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Journal of Macromolecular Science Part B-Physics · 2013 · IF 0.628

Study on the Nonisothermal Crystallization Kinetics of Poly(Vinylidene Fluoride)/Tributyl Citrate Blends Via Thermally Induced Phase Separation

Zhao-Cai Zhang,Chun-Gang Guo,Yi-Peng Guan,Jing-Lie Lv

The nonisothermal crystallization kinetics of poly (vinylidene fluoride) (PVDF) in PVDF/tributyl citrate (TBC) blends having undergone thermally induced phase separation were investigated through differential scanning calorimetry measurements. Ozawa theory, Mo's method and Kissinger model were used to analyze the kinetics of the nonisothermal crystallization process. The Ozawa theory failed to describe the crystallization behavior of PVDF in the PVDF/TBC blends, whereas the Mo model was able to describe the nonisothermal crystallization process fairly well. The crystallization activation energy was determined by the Kissinger method, and was in the range of 90–165 kJ/mol.

研究领域: 高分子材料科学 · 结晶动力学 · 热分析 · 功能高分子 · 相变行为

✓ 已验证 DOI 高影响因子

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Journal of Macromolecular Science Part B-Physics · 2021 · IF 1.504

Thermal Degradation, Kinetic Analysis and Char Formation in the Pyrolysis of Poly(melamine-co-phenolic resin) Copolymer

Hengyu Feng,Qingshi Cui,Yu Zhou,Jinglong Dong,Ming Li,Linghan Xiao,Yuhui Ao

Understanding the mechanism of thermal degradation of a material may suggest a promising way for further improving its thermal properties. poly(melamine-co-phenolic resin) (P(M-co-PR)) has been widely used in flame resistant and fire-proof materials. Our characterization of the thermal degradation of P(M-co-PR) is described in this work. Fourier-transform infrared (FTIR) and X-ray photo-electron spectroscopy (XPS) analyses were used to investigate the structural evolution during the thermal degradation of the copolymer. The evolutions of C = N and C-N bonding in heteroaromatic rings were monitored during the degradation process by C1s and N1s XPS spectra. The degradation processes of P(M-co-PR) is divided into three stages. The degradation kinetics of P(M-co-PR) was researched by using the Ozawa and Kissinger activation energy equation methods. The conclusion is that the Kissinger equation applied to the first stage, and the Ozawa equation applied to the second and third stages.

研究领域: 高分子科学 · 热分析 · 材料化学 · 阻燃材料 · 光谱学

✓ 已验证 DOI 高影响因子

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Journal of Energetic Materials · 2024 · IF 1.7

Efficient Synthesis, Characterization, and DFT Calculation of 4,4’-Azo-1,2,4-triazole

Ying Wu,Yong Liu,Shuai Hou,Qizhi Zhao,Han Gao,Xiao Yan

4,4’-Azo-1,2,4-triazole (atrz) is a new high nitrogen energetic material with high energy density, high gas yield and wide application prospects, but the low synthesis temperature and long time are the main reasons limiting its application. To achieve efficient synthesis of atrz, the double drop synthesis method was designed to solve the problem of unstable concentration of oxidant (HClO) due to batch feeding. The reaction temperature, reaction time, and molar ratio of reactants of n(4-amino-1,2,4-triazole):n(ClO−) were studied and optimized using the single factor variable method; Characterization and analysis of atrz using theoretical calculations with elemental analysis, infrared spectroscopy, crystal morphology, and nuclear magnetic resonance; The thermal properties and stability of atrz were tested and analyzed using TG-DTA. The results showed that the reaction time of the double drop synthesis method was shortened from 5 hours to 1.5 hours under the conditions of similar yield, and the efficiency was increased by 2.3 times. The optimized process was a reaction temperature of 5°C-10°C, reaction time of 1.5 hours, n(4-amino-1,2,4-triazole):n(ClO−) of 1:2, and the yield reached 73%. The product was white, needle-like crystals, which were determined to be atrz by means of characterization and theoretical calculations. Atrz’s decomposition peak temperature is 309.0°C, and when the temperature is below 271.7°C, atrz is thermally stable. The activation energies of atrz calculated by Kissinger and Flynn-Wall-Ozawa methods were 195.0 kJ·mol−1 and 194.6 kJ·mol−1.

研究领域: 化学 · 材料科学 · 能材料 · 理论计算 · 热分析

✓ 已验证 DOI 高影响因子

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Study on the Nonisothermal Crystallization Kinetics of Poly(Vinylidene Fluoride)/Tributyl Citrate Blends Via Thermally Induced Phase Separation

Thermal Degradation, Kinetic Analysis and Char Formation in the Pyrolysis of Poly(melamine-co-phenolic resin) Copolymer

Efficient Synthesis, Characterization, and DFT Calculation of 4,4’-Azo-1,2,4-triazole