scholarly journals Improving UV Curing in Organosolv Lignin-Containing Photopolymers for Stereolithography by Reduction and Acylation

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3473
Author(s):  
Jordan T. Sutton ◽  
Kalavathy Rajan ◽  
David P. Harper ◽  
Stephen C. Chmely
Keyword(s):  
Thermal Stability ◽  
3D Printing ◽  
Uv Curing ◽  
Uv Curable ◽  
Commercial Use ◽  
Organosolv Lignin ◽  
Resin Formulation ◽  
Modified Lignin ◽  
Unmodified Sample ◽  
Acylation Reactions

Despite recent successes in incorporating lignin into photoactive resins, lignin photo-properties can be detrimental to its application in UV-curable photopolymers, especially in specialized engineered resins for use in stereolithography printing. We report on chemical modification techniques employed to reduce UV absorption by lignin and the resulting mechanical, thermal, and cure properties of these modified lignin materials. Lignin was modified using reduction and acylation reactions and incorporated into a 3D printable resin formulation. UV–Vis absorption at the 3D printing range of 405 nm was reduced in all modified lignins compared to the unmodified sample by 25% to ≥ 60%. Resins made with the modified lignins showed an increase in stiffness and strength with lower thermal stability. Studying these techniques is an important step in developing lignin for use in UV-curing applications and further the effort to valorize lignin towards commercial use.

scholarly journals Improving UV Curing in Lignin-Containing Photopolymers for Stereolithography by Chemical Reduction and Acetylation

2019 ◽  
Author(s):  
Jordan T. Sutton ◽  
Kalavathy Rajan ◽  
David P. Harper ◽  
Stephen Chmely
Keyword(s):  
Thermal Stability ◽  
Chemical Modification ◽  
Chemical Reduction ◽  
Uv Curing ◽  
Uv Absorption ◽  
Uv Curable ◽  
Reduction Reactions ◽  
Commercial Use ◽  
Resin Formulation ◽  
Modified Lignin

Despite recent successes incorporating lignin into photoactive resins, lignin photo-properties can be detrimental to its application in UV-curable photopolymers, especially to customized, engineered resins for use in stereolithography printing. We report on chemical modification techniques employed to reduce UV absorption in lignin and the resulting mechanical, thermal, and cure properties in these lignin-containing materials. Pine lignin was modified using acetylation and reduction reactions and incorporated into a printable resin formulation. Modified lignin displayed enhanced printing properties because UV absorption at the 3D printable range was reduced in all acylated lignin from 25% up to greater than 60%. Resins made with the modified lignin showed increased stiffness and strength with lower thermal stability. Investigating these techniques is an important step in developing lignin for use in UV-curing applications and furthers the effort to valorize lignin toward commercial use.

scholarly journals Improving UV Curing in Lignin-Containing Photopolymers for Stereolithography by Chemical Reduction and Acetylation

2019 ◽  
Author(s):  
Jordan T. Sutton ◽  
Kalavathy Rajan ◽  
David P. Harper ◽  
Stephen Chmely
Keyword(s):  
Thermal Stability ◽  
Chemical Modification ◽  
Chemical Reduction ◽  
Uv Curing ◽  
Uv Absorption ◽  
Uv Curable ◽  
Reduction Reactions ◽  
Commercial Use ◽  
Resin Formulation ◽  
Modified Lignin

Despite recent successes incorporating lignin into photoactive resins, lignin photo-properties can be detrimental to its application in UV-curable photopolymers, especially to customized, engineered resins for use in stereolithography printing. We report on chemical modification techniques employed to reduce UV absorption in lignin and the resulting mechanical, thermal, and cure properties in these lignin-containing materials. Pine lignin was modified using acetylation and reduction reactions and incorporated into a printable resin formulation. Modified lignin displayed enhanced printing properties because UV absorption at the 3D printable range was reduced in all acylated lignin from 25% up to greater than 60%. Resins made with the modified lignin showed increased stiffness and strength with lower thermal stability. Investigating these techniques is an important step in developing lignin for use in UV-curing applications and furthers the effort to valorize lignin toward commercial use.

Photosensitive poly(ether sulfone)s for thiol/ene UV curable coatings: synthesis, characterization and crosslinking

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhi Zeng ◽  
Shaowei Guan ◽  
Haibo Zhang ◽  
Linlin Zhang ◽  
Baijun Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Fourier Transform ◽  
Thermal Properties ◽  
Room Temperature ◽  
Uv Curing ◽  
Acid Salt ◽  
Uv Curable ◽  
New Approach ◽  
Good Thermal Stability ◽  
Crosslinking Process

AbstractNovel photocrosslinkable poly(ether sulfone)s copolymers with allyl pendants (AS-PES) have been synthesized from 3,3’-diallyl-4,4’-dihydroxydiphenyl sulfone (DA-DHDPS), 4,4’-dihydroxydiphenyl sulfone (DHDPS) and 4,4’- dichlorophenylsulfone (DCDPS). The resulting polymers could be photocrosslinked in the presence of thiol at room temperature. The crosslinking process was monitored by “Real Time Fourier Transform Infrared Spectroscopy” (RTIR). It proves that a small amount (1.0 wt%) of the thiol crosslinker addition is sufficient to form a chemical network under UV irradiation. After UV curing, AS-PES-20 coating showed high Tg, good thermal stability and excellent resistance to the acid, salt, and alkali. Accordingly, this method could successfully provide a new approach to make rapidly photocrosslinking poly(ether sulfone) coatings without losing their good thermal properties.

scholarly journals Directly Printed Hollow Connectors for Microfluidic Interconnection with UV-Assisted Coaxial 3D Printing

2020 ◽  
Vol 10 (10) ◽  
pp. 3384
Author(s):  
Qianwen Xu ◽  
Jeffery Lo ◽  
Shi-Wei Lee
Keyword(s):  
3D Printing ◽  
Sacrificial Layer ◽  
Gelation Time ◽  
Three Dimensional ◽  
Uv Curing ◽  
Channel Diameter ◽  
Uv Curable ◽  
Outer Flow ◽  
Coaxial Nozzle ◽  
Cure Time

Effective and reliable interconnections are crucial for microfluidics to connect with the macro world. Current microfluidic interfaces are still bulky, expensive, or with issues of clogging and material limitation. In this study, a novel ultraviolet (UV)-assisted coaxial three-dimensional (3D) printing approach was proposed to fabricate hollow microfluidic connectors with advantages of rapid prototyping, fixture-free, and materials compatible. An assembled coaxial nozzle was designed to enable co-flow extrusion, where the inner flow (water) served as the sacrificial layer and the outer flow (adhesive) was cured for shell formation. Furthermore, a converged UV-LED light source was attached to the coaxial nozzle for UV curing of adhesives. UV rheological characterizations were performed to study the UV curing kinematics, and the gelation time was employed to describe the state transition behaviors of UV curable adhesives used in the study. To explore requirements for successful hollow connectors direct printing, processing criteria such as co-flow regime and pre-cure time were investigated. The hollow connectors with an inner channel diameter of ~150 μ m and a height of 5 mm were successfully printed on polymethyl methacrylate (PMMA) and glass substrate. The integration feasibility of the proposed method was also demonstrated by the presented microfluidic device with printed hollow connectors.

Continuous 3D printing by controlling the curing degree of hybrid UV curing resin polymer

Polymer ◽  
2021 ◽  
pp. 124284
Author(s):  
Xiaoqing Kang ◽  
Xiaogang Li ◽  
Yuexuan Li ◽  
Xiaohui Zhang ◽  
Yugang Duan
Keyword(s):  
3D Printing ◽  
Uv Curing

scholarly journals Benzoxazines with enhanced thermal stability from phenolated organosolv lignin

RSC Advances ◽  
2016 ◽  
Vol 6 (109) ◽  
pp. 107689-107698 ◽  
Author(s):  
Ghizelle Jane Abarro ◽  
Jacob Podschun ◽  
Leslie Joy Diaz ◽  
Seishi Ohashi ◽  
Bodo Saake ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Thermal Stability ◽  
Organosolv Lignin

Phenolated lignin was modified with propargyl amine and aniline to benzoxazines, which exhibit high thermal stability and were classified as self-extinguishing.

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.

scholarly journals 3D Printed Chromophoric Sensors

Chemosensors ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 317
Author(s):  
Zachary Brounstein ◽  
Jarrod Ronquillo ◽  
Andrea Labouriau
Keyword(s):  
Thermal Stability ◽  
3D Printing ◽  
Material Properties ◽  
Chemical Structure ◽  
Elevated Temperatures ◽  
Advanced Manufacturing ◽  
Color Changes ◽  
Printed Sensors ◽  
3D Printed ◽  
Manufacturing Techniques

Eight chromophoric indicators are incorporated into Sylgard 184 to develop sensors that are fabricated either by traditional methods such as casting or by more advanced manufacturing techniques such as 3D printing. The sensors exhibit specific color changes when exposed to acidic species, basic species, or elevated temperatures. Additionally, material properties are investigated to assess the chemical structure, Shore A Hardness, and thermal stability. Comparisons between the casted and 3D printed sensors show that the sensing devices fabricated with the advanced manufacturing technique are more efficient because the color changes are more easily detected.

Formation of Barrier Ribs via Micro Molding Process Using UV-Curable Paste

2007 ◽  
Vol 534-536 ◽  
pp. 1029-1032
Author(s):  
Yong Seog Kim ◽  
Tae Gum Koh ◽  
Yoo Seong Kim
Keyword(s):  
Uv Curing ◽  
Processing Route ◽  
Curing Process ◽  
Plasma Display Panel ◽  
Molding Process ◽  
Uv Curable ◽  
Processing Cost ◽  
Plasma Display ◽  
Uv Curing Process ◽  
Sintering Shrinkage

In an attempt to reduce processing cost and to improve the resolution of PDPs, a micro mold transfer processing route for barrier ribs of plasma display panel was attempted. In this study, the parameters that may cause defects during the process were identified, which include the shrinkage during the UV curing process, stress due to the evaporation of organic components, and sintering shrinkage. Considering such parameters, a UV curable paste was developed and the barrier ribs of PDPs were successfully processed via the process. This work demonstrated the possibility of a build-up route in manufacturing barrier ribs of PDP

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