MATERIALS LETTERS
·
2018
·
IF 2.687
Xue Chen,Ning Li,Yuan Li,Ping Che
In this work the CH 3 NH 3 PbI x Cl 3−x perovskite is obtained by applying vacuum-rotary evaporation procedure with a precursor solution of PbCl 2 and CH 3 NH 3 I in dimethylformamide. Thermal gravimetric and differential thermal analysis (TG-DTA) and the variable temperature powder X-ray diffraction ( in situ XRD) are employed to research the effect of thermal treatment on the decomposition and the crystal structure of perovskite . It is found that tetragonal to cubic phase transition in the typical perovskite disappears in mixed perovskite crystals because the stabilizing action of Cl. The excess Cl in the precursor leads to the intermediate structure CH 3 NH 3 PbCl 3 , and then transforms into CH 3 NH 3 PbI 3 with temperature increasing.
研究领域:
材料科学
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无机化学
·
固体物理
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能源材料
·
晶体学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 16
·13418-13425
·
IF 3.289
Fubin Luo,Kun Wu,Mangeng Lu
The influence of polybenzoxazine modified ammonium polyphosphate (BMAPP) on the thermal behavior and flame retardancy of a rigid polyurethane foam (PU) are investigated via thermogravimetric analysis (TG), TG coupled with infrared spectroscopy (TG-FTIR), UL-94 vertical burning testing and limit oxygen index (LOI). The TG testing results indicate that BMAPP can enhance the thermal stability of PU, both under air and nitrogen conditions. The initial degradation temperature of the BMAPP/PU composites is 264 °C in air, which is 22 °C and 30 °C higher than that of ammonium polyphosphate (APP)/PU composites and neat PU, respectively. The reason might be attributed to the better dispersion and compatibility of BMAPP particles in PU compared with APP, which can prevent the PU chain from degrading at low temperatures. The LOI value results demonstrate that BMAPP has higher flame retardancy in PU than APP. Residue analysis implies that polybenzoxazine is partially converted into Si–O as char residue during combustion.
研究领域:
高分子材料科学
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阻燃材料
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热功能材料
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复合材料学
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材料化学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2017
·Vol. 28
·期 11
·1438-1447
·
IF 1.907
Xin Liu,Xuewen Guo,Yunfei Zhi,Shaoyun Shan,Yonghao Ni,Qingming Jia
The recent development of sulfur dioxide (SO 2 ) polymerization has seen a renaissance in its chemistry, especially poly(olefin sulfone)s from the copolymerization of SO 2 , and unsaturated hydrocarbons can be found to have many applications, including transient electronic packaging, drug delivery, and electron beam-resistant materials. In this work, a type of functional poly(norbornene sulfone) was synthesized via two different polymerization methods. Aiming to understanding the effects of different polymerization methods on poly(olefin sulfone)s and gain further understanding on the kinetics of poly(olefin sulfone)s's thermal instability, we investigated their detailed thermal degradation behaviors using thermogravimetry and analyzed the resultant kinetics in accordance with three kinetic models. The results supported the conclusion that although the poly(norbornene sulfone)s obtained have different activation energy, the thermal degradation kinetics are the same and also obey the D n type. Copyright © 2017 John Wiley & Sons, Ltd.
研究领域:
高分子化学
·
材料科学
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热分析
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功能高分子
·
可控降解材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 45
·48187
·
IF 2.188
Yan Zhang,Shili He,Jianing Wu,Junjie Ma,Shengdong Shao,Lingjie He,Xiaonan Li,Zhengping Fang,Hongwei Cao,Zhichao Xi
The waste silicon rubber composite insulator (WSiRC) was applied along with ammonium polyphosphate (APP) and pentaerythritol (PER) to improve the flame retardancy of polypropylene (PP) in this study. Considering the compatibility among PP, WSiRC, and flame-retardant additives, WSiRC was treated by acid and N 2 plasma to obtain the plasma-treated WSiRC (PLSiR), which decreases the amount of the inorganic additive and grafts amino groups onto the surface of the silicon rubber. The infrared spectrocopy (IR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA) confirm that NH 2 groups have been grafted onto the surface of PLSiR. The TGA data also show that PLSiR had the char improving ability and promote the crosslink of APP, which results in its promotion for the flame retartancy of PP proved by the data of limiting oxygen index (LOI), UL94 rating and cone tests. It is also showed that PLSiR is superior than the WSiRC treated only by acid (ASiR) due to the differences in the structure and polarity. Moreover, the improvement of PLSiR on the flame retardancy of PP is dependent on its amounts. It is indicated that the 1 wt % loading of PLSiR in PP with APP and PER has the highest LOI value of 30.9 and reached UL94 rating V-0. The peak heat release rate (pHRR) and total heat release (THR) values are also decreased by 68.7 and 15%, respectively. SEM and Raman results show the condensed mechanism is ascribed to the PP/APP-PER/PLSiR system because the quality of char affect the flame retardancy of PP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48187.
研究领域:
高分子材料科学
·
阻燃化学
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材料表面改性
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环境功能材料
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废弃资源再利用
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Baoqin Mu,Bin Li,Bin Qi
Lanthanide metal–organic framework Ln-MOFs(Ln = Sm, Dy, Dy/Sm) were synthesized by hydrothermal method at 100 °C for 12 h using lanthanide metals (Ln = Sm, Dy, Dy/Sm) as metal ion centers and 1,3,5-benzotrioic acid (H 3 BTC) as ligands. The structural characteristics of Ln(BTC)(H 2 O)·(DMF) were characterized by X-ray Diffraction(XRD), Fourier Transform Infrared Spectroscopy(FT-IR) and Thermogravimetric Analysis(TGA). Scanning electron microscopy showed that the samples showed rod-like morphology, and the fluorescence spectra showed 478 nm and 573 nm corresponding to the characteristic transitions of 4 F 9/2 → 6 H 15/2 (blue light) and 4 F 9/2 → 6 H 13/2 (yellow light) of Dy 3+ , respectively, while orange light at 600 nm and red light at 646 nm corresponded to the characteristic transitions of 4 G 5/2 → 6 H 7/2 and 4 G 5/2 → 6 H 9/2 of Sm 3+ , demonstrating that the double-doped lanthanide metal ions MOF were successfully synthesized. H 7 (P(Mo 2 O 7 ) 6 )/(Dy/Sm-MOF) was used as a sensor for the determination of H 2 PO 4 − , the results of performance evaluation showed that the electrochemical sensor showed a linear relationship between 0.01 and 0.17 mM for H 2 PO 4 − , with a detection limit of 0.005 mM/L, good stability and reproducibility, which opened up a new way for the detection of orthophosphate dihydrogen.
研究领域:
分析化学
·
材料科学
·
电化学
·
无机化学
·
传感器技术
✓ 已验证
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2022
·Vol. 17
·期 5
·e2790
·
IF 1.777
Bingyi Zhou,Tao Ge,Xiaoman Luo,Zhaohui Wang,Yueyue Qiao,Chuanchuan Cai,Jingyao Xu
Under the two frequency microwave conditions of 915 and 2450 MHz, orthogonal tests were designed to investigate the effects of organic acid reagent, microwave irradiation time, and mixing time of additives and coal samples on the desulfurization effect of coal. Results show that the effect of irradiation time on the experimental desulfurization efficiency under frequency microwave conditions is large and is the main factor. The desulfurization effect under 915 MHz microwave condition is better than 2450 MHz microwave condition. Two sets of experimental optimal coal samples were used for characterization and analysis. Thermogravimetric analysis revealed that the combustion temperature range of the coal samples is shortened and the integrated combustion index is considerably higher after the microwave irradiation experiment. Fourier-transform infrared spectroscopy analysis showed that the overall chemical structure of the coal samples does not change significantly after the experimental treatment. X-ray photoelectron spectroscopy analysis showed that the intensity of organic sulfur in coal samples is weakened after microwave irradiation, the characteristic peaks of thiols and thioethers are reduced to a great extent, and an increase in the intensity of sulfoxide organic sulfur is observed. On the basis of the results of experimental analysis and quantum chemical simulation calculations, the mechanism of organosulfur structure removal under the action of microwave is revealed.
研究领域:
能源化学
·
煤化学
·
环境工程
·
材料科学
·
物理化学
·
分析化学
·
清洁燃料技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）