scholarly journals UV-Light Curing of 3D Printing Inks from Vegetable Oils for Stereolithography

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1195
Author(s):  
Anda Barkane ◽  
Oskars Platnieks ◽  
Maksims Jurinovs ◽  
Sigita Kasetaite ◽  
Jolita Ostrauskaite ◽  
...  
Keyword(s):  
Vegetable Oils ◽  
Uv Light ◽  
Irradiation Time ◽  
Uv Curing ◽  
Crosslinking Density ◽  
Reactive Diluents ◽  
Trimethylolpropane Triacrylate ◽  
Double Bond Conversion ◽  
Light Curing ◽  
Mechanical Performances

Typical resins for UV-assisted additive manufacturing (AM) are prepared from petroleum-based materials and therefore do not contribute to the growing AM industry trend of converting to sustainable bio-based materials. To satisfy society and industry’s demand for sustainability, renewable feedstocks must be explored; unfortunately, there are not many options that are applicable to photopolymerization. Nevertheless, some vegetable oils can be modified to be suitable for UV-assisted AM technologies. In this work, extended study, through FTIR and photorheology measurements, of the UV-curing of epoxidized acrylate from soybean oil (AESO)-based formulations has been performed to better understand the photopolymerization process. The study demonstrates that the addition of appropriate functional comonomers like trimethylolpropane triacrylate (TMPTA) and the adjusting of the concentration of photoinitiator from 1% to 7% decrease the needed UV-irradiation time by up to 25%. Under optimized conditions, the optimal curing time was about 4 s, leading to a double bond conversion rate (DBC%) up to 80% and higher crosslinking density determined by the Flory–Rehner empirical approach. Thermal and mechanical properties were also investigated via TGA and DMA measurements that showed significant improvements of mechanical performances for all formulations. The properties were improved further upon the addition of the reactive diluents. After the thorough investigations, the prepared vegetable oil-based resin ink formulations containing reactive diluents were deemed suitable inks for UV-assisted AM, giving their appropriate viscosity. The validation was done by printing different objects with complex structures using a laser based stereolithography apparatus (SLA) printer.

Study on the UV Curing Reactivity of Micro-Injection UV-Curing Molding

2018 ◽  
Vol 777 ◽  
pp. 65-69
Author(s):  
Jia Wei Li ◽  
Jian Yun He ◽  
Xi Dan Luo ◽  
Chang Song Zhao ◽  
Peng Cheng Xie ◽  
...  
Keyword(s):  
Uv Light ◽  
Uv Curing ◽  
Process Conditions ◽  
Uv Curable ◽  
Functional Monomers ◽  
Molding Method ◽  
Curing Reaction ◽  
Double Bond Conversion ◽  
Light Curing ◽  
Kinetics Of

In this paper, UV irradiation curing technology is used in the processing and manufacturing of micro structure parts and a micro-injection molding method of UV-curable molding was proposed to process microstructures. The special material for UV light curing injection of microstructural products was developed. The light curing reactivity of the micro injection light curing special material and its effect on the processing molding are studied. The kinetics of light curing reaction of UV curing injecting material were studied by online infrared spectroscopy (RT-IR). The contribution of mono functional monomers to the double bond conversion rate of microstructures is higher than that of high functional monomers. Under the same condition, the mono functional monomer can make the UV curing reaction more complete. Under the same process conditions, the rate of UV curing reaction of high functional monomers is higher than that of mono functional monomers.

Research of UV Curing PUA/EP Damping Coating

2014 ◽  
Vol 1030-1032 ◽  
pp. 161-164
Author(s):  
Ya Jun Tong ◽  
Wei Cai Peng ◽  
Zhi Xiong Huang ◽  
Min Xian Shi ◽  
Xue Song Lv
Keyword(s):  
Theoretical Basis ◽  
Orthogonal Experiment ◽  
Uv Curing ◽  
Urethane Acrylate ◽  
Reactive Diluents ◽  
Experiment Method ◽  
Light Curing ◽  
Orthogonal Experiment Method ◽  
The Impact ◽  
Synthesis Experiment

In this experiment, we examine the impact of photoinitiator and reactive diluents for the UV curing of epoxy resin and Urethane acrylate in detail, so as to provide a theoretical basis for obtaining a satisfactory light curing system. We conducted a number of UV curing experiments, discussed the key influencing factors of the success in Synthesis experiment, explored and researched the Reaction mechanism to some certain extent. The performance was tested after curing, according to the orthogonal experiment method, we analyses the effect of different factors.

scholarly journals Effect of curing parameters and configuration on the efficacy of ultraviolet light curing self-adhesive masks used for abrasive jet micro-machining and microfluidic device fabrication

2021 ◽  
Author(s):  
Farbod Ahmadzadeh
Keyword(s):  
Microfluidic Chip ◽  
Biomedical Applications ◽  
Uv Light ◽  
Three Dimensional ◽  
Uv Curing ◽  
Device Fabrication ◽  
Flow Focusing ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Light Curing

Soft lithography techniques has been used widely in the past decade to fabricate microfluidic chips used in biomedical applications. Abrasive jet machining (AJM) has been used to fabricate similar chips using particle erosion mechanisms. This thesis proposes a new technique using a UV light sensitive self-adhesive mask (RapidMask) and AJM to fabricate a three dimensional flow focusing microfluidic chip where the depth of the channel is allowed to vary along the channel length. A detailed characterization of the effect of curing parameters of a UV light curing self-adhesive mask on the resulting feature resolution is reported. Instead of relying on the manufacturer recommended curing parameters which were vaguely described for specific UV curing units, it was found that measured energy density could be used to quantify a recommended cure that is independent of the curing unit. The best achievable pattern on borosilicate glass using RM and AJM was found and reported along with the erosion rates of uncured, cured RM during AJM. A new methodology was introduced to use multiple layers of the RM in order to increase the achievable feature aspect ratio. The results of the RM curing and multiple layer investigation were then used to fabricate a three dimensional flow focusing chip with a varying depth at the focusing junction. The chip was then sealed and tested to demonstrate its capabilities and potential in healthcare and biomedical applications. To the best knowledge of the author, this thesis is the first to report using a double layer RM to fabricate a microfluidic chip using AJM.

scholarly journals Effect of curing parameters and configuration on the efficacy of ultraviolet light curing self-adhesive masks used for abrasive jet micro-machining and microfluidic device fabrication

2021 ◽  
Author(s):  
Farbod Ahmadzadeh
Keyword(s):  
Microfluidic Chip ◽  
Biomedical Applications ◽  
Uv Light ◽  
Three Dimensional ◽  
Uv Curing ◽  
Device Fabrication ◽  
Flow Focusing ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Light Curing

Soft lithography techniques has been used widely in the past decade to fabricate microfluidic chips used in biomedical applications. Abrasive jet machining (AJM) has been used to fabricate similar chips using particle erosion mechanisms. This thesis proposes a new technique using a UV light sensitive self-adhesive mask (RapidMask) and AJM to fabricate a three dimensional flow focusing microfluidic chip where the depth of the channel is allowed to vary along the channel length. A detailed characterization of the effect of curing parameters of a UV light curing self-adhesive mask on the resulting feature resolution is reported. Instead of relying on the manufacturer recommended curing parameters which were vaguely described for specific UV curing units, it was found that measured energy density could be used to quantify a recommended cure that is independent of the curing unit. The best achievable pattern on borosilicate glass using RM and AJM was found and reported along with the erosion rates of uncured, cured RM during AJM. A new methodology was introduced to use multiple layers of the RM in order to increase the achievable feature aspect ratio. The results of the RM curing and multiple layer investigation were then used to fabricate a three dimensional flow focusing chip with a varying depth at the focusing junction. The chip was then sealed and tested to demonstrate its capabilities and potential in healthcare and biomedical applications. To the best knowledge of the author, this thesis is the first to report using a double layer RM to fabricate a microfluidic chip using AJM.

Study Main Properties of Two Systems Watermark Varnish

2011 ◽  
Vol 380 ◽  
pp. 117-120
Author(s):  
Ling Ya Gu ◽  
Bei Qing Huang ◽  
De Ping Zhao ◽  
Wei Yuan
Keyword(s):  
Refractive Index ◽  
Specific Gravity ◽  
Vegetable Oil ◽  
Screen Printing ◽  
Uv Light ◽  
Uv Curing ◽  
Index Study ◽  
Two Systems ◽  
Light Curing ◽  
Better Than

In order to obtain good watermark on paper by printing, vegetable oil system and UV light-curing system watermark varnish were prepared by changing the type of vegetable oil, prepolymer and monomer, then test its permeability and refractive index, study the effects of these components on the performance of watermark varnish. Print watermark varnish by screen printing to examine the watermark. The results show that watermark varnish prepared with different type of vegetable oil has different permeability, but refractive index is very close. Adding prepolymer can improve permeability and refractive index of vegetable oil system watermark varnish. If the specific gravity of prepolymer and monomer is greater, permeability of UV curing system watermark varnish is higher. If refractive index of prepolymer and monomer is bigger, refractive index of varnish is bigger. Printing effect of UV curing system watermark varnish is better than vegetable oil system watermark varnish.

scholarly journals Water-Tree Resistant Characteristics of Crosslinker-Modified-SiO2/XLPE Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1398
Author(s):  
Yong-Qi Zhang ◽  
Xuan Wang ◽  
Ping-Lan Yu ◽  
Wei-Feng Sun
Keyword(s):  
Electric Fields ◽  
Tree Growth ◽  
Mechanical Analysis ◽  
Water Molecules ◽  
Crosslinking Degree ◽  
Water Tree ◽  
Tree Resistance ◽  
Alternating Electric Fields ◽  
Trimethylolpropane Triacrylate ◽  
Mechanical Performances

Trimethylolpropane triacrylate (TMPTA) as a photoactive crosslinker is grafted onto hydrophobic nanosilica surface through click chemical reactions of mercapto double bonds to prepare the functionalized nanoparticles (TMPTA-s-SiO2), which are used to develop TMPTA-s-SiO2/XLPE nanocomposites with improvements in mechanical strength and electrical resistance. The expedited aging experiments of water-tree growth are performed with a water-knife electrode and analyzed in consistence with the mechanical performances evaluated by means of dynamic thermo-mechanical analysis (DMA) and tensile stress–strain characteristics. Due to the dense cross-linking network of polyethylene molecular chains formed on the TMPTA-modified surfaces of SiO2 nanofillers, TMPTA-s-SiO2 nanofillers are chemically introduced into XLPE matrix to acquire higher crosslinking degree and connection strength in the amorphous regions between polyethylene lamellae, accounting for the higher water-tree resistance and ameliorated mechanical performances, compared with pure XLPE and neat-SiO2/XLPE nanocomposite. Hydrophilic TMPTA molecules grafted on the nano-SiO2 surface can inhibit the condensation of water molecules into water micro-beads at insulation defects, thus attenuating the damage of water micro-beads to polyethylene configurations under alternating electric fields and thus restricting water-tree growth in amorphous regions. The intensified interfaces between TMPTA-s-SiO2 nanofillers and XLPE matrix limit the segment motions of polyethylene molecular chains and resist the diffusion of water molecules in XLPE amorphous regions, which further contributes to the excellent water-tree resistance of TMPTA-s-SiO2/XLPE nanocomposites.

UV-Curable organic-inorganic hybrid films based on tetraethylorthosilicate oligomer and special acrylated polyester

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianyun He ◽  
Jinping Xiong ◽  
Bingqian Xia
Keyword(s):  
Uv Light ◽  
Uv Curing ◽  
Organic Matrix ◽  
Dynamic Mechanical Properties ◽  
Hybrid Films ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Dynamic Mechanical ◽  
H Nmr ◽  
Uv Curing Process

AbstractOrganic-inorganic hybrid films were prepared using tetraethylorthosilicate (TEOS) oligomer and special acrylated polyester (SAP) via a UV-curing process. TEOS oligomers were prepared in the presence of water and ethanol using hydrochloric acid as the catalyst and characterized using 1H NMR, 29Si NMR and MALDI-TOF mass spectra. Special acrylated polyester was synthesized by 1,4-cyclohexane dimethanol, neopentyl glycol, 1,4-butanediol, maleic anhydride, adipic acid, and acrylic acid. Hybrid films were cured by UV light and the thermal properties, dynamic mechanical properties, and tensile properties of the hybrid films were evaluated as the function of TEOS oligomer content. The morphology of the hybrid films was examined using atomic force microscopy (AFM). The microscopy and dynamic mechanical data indicated that the hybrid films were heterogeneous materials with various inorganic particle sizes dispersed within the organic matrix. The results indicated that after incorporating the TEOS oligomer, the strength and thermal stability of the hybrid films were enhanced.

Photoinitiators in Dentistry: A Review

2013 ◽  
Vol 2 (4) ◽  
pp. 30-33 ◽  
Author(s):  
Ario Santini ◽  
Iranzihuatl Torres Gallegos ◽  
Christopher M. Felix
Keyword(s):  
Light Transmission ◽  
Uv Light ◽  
Energy Levels ◽  
Polymer Network ◽  
Filling Material ◽  
Restorative Material ◽  
Spectral Emission ◽  
Potential Health ◽  
Posterior Teeth ◽  
Light Curing

Polymerization of Resin Based Composites (RBCs) initiated by a light curing unit activating photoinitiators. Different RBCs require different light energy levels for proper curing. Manufacturers are now producing RBCs with more than one initiator and not all of these will be properly polymerised with blue LED lights. An added problem is that manufacturers do not always indicate the type of photoinitiators in their materials. This review discusses the importance of matching the spectral output of LCUs to the absorption spectra of RBCs and the consequences of spectral mismatch. Resin based composites (RBCs) were first introduced in the 1960s1 and with development of effective and reliable dentine bonding systems2, have been used routinely as a filling material for both anterior and posterior teeth. The early RBCs were either chemically cured two component materials or photo-initiated materials that used UV initiators in the beginning and then transitioned to visible light initiators such as camphorquinine which was introduced in 1978.3 The first report of a light curing material was of an ultraviolet (UV) cured fissure sealant.4 However, due to the limited penetration depth of the UV light and the potential health hazards, this system was quickly abandoned. The advancement of science yielded light curing materials which contributed to a significant clinical progress over the UV and chemically cured RBCs.4 Additional advancements to direct RBC restoration materials included luting agents for ceramic restorations, pit and fissure sealants and resin modified glass ionomers. Polymerization in an RBC is initiated by a light curing unit (LCU); this technology is based on the use of photoreactive systems that absorb light irradiation from the LCUs at appropriate wavelength. Then the photoinitiators contained in the RBCs, absorb the incoming photons from the LCU and the monomers in the molecular structure become excited and in that active state, there is a change from monomers into a polymer network6. The success of this technology hinges on matching the spectral emission of the LCU with the requirements of the photoinitiator system to convert the monomers into a polymer network. The amount of activated photo initiator depends on the concentration of photoinitiator in the material, the number of photons to which the material is exposed and the energy of the photons (wavelength), the latter depending on the curing light.6 The most common photoinitiator in dental materials today is camphorquinone, which has a peak activity around 470 nanometres.6 The factors affecting polymerization include filler type, size and loading, the thickness and shade of the restorative material, the effectiveness of light transmission (eg. light guide tips being free from debris and scratches), exposure time, distance of the light source from the restorative material and light intensity.7 It is important to note that the photoinitiator activation occurs at specific wavelengths, in other words, the optimum efficiency is obtained when the peak absorptivity of the photoinitiator corresponds with the spectral emission from the LCU. Commercially available curing units have different light intensities and light sources, with energy levels in QTH, LED and other LCUs ranging from 300 to more than 2000 mW/cm.

Intense Photoluminescence and Photoluminescence Enhancement of Silicon Nanocrystals by Ultraviolet Irradiation

2007 ◽  
Vol 31 ◽  
pp. 74-76 ◽  
Author(s):  
P.T. Huy ◽  
P.H. Duong
Keyword(s):  
Silicon Nanocrystals ◽  
Room Temperature ◽  
Laser Excitation ◽  
Uv Light ◽  
Irradiation Time ◽  
Excitation Wavelength ◽  
Nonradiative Recombination ◽  
Emission Yield ◽  
Recombination Centers ◽  
Pl Intensity

Photoluminescence (PL) from silicon nanocrystals deposited on top of silica-glass template and from silicon nanocrystals in nc_Si/SiO2 multilayer films were studied as a function of ultraviolet (UV) laser irradiation time in vacuum. Both the films exhibit intense visible PL at room temperature under laser excitation. It was found that upon prolong irradiation time using a He-Cd laser (325 nm) the PL intensity of the films was spectacularly enhanced. The process is reversible and does not happen with excitation wavelength longer than 400 nm. Upon introducing air into the measurement chamber, a rapid decrease of the PL intensity was recorded. This observation suggests that the UV light may lead to modification of nonradiative recombination centers in the films and thus improves the emission yield of silicon nanocrystals.

UV Based Advanced Oxidation Process for Degradation of Ciprofloxacin: Reaction Kinetics, Effects of Interfering Substances and Degradation Product Identification

2021 ◽  
Author(s):  
Bijoli Mondal ◽  
Shib Sankar Basak ◽  
Arnab Das ◽  
Sananda Sarkar ◽  
Asok Adak
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Uv Light ◽  
Degradation Products ◽  
Irradiation Time ◽  
Advanced Oxidation ◽  
Quantum Yields ◽  
Photon Flux ◽  
First Order

Abstract In the photochemical UV-H2O2 advanced oxidation process, H2O2 absorbs UV light and is decomposed to form hydroxyl radicals (OH·), which are highly excited and reactive for electron-rich organic compounds and hence can degrade organic compounds. In the present work, the UV-H2O2 process was investigated to degrade ciprofloxacin (CIP), one of India's widely used antibiotics, from aqueous solutions using a batch type UV reactor having photon flux = 1.9 (± 0.1) ×10-4 Einstein L-1 min-1. The effects of UV irradiation time on CIP degradation were investigated for both UV and UV-H2O2 processes. It was found that about 75% degradation of CIP was achieved within 60 s with initial CIP concentration and peroxide concentration of 10 mg L-1 and 1 mol H2O2/ mol CIP, respectively, at pH of 7(±0.1) and fluence dose of 113 mJ cm-2. The experimental data were analyzed by the first-order kinetics model to find out the time- and fluence-based degradation rate constants. Under optimized experimental conditions (initial CIP concentration, pH and H2O2 dose of 10 mg L-1, 7(±0.1) and 1.0 mol H2O2 / mol CIP, respectively), the fluence-based pseudo-first-order rate constant for the UV and UV-H2O2 processes were determined to be 1.28(±0.0) ×10-4 and 1.20(±0.04) ×10-2 cm2 mJ-1 respectively. The quantum yields at various pH under direct UV were calculated. The impacts of different process parameters such as H2O2 concentration, solution pH, initial CIP concentration, and wastewater matrix on CIP degradation were also investigated in detail. CIP degradation was favorable in acidic conditions. Six degradation products of CIP were identified. Results clearly showed the potentiality of the UV-H2O2 process for the degradation of antibiotics in wastewater.

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