硅溶胶改性水性超薄型钢结构防火涂料的研究

以过硫酸铵为引发剂,OP-10为乳化剂,在聚乙烯醇保护下,用甲基丙烯酸甲酯、丙烯酸丁酯进行共聚,合成乳液型丙烯酸酯树脂,并用红外光谱表征.用磷酸、五氧化二磷、季戊四醇反应生成的酯型中间体与三聚氰胺混合,制得膨胀型阻燃剂,用红外光谱表征并对其进行热重分析.用自制膨胀型阻燃剂与乳液型丙烯酸树脂及少量硅溶胶按一定比例混合调匀,制备超薄型钢结构防火涂料,根据国家标准对涂料性能进行检测,其基本性能达到防火涂料要求.     

高热稳定性三聚氰胺聚磷酸盐的合成

以三聚氰胺和磷酸为原料,以去离子水为溶剂,在杂多酸A催化下,制得改性三聚氰胺磷酸盐(MP);将MP在箱式气氛炉中进行多温度段热缩合反应合成了三聚氰胺聚磷酸盐(MPP),其结构经~(31)P NMR,IR和元素分析表征。通过TG对MPP的热稳定性和成炭性能进行了分析。结果表明:MPP失重1%时温度为372.1℃,失重5%时温度为382.7℃,700℃时残炭率为37.36%。     

鲍鱼多糖Hal-A的热分析研究

采用热重、热重-红外谱联用及差示扫描量热法，对鲍鱼多糖进行热分析研究 ，结果表明鲍鱼多糖在空气和氮气氛中，230 ～ 340 ℃之间发生剧烈的分解反应 。氮气氛中，是吸热的分解过程；而空气氛中，是放热氧化反应，并且在453 ℃左 右，有另一个急剧的氧化裂解过程。与淀粉、肝素、甲壳素和半乳糖的热分析比较 ，含有硫酸酯的鲍鱼多糖和肝素热稳定性较低，含氨基的甲壳素最高，这反映出不 同基团对多糖热稳定性的影响。     

膨胀型类磷酸酯蜜胺盐阻燃剂的合成及应用研究

以双季戊四醇(DPE)、五氧化二磷、水和三聚氰胺为原料,合成了膨胀型环状类磷酸酯蜜胺盐阻燃剂。通过实验提出了合成该阻燃剂的最佳反应条件为：双季戊四醇(DPE)、五氧化二磷、水和三聚氰胺反应物料摩尔配比为1／2．5／2.0／3．45、反应时间4h和反应温度120℃。红外吸收图谱分析表明该阻燃剂具有环状结构,在热重分析和差热分析中该阻燃剂显示出优异的热稳定性和很高的成碳性。以该阻燃剂掺入聚丙烯中,阻燃效果显著,经测试阻燃聚丙烯的极限氧指数(LOI)为33．6,烟密度等级(SDR)为44．25,通过了UL94V-0级。     

Pd/HZSM-5涂层催化吸热燃料超临界裂解

超临界催化裂解反应是实现吸热燃料功能的关键途径.采用气体辅助涂层和化学镀方法在ψ3管内壁制备了Pd/HZSM-5双功能涂层催化剂.利用SEM、XRD和XPS等对涂层进行了表征,结果显示催化剂涂层表面平整,涂层厚度为12μm～16μm,催化剂粒径为1μm～5μm;Pd颗粒分散均匀,主要以零价态存在.考察了模型吸热燃料正十二烷在反应管内的超临界催化裂解反应,结果表明,Pd/HZSM-5涂层能显著促进裂解反应,在温度640℃、压力4 MPa、停留时间10 s下,吸热燃料裂解率为55.5%,产氢率为3.1%,热沉为3 470 kJ/kg,较HZSM-5涂层分别提高了8.5%,58.7%和10.5%;较热裂解分别提高了17.3%,78.1%和13.5%.     

接枝三聚氰胺粘胶纤维的合成及优化工艺

以表面羧基化粘胶纤维为基材,以三聚氰胺为阻燃功能基,二环己基碳二亚胺(DCC)为交联剂,合成接枝三聚氰胺粘胶纤维并表征其形貌、力学及热性能,探索其优化合成工艺。合成接枝三聚氰胺粘胶纤维的优化工艺为:DCC用量为羧基化粘胶纤维质量的0.6%,温度65℃,pH4.0,在此条件下反应2h,三聚氰胺对羧基化粘胶纤维的接枝率达到了5.57%。接枝三聚氰胺粘胶纤维其平均直径为4.643μm;其干态强度与干态断裂伸长率分别增加了20.99%、18.13%;接枝三聚氰胺粘胶纤维的LOI为29.2%,燃烧时间为26.9s,分别比粘胶纤维增加62.2%和76.97%,热释放量减少10.12%,有显著的阻燃效果。     

二苯氧基磷酸三聚氰胺盐阻燃改性环氧树脂

本文通过二苯氧基磷酸(DPHP)与三聚氰胺之间的一步中和反应成功地合成了二苯氧基磷酸三聚氰胺盐(MDHP),并将其作为添加型阻燃剂应用于环氧树脂中。热重分析结果显示,MDHP的加入使环氧固化物的分解提前且氮气氛下残炭量显著增加。阻燃性能测试结果表明,环氧固化物的氧指数(LOI)在阻燃剂添加量为5 phr时即可达到32.9%,锥形量热数据表明MDHP的加入能显著降低其峰值热释放(PHRR)、总热释放(THR)、总烟释放(TSP)等,同时残余质量(Mass)有所增加。另外,固化物的弯曲和冲击性能均能得到很好的保持,表现出潜在的应用前景。     

三季戊四醇亚磷酸酯阻燃剂的合成及应用研究

以三季戊四醇(TPE)、亚磷酸三苯酯(TPP)为反应原料,氢氧化钠为催化剂,采用非溶剂酯交换一步法合成了三季戊四醇亚磷酸酯膨胀型阻燃剂。用红外光谱与元素分析初步确定了三季戊四醇亚磷酸酯类的物质。热分析表明,10％的失重所对应的温度为122℃,50％的失重对应的温度为371℃;其失重速率最大时的峰顶温度为329℃;在500℃时的成炭量高达40％。以三季戊四醇亚磷酸酯和三聚氰胺复配阻燃的环氧树脂,添加量为19％时其极限氧指数(LOI)为35％,通过了UL94V-0级,表明该阻燃剂具有优良的阻燃性能。     

新型热量计的研制及其在吸热型碳氢燃料热沉测定中的应用

建立并完善了一套高温流动型热导式量热装置,实现了量热与色谱在线分析的有机结合。对该系统的仪器常数、热量常数、时间常数进行了精确的标定,并采用标准物质氮气、正庚烷等对仪器的准确性进行了考察,测量结果误差在2.2%～4.7%之间。同时还实测了吸热型碳氢燃料S-1,R-1等的热裂解热沉值。S-1在700℃时的热沉为2.99MJ/kg,而R-1的热沉为2.82MJ/kg。     

三聚氰胺三聚硫氰酸盐的合成

以三聚氰胺和三聚硫氰酸为原料合成了一种新型含硫三聚氰胺基阻燃剂——三聚氰胺三聚硫氰酸盐(MSA),其结构和热性能经1H NMR,13C NMR,FT-IR,元素分析和TGA表征。确定了合成MSA的最优工艺条件为:去离子水为溶剂,三聚硫氰酸和三聚氰胺摩尔比为1∶1,反应时间为3 h。TGA分析表明:MSA失重5%时,温度为308.8℃,600℃时分解基本完全,残碳率为0.86%。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.