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Effect of Added Poly (vinyl pyrrolidone) during Condensation on Properties of Poly(p-phenylene terephthalamide)Pulp 被引量:1
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作者 李锦春 尤秀兰 +1 位作者 曹煜彤 刘兆峰 《Journal of Donghua University(English Edition)》 EI CAS 2009年第2期147-153,共7页
Poly(p-phenylene terephthalamide)(PPTA)pulp was prepared by polycondensation of the p-phenylene diamine(PPDA)with terephthaloyl chloride(TPC)in the completely anhydrous solvent system of N-methyl pyrrolidone(NMP)havin... Poly(p-phenylene terephthalamide)(PPTA)pulp was prepared by polycondensation of the p-phenylene diamine(PPDA)with terephthaloyl chloride(TPC)in the completely anhydrous solvent system of N-methyl pyrrolidone(NMP)having calcium chloride,in the presence of poly(vinyl pyrrolidone)(PVP)having a viscosity average molecular weight lower than 40 000.It was confirmed that the polycondensation could be accelerated,the inherent viscosity of the polymer could be increased,and the polymers could be fibrillated more easily by the addition of the PVP.FTIR and X-ray spectra proved that PVP had not combined into molecular chains of the resultant PPTA pulps.The morphology of the resultant pulps,the effect of viscosity average molecular weight,amount and adding mode of PVP on inherent viscosity,specific surface area,and mean length of the resultant pulps were discussed in detail.And the friction and wear properties of the compound reinforced by the resultant pulps were simply investigated. 展开更多
关键词 poly p-phenylene terephthalamide pulp PPTA pulp poly (vinyl pyrrolidone PVP POLYCONDENSATION friction material
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Study on Drying Process of 3Al_2O_3·2SiO_2 Mullite Gel
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作者 宋会锋 康庄 顾利霞 《Journal of Donghua University(English Edition)》 EI CAS 2008年第6期616-620,共5页
Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with differe... Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with different drying control chemical additives(DCCAs) and polyvinylpyrrolidone(PVP) as spinning assistant were dried at several temperatures. The influences of temperature, DCCAs and PVP in the drying process were investigated. N,N-dimethylformamide(DMF) was the optimum DCCA at 70℃ in the drying process. PVP decreased the solvent volatilization speed and prevented gel crack to a certain extent. FTIR results revealed that free water, ethanol, and isopropanol were completely removed by the drying procedure. 展开更多
关键词 sol-gel process DCCAs PVP CRACK-FREE
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5-(1-氨基-2-苯氧亚乙基)巴比妥酸衍生物的合成及除草活性研究 被引量:2
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作者 王超超 刘会 +5 位作者 赵微 李攀 冀庐莎 柳仁民 雷康 徐效华 《有机化学》 SCIE CAS CSCD 北大核心 2021年第5期2063-2073,共11页
基于具有生物活性的烯胺二酮骨架及前期报道的先导化合物5-酰基巴比妥酸I的结构,设计、合成了26个结构新颖的5-(1-氨基-2-苯氧亚乙基)巴比妥酸衍生物.生物活性测试结果表明,化合物5-(2-(2-氯-4-氟苯氧基)-1-(戊基氨基)亚乙基)-1,3-二甲... 基于具有生物活性的烯胺二酮骨架及前期报道的先导化合物5-酰基巴比妥酸I的结构,设计、合成了26个结构新颖的5-(1-氨基-2-苯氧亚乙基)巴比妥酸衍生物.生物活性测试结果表明,化合物5-(2-(2-氯-4-氟苯氧基)-1-(戊基氨基)亚乙基)-1,3-二甲基嘧啶-2,4,6(1H,3H,5H)-三酮(APB-5)在苗后处理,187.5 g•ha-1剂量时,对双子叶植物(油菜、苋菜)具有100%的抑制活性.更重要的是,化合物APB-5在375 g•ha-1的剂量时具有宽的除草谱且对玉米、小麦和谷子安全,这说明该化合物具有成为除草剂的潜力.此外,通过研究拟南芥的表型及化合物对激素响应基因的影响发现,化合物APB-5具有与激素类除草剂2,4-二氯苯氧乙酸(2,4-D)相似的作用机制.目前的研究表明,化合物APB-5可以作为进一步开发新型生长素类除草剂的先导结构. 展开更多
关键词 巴比妥酸 烯胺二酮 合成 除草活性 激素
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铁盐催化的高选择性合成2-取代的吡啶并[2,3-b]吲哚衍生物 被引量:3
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作者 卢小彪 肖茜 +3 位作者 章明 万常峰 侯豪情 万结平 《有机化学》 SCIE CAS CSCD 北大核心 2021年第11期4444-4449,共6页
多环稠合的芳香含氮杂环化合物是一类非常重要的含氮杂环化合物,在药物和材料中得到了广泛的应用,而吡啶并吲哚类化合物是其重要的一类.目前,这类化合物的合成方法并不是很多,基于之前的工作基础,发展了一个在三氟甲磺酸铁作为催化剂条... 多环稠合的芳香含氮杂环化合物是一类非常重要的含氮杂环化合物,在药物和材料中得到了广泛的应用,而吡啶并吲哚类化合物是其重要的一类.目前,这类化合物的合成方法并不是很多,基于之前的工作基础,发展了一个在三氟甲磺酸铁作为催化剂条件下,利用邻氨基苯乙腈衍生物和3-二甲胺基烯胺酮类化合物作为反应原料,在温和的反应条件下,高效地选择性构建2-取代的吡啶并[2,3-b]吲哚结构的方法. 展开更多
关键词 吡啶并[2 3-b]吲哚 铁盐 N N-甲基 高选择性
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Theoretical studies on selectivities in the Staudinger reaction of vicinal diimines and ketenes 被引量:1
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《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第3期370-379,共10页
The selectivities, including peri-, regio-, and diastereoselectivities, in the Staudinger reaction involving vicinal diimines and ketenes were investigated theoretically via the density functional theory (DFT) calcu... The selectivities, including peri-, regio-, and diastereoselectivities, in the Staudinger reaction involving vicinal diimines and ketenes were investigated theoretically via the density functional theory (DFT) calculation. The results indicate that vicinal diimines prefer stepwise [2+2] cycloaddition rather than [2+4] cycloaddition to generate cis-4-imino-β-lactams. The diimines attack the less sterically hindered exo-side of ketenes to generate zwitterionic intermediates, which directly undergo a conrota- tory ring closure to produce cis-4-imino-β-lactams whatever diimines with less or more bulky N-substituents. For unsymmetric vicinal ketoaldehyde-derived diimines, their ketimines attack the exo-side of ketenes and undergo a conrotatory ring closure to produce cis-4-aldimino-β-lactams due to less steric effect. The current theoretical studies provide very important information for in-depth understanding of the selective formation of mono-cis-β-lactams from vicinal diimines and ketenes. 展开更多
关键词 density functional theory (DFT) selectivity DIIMINE KETENE CYCLOADDITION Staudinger reaction
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