有机阴离子柱撑水滑石的插层组装及超分子结构

以水滑石Mg4Al2(OH)12CO3.4H2O为前体，采用离子交换法进行插层组装制备了丁二酸、己二酸、十二烷基磺酸、对羟基苯甲酸、苯甲酸和对苯二甲酸柱撑水滑石，并用XRD, FTIR和DTA测试技术对样品进行了表征. 结果表明，通过控制离子交换条件，6种有机酸根离子可以插入水滑石的层间完全取代CO32–离子，并形成具有超分子结构的稳定有机阴离子柱撑水滑石.     

采用手性固定相高效液相色谱法拆分D-(+)-二苯甲酰酒石酸无水物的异构体

目的：建立了采用高效液相色谱法拆分D-(+)-二苯甲酰酒石酸无水物异构体的方法。方法：采用高效液相色谱法,色谱柱(CHIRALPAK AD-H,4.6 mm×250 mm, 5μm);以正己烷-无水乙醇-三氟乙酸(500∶500∶1,体积比)为流动相,等度洗脱10 min;流速为0.8 mL/min;检测波长为230 nm;柱温为35℃;进样体积为10μL。结果：D-(+)-二苯甲酰酒石酸无水物及其异构体在此条件下分离度为6.0,且峰面积与浓度在一定的范围内均呈良好的线性关系。结论：方法验证的结果证明该方法可用于D-(+)-二苯甲酰酒石酸无水物及其异构体的分离,可以准确地检测D-(+)-二苯甲酰酒石酸无水物中异构体的含量。     

L-(-)-二对甲氧基苯甲酰酒石酸的合成

以对甲氧基苯甲酸、二氯亚砜、L-酒石为原料,经过生成酰氯、酯化、酐化和水解反应得到L-(-)-二对甲氧基苯甲酰酒石酸。研究了对甲氧基苯甲酰氯的用量、反应时间和酸酐水解体系、水解时间等因素对产率的影响。确定了最佳工艺条件。结果表明,L-酒石酸与对甲氧基苯甲酰氯的摩尔比为1∶2.4,反应时间4 h及酸酐水解体系为丙酮-水(V/V=1∶1),水解时间3 h,目标产物的产率为88.0%。     

二苯甲酰-D-酒石酸及其一水盐的合成

以D-酒石酸与苯甲酰氯为原料反应合成二苯甲酰-D-酒石酸与其一水盐，两者均为重要的手性拆分剂。     

酒石酸根阴离子柱撑Mg-Al-LDHs水滑石的合成

采用共沉淀法制备纳米Mg-Al-LDHs水滑石,并以纳米Mg-Al水滑石为前体,采用返混沉淀法进行插层组装,合成酒石酸根阴离子柱撑水滑石。采用红外光谱、X射线衍射对样品进行了表征。结果表明,酒石酸根阴离子可以插入纳米Mg-Al水滑石层间,完全取代CO32-,形成具有超分子结构的稳定酸根阴离子柱撑水滑石,其尺寸达到纳米级。     

L-(-)-二邻甲基苯甲酰酒石酸的合成研究

以邻甲基苯甲酸和二氯亚砜为原料,合成了邻甲基苯甲酰氯;再以L-酒石酸与邻甲基苯甲酰氯反应,生成L-(-)-二邻甲基苯甲酰酒石酸酐;该酸酐经水解得到目标化合物L-(-)-二邻甲基苯甲酰酒石酸。探讨了邻甲基苯甲酰氯用量、回流反应时间和酸酐水解时间等对合成反应的影响。结果表明,在L-酒石酸与邻甲基苯甲酰氯的摩尔比为1.0∶2.4、回流反应时间为3h、酸酐水解时间为2h的最佳工艺条件下,总产率为88.2%。     

手性拆分剂L-二苯甲酰酒石酸和L-二乙酰酒石酸的合成工艺研究

研究了手性拆分剂L-二苯甲酰酒石酸和L-二乙酰酒石酸的合成工艺及各种反应条件对收率和产物旋光纯度的影响。在路易斯酸催化下,L-酒石酸与苯甲酰氯及二氯亚砜作用生成L-二苯甲酰酒石酸酐,然后L-二苯甲酰酒石酸酐再水解成L-二苯甲酰酒石酸,二步总收率86%,旋光纯度大于99%;在硫酸催化下,L-酒石酸与乙酐作用生成L-二乙酰酒石酸酐,再水解成L-二乙酰酒石酸,二步总收率为75%,旋光纯度大于99%。     

3,6-二苯甲酰苊的合成与表征

为制备新型精细化工和功能高分子中间体,研究了在高活性Lewis酸无水AlCl3催化下,苊与苯甲酰氯的Friedel-Crafts酰基化反应,GC/MS分析发现生成了3,6-二苯甲酰苊;用GC法考察了各种反应条件对3,6-二苯甲酰苊收率的影响,结果表明,在以1 mmol苊为基准,苯甲酰氯8mmol,AlCl38 mmol,溶剂为CCl4(15 mL),反应温度45℃,反应时间10 h的条件下,3,6-二苯甲酰苊的收率可达到84.2%,选择性达89.9%。通过萃取、重结晶等方法得到3,6-二苯甲酰苊的纯品。通过FT IR、GC/MS和1H NMR等分析测试手段鉴定了其结构。     

牛磺酸插层水滑石的制备及其阻燃EVA

采用离子交换法制备了牛磺酸插层水滑石(T-LDH),通过红外光谱(FTIR)和X射线衍射(XRD)对NO3-LDH与T-LDH的结构进行了表征,结果表明牛磺酸成功插层到水滑石层间。通过双螺杆挤出机将NO3-LDH与T-LDH和乙烯-乙酸乙烯共聚物(EVA)熔融共混,采用热重分析(TGA)和锥形量热法(CCT)对EVA复合材料的热稳定性和阻燃性能进行了表征,结果表明T-LDH能进一步提高EVA基体的热稳定性和阻燃性能。分析了LDHs对EVA的阻燃机理:LDHs的吸热分解能有效降低基体的热量,同时释放出的H2O能有效地降低聚合物周围氧气的浓度。EVA/T-LDH形成的较完整炭层与牛磺酸所含的S元素都能更好地提高材料的阻燃性能。     

Surface Areas of Nitrated Hydrotalcites

Hydrotalcites in the nitrate form were prepared using microwave irradiation in the hydrotreatment step. The surface area (BET) of nitrated hydrotalcites was evaluated. Solids were characterized by atomic absorption, X-ray diffraction and BET analysis. Thermal pretreatment temperature determined the surface area of the hydrotalcites.     

Intercalation Assembly Method and Intercalation Process Control of Layered Intercalated Functional Materials

Layered intercalated functional materials of layered double hydroxide type are an important class of functional materials developed in recent years. Based on long term studies on these materials in the State Key Laboratory of Chemical Resource Engineering in Beiiing University of Chemical Technology, the orinciole for the design of controlled intercalation processes in the light of tuture production processing requirements has been developed. Intercalation assembly methods and technologies have been invented to control the intercalation process for preparing layered intercalated materials with various structures and functions.     

磷钨酸插层锌钛水滑石的制备及催化脂肪酸甲酯环氧化反应

采用离子交换法制备了一系列磷钨酸根插层Zn-Ti水滑石,利用XRD、FTIR、SEM对所制催化剂进行了表征。结果表明,磷钨酸根插层锌钛水滑石后仍保持原有的骨架结构。用制备的类水滑石催化脂肪酸甲酯环氧化反应,考察了所制催化剂的催化性能。当n(过氧化氢)∶n(原料双键)=1.5∶1,催化剂用量为脂肪酸甲酯质量的7.0%,在70℃下反应7 h时,脂肪酸甲酯转化率可达90.6%,环氧化产物选择性可达86.0%,优于Zn-Ti水滑石,其对脂肪酸甲酯环氧化反应显示出较高的催化活性。插层水滑石重复使用5次后,催化性能仍较稳定。     

PVC用水滑石类热稳定剂的研究开发进展

介绍了PVC用水滑石类化合物（LDHs）热稳定剂的制备方法、作用机理以及应用进展,指出了其今后的发展方向。     

聚合物/CdS纳米杂化材料的组装与应用

聚合物/无机纳米杂化材料兼具聚合物材料的可加工性和无机纳米材料的功能性与结构特征,已成为目前材料学科的研究热点。综述了聚合物/CdS纳米杂化材料的制备方法、表征手段,并对这种杂化材料的应用做了简要介绍。     

对化工管路装拆实训的初探

管路是由管子、管件和阀门组成。在生产中,只有管路畅通,阀门调节适当,生产才能正常运行。本文介绍了化工管路布置的一般要求及如何培养学生进行管路拆装。     

Wide Area Reversible Adhesive for In‐Space Assembly

The design of future space structures may anticipate a greater need for in‐space assembly due to larger planned space structures and changes in mission profiles over their operational lifetimes. A rapid and reversible adhesive coating over the structure’s surface would allow additional components to be bonded at any arbitrary time in the future. A scalable wide‐area reversible adhesive utilizing a high glass transition thermoset polymer possessing thermally exchangeable bonds can serve as an enabling technology for in‐space assembly. Coatings of aromatic thermosetting copolyesters can be deposited on aluminum and titanium coupons, which bond when heated to 400 °C with the counterpart surfaces under pressure. Reversibility over multiple cycles is shown within a dynamic mechanical analyzer with the limiting constraint being the necessity of nondelaminatory (cohesive) debonding of the bonded coupons. Bonded coupons can sustain a thermal cycle spanning the representative temperatures in low earth orbit under tension with no failure. A localized rapid heating method amenable for in‐space assembly can be used to bond titanium coupons using induction heating with a bonding time of 40 s.     

Enhanced Combustion Characteristics of Bismuth Trioxide‐Aluminum Nanocomposites Prepared through Graphene Oxide Directed Self‐Assembly

We present a facile, spontaneous, and surfactant‐free method to controllably self‐assemble aluminum and bismuth trioxide nanoparticles through the introduction of graphene oxide as a self‐assembly directing agent. The self‐assembled nanocomposites demonstrate significant combustion performance improvements in comparison to randomly mixed aluminum and bismuth trioxide nanoparticles with enhanced pressure generation from 60 to 200 MPa, pressurization rate from 3 to 16 MPa μs⁻¹, burning rate from 1.15 to 1.55 km s⁻¹, and specific impulse from 41 to 71 s. The sensitivity of the self‐assembled aluminum and bismuth trioxide to electrostatic discharge was reduced by four orders of magnitude, without decreasing the combustion performance. Graphene oxide directed self‐assembly can be used to synthesize nanocomposites with diverse combustion properties and controlled ignition sensitivity, which lays the foundation for preparing multi‐functional, highly‐reactive, combustion systems in the future.     

Vapor-Phase Alkylation of Toluene with Isopropanol over Mg/Al, Ni/Al and Cu/Al Hydrotalcites (Layered Double Hydroxide)

Vapor-phase isopropylation of toluene has been carried out over Mg/Al, Ni/Al and Cu/Al calcined hydrotalcites (CHTs). Reaction conditions were optimized for alkylation by varying temperature, weight hourly space velocity and reactant mole ratio. Side-chain alkylation is found to be more predominant than ring alkylation over Mg/Al CHT, while Ni/Al and Cu/Al CHTs favored ring alkylation. The main products were isobutylbenzene and cymene. The combined participation of acidic and basic sites of the materials is found to be crucial for both side-chain and ring alkylation of toluene with isopropanol. An X-ray diffraction pattern of the resulting oxide indicates a diffuse MgO structure. The incorporation of small amounts of Al³⁺ to MgO generates new surface Lewis acid--base pair sites.