- Modulation of Thermally Activated Delayed Fluorescence in Waterborne Polyurethanes via Charge-Transfer Effect
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Here, we designed several waterborne polyurethanes (WPUs) with efficient thermally activated delayed fluorescence (TADF) via serving charge-transfer (CT) states as a mediate bridge between singlet and triplet states to boost reverse intersystem crossing (RISC). By tuning substituents of diphenyl sulfone (DS), we found that O,O′- and S,S′-substituted DS covalently incorporated in WPUs solely show typical fluorescence emission with lifetimes in the nanosecond range. Interestingly, TADF appears by replacing the substituent with the nitrogen atom, of which lifetimes are up to ≈10 microseconds and ≈1 millisecond in air and vacuum, respectively, even though the energy gap between singlet and triplet states (ΔEST) is still large for generating TADF. To explain this phenomenon, an energy level mode based on CT states and an 3(n-π*) receiver state was proposed. By the rational modulation of CT states, it is possible to tune the ΔEST to render TADF-based materials suitable for versatile applications.
- Li, Zongren,Wang, Tao,Xu, Dong,Zuo, Jie,Li, Xinyu,Li, Zhiwei,Xu, Fei,Zhang, Xingyuan
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- Poly(butylene terephthalate) modified with ethoxylated bisphenol S with increased glass transition temperature and improved thermal stability
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Novel copolyesters have been prepared by polycondensation and by melt mixing of poly(butylene terephthalate) with an ethoxylated bisphenol S. No side reactions occur during the synthesis of the samples, as proved by NMR analysis. The polyesters were examined by TGA and DSC. The insertion of the bisphenol S (sulfonyldiphenol) group significantly improved the thermal stability of the polymer. The thermal analysis carried out using DSC technique showed that the Tm of the copolymers decreased with increasing co-unit content, differently from Tg, which on the contrary increased, exceeding in some cases 100 °C, and crystallization rate decreased. A polymer containing only terephthalate moieties and ethoxylated bisphenol S has been prepared for the first time.
- Lotti,Colonna,Fiorini,Finelli,Berti
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- Ethoxylated (2) bisphenol S diacrylate and its preparation method
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The invention provides an ethoxy (2) bisphenol S diacrylate and a preparation method thereof. The method comprises the following steps: carrying out esterification reaction on dihydroxyethyl bisphenol S and acrylic acid in a nitrogen protective atmosphere by using toluene as a solvent, organic acid as a catalyst and p-hydroxyanisole as a polymerization inhibitor; and after the esterification reaction finishes, removing the toluene by alkali washing, water washing, drying and depressurizing, recrystallizing the product with ethanol to obtain the ethoxy (2) bisphenol S diacrylate. The method is simple in technique, and can be used for preparing the bifunctional high-refractivity monomer ethoxy (2) bisphenol S diacrylate which simultaneously contains sulfur and benzene ring.
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Paragraph 0037; 0038; 0039
(2017/07/14)
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- Preparation method of bis[4-(2-hydroxyethoxy)phenyl] sulphone and derivative of bis[4-(2-hydroxyethoxy)phenyl] sulphone as well as catalyst of bis[4-(2-hydroxyethoxy)phenyl] sulphone and derivative of bis[4-(2-hydroxyethoxy)phenyl] sulphone
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The invention relates to a preparation method of bis[4-(2-hydroxyethoxy)phenyl] sulphone and a derivative of bis[4-(2-hydroxyethoxy)phenyl] sulphone as well as a catalyst of bis[4-(2-hydroxyethoxy)phenyl] sulphone and the derivative of bis[4-(2-hydroxyethoxy)phenyl] sulphone. The preparation method comprises steps as follows: under the action of the catalyst, a compound represented as the structure I is subjected to a reaction with ethylene glycol for 0.5-2 h at the temperature of 100-200 DEG C, a compound represented as a structure II is prepared, wherein the catalyst comprises components of graphene oxide, Lewis acid and alkyl ester titanate, and a mass ratio of graphene oxide to Lewis acid to alkyl ester titanate is (0.05-0.25):(0.02-1):(0.0125-1), the components are mixed in the ratio, added to ethanol and uniformly stirred, a mixture is subjected to a refluxing reaction for 1 h after azeotropic dehydration, a solvent is removed through steaming, and an additive product is obtained. The reaction time is short, and the yield is high.
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Paragraph 0012
(2018/02/04)
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- Aromatic ethers and process for producing aromatic ethers
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According to a production process, aromatic ethers are producible by reacting phenols with an oxirane compound with use of an anion exchange resin as a catalyst. According to another production process, aromatic ethers having an alcoholic hydroxyl group are producible by a crystallization-purification step of using a solvent having a solubility parameter ranging from 7.5 to 12.5 for purification by crystallization. Further, according to still another production process, producible are aromatic ethers having an alcoholic hydroxyl group, wherein the content of a metal in the aromatic ethers is less than 100 ppm by mass, and the content of a halogen element in the aromatic ethers is less than 100 ppm by mass.
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