virtual Phys. Prototyp."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1097","DOI":"10.1122\/1.5022982","article-title":"Rheological and heat transfer effects in fused filament fabrication","volume":"62","author":"Phan","year":"2018","journal-title":"J. Rheol."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1016\/j.polymdegradstab.2005.04.011","article-title":"Global weathering of aromatic engineering thermoplastics","volume":"90","author":"Pickett","year":"2005","journal-title":"Polym. Degrad. Stabil."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1002\/(SICI)1097-4628(19991010)74:2<306::AID-APP11>3.0.CO;2-C","article-title":"Two-step photodegradation process of poly(ethylene terephthalate)","volume":"74","author":"Wang","year":"1999","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_68","doi-asserted-by":"crossref","unstructured":"Wickramasinghe, S., Do, T., and Tran, P. (2020). FDM-Based 3D Printing of Polymer and Associated Composite: A Review on Mechanical Properties, Defects and Treatments. Polymers, 12.","DOI":"10.3390\/polym12071529"},{"key":"ref_69","doi-asserted-by":"crossref","unstructured":"Wang, X., Zhao, L., Fuh, J.Y.H., and Lee, H.P. (2019). Effect of Porosity on Mechanical Properties of 3D Printed Polymers: Experiments and Micromechanical Modeling Based on X-ray Computed Tomography Analysis. Polymers, 11.","DOI":"10.3390\/polym11071154"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/0141-3910(94)90074-4","article-title":"Physicochemical aspects of the environmental degradation of poly(ethylene terephthalate)","volume":"43","author":"Allen","year":"1994","journal-title":"Polym. Degrad. Stabil."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"102778","DOI":"10.1039\/C6RA21985C","article-title":"Photodegradation behavior and mechanism of poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG) random copolymers: Correlation with copolymer composition","volume":"6","author":"Chen","year":"2016","journal-title":"RSC Adv."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.eurpolymj.2013.10.011","article-title":"Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties","volume":"50","author":"Rasselet","year":"2014","journal-title":"Eur. Polym. J."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"2489","DOI":"10.1177\/0021998319899140","article-title":"Performance of polylactide against UV irradiation: Synergism of an organic UV absorber with micron and nano-sized TiO2","volume":"54","author":"Can","year":"2020","journal-title":"J. Compos. Mater."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1186\/2193-1801-2-398","article-title":"Photodegradation and photostabilization of polymers, especially polystyrene: Review","volume":"2","author":"Yousif","year":"2013","journal-title":"SpringerPlus"},{"key":"ref_75","doi-asserted-by":"crossref","unstructured":"Sala\u010d, J., Sera, J., Jur\u010da, M., Verney, V., Marek, A., and Koutny, M. (2019). Photodegradation and Biodegradation of Poly(Lactic) Acid Containing Orotic Acid as a Nucleation Agent. 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