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Castor oil based high transparent silicone modified UV cured polyurethane acrylate coatings with outstanding tensile strength and good chemical resistance were developed with castor oil based polyurethane acrylates and thiol silicone resin. The UV cured coatings are with transparency in range of 90–98%, tensile strength as high as 10.2 MPa and elongation at break in the range of 88.4–162.5%. It is worth noting that the tensile strength of the coatings immersed in 3.5 wt% hydrochloric aqueous solution 144 h increased from 6.2 MPa to 15.5 MPa while the elongation at break is almost not changed, which reveals that the UV cured coatings also exhibit good chemical anti–corrosion performance. The UV cured coatings also show quite good UV resistance and adhesive properties. [Display omitted] • Extraordinary high transparency is in range of 90–98%. • The tensile strength can reach 10.2 MPa and elongation at break is in the range of 88.4–162.5%. • Good chemical anti–corrosion performance • Quite good UV resistance [ABSTRACT FROM AUTHOR]

A kind of hyperbranched silicone containing macrophotoinitiators (HBSMIs) were synthesized from 2-hydroxy-2-methyl-1-phenyl propanone (HMPP) and the UV-curing behaviors of HBSMIs were investigated in UV-cured transparent polyurethane-acrylate (PUA) coatings. HBSMIs show higher UV-initiating efficiency than HMPP. The migration of HBSMIs from the UV-cured coatings can be as low as 1.7–6.0 wt%, which is obviously lower than the migration of HMPP. There is a remarkable improvement of the tensile strength of the UV-cured materials initiated by HBSMI in comparison to that of the materials prepared with the same PUA initiated by HMPP. Especially for the UV-cured materials prepared from PUA with 20 wt% 1,1,1-tris(hydroxymethyl)propane (TMP), the tensile strength and the strain at break increased from 6.81 MPa to 12.14 MPa and from 43.0% to 71.9%, respectively. The fraction of improvement for the tensile strength and the strain at break is as high as 78.9% and 67.2%, respectively. The coatings prepared with HBSMI also have better UV resistance ability than those coatings prepared with HMPP because they turn slightly yellow when they are aged by UV for about 15 min while the coating prepared with 4 wt% of HMPP will turn yellow only aged by UV for 2 min. These results suggest that preparation hyperbranched silicone containing macrophotoinitiators will be one of the good strategies to improve the curing efficiency of the UV-curing system, reduce the migration of UV initiator from cured material, improve the mechanical and UV resistance performance of UV-cured materials. [ABSTRACT FROM AUTHOR]

UV–curable polyacrylate is widely used in free–radical type UV–cure coating systems, the disadvantages of which including poor thermal stability and UV resistance can be overcome through chemical modification by silicone. However, it is a remarkable fact that the strategies for fabrication UV–cured silicone modified polyacrylates are somewhat complicated and the price of the products may be much expensive than pure UV–cured polyacrylates. In this work, an easy fabrication method to prepare inexpensive UV–cured transparent silicone modified polyacrylate coatings with good adhesion and UV resistance performance was developed from copolymers of acylates and thiol silicone resin by UV initiated thiol–ene click reaction without UV initiator. The striking results with a high application value should be emphasized that when the amount of thiol silicone resin is only one wt.% of the copolymer of acrylates, the UV–cured coatings obtained exhibit fairly good performance. These coatings prepared exhibit transparency higher than 96% (800 nm), adhesion property to glass slides can reach grade 0, pencil hardness can reach 6H, water absorption is less than 0.16%. In particular, it is observed obviously that the silicone modified polyacrylate coatings exhibit better UV resistance performance than the coating prepared with only copolymers of acrylates initiated by UV initiator 1173. It is proved that it is actually an easy fabrication method to prepare inexpensive UV–cured transparent silicone modified polyacrylate coatings with high performance by UV initiated thiol–ene click reaction of copolymers of acylates and thiol silicone resin. [ABSTRACT FROM AUTHOR]

A kind of UV-curable silicon-containing hyperbranched polyurethane-acrylate coating was prepared and the features of UV curing reaction were investigated in detail. These UV cured coatings exhibit unexpected fluorescence emission under the excitation of UV and the fluorescence peaks of these UV cured products appear at about 320 nm with unimodal distributions. The UV cured coatings also exhibit unexpected temperature-sensitive transparency. The transmittance of these coatings is in the range of 85–98% at room temperature, however, the transmittance reduced significantly to be no more than 62% at 10 °C, especially, the transmittance of UV-HPSiPUA-HP3 is lower than 10%. The other performances such as pencil hardness, water contact angle, grade of adhesion and thermal stability of these coatings were also investigated. The UV cured silicon-containing polyurethane-acrylate coatings with non-traditional fluorescence and temperature-sensitive transparency have potential applications in chemical sensing, bio-imaging, anti-counterfeiting technology, temperature-sensitive optical sensors, etc. • Non-traditional fluorescence emission under the excitation of ultraviolet light at about 320 nm with unimodal distributions. • Temperature-sensitive transparency • Good thermal stability and Td 5% is in the range of 239.5–268 °C [ABSTRACT FROM AUTHOR]

• The Pencil hardness can reach 9H and the coatings are with excellent scratch resistance. • Fairly high initial thermal decomposition temperature in the range of 297 °C–306 °C. • Adhesive properties to the slides can reach grade 0. • Transparency in the range of 85 %–99 %. Conventional UV cured PUs suffer from low hardness, which will be scratched during the course of storage and transportation. They also undergoes severe pyrolysis when the temperature exceeds 200 °C, and the poor heat resistance limit their application in the high-temperature field. To address these challenges, a type of UV cured transparent coatings were prepared with thiol silicone resin and polyurethane-acrylate through thiol-ene click reaction. The coatings obtained are with high hardness, excellent scratch resistance, good thermal stability, fairly strong adhesion, efficient water resistance and good UV radiation resistance. More specifically, the pencil hardness and initial thermal decomposition temperature are in the range of 6 B–9 H and 297 °C–306 °C respectively, which are more superior to those of the conventional UV cured PUs. More strikingly, the coatings obtained with excellent scratch resistance because there are no traces on the coatings, even the slides are broken, when the cross cut tests were carried out on the coatings cured for 40 s–60 s. The coatings obtained are also with transmittance in the range of 85 %–99 %, adhesive properties to the slides can reach grade 0, water absorption in the range of 0.23 wt%–0.60 wt%, exposed to UV (7.8 mw.cm−2) at ambient for 180 min without turn yellow. The transparent silicone modified polyurethane–acrylate coatings prepared are promising for widespread applications in the information technology devices and automobile, etc. [ABSTRACT FROM AUTHOR]