不同分子量聚酯的羟值分析方法

用醋酐／高氯酸／乙酸乙酯法，醋酐吡啶回流法，分别对相对分子质量为１１００－１２０００的聚酯进行了羟值的测定，并用气压渗透法和析出物溶解重滴法进行了核对。结果表明醋酐／高氯酸／乙酸乙酯法对于Ｍ〈５０００的聚酯是适用的，而高分子量的聚酯则必须用醋酐／吡啶回流法，才能获得满意的结果。     

关于醋酐—吡啶法测定羟值的探讨与改进

目前,有关羟值分析的方法有高氯酸法、苯基异氰酸酯法、醋酐—吡啶法和红外光谱法等。较为常用的为醋酐—吡啶法,其优点是快速、准确和操作简单,易于掌握。根据多年的实践,笔者对醋酐—吡啶法进行了探讨,并提出改进的醋酐—吡啶法。问题的提出羟值分析的基本原理是试剂能和试样中的羟基,在规定分析条件下快速定量地反应。试剂中未反应的官能团可通过适当的化学方法测定出来,由此计算出样品中的羟值。醋酐—吡啶法的反应为:     

聚烷基酚聚氧乙烯醚型表面活性剂的表面性能分析

合成了一系列不同聚合度的聚烷基酚聚氧乙烯醚(HHL)型非离子表面活性剂。通过红外光谱,核磁共振等仪器对其结构进行表征,用表面张力法对不同聚合度的合成产物的表面性能进行研究,并对不同聚合度的表面活性剂的物理化学参数进行理论分析。结果表明:三聚烷基酚聚氧乙烯醚型非离子表面活性剂较相应单体的烷基酚聚氧乙烯醚表面活性剂,表面活性和吸附能力有较大的提升。     

席夫碱配合物在表面活性剂胶束中对过氧化氢分解的催化作用

合成了水杨醛缩牛磺酸席夫碱合铜配合物,研究了该配合物分别在阴离子表面活性剂十二烷基苯磺酸钠(SDBS)、阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和非离子表面活性剂辛基酚聚氧乙烯醚(OP-10)的胶束中对H2O2分解的催化性能,探讨了pH、过氧化氢浓度对催化性能的影响。结果表明:该配合物在阳离子胶束中对H2O2的分解具有快速催化作用,其催化速率远远高于铜离子本身的催化速率,而且在碱性介质中催化速率明显提高;非离子和阴离子表面活性剂胶束对配合物的催化有禁阻作用。     

羟值法测定脂肪醇聚氧乙烯醚的分子量

通过测定羟值的方法对非离子表面活性剂脂肪醇聚氧乙烯醚的分子量进行了测定，并对该方法的精密度和精确度进行了分析。     

松香聚氧乙烯醚非离子表面活性剂的合成

以松香和环氧乙烷为主要原料合成松香聚氧乙烯醚非离子表面活性剂,通过羟值的分析,探讨不同催化剂、反应温度、压力对环氧乙烷加成数及断链的影响。     

Mannich反应合成壬基酚聚氧乙烯醚Gemini表面活性剂

以壬基酚、无水哌嗪、多聚甲醛为原料经Mannich反应合成N,N’-二(2-羟基-5-壬基苯甲基)哌嗪中间体,再经过环氧乙烷加成合成了系列壬基酚聚氧乙烯醚型Gemini非离子表面活性剂Bis(NP)。用核磁波谱、红外光谱对其分子结构进行了表征,探讨了反应温度、溶剂用量、反应时间对Mannich反应产率的影响,并用表面张力法和稳态荧光探针法对Bis(NP)的表面性能进行了研究。结果表明:Bis(NP)的临界胶束浓度(CMC)值较相应的单体壬基酚聚氧乙烯醚型非离子表面活性剂(NP)降低了2～7倍,显示出较高的表面活性。     

期刊文献

聚氧乙烯醚型表面活性剂的合成及表面性质黄海龙,李红玉,张雷,任天瑞摘要:合成了一系列不同聚合度的聚壬基酚聚氧乙烯醚型非离子表面活性剂,通过红外光谱和核磁共振等手段对其结构进行表征,用表面张力法对合成产物的表面性能进行研究。结果表明,随着表面活性剂分子中亲水基团环氧乙烷(EO)片段的增加,单体、二聚体和三聚体的临界胶束浓度(cmc)值都逐渐增大,当EO数目相同时,单体、二聚体和三聚体的cmc值依次明显降低。二聚体与三聚体都显示出很好的表面性质,其中三聚体的     

硫酸氢钠催化合成阿司匹林的研究

用一水硫酸氢钠为催化剂由水杨酸与乙酐酯化合成阿司匹林。研究了酯化反应的优化条件 ,结果表明 :硫酸氢钠与浓硫酸催化合成阿司匹林的催化效果相当 ,但操作安全 ,极少有碳酸氢钠的不溶副产物产生 ,产品呈纯白结晶 ,且硫酸氢钠难溶于有机溶剂 ,易于分离回收 ,可重复使用     

聚氧乙烯醚型非离子表面活性剂的乳化性能的比较研究

以环氧乙烷加成数接近9的烷基醇聚氧乙烯醚为研究对象,比较性研究了壬基环己醇聚氧乙烯醚(9)、壬基酚聚氧乙烯醚(10)、异构十三醇聚氧乙烯醚(9)、仲醇聚氧乙烯醚(9)以及十二醇聚氧乙烯醚(9)五种非离子表面活性剂对几种日用化学品用油及其混合物的乳化力。实验结果表明,支链化疏水基更有利于非离子表面活性剂对油的乳化,壬基环己醇聚氧乙烯醚(9)具备替代壬基酚聚氧乙烯醚(10)在日用化学品中应用的潜力。     

Enzymatic preparation of polyethylene glycol esters of castor oil fatty acids and their surface-active properties

This study concerns the preparation and evaluation of nonionic surfactants prepared from polyethylene glycol (PEG) esters of castor oil fatty acid, a source of hydroxy fatty acid. A lipase-catalyzed esterification reaction has been employed to prepare PEG esters of hydroxy acid to overcome problems associated with chemical processes. Castor oil fatty acid (85% ricinoleic acid) was mixed with PEG of different molecular weight. Rhizomucor miehei lipase was added as catalyst (10% level) and the reaction was continued at 60°C under 2 mm Hg pressure for 360 min. Conversion of PEG to esters was in the range of 86–94%, depending on the molecular size of PEG. The products were isolated and examined for surface activity by surface tension measurement. Surface tension values measured at 25°C were about 36–37 dynes/cm.     

介孔SiO2负载SO4^2-／ZrO2固体超强酸催化剂的制备及其酯化催化活性研究

以稻壳SiO2为原料,非离子表面活性剂TX-100为模板,制备了介孔SiO2(MSU-2)及其负载SO42-/ZrO2固体超强酸催化剂。以乙酸和正丁醇的酯化反应为探针,研究了载体类型、ZrO2的负载量、催化剂用量和反应时间对催化剂性能的影响。结果发现,当SO42-/ZrO2的负载量在10wt%以上时,催化剂具有超强酸性;SO42-/ZrO2负载量为20wt%时,催化剂(SO42-/ZrO2/MS-60)具有最优的催化酯化反应活性。     

Alkyd emulsions

Various aspects of alkyd emulsion technology have been investigated. The influence of alkyd oil length, acid value and hydroxyl number and type of surfactant used as emulsifier, on shear stability of alkyds emulsions have been studied. It was found that the acid value was the most important alkyd parameter, the stability increasing with increasing oil length. It is also shown that anionic surfactants give emulsions with small droplet sizes at lower concentrations than do nonionics. Polymerizable nonionic surfactants have been tested as emulsifiers and compared with conventional surfactants of the same hydrophilic lipophilic balance (HLB). It was found that surfactants capable of participating in the autoridative curing process give faster drying and improved film hardness compared with nonreactive surfactants. The distribution of driers between the alkyd phase and the water phase has been investigated. It was found that low pH and the use of hydrophilic anionic surfactants, such as sodium dodecyl sulphate, favour partitioning of cobalt into the aqueous phase which is unfavourable with respect to drying properties.     

水基金属除油清洗剂的复配与应用

通过对几种非离子和阴离子表面活性剂的除油效果比较,筛选出了适用于金属除油的表面活性剂：壬基酚聚氧乙烯醚（TX-10）、脂肪醇聚氧乙烯醚（MOA-5）、脂肪酸甲酯乙氧基化物磺酸盐（FMES）、十二烷基苯磺酸（LAB）。通过正交实验,确定了4种表面活性剂之间最佳协同增效配比为m（TX-10）：m（MOA-5）：m（FMES）：m（LAB）=4：1：3：1。将该配比的除油剂用于金属表面除油,最佳的除油温度为50℃-60℃,除油时间控制在5min。     

Making homogeneous and fine droplet O/W emulsions using nonionic surfactants

In many emulsion systems, creaming occurs during the first stage of emulsion breakdown. To reduce the rate of creaming, emulsions having small and uniform droplets are desirable. In this work, types and HLB of nonionic surfactants, emulsification methods, and combinations of oils and nonionic surfactants were investigated in order to make stable and homogeneous emulsions. Emulsification was attained by dissolving the surfactants in the oil phases. The addition speed and volume of water to the oil phases were important factors affecting the emulsion droplet size. The change of the solute state in the process of emulsification was observed stage by stage, and the mechanism of emulsification was elucidated. Homogeneous emulsions were formed in the HLB region, showing liquid crystalline and gel phases in the emulsifying process. The addition speed of water to the oil phase was very important in forming the liquid crystalline and gel phases. Polyoxyethylene(n)sorbitan monostearate could emulsify three kinds of oils (hydrocarbon, fatty acid ester and triglyceride). Polyoxyethylene(n)alkyl ether could emulsify hydrocarbon and fatty acid ester. Polyoxyethylene(n)-monostearate could emulsify only hydrocarbon. Surfactants with proper HLB which were soluble in the oil phase and in the presence of a very small amount of water formed a stable emulsion. The solubility state of oil and surfactant was the key to making a fine emulsion.     

Utilization of acid oils in making surface-active compounds by lipase-catalyzed hydrolysis and esterification reactions

Nonionic surface-active molecules were made from acid oils such as mustard, sunflower, rice bran, soybean, coconut, and polyethylene glycols (PEG) of varying molecular weights (200, 300, 400, 600), using processes based on lipasecatalyzed hydrolysis with Candida cylindracea lipase and esterification with Mucor miehei lipase. Both the PEG molecular weight and the acid oil influence the yield of ester. Molar concentration of reatants also influences the rate and yield of ester. Surface tension values of ester products reveal that maximal lowering of surface tension of water occurs in the case of PEG 600 and coconut acid oil ester. This work demonstrates an important technological advance in the synthesis of nonionic surfactants of the alkyl ethoxylate type from a variety of acid seed oils in high yields by using lipase technology involving first hydrolysis and then esterification with another lipase.     

自动电位滴定在大分子量聚酯多元醇羟值测定中的应用

在目前通用的乙酸酐-吡啶法测羟值的基础上,针对低羟值聚酯多元醇建立了准确度更高的分析方法,并采用自动电位滴定法测定聚酯多元醇的羟值。测试结果表明,该法提高了测试的准确度,并可解决深色和浑浊样品无法手动滴定的问题。     

不需预保护羟基的侧链亲水非离子水性聚氨酯的制备与性能

以酒石酸与聚乙二醇单甲醚(MPEG)为原料,在不需预保护酒石酸中羟基的情况下,经过酯化反应合成了酒石酸聚乙二醇单甲醚酯(TMPEG),以其为亲水单体通过预聚体法制备了一系列非离子型水性聚氨酯(TWPU)。通过1HNMR、FTIR、TGA、拉伸测试对TMPEG和TWPU进行了结构表征与性能测试。考察了亲水单体TMPEG质量分数对TWPU贮存稳定性、力学性能、吸水率的影响。结果表明：当TMPEG质量分数为24%（以TMPEG、聚己二酸-1,4-丁二醇酯二醇、异佛尔酮二异氰酸酯、三羟甲基丙烷、乙二胺反应合成的预聚体的总质量为基准,下同）时,TWPU乳液平均粒径为85nm,TWPU胶膜接触角为84°,拉伸强度为7.9MPa,断裂伸长率为768%。     

Application of Oil/Water Nanoemulsions as a New Alternative to Demulsify Crude Oil

Oil-in-water nanoemulsions were developed and evaluated for effectiveness in breaking down crude oil emulsions. The nanoemulsions were prepared using two types of ethoxylated nonionic surfactants: nonylphenol and lauryl ether, at a concentration of 12 wt%, and the solvent xylene as the oil phase, at different concentrations (5, 7, and 10 wt%). The results of the demulsification tests showed that the nanoemulsions developed are a viable alternative to break down petroleum emulsions, with efficiency ranging from 90 to 95%. Also, the greater the xylene concentration in the nanoemulsion, the faster the demulsification process was.     

Preparation of Comb-Like Amphiphilic Styrene Maleic Anhydride Copolymer Derivatives and Their Modification to Surface of Chrome-Tanned Collagen Fiber

A series of comb-like amphiphilic surfactants of sodium salts of fatty alcohol polyoxyvinethene monoester, i.e., SMA-g-O-3, SMA-g-O-6, SMA-g-O-10, SMA-g-O-15 and SMA-g-O-20, were prepared through the esterification modification to styrene-maleic anhydride copolymer (SMA) using fatty alcohol polyoxyethylene ether in dimethylformamide(DMF). The products of esterification modification were characterized by FTIR and GPC analysis, and the esterification reaction rate was calculated by measuring the acid values of SMA and its esterification product. Then, sodium salts of those esterification substances were applied to the leather retaining and fatliquoring process to study their effects on hydrophobicity of the treated leather fiber, such as static Water Contact Angle (WCA) on the leather surface and water absorption of the treated leather. Results showed that all the esterification rates were more than 90 %; moreover, both the WCA and water absorption of the processed chrome-tanned collagen fibers were related to the number of oxyethyl groups in the fatty alcohol polyoxyethylene ether. WCA decreases and water absorption increases instead with augmentation of the oxyethyl group number.