EGEEA合成中焙烧温度对Mg-Al-O催化性能的影响研究

用共沉淀法制备了Mg-Al水滑石(LDH),经焙烧得Mg-Al-O体系(镁铝复合氧化物,LDO),运用X衍射对其进行初步表征,考察了在一步法合成乙二醇单乙醚醋酸酯(EGEEA)中焙烧温度对LDO催化性能的影响,结果表明焙烧温度为1000℃时其结晶度好,表面带有酸碱活性中心,可作为一步法合成EGEEA的催化剂,EGEEA的收率达68.62%。     

A clean process for the production of oxygenated limonene derivatives starting from orange oil

The production of several oxygenated derivatives of limonene was carried out by using orange oil and molecular oxygen as the sole initial reactants under solvent‐free conditions. Palladium–copper supported on carbon and hydrotalcite‐like compounds displayed good catalytic properties to accelerate autoxidation reactions of limonene yielding a mixture of the different oxygenated derivatives, mainly 1,2‐ and 8,9‐epoxylimonene, 1,2,8,9‐diepoxylimonene, carveol and carvone. Palladium supported on copper–magnesium–aluminium hydrotalcite displayed the best properties due to its higher catalytic activity and lifetime. The pelletized form of these catalysts can be easily recovered and reused. A reactor design combining recirculation and oxygen bubbling through a catalytic bed of the pelletized catalyst produced the highest reaction rate. Vacuum distillation of the final product mixture allowed easy separation of the 1,2/8,9‐limonene epoxides. The other required compounds, mainly carveol and carvone, were not completely separated and remained together with the other oxygenated products, such as the di‐epoxylimonene isomers. Copyright © 2007 Society of Chemical Industry     

Ultrasound accelerated sulfonylation of amines by p-acetamidobenzenesulfonyl chloride using Mg–Al hydrotalcite as an efficient green base catalyst

The sulfonylation reaction of various aliphatic, alicyclic, aromatic, and hetero-aromatic amines with p-acetamidobenzenesulfonyl chloride has been investigated using different types of base catalysis under varied reaction conditions. Mg–Al hydrotalcite, characterizable as an inexpensive, reusable, and green solid catalyst, was found to be the most efficient catalyst, when the reaction is carried out in a minimum volume of solvent (acetone). The reaction was found to be accelerated drastically with the support of ultrasound irradiation, affording the sulfonamides in yields better or equivalent to those obtained under the longer lasting conventional stirring conditions.     

新型矿物材料——水滑石

以菱镁矿或水镁石焙烧后的ＭｇＯ为原料，采用水热法合成新型矿物水滑石，并且回收了母液。是易于工业化的合成水滑石新法。     

铁镁铝三元类水滑石对磷的吸附特性研究

采用低饱和共沉淀的方法合成了n(Fe)∶n(Mg)∶n(Al)=1∶1∶1的铁镁铝三元类水滑石。研究其对磷的吸附特性,考察了吸附时间、投加量、温度、p H等因素对吸附效果的影响。结果表明:此类水滑石对磷的吸附在前20 min吸附量急剧增加,40 min之后趋于稳定;当投加量为1.0 g/L时,吸附率和吸附容量都相对较高;初始p H为3~10时,对吸附效果无明显影响;温度对吸附效果影响较大,温度升高吸附量增加,表明此吸附过程是吸热过程。此类水滑石对磷的等温吸附数据与Langmuir方程的相关系数很高,45℃时饱和吸附量高达13.15 mg/g,同时吸附过程符合二级动力学模型。     

改性水滑石处理垃圾渗滤液生化尾水的试验研究

采用焙烧法对水滑石(HT)进行改性处理,探讨了改性水滑石(MHT)对垃圾渗滤液生化尾水中TN、NH4+-N、CODCr、TP的吸附性能及其再生性能。结果表明:当MHT投加质量浓度为6 g/L、振荡时间为60 min、振速为150 r/min、p H=7时,MHT对TN、NH4+-N、CODCr、TP的吸附量分别可达70.29、31.75、171.49、5.11 mg/g,吸附过程符合准二级动力学模型。     

水滑石材料再水合性能的研究

采用共沉淀法制备了碳酸根型和硝酸根型镁铝水滑石材料,同时制备了2种类型的钡掺杂水滑石,研究了以上4种水滑石材料焙烧后混合氧化物的再水合性能以及钡离子存在对水滑石再水合性能的影响,发现硝酸根型水滑石较碳酸根型水滑石难重构,并对重构能力的区别进行了探讨;钡掺杂的硝酸根型水滑石实际引入的钡很少,表现出和硝酸根型水滑石相同的衍射峰,但材料的再水合性能降低。     

碳酸根柱撑镁铝水滑石的超声辅助合成研究

采用共沉淀法合成镁铝水滑石,研究了超声辅助手段和表面活性剂对晶核的形成和晶粒尺寸的影响。结果表明,超声能量能促进水滑石的分散,在超声场下表面活性剂能有效地控制晶粒团聚;成核过程中有机溶剂对水滑石晶粒尺寸有较大的影响。自制水滑石结晶颗粒更小、更薄,比表面积更大。     

复原镁铝水滑石固体碱在Aldol反应中的应用

以镁铝水滑石为前体焙烧制得镁铝复合氧化物,在含水体系中水合催化取代苯甲醛和丙酮的aldol反应。结果显示,水滑石前体经过复原处理后活性高于普通Mg/Al水滑石;Mg/Al比为4∶1,NaOH/Na2CO3为沉淀剂,镁铝的硝酸盐作为金属盐来源制备的催化剂对对硝基苯甲醛和丙酮之间的aldol反应具有最好的催化效果。     

水滑石填充PVC复合材料的制备及性能研究

采用液态丁腈橡胶（LNBR）对水滑石（HT）进行表面包覆改性制备了LNBR/HT,并用其填充聚氯乙烯（PVC）制备了复合材料,采用红外光谱仪（FTIR）简支梁冲击试验机、万能试验机、氧指数测定仪、动态力学分析仪（DMA）、、扫描电子显微镜（SEM）等仪器研究了LNBR对HT的改性方式和改性前后HT含量对复合材料力学性能、阻燃性能、动态力学性能及微观形貌的影响。结果表明,LNBR对HT的改性为物理改性,由于LNBR与PVC基体有良好的相容性,经LNBR改性的HT在PVC基体中的分散性得以改善,其与PVC基体的界面黏结作用增强;PVC/LNBR/HT复合材料较PVC/HT表现出优异的力学性能和阻燃性能;PVC/LNBR/HT复合材料的拉伸强度和缺口冲击强度在LNBR/HT含量分别为5 份和10 份时分别达最大值,为29.8 MPa和17.7 kJ/m²;PVC/LNBR/HT复合材料的极限氧指数在LNBR/HT含量为40 份时达34.6 %;由于LNBR在复合材料体系中充当增容剂和增塑剂的双重作用,PVC/LNBR/HT复合材料的刚性增加,但耐热性出现小幅下降。