2,118 research outputs found
Author Lev Raphael reads from his work at the Michigan Writers Series
No full textInternationally acclaimed author and Greater Lansing resident, Lev Raphael, reads from his memoir "My Germany". He recounts his travels to the NAZI labor camp where his mother was held during World War II and coming to terms with his mother's traumatic past. Introduced by Michigan State University Librarian Michael Rodriguez at an event held at the MSU Main Library. Part of the Michigan State University Libraries' Michigan Writers Series
Nanomaterials for 3D Printing of Polymers via Stereolithography: Concept, Technologies, and Applications
No full textStereolithography (SLA) is an additive manufacturing method with one of the highest accuracies (down to 100 nm) of all solid freeform techniques and has been used in various areas, such as medicine, automotive, aerospace, electronics, and others. However, most resins available nowadays are derived from petroleum. Its toxicity, low biocompatibility, and growing environmental concerns are limiting its application. This review discusses the development of biobased and biocompatible materials for different SLA processes as well as the usage of nanocomposites to increase their applicability. A comprehensive overview of the SLA technologies, photopolymerization chemistry, and resin properties are also provided. Finally, various examples using different types of materials are explored, to show the current and future capabilities of the SLA technique
Synthesis and characterization of bio-based polymers for innovative additive manufacturing applications via stereolithography 3D printing
No full textThis thesis focused on the study and development of bio-based and biocompatible photosensitive resin for stereolithography 3D printing.
One of the seven additive manufacturing technologies, vat photopolymerization, utilizes a combination of liquid photosensitive polymers with a photoinitiator and a UV emitter to fabricate objects. The main advantage of this method is that it allows the creation of highly detailed objects. Indeed, this is the main reason why vat photopolymerization is interesting for biomedical applications, whereby combining it with other imaging techniques, it is possible to create patient-made prothesis and implants. Unfortunately, most resins used nowadays are derived from petroleum, limiting their application.
Different types of materials were proposed to expand the variety of bio-resins. Among all, vegetable oils and plant-based resins demonstrated some promising properties. They are available worldwide and have relatively low production costs. Moreover, they can be easily functionalized to be suitable for photopolymerization. Soybean oil being a good example. Its functionalization is already used for UV coating, but its full potential in 3D printing is yet to be explored.
In this research study, the utilization of functionalized soybean oil, more precisely, acrylated epoxidized soybean oil (AESO), for 3D-printing was investigated. Here, AESO was tested for different application: from improving the biobased content of commercial a resin, to the synthesis and optimization of complete biobased and biocompatible resins.
For the first study, increasing concentrations of neat AESO were combined with Peopoly moai standard clear resin, where its influence on the resin performance was tested using different characterization techniques. Tensile test results were also compared with data from other standards of commercial resins to see how it would scale. The doping of petroleum-based resins with biobased resins is interesting since it is a simple method to increase the bio-renewable content of such materials.
However, the main objective is the transitioning from petroleum-based to complete bio resins, thus for that, in the subsequent study, AESO was combined with another plant-based material to develop a biobased resin. The mechanical and curing properties of this new resin were again compared with various standard resins to verify its performance. Furthermore, other characterization analyzes were done to better understand its photopolymerization reaction and final application.
Based on the information obtained from developing a biobased resin, AESO was used for creating a biocompatible resin. For that, it was combined with a known biocompatible material, poly(ethylene) diacrylate, and different physical and chemical properties were studied. Furthermore, the mixture which demonstrated the best performance was used in a following study that had the objective to add nanoparticles to improve its mechanical properties. The fillers used were micro- and nano- crystalline cellulose, a natural material that has already shown remarkable properties at low dosages.
The studies presented in this work are only the beginning. Further research needs to be carried out to test the performance of the biocompatible resins developed in cell cultures. Future perspectives can also consist of the evaluation of different vegetable oils, or the usage of non-food related materials (ex: algae) to develop these new bio-resins. Additionally, other types of particles can be explored as well to add new properties, such as flame retardancy, conductivity, memory shape, and others
Evaluation of a biobased resin with micro- or nanocrystalline cellulose for 3D-printing application
No full textInvestigation of epoxy-acrylate soybean oil as a bio-enhancer for 3D printing application
No full textPreparation and characterization of a fully biobased resin system for 3d-printing, suitable for replacing fossil-based acrylates
No full textThe exploitation of plant-based monomers for additive manufacturing is a very promising approach to reduce the usage of petroleum-based plastics. In vat photopolymerization, acrylate epoxidized soybean oil (AESO) stands out as a versatile photocurable resin that can be modified and combined with other materials for multiple applications. In this work, different ratios of AESO were combined with isobornyl methacrylate (IBOMA), to develop a resin that exhibits similar mechanical properties to standard fossil-based resins. The photopolymerization reaction and conversion rate was monitored using FT-IR analysis, which showed conversions above 80%. Furthermore, curing tests revealed that the biobased resin needed less energy to cure when compared to commercial resins. The parts fabricated using the biobased resin also demonstrated enhanced tensile strength, tunable elongation at break and swelling resistance, which were comparable to standard fossil-based resins. This work demonstrates the potential of the proposed systems as a valuable alternative to traditional resins, paving the way for the development of high-performance materials for stereolithographic applications
Photosensitive acrylates containing bio-based epoxy-acrylate soybean oil for 3D printing application
No full textStereolithography is a 3D-printing process that is rapidly shifting from being an expensive and limited technology to an affordable, precise, and fast method of mass production. However, most of the current resins are petroleum-based, which makes them toxic, non-degradable and with poor biocompatibility. In this study, a standard petroleum-based resin containing urethane acrylate and acrylic monomers was combined with epoxy-acrylate soybean oil (EASO), aiming to reduce its impact on the environment. Ratios varying from 10 to 50 wt% of EASO were incorporated into the commercial resin while maintaining the viscosity low, between 0.27 and 1.06 Pa s. The printed samples showed good quality and complete integration between the layers. The addition of 50 wt% of EASO increased the samples elongation at break by 108% (from 2.3% to 4.8%) and decreased the contact angle by 26.4% (from 72 to 53°). Moreover, the mixture showed good thermal and swelling stability and tensile strength in the range of other commercial cured systems. The addition of EASO may significantly contribute to the exploitation of greener materials, which well matches today's circular economy concept
Preparation and Characterization of 3D-Printed Biobased Composites Containing Micro-or Nanocrystalline Cellulose
No full textStereolithography (SLA), one of the seven different 3D printing technologies, uses photosensitive resins to create high-resolution parts. Although SLA offers many advantages for medical applications, the lack of biocompatible and biobased resins limits its utilization. Thus, the development of new materials is essential. This work aims at designing, developing, and fully characterizing a bio-resin system (made of poly(ethylene glycol) diacrylate (PEGDA) and acrylated epoxidized soybean oil (AESO)), filled with micro- or nanocellulose crystals (MCC and CNC), suitable for 3D printing. The unfilled resin system containing 80 wt.% AESO was identified as the best resin mixture, having a biobased content of 68.8%, while ensuring viscosity values suitable for the 3D printing process (>1.5 Pa s). The printed samples showed a 93% swelling decrease in water, as well as increased tensile strength (4.4 +/- 0.2 MPa) and elongation at break (25% +/- 2.3%). Furthermore, the incorporation of MCC and CNC remarkably increased the tensile strength and Young's modulus of the cured network, thus indicating a strong reinforcing effect exerted by the fillers. Lastly, the presence of the fillers did not affect the UV-light penetration, and the printed parts showed a high quality, thus proving their potential for precise applications
Recent Advancements in Acrylic Fabric Applications: A Comprehensive Review and Future Trends
No full textAcrylic fibres, as synthetic polymers, have been used extensively in the textile industry to create a wide variety of products, ranging from apparel and home furnishings to car rooftops and carbon fibres. Their widespread application is attributed to a combination of desirable properties, including a soft, wool-like texture, chemical stability, and robust mechanical characteristics. Furthermore, the chemical structure of acrylic fibres can be modified to imbue them with additional features, such as antimicrobial properties, fire resistance, conductivity, water repellency, and ultraviolet protection. This review explores the technological methods employed to functionalise acrylic fibres and discusses future trends in their development
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