Photosensitive naturally derived resins toward optical 3-D printing (original) (raw)

Photopolymer Resins with Biobased Methacrylates Based on Soybean Oil for Stereolithography

ACS Applied Polymer Materials, 2020

The accessibility of renewable materials that are both sustainable and competitive is essential to accommodate the rapid growth in consumption of 3D printing materials. We have developed biobased photopolymer resins based on modified soybean oil for application in commercial stereolithography printers. First, soybean oil methacrylates with various functionalities were successfully synthesized from epoxidized soybean oil as an alternative to commercially available soybean oil acrylate. A library of photoresins was created by mixing up to 80% of the biobased (meth)acrylate oligomers with biobased diluents and a photoinitiator. The resin composition was optimized to achieve a maximum biobased content and a low viscosity. The manufactured parts demonstrated complete layer fusion and accurate print quality. Stiffness and toughness can be tuned by altering the chemical composition or the number of functional groups per oligomer. These biobased materials can be employed to reduce the environmental impact of additive manufacturing while being competitive with current fossil-based resins from commercial manufacturers.

Biobased Acrylate Photocurable Resin Formulation for Stereolithography 3D Printing

ACS Omega, 2018

To facilitate the ongoing transition toward a circular economy, the availability of renewable materials for additive manufacturing becomes increasingly important. Here, we report the successful fabrication of complex shaped prototypes from biobased acrylate photopolymer resins, employing a commercial stereolithography apparatus (SLA) 3D printer. Four distinct resins with a biobased content ranging from 34 to 67% have been developed. All formulations demonstrated adequate viscosity and were readily polymerizable by the UV-laser-based SLA process. Increasing the double-bond concentration within the resin results in stiff and thermally resilient 3D printed products. High-viscosity resins lead to high-resolution prototypes with a complex microarchitecture and excellent surface finishing, comparable to commercial nonrenewable resins. These advances can facilitate the wide application of biobased resins for construction of new sustainable products via stereolithographic 3D printing methods.

Biodegradable Poly(ester) Urethane Acrylate Resins for Digital Light Processing: From Polymer Synthesis to 3D Printed Tissue Engineering Constructs

Digital light processing (DLP) is one of the most accurate and fastest additive manufacturingtechnologies to produce a variety of products, from patient-customized biomedical implants toconsumer goods; however, DLP’s use in tissue engineering is limited largely due to a lack ofbiodegradable resins. Herein, a library of biodegradable urethane acrylate-capped poly(esters)(with variations in molecular weight) is investigated as the basis for a DLP printable ink fortissue engineering. The synthesized oligomers show good printability in a DLP resin, capableof creating complex structures with mechanical properties matching those of medium-softtissues (1–3 MPa). While fabricated films from different molecular weight resins showed fewdifferences in surface topology, wettability, and protein adsorption, the adhesion and metabolicactivity of L929 and human dermal fibroblasts (HDFs) were significantly different: resins fromhigher molecular weight oligomers provided greater cell adhesion and me...

Novel Formulations Containing Fluorescent Sensors to Improve the Resolution of 3D Prints

International Journal of Molecular Sciences

Three-dimensional printing in SLA (stereolithography) and DLP (digital light processing) technologies has recently been experiencing a period of extremely rapid development. This is due to the fact that researchers recognise the many advantages of 3D printing, such as the high resolution and speed of the modelling and printing processes. However, there is still a search for new resin formulations dedicated to specific 3D printers allowing for high-resolution prints. Therefore, in the following paper, the effects of dyes such as BODIPY, europium complex, and Coumarin 1 added to light-cured compositions polymerised according to the radical mechanism on the photopolymerisation process speed, polymerisation shrinkage, and the final properties of the printouts were investigated. The kinetics of the photopolymerisation of light-cured materials using real-time FT-IR methods, as well as printouts that tangibly demonstrate the potential application of 3D printing technology in Industry 4.0, ...

4D printed stereolithography printed plant‐based sustainable polymers: Preliminary investigation and optimization

Journal of Applied Polymer Science, 2021

The increasing demand for applying shape memory polymer to tissue culture and biomedical engineering has opened up research opportunities in the field of 4D Printing. The biocompatibility of the scaffolds as a culture medium resulted in the use of plant‐based polymers to provide an ambient environment for the growth of cells. This research investigates the 4D printing of acrylated epoxidized soybean oil (AESO), a plant‐based shape polymer. The objective of the present work is to establish the relationship between the 4D printing parameters (laser power frequency and print speed) and different properties of the printed material viz. tensile stress, surface roughness, wettability, recovery time, strain fixity and glass transition temperature. The maximum fixity was about 85%, while the recovery time as low as 1.6 s. The print parameters are optimized using regression modeling and multi‐objective optimization techniques. The shape memory effect of the polymer is demonstrated by printin...

Urethane dimethacrylate-based photopolymerizable resins for stereolithography 3D printing: A physicochemical characterisation and biocompatibility evaluation

Drug Delivery and Translational Research

Vat photopolymerisation (VP) three-dimensional printing (3DP) has attracted great attention in many different fields, such as electronics, pharmaceuticals, biomedical devices and tissue engineering. Due to the low availability of biocompatible photocurable resins, its application in the healthcare sector is still limited. In this work, we formulate photocurable resins based on urethane dimethacrylate (UDMA) combined with three different difunctional methacrylic diluents named ethylene glycol dimethacrylate (EGDMA), di(ethylene glycol) dimethacrylate (DEGDMA) or tri(ethylene glycol) dimethacrylate (TEGDMA). The resins were tested for viscosity, thermal behaviour and printability. After printing, the 3D printed specimens were measured with a digital calliper in order to investigate their accuracy to the digital model and tested with FT-IR, TGA and DSC. Their mechanical properties, contact angle, water sorption and biocompatibility were also evaluated. The photopolymerizable formulatio...

Mechanically tunable resins based on acrylate-based resin for digital light processing (DLP) 3D printing

Scientific Reports

Until now, only a few materials are available for additive manufacturing technologies that employ photopolymerization, such as stereolithography (SLA) and digital light processing (DLP) 3D printing systems. This study investigates a newly formulated resins as an alternative 3D printing materials with tunable mechanical properties to expand the potential applications of advanced engineering products such as wearable devices and small reactors. A commercial acrylate-based resin was selected as a standard resin (STD). The resin was formulated by combining various volume ratios of a low-cost polypropylene glycol (PPG) having various molecular weights (400, 1000, and 2000 g/mol) with the STD resin. The printability of the formulated resins was optimized using the digital light processing (DLP) 3D printing technique. The effects of the PPG contents on the properties of the printed parts were studied, including printability, thermal properties, mechanical properties, and thermo-mechanical ...

Vegetable Oil-Based Thiol-Ene/Thiol-Epoxy Resins for Laser Direct Writing 3D Micro-/Nano-Lithography

Polymers

The use of renewable sources for optical 3D printing instead of petroleum-based materials is increasingly growing. Combinations of photo- and thermal polymerization in dual curing processes can enhance the thermal and mechanical properties of the synthesized thermosets. Consequently, thiol-ene/thiol-epoxy polymers were obtained by combining UV and thermal curing of acrylated epoxidized soybean oil and epoxidized linseed oil with thiols, benzene-1,3-dithiol and pentaerythritol tetra(3-mercaptopropionate). Thiol-epoxy reaction was studied by calorimetry. The changes of rheological properties were examined during UV, thermal and dual curing to select the most suitable formulations for laser direct writing (LDW). The obtained polymers were characterized by dynamic-mechanical thermal analysis, thermogravimetry, and mechanical testing. The selected dual curable mixture was tested in LDW 3D lithography for validating its potential in optical micro- and nano-additive manufacturing. The obta...

New stereolithographic resin providing functional surfaces for biocompatible three-dimensional printing

Journal of tissue engineering

Stereolithography is one of the most promising technologies for the production of tailored implants. Within this study, we show the results of a new resin formulation for three-dimensional printing which is also useful for subsequent surface functionalization. The class of materials is based on monomers containing either thiol or alkene groups. By irradiation of the monomers at a wavelength of 266 nm, we demonstrated an initiator-free stereolithographic process based on thiol-ene click chemistry. Specimens made from this material have successfully been tested for biocompatibility. Using Fourier-transform infrared spectrometry and fluorescent staining, we are able to show that off-stoichiometric amounts of functional groups in the monomers allow us to produce scaffolds with functional surfaces. We established a new protocol to demonstrate the opportunity to functionalize the surface by copper-catalyzed azide-alkyne cycloaddition chemistry. Finally, we demonstrate a three-dimensional ...

UV assisted photo reactive polyether‐polyesteramide resin for future applications in 3D printing

Journal of Polymer Science, 2021

Among additive manufacturing, photocuring 3D printing technologies are very relevant because of its high printing speed and high precision. However, the limited performance of photosensitive thermoset polymers is the bottleneck for the application of photocuring 3D printing in some fields, particularly in the biomedical sector. Thus, the development of biodegradable and biocompatible materials is highly desirable and of utmost importance. In this work, a biodegradable and non-cytotoxic thermoset polymer for photocuring 3D printing is reported. It consists of an unsaturated polyesteramide bearing phenylalanine, 2-butene-1,4-diol and fumarate building blocks, which is photocured under UV irradiation using a low molecular weight poly(ethylene glycol) diacrylate as crosslinker. The main characteristics of the new thermoset are: (1) very high volumetric and mechanical integrity stabilities, comparable to that of photocured epoxides; (2) very high degradation temperature; (3) very low water absorption capacity; (4) relatively fast enzymatic degradation, reaching 16.5% after 3 months; and (5) non-cytotoxic response in presence of epithelial cells, even when soluble molecular fragments coming from biodegradation are considered. These properties favor the future utilization of the new polyether-polyesteramide resin in the manufacturing of more sustainable products via 3D printing methods, such as stereolithography, that uses UV sources.