Pressure-controlled synthesis of high-performance SrLiAl3N4:Eu2+ narrow-band red phosphors

2018 ◽  
Vol 6 (38) ◽  
pp. 10174-10178 ◽  
Author(s):  
Mu-Huai Fang ◽  
Yi-Ting Tsai ◽  
Hwo-Shuenn Sheu ◽  
Jyh-Fu Lee ◽  
Ru-Shi Liu

SrLiAl3N4:Eu2+ (SLA) phosphors have gained increasing attention worldwide due to their narrow emission bandwidth and excellent thermal stability.

2011 ◽  
Vol 31 (4) ◽  
Author(s):  
Yi-Nan Zhang ◽  
Shu-Ling Zhang ◽  
Yan-Hua Yang ◽  
Hong-Yi Qin ◽  
Dong Jiang

Abstract A series of random polysulfone/polyethersulfone (PSF/PES) copolymers were synthesized by the polycondensation of 4,4′-isopropylidenediphenol, 4,4′-dihydroxyldiphenylsulfone, and 4,4′-dichlorodiphenylsulfone in the presence of potassium carbonate. The resulting copolymers displayed similar solubility with PSF and PES. The glass transition temperature and the 5% weight loss temperature of these copolymers varied in the range of 199°C–299°C and 467°C–498°C, respectively, which showed excellent thermal stability. Moreover, the elongation at break of these copolymers was much higher than that of PES, whereas the tensile strength was a little lower.


2019 ◽  
Vol 776 ◽  
pp. 606-613 ◽  
Author(s):  
Tao Liu ◽  
Fucheng Li ◽  
Anding Wang ◽  
Lei Xie ◽  
QuanFeng He ◽  
...  

2019 ◽  
Vol 125 (8) ◽  
Author(s):  
Jiangcong Zhou ◽  
Yiqing Lai ◽  
Xiaotian Huang ◽  
Hande Chen

2011 ◽  
Vol 199-200 ◽  
pp. 83-86
Author(s):  
Chang Wei Liu ◽  
Xiao Gang Zhao ◽  
Cheng Yang Wang ◽  
Xiao Hui Yu ◽  
He Jia ◽  
...  

To prepare novel polyimides with enhanced thermal stability and low melt viscosity, a novel three-branched phenylethynyl-terminated imide oligomer was introduced. The oligomer can be used to prepare high performance resin-based composite material via resin transfer molding (RTM) due to its low melt viscosity (<2Pa.s) between 250°C and 320°C. The cured resin exhibits excellent thermal stability and higher glass transition temperature than PETI series as a result of the introduction of star-branched units. In this research, the rheological properties of the oligomer were measured and numerically fit with the dual Arrhenius model to predict the progression of the viscosity during cure. The calculated kinetic activation energies for gelation with two different Arrhenius equations, 120.8kJ/mol and 164kJ/mol, respectively,had some differences. The numerical results were compared with the experimental measurements, and it was found that the model predicts the experimental observations quite well.


1987 ◽  
Vol 60 (1) ◽  
pp. 62-77 ◽  
Author(s):  
D. C. Edwards

Abstract 1. In halobutyl elastomers, zinc oxide interacts synergistically with aromatic amine antioxidants such as APDA 86, DPPD, or DNPD, to produce fast, tight cures. 2. In the case of DNPD, compound storage stability appears to be satisfactory, and the resistance to scorch at processing temperatures is ample. 3. The cure behavior of these systems, particularly in bromobutyl, is exceptionally favorable: a rapid rise to a remarkably flat plateau. 4. The vulcanizates exhibit excellent thermal stability (compression set) and excellent ozone resistance. Measurable elastic properties are retained following 72 h air aging at 200°C.


RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 40996-41003 ◽  
Author(s):  
Tianyun Li ◽  
Huahua Huang ◽  
Lei Wang ◽  
Yongming Chen

Highly soluble and optically transparent polyimides with excellent thermal stability were prepared by the introduction of alkyl and naphthalene groups into a single diamine monomer under microwave-assisted polymerization.


2019 ◽  
Vol 960 ◽  
pp. 140-147
Author(s):  
Na Li ◽  
Xing Ke Zhang ◽  
Jun Rong Yu ◽  
Yan Wang ◽  
Jing Zhu ◽  
...  

Copolymerized poly (m-phenylene isophthalamide) (co-PMIA) fibers with excellent thermal stability and good mechanical properties were developed via solution polycondensation process based on m-phenylenediamine (MPD), isophthaloyl dichloride (IPC), and 3,4′-oxydianiline (3,4′-ODA). Effects of the ether moiety on the structure and properties of the copolymers were investigated. A series of co-PMIA nascent fibers were produced using wet-spinning method. The coagulation process to form co-PMIA nascent fibers were studied by examination of SEM and strength tester. The co-PMIA nascent fibers with the MPD/3,4′-ODA molar ratio of 8:2 showed an optimum dye uptake. Keywords: Copolymerization; High performance material; Wet spinning; Dyeability.


2010 ◽  
Vol 123-125 ◽  
pp. 1275-1278
Author(s):  
Guang Yu Wu ◽  
Cheng Yao ◽  
Feng Xian Qiu

An intercalation nonlinear-optical (NLO) polyimide was synthesized based on the 3,3’, 4,4’- Bisphenyltetracarboxylic (BPDA) and [(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3- diamine (NBADA). Then, hybrid polymer was synthesized by the sol-gel technique. FT-IR spectroscopy and 29Si NMR were used to characterize the structure of the hybrid. The results revealed that Q3, Q4 and T3 are the major microstructure elements in forming a network structure. The surface morphology, particle size, crystallinity and the thermal stability of the hybrid were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC and TGA results showed that the glass transition temperature (Tg) and the decomposition temperature (Td) at 5% mass loss were 243, 359°C and 355, 456°C, respectively. These results showed that the hybrid material had excellent thermal stability than the pure polyimide. The electro-optic coefficients of nonlinear optical polyimide and hybrid were measured at the wavelength of 832 nm. The electro-optic coefficients were 22 and 19pm/V (poling voltage of 3.8KV, 210°C) and the values remained well (retained>93% for more than 100h). The results suggest that the materials have potential applications for high performance optical device.


2021 ◽  
Author(s):  
Menghao Chen ◽  
Xian He ◽  
Yuhang Guo ◽  
Jianghuai Hu ◽  
Bo Liang ◽  
...  

Tyramine was first introduced into high-performance polymers as a promising monomer platform; the derived phthalonitrile resin exhibits excellent thermal stability and a high Tg value.


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