waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively...waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snowwas chosen as dispersant instead of comm only used water. Preparation param eters such as intrinsic properties and molecular weight of polyols were discussed systematically. A chain structure was confirmed by Fourier transform infrared (FT-IR) spectroscopy. when com paring the nature of the polyols (PPG, PEG and PNA, 2000g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane perform ed differently and it exhibited higher therm al stability and crystallinity. When com paring the samples (WPU-N210, WPU-N220, WPU-N230 and WPU-N240) with different molecular weight of the same polyol (PPG) used as soft segment, the emulsion WPU-N220 with molecular weight of 2000g/mol PPG provided the highest solid content and lowest viscosity. It was observed th at particle size was uniform and highly dispersed for all sam ples from TEM images. Therm ogravim etric, differential scanning calorim etry (DSC) and X-ray diffraction results dem onstrated that the emulsion WPU-N230 with m olecular weight of 3000 g/mol PPG possessed higher therm al stability and crystallinity than the other samples. The reason was that the Tg and thermal stability were increased with increasing molecular weight. when molecular weight increased, the arrangem ent of soft segm ent became more regular and so did the regularity of the molecular chains. This work demonstrated that different polyols as soft segment applied could lead to great differences in the structure and property of the resulting WPU.展开更多
Fluorescent pigments, based on the optical or electrooptical properties of dyes, are the main component in fluorescent coatings and inks. In this study, three kinds of dyes（Rhodamine B, Light Green SF Yellowish, Coum...Fluorescent pigments, based on the optical or electrooptical properties of dyes, are the main component in fluorescent coatings and inks. In this study, three kinds of dyes（Rhodamine B, Light Green SF Yellowish, Coumarin） with four different ratios（2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%） were employed as luminophor,and the melamine-formaldehyde（MF） resin was used as curing resin to prepare fluorescent pigments in different color. Fourier transform infrared spectroscopy and X-ray diffractometry were carried out to analyze the structure of the fluorescent pigments. Scanning electron microscopy and particle size distribution were used to present the morphology of fluorescent pigments. UV–vis and fluorescence spectrum were used to demonstrate the optical properties. It can be concluded that, coumarin pigments possessed consecutive structure in MF resin while rhodamine B might be the best for the preparation of printing inks among the three kinds of dyes from the view of particle size. The TG results presented that all the pigments showed good thermal stability, which might possess potential application in high speed printing industry.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51772243)PhD Research Startup Foundation of Xi’an University of Technology (Grant No. 108256081703)+4 种基金Beijing Laboratory for Food Quality and Safety, Beijing Technology and Business University (Grant No. FQS-201709)the Innovative Team Support Program (2017KCT-17)Key Laboratory of Processing and Quality Evaluation Technology of Green Plastics of China National Light Industry Council, Beijing Technology and Business University (Grant No. BS201702)the China Postdoctoral Science Foundation Funded Project (Grant No. 2016M592824)the Science and Technology Plan of Yulin City (Grant No. 2016-16-7), and the Science and Technology Plan of Beilin District (Grant No. GX1710)
文摘waterborne polyurethane (WPU) dispersions have gained attention towards environm entally-friendly synthesis. In this article, a series of waterborne polyurethane em ulsions was successfully synthesized and extensively characterized in terms of thermal, mechanical properties, hydrophilic behavior and morphology. Snowwas chosen as dispersant instead of comm only used water. Preparation param eters such as intrinsic properties and molecular weight of polyols were discussed systematically. A chain structure was confirmed by Fourier transform infrared (FT-IR) spectroscopy. when com paring the nature of the polyols (PPG, PEG and PNA, 2000g/mol) of this study, as-synthesized polyether waterborne polyurethane provided higher solid content, viscosity and water-resistance. However, polyester waterborne polyurethane perform ed differently and it exhibited higher therm al stability and crystallinity. When com paring the samples (WPU-N210, WPU-N220, WPU-N230 and WPU-N240) with different molecular weight of the same polyol (PPG) used as soft segment, the emulsion WPU-N220 with molecular weight of 2000g/mol PPG provided the highest solid content and lowest viscosity. It was observed th at particle size was uniform and highly dispersed for all sam ples from TEM images. Therm ogravim etric, differential scanning calorim etry (DSC) and X-ray diffraction results dem onstrated that the emulsion WPU-N230 with m olecular weight of 3000 g/mol PPG possessed higher therm al stability and crystallinity than the other samples. The reason was that the Tg and thermal stability were increased with increasing molecular weight. when molecular weight increased, the arrangem ent of soft segm ent became more regular and so did the regularity of the molecular chains. This work demonstrated that different polyols as soft segment applied could lead to great differences in the structure and property of the resulting WPU.
基金support provided by Programs for New Century Excellent Talents in University of Ministry of Education of China (Grant No.: NCET-12-1045)Shaanxi Programs for Science and Technology Development (Fund No.2010K01-096)+1 种基金Key Program for Innovation Team in Shaanxi Province, Ph.D. Innovation fund projects of Xi’an University of Technology (Fund No. 310-252071501)Program for Innovation Team in Xi’an University of Technology (Grant No. 108-25605T401)
文摘Fluorescent pigments, based on the optical or electrooptical properties of dyes, are the main component in fluorescent coatings and inks. In this study, three kinds of dyes（Rhodamine B, Light Green SF Yellowish, Coumarin） with four different ratios（2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%） were employed as luminophor,and the melamine-formaldehyde（MF） resin was used as curing resin to prepare fluorescent pigments in different color. Fourier transform infrared spectroscopy and X-ray diffractometry were carried out to analyze the structure of the fluorescent pigments. Scanning electron microscopy and particle size distribution were used to present the morphology of fluorescent pigments. UV–vis and fluorescence spectrum were used to demonstrate the optical properties. It can be concluded that, coumarin pigments possessed consecutive structure in MF resin while rhodamine B might be the best for the preparation of printing inks among the three kinds of dyes from the view of particle size. The TG results presented that all the pigments showed good thermal stability, which might possess potential application in high speed printing industry.
