聚天冬氨酸的合成制备研究

以马来酸酐为原料合成聚天冬氨酸,研究了合成聚天冬氨酸时铵盐的种类、马来酸酐与碳酸铵的比例、合成时间以及合成温度对目的产物聚天冬氨酸产率和分子量的影响。得出产率最高的合成工艺条件为:n(马来酸酐)∶n(碳酸氨)=1∶1.2,聚合温度为180℃,聚合时间为1.0 h。制备的聚天冬氨酸纯度高达90%以上,产率也在94%以上。所制备的聚天冬氨酸具有一定的缓蚀阻垢作用,可广泛应用于工业循环冷却水处理、油田水处理等领域。     

聚天冬氨酸阻垢剂的制备及性能评价

聚天冬氨酸具有较好的阻垢效果。采用热引发聚合,以马来酸酐、氯化铵为原料,制备了绿色阻垢剂聚天冬氨酸,通过正交实验确定了最佳合成条件,并对其进行了性能评价。最佳合成条件为:马来酸酐和氯化铵的摩尔比为1∶1.2,反应温度为140℃,反应时间为5h。     

环保型阻垢剂PESA的合成及阻硫酸盐垢性能研究

以马来酸酐为原料,钨酸钠为催化剂,双氧水为氧化剂,氢氧化钙为引发剂,采用溶液聚合法合成了聚环氧琥珀酸。研究了催化剂用量、环化pH、引发剂用量、聚合温度和聚合时间对PESA阻BaSO4垢性能的影响,并用原子吸收分光光度法对在最佳工艺条件下合成的产品进行了阻垢性能评价。结果表明,合成PESA的最佳工艺条件为马来酸酐9.8 g,催化剂用量0.33 g,环化pH为4,引发剂加量0.5 g,聚合温度82℃,聚合时间2 h。当PESA加量为8 mg/L时,对硫酸钡的阻垢率达98.0%;当PESA加量为40 mg/L时,对硫酸锶的阻垢率达90.4%。     

绿色阻垢剂CL-2的合成及性能评价

聚天冬氨酸是一种优良的阻垢剂。本实验以马来酸酐与氨水为原料通过化学反应合成聚天冬氨酸,通过正交试验优化得出最佳合成条件如下：n（氨水）∶n（马来酸酐）=1∶1,聚合温度180℃,聚合时间1 h。采用静态阻垢法来评定合成聚合物阻垢剂的阻垢性能,结果表明聚天冬氨酸对碳酸钙的阻垢效果良好,阻垢率达到80.24%。     

薄层法制备聚天冬氨酸及其阻垢性能研究

以马来酸酐和碳酸铵为原料,通过薄层聚合制备了聚天冬氨酸,研究了反应物配比、聚合时间及反应温度等因素对聚合物产率、相对分子质量的影响;考察了聚合物用量及相对分子质量对阻垢性能的影响.结果显示:碳酸铵和马来酸酐的化学计量数为1.2∶1、反应温度185℃、反应时间50～60 min时,产率可达88%,产物对硫酸钙和碳酸钙均具有良好的阻垢性能.     

油田用绿色阻垢剂聚天冬氨酸的合成及性能评价?

以马来酸酐和碳酸铵为原料,磷酸为催化剂,在一定温度条件下合成了聚天冬氨酸(PASA),并对其阻垢性能进行了评价。实验结果表明,产物的相对分子量受聚合时间与聚合温度的双重影响,当聚合温度为170℃,聚合时间为2小时,产物对碳酸钙具有最佳的阻垢性能。通过室内动态试验表明该产物可运用于油田二次采油中,为阻垢剂与缓蚀剂保护生产管线,也可作为降粘剂运用于钻进液与堵漏液中。     

用不同方法制备聚天冬氨酸的比较

通过以L-天冬氨酸为原料的热缩催化聚合、以马来酸酐和碳酸铵为原料的常规合成和微波幅照合成等不同方法制备了聚天冬氨酸。分别通过红外光谱技术和粘度法对产物进行了结构和分子量的表征,并研究了每种制备方法对产物的产率、分子量及其阻垢性能的影响。结果表明所有聚合产物均具有聚天冬氨酸的结构特征。虽然由L-天冬氨酸法制备的产物产率和分子量最高,但是由微波辐照合成所得产物的阻垢性能最佳。     

用不同方法制备聚天冬氨酸的比较

通过以 L-天冬氨酸为原料的热缩催化聚合、以马来酸酐和碳酸铵为原料的常规合成和微波幅照合成等不同方法制备了聚天冬氨酸.分别通过红外光谱技术和粘度法对产物进行了结构和分子量的表征,并研究了每种制备方法对产物的产率、分子量及其阻垢性能的影响.结果表明所有聚合产物均具有聚天冬氨酸的结构特征.虽然由L-天冬氨酸法制备的产物产率和分子量最高,但是由微波辐照合成所得产物的阻垢性能最佳.     

氨气法合成聚天冬氨酸的合成工艺研究

以液氨和马来酸酐为原料合成聚天冬氨酸,研究了马来酸酐与液氨的摩尔比、顺丁烯二酸铵盐合成温度和时间、聚合反应温度和时间以及水解pH等对聚丁二酰亚胺产率和聚天冬氨酸分子质量的影响。并用FTIR对合成的聚天冬氨酸的结构进行表征。结果表明,较佳的反应条件为:n(顺酐)∶n(液氨)=1∶1.2,顺丁烯二酸铵盐合成温度为85℃,反应时间为2 h,聚合反应温度为210℃,聚合反应时间为4 h,水解pH为9.0。在无催化剂条件下,聚丁二酰亚胺产率可高达95%以上,聚天冬氨酸重均分子质量高于7 500。     

三元共聚物防垢剂的合成与性能研究

以水为溶剂,过硫酸铵为引发剂,马来酸酐、乙酸乙烯酯和丙烯酸为原料,合成了三元共聚物防垢剂,并对其进行了性能评价。研究了三元共聚物的质量浓度、温度及体系pH值等条件对其防垢率的影响。结果表明,合成的马来酸酐/乙酸乙烯酯/丙烯酸三元共聚物防垢剂对碳酸钙的防垢效果较好。     

聚天冬氨酸的合成及性能研究

以马来酸酐和氨合成聚天冬氨酸(PASP),探讨了物料比、反应温度对PASP收率的影响,评价了PASP的水溶性、生物降解性和防垢性能。结果表明,在原料马来酸酐与氨的物质的量比为1.0∶1.2条件下,温度为200℃时,PASP的收率为95.22%,分子量22 000,水溶性好;在26~28℃条件下降解30 d后,3%浓度PASP溶液的相对粘度为1.013,有较好的生物降解性;当Ca2+为400 mg/L,Ba2+为200 mg/L,pH=7.0,50~60℃恒温8 h,PASP用量为15 mg/L时,对碳酸钙、硫酸钡、硫酸钙的阻垢率接近100%。     

多支化聚天冬氨酸衍生物的合成及其阻垢性能研究

先以顺酐和氨水等为原料合成聚天冬氨酸(PASP),再以PASP和赖氨酸为原料进行接枝反应得到改性聚天冬氨酸衍生物(Lys-PASP)。实验结果表明,与聚天冬氨酸相比,在聚天冬氨酸与赖氨酸质量比为10∶1,改性时间2 h,改性温度120℃条件下得到的改性产品Lys-PASP不仅对碳酸钙具有更好的阻垢性能,而且对碳钢表面也有更好的缓蚀效果,并对氧化铁也具有很好的分散效果;Lys-PASP的加入,不仅改变了碳酸钙的晶型,而且大大降低了碳酸钙晶体的完整程度和有序度,达到了阻止碳酸钙垢形成的目的,起到了阻垢缓蚀的效果。     

Microwave‐assisted synthesis of polyaspartic acid and its effect on calcium carbonate precipitate

Without organic solvent or catalyst, polyaspartic acid (PASP) was synthesized from maleic anhydride (MA) and ammonia (AN) under microwave irradiation. The influences of the molar ratio of maleic anhydride to ammonia and the microwave output power and irradiation time on product yield were investigated. Also, the function of microwave in the process was simply addressed. The results showed that when the molar ratio of MA/AN was 1.2, the output power was 900 W, the irradiation time was 3.5 min, and the product yield was highest and its inhibition performance on calcium carbonate was as good as the polymer synthesized by conventional pyrocondensation polymerization. The main function of microwave was its heat effect. Characterization of the product was carried out by IR, ¹HNMR, and ¹³CNMR spectra and the results showed that the product was PASP. The microwave‐assisted synthesis process of PASP has many advantages, including quicker reaction rate, high purity, lower cost, and little pollution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:358–364, 2007     

碳酸甲乙酯制备新工艺研究

介绍了碳酸甲乙酯的用途与合成方法。重点阐述了以离子交换树脂为催化剂,碳酸二甲酯与乙二酸二乙酯在一定温度下合成碳酸甲乙酯的反应原理和工艺方法,考察了物料比、反应温度、反应时间等工艺条件对产物收率的影响,确定一种收率高、制备过程简单的碳酸甲乙酯合成新工艺。结果表明,在该催化剂下合成碳酸甲乙酯的最佳工艺条件为:n(草酸二乙酯):n(碳酸二甲酯)的物质的量比是1∶2,反应时间是5h,反应温度是109℃。     

聚天冬氨酸与丙烯酸共聚物复配物阻垢性能研究

以马来酸酐和碳酸铵为原料采取固相熔融法合成聚天冬氨酸。为了降低水处理运行成本,研究了聚天冬氨酸与丙烯酸共聚物复配阻垢性能。说明聚天冬氨酸能部分取代目前常用的共聚物阻垢剂。     

聚天冬氨酸与磷（膦）系复配物阻垢性能研究

以马来酸酐和碳酸铵为原料采取固相熔融法合成聚天冬氨酸,为了降低水处理运行成本,并研究了聚天冬氮酸与磷（膦）系复配物阻垢性能。说明聚天冬氨酸能部分取代目前常用的磷（膦）系阻垢剂。     

Preparation a novel pH‐sensitive blend hydrogel based on polyaspartic acid and ethylcellulose for controlled release of naproxen sodium

Hydrogels based on pH‐sensitive polymers are of great interest as potential biomaterials for the controlled delivery of drug molecules. In this study, a novel, pH‐sensitive hydrogel was synthesized by poly(aspartic acid) (PASP) crosslinked with 1,6‐hexanediamine and reinforced with ethylcellulose (EC). The loading and release characteristics of naproxen sodium (NS) were studied. The PASP–EC blend hydrogels had pH‐sensitive characteristics and were strongly dependent on the pH value. The release kinetics for NS from the PASP–EC blend hydrogels and PASP hydrogel were evaluated in simulated gastric fluid (pH = 1.05) and simulated intestinal fluid (pH = 6.8) at 37°C. The results showed that the drug‐loaded hydrogels were resistant to simulated gastric fluid, and hence, they could be useful for oral drug delivery. Compared with the PASP hydrogel, the PASP–EC blend hydrogels showed a lower release rate of NS in the same pH conditions. It was evident that the presence of hydrophobic groups (EC) retarded the release of NS and led to sustained release. The kinetics of NS release from the drug‐loaded hydrogels conformed to the Korsmeyer–Peppas model. The release exponent of the model was 0.7291, which indicated multiple drug release. The PASP–EC blend hydrogels were biodegradable and pH sensitive; there would be a wide range of applications for them in controlled drug‐delivery systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

N-(2-(5-溴-1H-吲唑-1-基)苯基)-2-氯烟酰胺的合成工艺研究

采用单因素试验法对N-(2-(5-溴-1H-吲唑-1-基)苯基)-2-氯烟酰胺合成反应的反应条件进行了优化和研究,对关键步骤中间体I的合成确定了各个因素的最佳取值:反应时间为22h;物料配比应为5-溴吲唑:邻硝基氯苯:碳酸钾=1:0.85:1.15;反应温度为120℃;碱为碳酸铯。大大的提高了目标产物的总收率,为以后的大批量生产提供了有效途径。     

绿色水处理剂聚天冬氨酸的研究进展

根据采用原料的不同总结了制备聚天冬氨酸（polyaspartic acid，以下简称PASP）的不同路线及方法，介绍了PASP的结构和降解性能以及其阻垢性能和相对分子质量之间的关系。并且从微观角度阐述了PASP与水形沉积物碳酸钙、磷酸钙和硫酸钡之间的作用情况，从而解释了PASP对三种矿物质在水溶液中成核及结垢过程中的影响行为。最后提出了有待进一步研究的一些问题。     

Room temperature synthesis of PbSe quantum dots in aqueous solution: stabilization by interactions with ligands

An aqueous route of synthesis is described for rapid synthesis of lead selenide quantum dots (PbSe QDs) at room temperature in an attempt to produce water-soluble and stable nanocrystals. Several thiol-ligands, including thioglycolic acid (TGA), thioglycerol (TGC), 3-mercaptopropionic acid (MPA), 2-mercaptoethylamine hydrochloride (MEA), 6-mercaptohexanoic acid (MHA), and l-cysteine (l-cys), were used for capping/stabilization of PbSe QDs. The effects of the ligands on the stability of PbSe QDs were evaluated for a period of two months at room temperature under normal light conditions and at 4 °C in the dark. The TGA- and MEA-capped QDs exhibited the highest stability prior to purification, almost two months when kept in the dark at 4 °C. However, the stability of TGA-capped QDs was reduced substantially after purification to about 5 days under the same conditions, while MEA-capped QDs did not show any significant instability. The stabilization energies of Pb-thiolate complexes determined by theoretical DFT simulations supported the experimental results. The PbSe QDs capped with TGA, MPA and MEA were successfully purified and re-dispersed in water, while those stabilized with TGC, MHA and l-cys aggregated during purification attempts. The purified PbSe QDs possess very susceptible surface resulting in poor stability for about 30-45 min after re-dispersion in water. In the presence of an excess of free ligand, the stability increased up to 5 days for TGA-capped QDs at pH 7.19, 9-12 days for MPA-capped QDs at pH 7.3-7.5 and 45-47 days for MEA-capped QDs at pH 7.35. X-Ray diffraction (XRD) results showed that the QDs possess a cubic rock salt structure with the most intense peaks located at 2θ = 25.3° (200) and 2θ = 29.2° (100). TEM images showed that the size of the QDs ranges between 5 and 10 nm. ICP-MS results revealed that Pb?:?Se ratios were 1.26, 1.28, 3.85, 1.18, and 1.31 for the QDs capped with TGA, MPA, MEA, l-cys, and TGC, respectively. The proposed method is inexpensive, simple and utilizes environmentally friendly chemicals and solvents.