Study on Shrinkage of Cured Volume for UV-Curing Coatings

2015 ◽  
Vol 731 ◽  
pp. 588-592 ◽  
Author(s):  
Qing Kai Wang ◽  
Bei Qing Huang ◽  
Xian Fu Wei ◽  
Hao Chen Shen

UV-Curable Coatings, Have been Widely Used in Machinery, Chemical Engineering, Biology, Medicine, Electronics and so on, due to their Fast Curing, Low Curing Temperature, Low VOC Emissions and Low Energy Cost. however, the Volume Shrinkage during the Curing Process Have a Great Influence on the Performance of the Coating, which Ofen Lowering Coating Adhesive Strength and Accelerating the Aging Process of Coatings Film.The Paper Select Different Kinds of Monomers (EOEOEA, HDDA, TPGDA, NPGDA, TMPTA and EO3- TMPTA) and Light Cured Resin (free Radical Type: Polyester Acrylate Resin 5600, Polyurethane Acrylate UA VP 2396, the Pure Acrylic 6536-1,cationic Resin: Epoxy Cationic Resin Omnilance OC3005) to Prepare the UV Curing Coatings. Study on the Influence of Amount of Monomer and Polymer on Polyreaction Reaction by Using Orthogonal Experimental Design Method in Order to Choose the Monomer and Polymer that has the Least Volume Shrinkage Rate, then Develop Photocureable Coating Based on Free Radical Type and Cationic Resin above. the Results Indicate that the UV-Light Photocureable Coating Prepared by Single Functionality Monomer EOEOEA and the DPGDA that Doesn’t Have Neat Molecular Structure has the Less Volume Shrinkage Rate; however, in the Aspect of Prepolymer, the Preparation of UV-Light Photocureable Coating Based on Polyester Acrylate 5600 has the Least Volume Shrinkage Rate. Rely on the Experiment Results above, Prepare the New Kind of UV-Light Photocureable Coating that has Little Volume Shrinkage Rate.

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianyun He ◽  
Jinping Xiong ◽  
Bingqian Xia

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.


Segmented thermoset polymeric materials properties mainly classified through its carbonyl hydrogen bonding. The addition of graphite particle loading in polymeric materials tailored the functional characteristic of the composites. Therefore, the carbonyl hydrogen bonding in the hard segments of the synthesized segmented ultraviolet (UV) curable thermoset polyurethanes-graphite (TPU-G) composites was identified. This composites based green polymer incorporated with varying graphite particles loading were prepared through slip casting method which cure upon UV light. These result in an enhancement of the carbonyl hydrogen bonding which tribute to degree of phase separation (DPS %) in the TPU-G composites ranged from 10-20%, as compared to that in the pure TPU. In addition, the spectroscopy detects the formation of carbonyl hydrogen groups within the TPU-G composites although they are prone to chain scission and undergo photo oxidation subjected to ultraviolet (UV) curing. Upon UV curing, higher graphite weight loading (TPU-G20, TPU-G25 and TPU-G30 composites), shows higher and stable DPS% value, attribute to soft segment- soft segment and hard segment- hard segment establishment. Therefore, the graphite particles dominantly absorb the incident radiation instead of thermoset polyurethane without changing its based.


2005 ◽  
Vol 127 (1) ◽  
pp. 52-58 ◽  
Author(s):  
K. K. Lee ◽  
S. C. Tan ◽  
Y. C. Chan

Generally, adhesive materials can be cured in a short time under high curing temperature. High curing temperature usually leads to an increase in cross-link density and a homologous increase in heat resistance. Nevertheless, curing process under high temperature problems can occur such as the inclination for the adhesive materials to shrinkage, cracks, voids and it would probably lower the dielectric properties. UV curing of anisotropic conductive adhesives (ACAs) offers several advantages over the conventional epoxy resin, including rapid cure, little to no emission of volatile organic compounds and without affecting other components in the assembly [Pataki, W. S., 1997, “Optimization of Free-Radical Initiation Reactions in the Electrical Industry,” Electrical Insulation Conference and Electrical Manufacturing and Coil Winding Conference Proceedings, pp. 745–751]. Based on the aforementioned advantages, it is worth investigating the bonding properties at different curing conditions. In this work, a new type of UV curable ACA for chip-on-flex application is presented. The adhesive bonds of the chip-on-flex application are cured at different cure cycles within a range of UV frequencies. Cure cycles in this work were the different periods of time that were needed to cure the ACAs under different UV light intensities. Fourier transform infrared spectroscopy with attenuated total internal reflection was used to investigate the curing degree of the ACAs at different cure cycles. The result shows that the longer the curing time and the larger the UV intensity, the higher the curing degree can be obtained. Furthermore, the curing time in the UV curable ACA was much shorter than that of the conventional thermal curable ACAs. Shear test was done to find out the shear strength of the bonding. Finally, after shear test, scanning electron microscope was used to investigate the fracture mode of the chip-on-flex application at different curing cycles.


2012 ◽  
Vol 549 ◽  
pp. 457-461
Author(s):  
Jun Gang Gao ◽  
Feng Li Zhu ◽  
Jiang Bo Yang ◽  
Xiao Qian Liu

In ouder to prepare the waterborne UV-curable polyurethane acrylate coatings, the anionic polyurethane acrylate emulsifier and bisphenol-S eopxy acrylate were synthesized. The curing process, kinetics and properties of waterborone UV-curable epoxy acrylate/polyurethanes acrylate coating were investigated by FTIR, DSC and DMA. The results show that the static initial curing temperature Ti is 52.36 oC, peak temperature Tp is 71.58 oC, the finished temperature Tf is 89.15 oC. The curing reaction can be described by two-parameter autocatalytic Šesták-Berggren (S-B) model.This coating has a better UV-curing property. The dynamic mechanical analysis showed that the glass transition temperature Tg of coating film is 52.70 oC.


2013 ◽  
Vol 470 ◽  
pp. 141-145 ◽  
Author(s):  
Li Juan Zhang ◽  
Chen Bo Wu ◽  
Fei Yang ◽  
Xiao Yi Geng ◽  
Meng Qian Li ◽  
...  

A UV curable hybrid system with a dual mechanism of radical and cationic photo-polymerization, was investigated. A kind of free radical oligomer with low viscosity named hexahydrophthalic acid diglycidyl acrylate was first synthesized. The structure of the oligomer was characterization by FTIR. The UV curing processing of hybrid system was traced by real-time FTIR, and compared with free radical, cationic system. Thermal decomposition temperature and glass transition temperature of UV curing film for various system were determined by thermogravimetric analysis (TGA) and differental scanning calorimetry (DSC), respectively. And physical and mechanical properties of those curing films were analyzed and compared. The results show that the radical polymerization of double bond and cationic polymerization of epoxy group could occur simultaneously in hybrid system. The conversion rate of epoxy group for hybrid system was higher than that of epoxy group for cationic system, which demonstrated that the cationic photo-initiator (DPI·PF6) can be sensitized by the free radical photo-initiator (Irgacure 184). Compared with free radical and cationic system, the hardness and mechanical properties of hybrid system curing film were better than those of the cationic system curing film, while closed to those of free radical system.


2018 ◽  
Vol 777 ◽  
pp. 65-69
Author(s):  
Jia Wei Li ◽  
Jian Yun He ◽  
Xi Dan Luo ◽  
Chang Song Zhao ◽  
Peng Cheng Xie ◽  
...  

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.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 405
Author(s):  
Demei Lee ◽  
Ya-Ling Tang ◽  
Shih-Jung Liu

We report the fabrication of nanofeatured polymeric films using nanosphere lithography and ultraviolet (UV) soft-mold roller embossing and show an illuminative example of their application to solar cells. To prepare the nanofeatured template, polystyrene nanocolloids of two distinct sizes (900 and 300 nm) were overlaid on silicon substrates using a spin coater. A lab-made soft-mold roller embossing device equipped with a UV light source was adopted. A casting method was employed to replicate the nanofeatured template onto polydimethylsiloxane, which was used as the soft mold. During the embossing procedure, the roller was driven by a step motor and compressed the UV-curable resin against the glass substrate to form the nanofeatured layer, which was subsequently cured by UV radiation. Polymer films with nanoscaled features were thus obtained. The influence of distinct processing variables on the reproducibility of the nanofeatured films was explored. The empirical outcomes demonstrate that UV soft-mold roller embossing offers a simple yet potent way of producing nanofeatured films.


2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Gongpu Wen ◽  
Kun Chen ◽  
Yanhong Zhang ◽  
Yue Zhou ◽  
Jun Pan ◽  
...  

AbstractA novel strategy was proposed to fabricate alkali-resistant PVDF membrane via sodium lauryl sulfate (SDS) attached to the surface of membrane and immobilized by UV-curable polyester acrylate and tri(propylene glycol) diacrylate (TPGDA). The attached anionic surfactant, SDS, on the membrane surface can resist the alkali corrosion by NaOH, and the curing of the resin can immobilize the SDS on the membrane firmly. Due to the unique alkali resistance of SDS and resin formed, the UV-curable resin-modified PVDF membrane showed greatly enhanced alkali-resistant ability. Characterization of SEM and FTIR showed that polyester acrylate and TPGDA were cured successfully under the action of 1-hydroxycyclohexyl phenyl ketone (184) and ultraviolet light. Whiteness, differential scanning calorimeter and X-ray photoelectron spectrometer characterization showed that the modified PVDF membrane had a lower degree of dehydrofluorination than the pristine PVDF membrane after alkali treatment. Results of the detailed alkali-resistant analysis indicated that the F/C ratio of the UV-curable resin-modified PVDF membrane decreased by 2.6% after alkali treatment compared to pristine PVDF membrane decreased by 19.28%. The alkali-resistant performance was mainly attributed to the immobilized SDS. This study provided a facile and scalable method for designing alkali-resistant PVDF membrane, which shows a promising potential in the treatment of alkaline wastewater and alkaline-cleaning PVDF membrane.


Author(s):  
Shriram Pillapakkam ◽  
N. A. Musunuri ◽  
P. Singh

In this paper, we present a technique for freezing monolayers of micron and sub-micron sized particles onto the surface of a flexible thin film after the self-assembly of a particle monolayer on fluid-liquid interfaces has been improved by the process we have developed where an electric field is applied in the direction normal to the interface. Particles smaller than about 10 microns do not self-assemble under the action of lateral capillary forces alone since capillary forces amongst them are small compared to Brownian forces. We have overcome this problem by applying an electric field in the direction normal to the interface which gives rise to dipoledipole and capillary forces which cause the particles to arrange in a triangular pattern. The technique involves assembling the monolayer on the interface between a UV-curable resin and another liquid by applying an electric field, and then curing the resin by applying UV light. The monolayer becomes embedded on the surface of the solidified resin film.


2019 ◽  
Author(s):  
Jordan T. Sutton ◽  
Kalavathy Rajan ◽  
David P. Harper ◽  
Stephen Chmely

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.


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