碳酸酯类化合物是21世纪最重要的绿色化学品,最典型的碳酸酯化合物碳酸二甲酯(DMC)是工业上广泛应用于溶剂、燃料添加剂以及化学试剂方向的重要化学品.由于DMC毒性很小,可以替代一些剧毒的化学品,如取代硫酸二甲酯和甲基卤化物用于甲基化反应.由于其高电介质常数、低黏度、低毒性以及优秀的溶解能力等性质,DMC被用作锂离子电池的电解液.微波技术能有效地提高催化剂活性组分的分散度,改善催化剂表面的晶体类型,提高催化剂的活性,在催化领域具有广阔的应用前景.介绍了微波技术应用于合成DMC反应中的催化剂制备,探究了微波技术对不同合成路径、不同催化剂合成DMC反应的影响,最后对微波技术对目前非均相催化剂合成DMC存在的问题以及今后的发展方向进行了总结与展望.

金霉素、四环素和土霉素等是常用兽用抗生素,随着家畜排泄物堆肥的使用,3种抗生素进入到环境中成为新兴的污染物.本文采用一锅法,以葡萄糖为还原剂,制备了自组装的Fe3O4纳米颗粒与还原氧化石墨烯的纳米复合材料(Fe3O4@rGO),采用平衡吸附法研究了Fe3O4@rGO对3种抗生索的吸附性能和行为.表征结果显示,Fe3O4@rGO具有两种前驱体的特征,Fe3O4纳米颗粒均匀分散在rGO表面上.吸附结果表明,Fe3O4@rGO对3种抗生素的吸附速率很快,20min基本达到吸附平衡;当溶液pH值在4～8时,pH值对3种抗生素的吸附容量没有显著性的影响;Fe3O4@rGO对3种抗生素的吸附容量均大于单纯的Fe3O4和rGO;Fe3O4@rGO对金霉素(189.2mg/g)和四环素(199.7mg/g)有较高的吸附容量,而对土霉素(112.5mg/g)的吸附容量相对较低,这是由于土霉素与Fe3O4和rGO的结合力均相对较弱造成的:3种抗生素在Fe3O4@rGO上的吸附过程可用Langmuir等温吸附模型和准二级动力学方程来描述.

A new copolymer,maleic ester-maleic amide-vinyl acetate(PMMVA)for reducing solidification point(SP)of lubricating oil was synthesized at low temperature.The raw materials are maleic anhydride,mixed higher alcohols,octadecyl amine and vinyl acetate.The synthetic method is first condensation and then polymerization.Condensation products were prepared through alcoholysis and aminolysis.In polymerization process,pour point depressant(PPD)copolymer was obtained.Through orthogonal experiment,the optimal procedure has determined.Condensation procedure is:n(maleic anhydride):n(mixed alcohols)=1∶1,m(catalyst)∶m(reactants)= 2.0%,m(solvent)∶m(reactants)=40%,n(maleic anhydride)∶n(octadecyl amine)=1∶2.Polymerization procedure is:n(condensation products)∶n(vinyl acetate)=1∶1.5,m(initiator)∶m(polymeric monomer)=1.5%,m(solvent)∶m(polymeric monomer)=30%,polymerization temperature=75 ℃,polymerization time=4 h.The infrared analysis showed that the molecular functional group of the preparation product matches with the designing target product.SP of lubricating oil is lowered by 17 ℃ when the dosage of PPD is w(lubricating oil with PPD)=0.85% additive dosage.

Aimed at the nature of Panjin crude oil,apour point depressant and viscosity reducer-META-MA was successfully synthesized from methacrylic acid(ME)-tetradecyl alcohol(TA)-maleic anhydride(MA).Through the single factor experiments,the optimal conditions for preparing ME-TAMA are obtained:For esterification reaction:the molar ratio of methacrylic acid to tetradecyl alcohol is 1∶1.25,with catalyst(p-toluenesulfonic acid)of 2.0% and solvent(toluene)50%;For polymerization reaction:the molar ratio of tetradecyl methyl-acrylate to maleic anhydride of 1∶1,with initiator(BPO)of 1.5% and solvent(toluene)of 50wt%,and polymerization time is 3h,polymerization temperature of 80℃.The infrared analysis showed that the molecular functional group of the prepared products matches with the designed target products(copolymer of tetradecyl methyl-acrylate and maleic anhydride).Solidifying point can be lowered by 13℃ and viscosity lowered by 63.33% when 0.23% of the pour point depressant and viscosity reducer(ME-TA-MA)was added in the Panjin crude oil.

The copolymer maleic anhydride mixed alcohols ester-styrene(PMST) was synthetized from the raw materials of maleic anhydride,mixed alcohols and styrene.The reaction conditions were investigated and the pour point depressing effect was tested.The suitable esterification conditions are:molar ratio of mixed alcohols to maleic anhydride is 2:1,esterification time is 3 h,amount of catalyst is 1.5%,amount of esterification solvent is 20%;and the suitable polymerization conditions are:molar ratio of styrene to maleic anhydride mixed alcohols is 1:1,amount of polymerization solvent is 50%,polymerization temperature is 80 ℃,amount of initiator is 1.5%,polymerization time is 3 h.IR and 1HNMR spectra were used to confirm the structure of the products.When the addition dose of PMST is 0.4%(based on the mass of wax oil),and the heat treatment temperature is 70 ℃,PMST can make the pour point of wax oil used for experiment decrease by 26 ℃,which empowers the high freezing point wax oil to have an ideal fluidity at room temperature or even at lower temperature.

Using maleic anhydride, styrene and hexadecanol as raw materials, the diesel flow improver maleic anhydride-styrene-1-hexadecanol ester (SMAH) was synthesized via “first polymerization and then esterification”. Though orthogonal experiments, the best preparing conditions were determined as follows:during the polymerization, n(maleicanhydride)/n(styrene)=1:0.5, w(initiator)=1.5%, polymerizationtimet=4h, polymerization temperature T=85℃ ,w(xylene)=156%; During the esterification, n(maleicanhydride-styrene)/n(1-hexadecanol)=1:1.5,w(p-toluene sulphonic acid)=1.5%,esterification time t=3 h. The infrared analysis shows that the molecular functional group of prepared products matches with the target products. CFPP of the diesel oil can be most lowered by 10 ℃ when the dosage of the diesel flow improver is 0.42%in the diesel oil. The wax crystal was analyzed by XRD and polarizing microscope. The result shows that both structure and morphology of wax crystal have changed.

Through a successive procedure of polymerization and esterification,a new lubrication oil pour point depressant,the polymer of fumaric acid mixed with higher alcohols ester-vinyl acetate(PPFVA),was synthesized with fumaric acid,vinyl acetate and mixed higher alcohols as raw materials.Through single factor and orthogonal experiments,the optimum polymerization conditions for preparing PPFVA were ascertained as follows:n(fumaric acid)∶n(vinyl acetate)=1∶0.75,w(BPO)=1.5%,polymerization time 3.5 h,polymerization temperature 70 ℃,w(toluene)=55%,while the optimum conditions for esterification were as follows,n(fumaric acid-vinyl acetate polymer)∶n(mixed higher alcohols)=1∶2,w(p-toluenesulfonic acid)=1.5%,w(toluene)=50%.The infrared analysis shows that the molecular functional group of the prepared products matches with that of the designed target products.When the dosage of the pour point depressant was 1.16%(mass fraction) in the lubrication oil,△SP of the lubrication oil could be lowered by 17 ℃ at best.

Using paraffin and boric acid as raw material for the first time,boric acid ester was synthesized by liquid phase oxidation,and the high-carbon alcohol was obtained by hydrolysis reaction of sodium hydroxide with the prepared boric acid ester.Then,infrared quantitative principle was used to analyse it.The optimum preparation conditions: The mole ratio of paraffin and boric acid was 1 to 4,the oxidation time was 6 h,the oxidation temperature was 170 ℃,the hydrolysis temperature was 80 ℃,the hydrolysis time was 1 h.The yield was about 12.7%.

Throughout Chinese history,there are always two economic elements in rural areas:one is the sea of self-sufficient small-scale peasants,the other is the landowner who relies on the advantages of their social,political,and economic status to possess extraordinary amount of land.Thus,the landowners can have the power of controlling labor,using the exploitative way to do production and management.The modes of landowner's operation can be summed up as follows:using serves,using employees or renting their land to tenant farmers.The extensive operation of tenancy in China after Song dynasty was a historical choice.Tenancy has been stimulating the transference of land ownership,and it's still an active mode in China's agricultural economy.