scholarly journals Synthesis and Characterization of Hyperbranched and Organosilicone Modified Waterborne Polyurethane Acrylates Photosensitive Resin

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2039
Author(s):  
Na Wang ◽  
Xinhui Wang ◽  
Jinyan Lang ◽  
Zhenhua Hu ◽  
Heng Zhang

A new type of waterborne polyurethane acrylate was synthesized for use as a UV curing coating. The N,N-dihydroxy methyl ethyl-3-Methyl aminopropanoate monomer was first prepared via adding reactions of methyl acrylate and diethanol amine with methyl alcohol as the solvent. Then, the hyperbranched prepolymer was obtained by addition of trimethylolpropane with toluenesulfonic acid as catalyst and N,N-dimethyl formamide as solvent. The resulting hyperbranched and organosilicone modified waterborne polyurethane acrylates was synthesized through the mixed reaction of prepolymer and Hydroxy silicone oil, polyethylene glycol-1000, toluene diisocynate, dimethylolpropionic acid, 1,2-propylene glycol, hydroxyethyl acrylate, and triethylamine with dibutyltin dilaurate as the catalyst. The molecular structures were characterized by FT-IR and 1H NMR spectroscopy and GPC analysis and the thermal stability was studied by using TGA. Moreover, the influence of contemodnt of hydroxyl silicone oil, dimethylolpropionic acid, polyethylene glycol-1000, and prepolymer to various of properties such as glossiness, hardness, adhesive force, abrasion resistance, water absorption, elongation at break and tensile strength of films were analyzed. The temperature and catalyst dosage impact on percent conversion of isocyanate group (–NCO) were also studied. It was proven that the best dosage of hydroxyl silicone oil and dimethylolpropionic acid were 4.6%, the dosage of polyethylene glycol-1000 was 50%, and the amount of hyperbranched prepolymer was 0.5%, which could make the film achieve the optimum properties. The percent conversion of isocyanate group (–NCO) was maximum when reacting two hours at 80 °C with 0.2% catalyst.

2014 ◽  
Vol 1 (1) ◽  
pp. 24-34
Author(s):  
Alireza K. ◽  
Hossein Ahmadi ◽  
Mohsen Mohammadi

Lubricants and leather dressings are the most common treatments of dry and water logged historical leathers. Color change has a great importance during the time and treatment process, due to visual and aesthetic values of historic leather relics. Polyethylene glycol (PEG) and silicone oil (SiO) are frequently used leather dressings in the conservation procedures. Therefore, color stability of treated leathers with PEG and SiO were investigated before and after heat accelerated aging. Moreover, application of ascorbic acid was evaluated as an antioxidant additive for PEG (PEG+AA).Color change after treatment and aging were studied by colorimetry technique in the CIE *L*a*b system. Results indicated to severe color alteration in PEG treated and aged leathers with or without ascorbic acid. Whereas, SiO treated samples showed better stability and minimum color shift after aging. Silicone oil was characterized as the best dressing for historical leathers with compared to PEG and PEG+AA, due to its high stability and aesthetical properties.


2018 ◽  
Vol 18 (8) ◽  
pp. 1138-1147 ◽  
Author(s):  
Esra Metin ◽  
Pelin Mutlu ◽  
Ufuk Gündüz

Background: Although conventional chemotherapy is the most common method for cancer treatment, it has several side effects such as neuropathy, alopecia and cardiotoxicity. Since the drugs are given to body systemically, normal cells are also affected, just like cancer cells. However, in recent years, targeted drug delivery has been developed to overcome these drawbacks. Objective: The aim of this study was targeted co-delivery of doxorubicin (Dox) which is an anticancer agent and D-α-Tocopherol polyethylene glycol 1000 succinate (vitamin E TPGS or simply TPGS) to breast cancer cells. For this purpose, Magnetic Nanoparticles (MNPs) were synthesized and coated with Oleic Acid (OA). Coated nanoparticles were encapsulated in Poly Lactic-co-Glycolic Acid (PLGA) and TPGS polymers and loaded with Dox. The Nanoparticles (NPs) were characterized by Fourier Transform Infrared (FTIR) spectroscopy, zetapotential analysis, Dynamic Light Scattering (DLS) analysis, Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscope (SEM) analysis. Results: The results showed that NPs were spherical, superparamagnetic and in the desired range for use in drug targeting. The targetability of NPs was confirmed. Moreover, TPGS and Dox loading was shown by TGA and FTIR analyses. NPs were internalized by cells and the cytotoxic effect of drug loaded NPs on sensitive (MCF-7) and drug-resistant (MCF-7/Dox) cells were examined. It was seen that the presence of TPGS increased cytotoxicity significantly. TPGS also enhanced drug loading efficiency, release rate, cellular internalization. In MCF- 7/Dox cells, the drug resistance seems to be decreased when Dox is loaded onto TPGS containing NPs. Conclusion: This magnetic PLGA nanoparticle system is important for new generation targeted chemotherapy and could be used for breast cancer treatment after in vivo tests.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 628
Author(s):  
Im-Sook Song ◽  
So-Jeong Nam ◽  
Ji-Hyeon Jeon ◽  
Soo-Jin Park ◽  
Min-Koo Choi

We evaluated the bioavailability, liver distribution, and efficacy of silymarin-D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) solid dispersion (silymarin-SD) in rats with acetaminophen-induced hepatotoxicity (APAP) compared with silymarin alone. The solubility of silybin, the major and active component of silymarin, in the silymarin-SD group increased 23-fold compared with the silymarin group. The absorptive permeability of silybin increased by 4.6-fold and its efflux ratio decreased from 5.5 to 0.6 in the presence of TPGS. The results suggested that TPGS functioned as a solubilizing agent and permeation enhancer by inhibiting efflux pump. Thus, silybin concentrations in plasma and liver were increased in the silymarin-SD group and liver distribution increased 3.4-fold after repeated oral administration of silymarin-SD (20 mg/kg as silybin) for five consecutive days compared with that of silymarin alone (20 mg/kg as silybin). Based on higher liver silybin concentrations in the silymarin-SD group, the therapeutic effects of silymarin-SD in hepatotoxic rats were evaluated and compared with silymarin administration only. Elevated alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels were significantly decreased by silymarin-SD, silymarin, and TPGS treatments, but these decreases were much higher in silymarin-SD animals than in those treated with silymarin or TPGS. In conclusion, silymarin-SD (20 mg/kg as silybin, three times per day for 5 days) exhibited hepatoprotective properties toward hepatotoxic rats and these properties were superior to silymarin alone, which may be attributed to increased solubility, enhanced intestinal permeability, and increased liver distribution of the silymarin-SD formulation.


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