共查询到20条相似文献，搜索用时 375 毫秒
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介绍了丙烯酸树脂及改性DGN丙烯酸树脂的研制方法，通过可控下的多种单体的聚合得到的共聚物，具有优良的涂饰特性。 相似文献
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本文探讨了以环氧树脂和丙烯酸为原料的酯化反应,合成了紫外光固化的环氧丙烯酸树脂．通过研究催化剂的种类、加入量、聚合方式、加料方式和反应温度等因素对转化率的影响,得到了合成环氧丙烯酸树脂的较佳工艺条件。并用IR对环氧树脂与环氧丙烯酸树酯的结构进行了表征。 相似文献
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玉米淀粉接枝高吸水性树脂的合成研究 总被引：1，自引：0，他引：1
对影响淀粉—丙烯酸接枝共聚反应的引发剂用量、淀粉／单体比例、聚合温度和聚合时间等因素进行了实验考察，确定了合成玉米淀粉接枝高吸水性树脂的最佳工艺条件。合成了吸水率为400g．g^-1～600g．g^-1的高吸水性树脂．为其工业化生产提供了技术参数。 相似文献
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成志良 《南通职业大学学报》1995,(1)
高吸水树脂是一种新型功能高分子材料,由于它的高吸水性,在各个领域得到了应用.并且随着应用的开发,会对它的需求量愈来愈多.(?)丙烯酸为原料,可以通过乳液聚合工艺,也可通过悬浮聚合工艺获得高吸水树脂.但这些工艺中会遇到溶剂的回收,废水的排放等诸问题.本体聚合工艺可以避免这些缺点,且获得高吸水性能的树脂.本文就本体聚合过程中的工艺条件作些探讨.一、原料及投料量丙烯酸 工业级25g 吉林化工厂北京东方化工厂氢氧化钠(片碱)工业级 12g蒸馏水 适量 引发剂 25mg交联剂 15mg以此配方可获得900～950g/g的吸水性能. 相似文献
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为研究腐殖酸钠高吸水性树脂对小麦幼苗生长的影响,采用水溶液聚合法合成含腐殖酸钠的丙烯酸/丙烯酰胺高吸水性树脂,并通过正交试验筛选出最高吸水倍率的配方。利用小麦种子生物测定法测定了最高吸水倍率的含腐殖酸钠的吸水树脂对小麦芽长、根长和鲜质量的作用。方差分析表明：腐殖酸钠吸水性树脂对小麦鲜质量、芽长的影响显著高于对照,但根长均表现为不显著。说明腐殖酸钠吸水性树脂对小麦生长有一定的促进作用。 相似文献
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高岭土-聚乙烯醇高吸水性复合树脂的合成及性能研究 总被引：2，自引：0，他引：2
高吸水树脂属于新型功能高分子材料，其应用广泛．我国主要研究对象是淀粉接枝丙烯脂和丙烯酸盐系，聚乙烯醉(PVA)系高吸水树脂只有少数单位进行过研制．章采用悬浮聚合法，以顺丁烯二酸酐为交联剂，添加来源广泛、价格非常低廉的高岭土，制得了聚乙烯醇高吸水性复合树脂．该树脂的吸水倍率和吸盐水倍率分别为256和29倍．通过实验，讨论交联剂用量、高岭土添加量、水解程度等因素对吸水性能的影响．并对树脂吸水速率和保水性能进行实验． 相似文献
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采用量子化学中的密度泛函理论计算方法B3LYP/6-311++G(3df,3pd)对反应B rONO2+H2O=HNO3+HOB r进行了研究.研究发现该反应随着水团簇中分子数目的增加反应的势垒逐渐减小,当水分子数为2时,该反应已经是一个快反应了.计算结果表明在冰表面上在平流层条件下标题反应是通过结构催化和水催化进行反应的.其反应条件即使在南极的夏季和北极极低的温度下也极易满足.研究结果与现阶段已有的实地观察和实验结果相一致. 相似文献
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Reaction thrust of water jet for conical nozzles 总被引：1，自引：0，他引：1
Clear knowledge on the reaction thrust of water jet is valuable for better design of water jet propulsion system. In
this paper, theoretical, numerical and experimental studies were carried out to investigate the effects of the nozzle geometry
as well as the inlet conditions on the reaction thrust of water jet. Comparison analyses reveal that the reaction thrust has a
direct proportional relationship with the product of the inlet pressure, the square of flow rate and two-thirds power exponent
of the input power. The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence
on the reaction thrust characteristics. In addition, the best values of the half cone angle and the cylinder column length exist
to make the reaction thrust reach its maximum under the same inlet conditions． 相似文献
this paper, theoretical, numerical and experimental studies were carried out to investigate the effects of the nozzle geometry
as well as the inlet conditions on the reaction thrust of water jet. Comparison analyses reveal that the reaction thrust has a
direct proportional relationship with the product of the inlet pressure, the square of flow rate and two-thirds power exponent
of the input power. The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence
on the reaction thrust characteristics. In addition, the best values of the half cone angle and the cylinder column length exist
to make the reaction thrust reach its maximum under the same inlet conditions． 相似文献
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用脂肪酶在四氢呋喃中催化合成硬脂酸酯.研究了反应温度、时间、加水量、加酶量、不同的醇以及原料摩尔比对硬脂酸转化率的影响.最佳反应条件为:反应温度35℃,硬脂酸与乙醇的摩尔比为1∶1.3,加水量为0.4%,加酶量为600μg/g硬脂酸,反应时间24 h,硬脂酸转化率达72.4%. 相似文献
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水体富营养化的生物学防治 总被引：1，自引：0，他引：1
从生物学角度，提出利用生物硝化-反硝化、天然水体中种植水生植物、污水灌溉及氧化塘等生物学方法，达到去除水体中氮、磷等物质的目的，避免水体富营养化的发生。 相似文献
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The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. The simulation of the flow field characteristics was conducted via the FLUENT computational fluid dynamics package. Effects of the inlet conditions and the nozzle dimensions on the reaction thrust of a water jet were addressed particularly. The reaction thrust experiments were performed on a custom-designed test apparatus. The experimental results reveal that a） the nozzle diameter and the inlet conditions exert great influence on the water jet reaction thrust; and b） for L≤4d0, where the nozzle is treated as a thin plate-orifice, the reaction thrust is independent of nozzle length; for L〉4d0, where the nozzle is treated as a long orifice, the reaction thrust can reach maximum under the condition of a certain flow rate. These findings lay a theoretical foundation for the design of nozzles and have significant value, especially for the future development of high-oressure water-let orooulsion technology. 相似文献
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以5-磺基水杨酸为原料、碘化钾为碘化剂,以双氧水为活化剂,以乙醇—水溶液为溶剂,合成5-磺酸基-3-碘水杨酸。最佳反应条件为:乙醇—水体积比为1:3,氧化剂与原料摩尔比为2:1,反应时间6 h,反应温度70℃,5-磺酸基-3-碘水杨酸的最高产率可达到87.3%。 相似文献
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Water is the most abundant compound inherently existing in bio-oils. Thus understanding the role of water within bio-oils upgrading process is essential for future engineering scale-up design. In this study, furfural was chosen as bio-oils model compound, and the catalytic hydrogenation of furfural over commercial 5%, Ru/C catalyst was firstly investigated in a series of gradient variable water/ethanol mixture solvents. Water had a significant effect on the distribution of product yields. The dominant reaction pathways varied with the water contents in the water/ethanol mixture solvents. Typically, when ethanol was used as the solvent, the main products were obtained by the hydrogenation of carbonyl group or furan ring. When pure water was used as the solvent, the rearrangement reaction of furfural to cyclopentanone should be selectively promoted theoretically. However, serious polymerization and resinification were observed herein in catalytic hydrogenation system of pure water. The catalyst surface was modified by the water-insoluble polymers, and consequently, a relative low yield of cyclopentanone was obtained. A plausible multiple competitive reaction mechanism between polymerization reaction and the hydrogenation of furfural was suggested in this study. Characterizations(TG,FT-IR,SEM)were employed to analyze and explain our experiments. 相似文献
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用维生素C作催化剂,环己烷作带水剂,以草酸与正丁醇为原料合成了草酸二丁酯;考察了醇酸摩尔比、催化剂用量、带水剂用量、反应时间对草酸二丁酯收率的影响。结果表明,维生素C有着良好的催化活性,在草酸用量0.1 mol,醇酸摩尔比3.5∶1、催化剂用量为反应物总质量3.0%、环己烷用量32mL条件下回流反应40 min,草酸二丁酯收率可达94.8%。 相似文献
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在乙醇／水混合溶液介质中，以偶氮二异丁腈为引发剂，用分散聚合方法制备了聚苯乙烯微球。研究了引发剂浓度、反应温度和单体浓度变化对PS微球粒径的影响，实验结果表明引发剂浓度增大、反应温度升高、单体浓度增大都会使导致PS微球粒径增大及粒径分布加宽。 相似文献
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童彬 《安徽教育学院学报》2007,25(6):57-59
研究了醇解液中水含量、KOH含量和反应温度、反应时间等参数对醇解度的影响。研究结果发现，水含量的控制是控制醇解的有效方法。体系中KOH含量高，醇解度增大，但碱量过大反而降低醇解度。 相似文献