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31.
A series of new polyamides 3a–d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-(4-aminophenoxy)phenyl sulfone]
1 and several azo aromatic diacyl chlorides 2a–d by the low temperature solution polycondensation technique. FTIR spectroscopy, nuclear magnetic resonance (NMR) and elemental
analyses confirmed the structure of these polymers. Owing to the aryl and amide groups in the main chain, these polymers exhibit
photochromic properties as well as excellent thermal stabilities. The transition temperatures (T
g) are between 242 and 265 °C, and the char yields at 800 °C in nitrogen atmosphere were above 39%. Based on incorporation
of flexible ether linkages and polar sulfone groups, the polyamides show desirable solubility in organic solvents such as
DMAc, N,N-dimethylformamide (DMF), N-methyl-2-pyrroidinone (NMP) and dimethylsulfoxide (DMSO). And it is exemplified that
polyamide containing 2 and 2′ substitutes performed better solubility.
Funded by the National Natural Science Foundation of China (No. 50572081) 相似文献
32.
A series of dimer acid-based polyamides were synthesized by melt-polycondensation of dimer acid and various aromatic diamines,
and were characterized by Fourier transform infrared spectrum (FT-IR) and nuclear magnetic resonance (1H NMR). The physical properties of the polyamides, such as glass transition temperature, melting temperature, decomposition
temperature and mechanical properties were also investigated. The polyamides’ intrinsic viscosity ranges from 1.8 dL·g−1 to 2.2 dL·g−1, and the melting temperature ranges from 140 °C to 181 °C. The glass transition temperatures, observed from dynamic mechanical
analysis, fall in the range of 34.8–48.2 °C. The physical and mechanical properties of the resultant polyamides are similar
to those of the PA1212. The heat resistance and mechanical properties of poly (4, 4′-diphenylsulfone dimeramide) (PSD) and
poly(4, 4′-diphenyl dimeramide) (PPDI) are comparable to those of PA1212. 相似文献
33.
马尔可夫(Markov)链理论是用来描述随时间(空间)变化的一个离散状态序列的状态转移特性的,本文将其引入来研究土壤剖面多环芳烃有机污染物的垂向变化规律,建立了基于空间离散化的马尔可夫(Markov)链理论数学模型及垂向归趋极限.研究结果表明,基于空间离散化的马尔可夫(Markov)链理论数学模型及垂向归趋极限能够很好地模拟区域土壤剖面多环芳烃(菲)的垂向变化特征,并有迁移规律的识别功能. 相似文献
34.
为比较溶剂处理梗丝和常规工艺生产的梗丝的差别,采用溶剂处理烟梗梗条后在烟梗制丝线上制备梗丝,研究溶剂处理对梗丝内在质量的影响.通过仪器分析与感官质量对比,结果表明:与传统制备工艺相比,溶剂处理对烟梗的持水性、耐加工性和梗丝结构的影响较小,梗丝的填充值增加11.4%;其主要化学成分及致香成分含量有较大变化,对梗丝内在质量有一定程度的改善. 相似文献
35.
应用自制羟基-二苯并冠醚(OH-DB14C4/OH-TSO)为涂层的固相微萃取探头,采用气相色谱法测定苯胺(A)、间甲苯胺(MT)、N,N-二乙基苯胺(NNDEA)、N-乙基间甲苯胺(NEMT)和3,4-二甲基苯胺(3,4-DMA).并对固相微萃取的最佳条件进行了优化.顶空固相微萃取-气相色谱法的检测限(LOD)为0.17~0.98 ng·ml-1,相对标准偏差(RSD)为3.23%~6.20%,线性范围(LR)为0.11~29 μg·ml-1.对药厂废水的3,4-DMA进行了分析,其回收率为86%~90%. 相似文献
36.
合成了H-ZSM-5型分子筛,并用连续沉淀法制备了FT合成催化剂MnFe。对混合催化剂MnFe/H-ZSM-5上CO加氢合成芳烃的催化行为作了研究。并考察了分子筛组分、粒度、反应工艺条件对反应速度及芳烃收率的影响。试验结果表明,粒度在20μm-25μm范围内的反应已排除内扩散控制的影响,芳烃收率可达40%,烃类产物分子量的分布不再服从Schulz-Flory分子量分布规律。 相似文献
37.
Alaa?S.?Abd-El-AzizEmail author Nelson?M.?Pereira Waleed?Boraie Erin?K.?Todd Tarek?H.?Afifi Wes?R.?Budakowski Ken?J.?Friesen 《Journal of Inorganic and Organometallic Polymers and Materials》2005,15(4):497-509
The synthesis of the title complexes was achieved via the reaction of
-p-dichlorobenzene-
-cyclopentadienyliron cations with 4,4′-bis(4-hydroxyphenyl)valeric acid to produce the diiron complexes which were then reacted with a number of arylazo dyes to give cationic bis(cyclopentadienyliron)arene complexes containing the arylazo dyes. These iron-containing monomers were subsequently polymerized via nucleophilic aromatic substitution using 1,8-octanedithiol, 4,4′-thiobisbenzenethiol, or bisphenol A to produce the desired coloured cationic organoiron polymers. The weight – average molecular weights were estimated to range from 11,800 to 31,600. UV–vis studies conducted in dimethylformamide (DMF) showed that the metallated polymers exhibited
of 412–491 nm. Addition of HCl to the polymer solution caused a bathochromic shift into the range of 515–530 nm. Thermogravimetric analysis (TGA) revealed that the iron moieties were cleaved between 205 and 248 °C while the polyether/thioether backbone degraded between 380 and 613 °C. Differential scanning calorimetry (DSC) showed that the polymers exhibited glass transition temperatures (Tg) ranging from 106 to 184°C.This paper is dedicated to Professor Richard J. Puddephatt in recognition of his outstanding contribution to the field of metal-containing polymers. 相似文献
38.
Bioremediation strategies have been applied to clean up petroleum hydrocarbon (PHC) impacted sites. Introducing PHC degrading microorganisms (bioaugmentation) and enhancing the in‐situ nutrients availability (biostimulation) are widely used strategies. These strategies can be combined to lead to a better bioremediation performance. In this work, Pseudomonas fluorescens was isolated from a PHC impacted site. Through a 23 factorial design plan, the effect of various combinations of nitrate, sulphate, and phosphate ions on the PHC bioremediation performance by P. fluorescens was investigated using catechol, an essential metabolic intermediate of BTEX degradation, as the sole carbon source. The maximum specific catechol degradation rate was chosen as the response to evaluate the catechol bioremediation performance. The ANOVA results indicated that the presence of nitrate ions alone lowered the maximum specific catechol degradation rate, which can be explained by the accumulation of nitrites and ammonia during the denitrification process by P. fluorescens. It was noted that dosing sulphate ions alone did not affect the bioremediation performance, which indicates P. fluorescens can grow in a sulphur‐limited environment. In contrast, the presence of sulphate and nitrate ions together can lead to a higher specific catechol degradation rate. This may be caused by the presence of sulphate that can suppress the production of nitrites. The importance of phosphate ions on catechol biodegradation was investigated. The absence of phosphate led to incomplete biodegradation. Introducing phosphate ions can accelerate catechol degradation, which can be explained by the secretion of organic acids. 相似文献
39.
在线近红外光谱法测定乙烯装置进料石脑油的芳烃含量 总被引:1,自引:0,他引:1
介绍了在线近红外光谱测定乙烯装置进料石脑油的芳烃含量的方法.结果表明:在线近红外光谱法的分析结果能够完全满足生产中的精度要求,再现性和重复性优于ATSM D5443(多维气相色谱法)的要求.该方法除有测量速度快的优点之外,还具有分析成本低、无污染、操作简单方便等特点,在所建立模型的预测范围内,能对样品进行准确、经济的分析. 相似文献
40.
Yue Zhi Junyi Che Haofang Zhu Rui Liu Yuanjin Zhao 《Advanced functional materials》2023,33(43):2304353
In diabetic wound healing, M1 macrophage accumulation and elevated inflammation are prevalent issues. Intelligent delivery systems that can sustainably release antioxidizing and anti-inflammatory ingredients are expected for effective wound healing. Herein, a novel glycyrrhetinic acid (GA) liposomes encapsulated microcapsules delivery system that has desired features for inflammatory wound repair is presented. As the bacteria could break down the alginate shells, the GA liposomes could be controllably released from the microcapsules, which promotes M2 macrophage polarization and regulate their responses in the inflammatory wound microenvironment. Based on these, it is demonstrated that the GA liposomes encapsulated microcapsules delivery system exhibits an anti-inflammatory and immunomodulatory effect for diabetic wound healing in a full-thickness defect model in diabetic rats. These results indicate that the immunomodulatory capabilities of the microcapsules can be unitized for efficient wound repair, and such a delivery system is valuable for clinical wound healing applications. 相似文献