HDI缩二脲多异氰酸酯的合成

引　言ＨＤＩ缩二脲是指用ＨＤＩ(六亚甲基二异氰酸酯 ,ＮＣＯ— (ＣＨ2 ) 6—ＮＣＯ)和另一组分合成的具有缩二脲结构 (ＮＣＯ—ＮＨ—ＣＯ—ＮＨ— )的多异氰酸酯预聚物 ,属于脂肪族聚氨酯涂料广泛使用的固化剂之一 .脂肪族聚氨酯涂料因其具有其他类涂料无可比拟的耐候性和高装饰性 ,近年来在飞机蒙皮漆、汽车面漆、建筑外墙涂料等方面的应用越来越广泛 ,需求量逐步增加[1] .其中最广泛使用的固化剂是ＨＤＩ缩二脲多异氰酸酯 .生产该化合物的过程中 ,ＨＤＩ与水反应合成缩二脲反应体系的副反应非常多 ,产物组成很复杂 .如何控制反应过程 ,…     

端羟基聚丁二烯官能度及分布的测定

用凝胶渗透色谱法（GPC）测定端羟基聚丁二烯（HTPB）官能度分布。将HTPB用3,5-二硝基苯甲酰氯在一定条件下进行衍生化反应,衍生化后的HTPB经GPC的示差／紫外（RI／UV）双检测器进行检测,所得的色谱图经数据处理,得到HTPB的官能度及其分布。     

HDI缩二脲聚氨酯固化剂合成与残余HDI的分离

采用喷雾法合成了HDI缩二脲,采用短程蒸馏脱除残留在HDI缩二脲中的游离HDI单体,成功地制得了颜色浅、黏度低的HDI缩二脲多异氰酸酯样品,测i式样品的黏度56 s、-NCO含量21.4%,HDI残留量0.4%.探讨了反应合成机理,反应温度最好不低于90℃、不高于140℃;n(HDI):n(H2O)的值越大,合成的产物越趋于理想产物.     

超临界二氧化碳下以六亚甲基二异氰酸酯改性芳纶

借助超临界二氧化碳的溶胀及携带性能,将六亚甲基二异氰酸酯(HD)I携带进入芳纶中,并对纤维进行改性,利用力学性能测试、红外光谱、扫描电镜、X-射线光电子能谱方法测试了纤维的力学性能以及纤维与基体树脂的界面黏附性能,观察了纤维的表面形貌,分析了纤维表面的元素分布等。结果表明:经改性的纤维强度及模量均有提高;纤维表面变得粗糙,N元素含量明显增加,极性基团增加;复合材料界面剪切强力明显增加,表明纤维更适合用作复合增强材料。     

HDI的制备

综述了六亚甲基二异氰酸酯（HDI）的制备方法,主要有光气化法和热分解法。对光气化法若干工艺因素加以讨论。     

超声条件下二异氰酸酯桥联改性β-环糊精

二异氰酸酯在超声条件下对β-环糊精（β-CD）进行改性,制得改性环糊精的交联聚合物。用正交试验法,以交联聚合物产率为评价指标,筛选二异氰酸酯改性环糊精主要影响因素和最佳合成工艺条件：n(异氰酸酯)∶n(β-CD) 的摩尔比约为1∶9;二异氰酸酯选用六亚甲基而异氰酸酯（HDI）,超声声强0.1 W/cm²,反应温度60℃,反应时间7 h。用红外光谱（IR）、扫描电镜（SEM）、热重分析（TG）等检测方法对交联产物进行表征。结果表明：改性后的β-CD保留了其原有的空腔结构,环糊精与二异氰酸酯反应生成了氨基甲酸酯基键,交联后的聚合物形成了具有网络的形貌;超声条件下合成环糊精聚合物可以降低反应温度、缩短反应时间,交联聚合物形成了微球状表面和多孔的空腔结构。     

IPDI/HDI型水性聚氨酯分散体的合成及性能研究

以脂肪族异氰酸酯[异佛尔酮二异氰酸酯(IPDI)、六次甲基二异氰酸酯(HDI)]、聚醚(N-220)为主要原料,通过丙酮法合成了水性聚氨酯(WPU)分散体。探讨了n(IPDI中-NCO):n(HDI中-NCO)比例、后扩链剂用量和交联度等对WPU胶膜力学性能和耐溶剂(水和乙醇)性能的影响。结果表明:随着n(IPDI中-NCO):n(HDI中-NCO)比例的增加,WPU胶膜的拉伸强度提高,断裂伸长率、耐水性和耐乙醇性均下降;当n(IPDI中-NCO):n(HDI中-NCO)=0.25:1时,WPU胶膜的吸水率只有6%;随着后扩链剂用量或交联度的增加,WPU胶膜的拉伸强度提高、断裂伸长率下降。     

食品包装用聚丙烯树脂分子量及分布不确定度评定

依据ISO 16014:2012,采用高温三检测器凝胶色谱仪对食品包装用聚丙烯树脂分子量及分布进行测定,并对不确定度进行了研究。建立了数学模型,对检验过程中涉及的参数进行了详细分析,并对分子量及分布不确定度各个参数进行了评定,计算了分子量及分布的合成不确定度与扩展不确定度,分析了不确定度的来源和解决办法。     

不同官能度水性聚氨酯丙烯酸酯的合成及性能

以丙烯酸羟乙酯与季戊四醇三丙烯酸酯作为封端剂,分别合成了二官能度水性聚氨酯丙烯酸酯(WPUA2)和六官能度的水性聚氨酯丙烯酸酯(WPUA6),并用红外光谱、粒径仪、热重分析对合成产物结构和性能进行表征。研究表明,相比于使用低官能度WPUA2紫外光固化所得聚氨酯丙烯酸酯(PUA)涂膜,加入单体或使用多官能度WPUA6,都可使PUA固化膜凝胶率提高20%以上,吸水率降低30%;质量损失10%,分解温度增大82℃。提高预聚物官能度可有效提高涂膜交联密度和耐热性能,并具有与加入活性单体相似的应用效果。     

肺炎链球菌多糖结合物中游离蛋白含量测定方法的建立

目的建立肺炎链球菌多糖结合物中游离蛋白含量的测定方法。方法采用Lowry法与凝胶色谱法相结合的方法检测结合物中游离蛋白浓度,再计算出结合物中游离蛋白含量,并对建立的方法进行准确性和精密性验证。结果采用本方法测定3个浓度肺炎链球菌多糖结合物中游离蛋白含量的平均回收率分别为98.6%、98.5%和97.0%;检测同一批肺炎链球菌多糖结合物的试验间变异系数CV值为3.0%。结论该方法简便、易行,准确性和精密性较好,可准确检测出肺炎链球菌多糖结合物中游离蛋白的含量。     

Derivatization of carboxyl‐terminated polybutadiene for determining relative functionality distribution

A new and highly efficient method for determining relative carboxyl group distribution in carboxyl‐terminated polybutadiene has been developed using practical synthetic and analytical techniques. Using oxalyl chloride, samples of carboxyl‐terminated polybutadiene were rapidly transformed to acid chlorides that were then chemically derivatized with benzyl alcohol, 4‐nitrobenzyl alcohol, and 3,5‐dinitrobenzyl alcohol. This provided quick and quantitative conversion to the corresponding benzyl ester derivatives. Each new derivative was fully characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. The benzyl ester modified polymers were investigated in detail to determine their relative carboxyl group concentrations. To do this, gel permeation chromatography combined with ultra violet/refractive index dual detection was employed. The 4‐nitrobenzyl ester, having the highest extinction factor at 270 nm provided the best UV data for analysis. The ultra violet/refractive index data of four separate polymer samples were plotted as a function of molecular weight. The data were compared with a theoretical plot (carboxyl group = two for all molecular weights) to illustrate the relative carboxyl concentration over the entire molecular weight range. Supplemental characterization of the 4‐nitrobenzyl modified polymer was carried out using matrix‐assisted laser desorption ionization coupled with time of flight mass spectrometry. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Peanut protein and product functionality

Interest in the potential of peanut seed as a source of edible vegetable protein products has been stimulated by an increase in our understanding of protein physicochemical properties, improved protein extraction, fractionation and characterization techniques, advanced technologies to produce high quality and diverse protein ingredients and understanding the interrelationship between physicochemical, functional and nutritional characteristics of protein products. Further expansion in the processing and utilization of peanut products may be constrained by economic conditions rather than by limitations in functionality, nutritional quality, or consumer acceptability. Should changes occur to improve the competitive position of peanuts, the potential contributions of their protein products may be more fully realized. Presented at the 78th Amercican Oil Chemists' Society Annual Meeting, May 17–21, 1987, New Orleans, LA. Mention of specific products/companies is for convenience, and does not constitute and endorsement by the U.S. Department of Agriculture, over other products/companies not mentioned.     

A modified method for determining free fatty acids from small soybean oil sample sizes

A modification of the AOCS Official Method Ca 5a-40 for determination of free fatty acids (FFA) in 0.3 to 6.0-g samples of refined and crude soybean oil is described. The modified method uses only about 10% of the weight of oil sample, alcohol volume, and alkali strength recommended in the Official Method. Standard solutions of refined and crude soybean oil with FFA concentrations between 0.01 and 75% were prepared by adding known weights of oleic acid. The FFA concentrations, determined from small sample sizes with the modified method, were compared with FFA percentages determined from larger sample sizes with the Official Method. Relationships among determinations obtained by the modified and official methods, for both refined and crude oils, were described by linear functions. The relationship for refined soybean oil had an R ² value of 0.997 and a slope of 0.99±0.031. The values for crude soybean oil are defined by a line with R ²=0.9996 and a slope of 1.01±0.013.     

油砂油泥含油率测定方法研究

以中国内蒙扎赉特旗油砂为例,利用有机溶剂抽提的方法测定油砂含油率,并通过实验及抽提溶剂的性质等确定了最佳实验操作条件.实验结果表明:选用120#溶剂油为抽提试剂,在抽提温度为115℃、抽提时间为3.5 h的条件下,可有效的把油砂油从油砂中抽提出来,从而根据重量法测得油砂油含率.该方法同时可适用于对油泥油含率的测定.     

An improvement in the method of determining the free caustic soda content of viscose

Conclusions In the accelerated method of determining the free alkali content of viscose, the operations of separating the cellulose xanthate and of oxidizing the sulfur-containing impurities with potassium ferricyanide are eliminated.Results from determinations by the accelerated method essentially coincide with the data obtained by calculation.Translated from Khimicheskie Volokna, No. 4, p. 59, July–August, 1983.     

Assessment of simple methods of determining the free chloride ion content of cement paste

A range of possible techniques for assessing the “free” chloride ion content of hydrated cement pastes dosed with sodium chloride or calcium chloride have been investigated. The techniques are based on mixing powdered samples with a solvent and measuring the amount of chloride passing into solution. The values obtained have been compared with the chloride ion content of pore solution expressed from parallel specimens. The results indicate that in the range of chloride additions considered several extraction techniques may be used to estimate the free chloride ion content of cement paste; the total chloride content will dictate the most appropriate extraction technique(s) to adopt.     

Instrument for determining gel-particle content of polycaproamide

Conclusions A semiautomatic unit for determining gel-particle content in a solution of polycaprolactam has been fabricated and operated, based on the use of an LG209 helium-neon laser; it has increased sensitivity.It has been shown that even extended solid-phase final polycondensation of polycaproamide does not lead to a considerable increase in its gel-particle content.Translated from Khimicheskie Volokna, No. 5, pp. 57–58, September–October, 1988.     

粉煤灰中fCaO和Ca(OH)2的检测方法

ｆＣａＯ含量测定的传统分析法是用有机溶剂将样品（粉煤灰、波特兰水泥、生石灰）中游离的ＣａＯ溶出 ,用标准酸或ＥＤＴＡ滴定 ,如甘油 -乙醇法、乙二醇法、新近提出的醋酸铵 -乙醇法〔１〕等。此外还有仪器分析的方法 ,如原子吸收法、荧光分析法等。当粉煤灰暴露于空气时 ,其中的ＣａＯ转化为Ｃａ（ＯＨ）２ 后 ,性能变得安定。容量法的主要缺点是将ＣａＯ和Ｃａ（ＯＨ） ２ 同时溶出 ,测定结果为样品所含ＣａＯ和Ｃａ（ＯＨ）２ 的总量。尤其当样品长期暴露于空气中时 ,测定结果不理想。本实验选取乙二醇作为溶剂 ,并结合卡尔 -费休法 ,…     

Determination of functionality and functionality distribution of polyether polyols by quantitative 13C NMR spectroscopy

A method is described for the determination of the number average functionality and functionality distribution of polyols based on the measured intensities of relevant end groups observed in ¹³C NMR spectra. Longitudinal (T1) relaxation time measurements on glycerol-, trimethylolpropane-, and pentaerythritol-initiated copolymers of propylene oxide and ethylene oxide show that the slowest relaxing moiety that needs to be quantified is the vinyl CH₂?group of the unsaturated side product of the propoxylation reaction. A. chromium (III)-containing relaxation reagent allows the analysis to be speeded up by decreasing the relaxation times. The relative precision of the functionality measurement is ca. ±1%, while determinations of the mole percentage levels of species with different functionalities can be carried out with a precision better than ±3 mol %. © 1994 John Wiley & Sons, Inc.