聚酯多元醇酸值测定方法的改进

建立了改进的聚酯多元醇酸值的测定方法,选用KOH水溶液替代KOH乙醇溶液作标准,滴定过程中不断加入乙醇作为溶剂.结果表明,该方法试验结果可行,避免了目前酸值测定中以全醇配制KOH溶液出现返黄现象及全水配制KOH溶液在滴定过程中出现的混浊且终点不清晰的现象,经与标准测定方法比较,结果的准确性在允许误差范围内,降低了分析成本,改善了工作环境.     

聚酯亚胺多元醇酸值分析的新方法

聚酯亚胺多元醇酸值是聚氨酯的一个重要指标一通常测定酸值时，一般使用酚酞作为指示剂。但是对于改性聚酯多元醇，用酚酞作为指示剂其终点难以判断，故采用电位滴定法测聚酯亚胺多元醇的酸值，同时使用各种酸碱指示剂用来指示滴定终点，结合两得出一个最件的指示剂。研究表明溴百里酚蓝为测定聚酯亚胺多元醇测定酸值最合适的指示剂。提供了聚酯亚胺多元醇起始电位值与酸值的标准曲线图．能快速、简便地查出相同条件下不同样品的酸值。     

松香甘油酯酸值测定的溶剂绿色化

采用中和法测定松香甘油酯的酸值，对溶解松香酯的溶剂进行了绿色化研究。比较了6种溶剂的毒性和挥发性，确定松节油作为松香酯酸值测定的绿色溶剂。考察了松节油与乙醇不同体积的混合比例对溶解松香甘油酯的影响，结果表明松节油与乙醇混合的体积比为1：2．5的互溶效果最好。分别以1：2．5的松节油-乙醇和国家标准GB 10287—88中所用的2：1苯-乙醇作溶剂，测定松香甘油酯的酸值，比较二者所测得的酸值之误差，经线性回归得到修正酸值的方程为Y=1．0022X-0．4264，由该方程计算修正后的酸值与国家标准GB 10287—88测定的酸值之间最大相对误差小于2．2％。     

咪唑-醋酸酐-DMF法测定聚酯多元醇的羟值

提出一种利用咪唑-醋酸酐-DMF法测定聚酯多元醇羟值的方法,总结出方法的适用范围和适用条件。该方法操作简单,数值稳定,与行标测试结果接近。     

聚酯酯化物非水溶液体系酸值的测定

0．2g酯化样用15mL无水乙醇和15mL氯仿加热溶解,溴百里酚蓝作指示剂,0．05mol／L氢氧化钾-乙醇标准溶液滴定溶液呈蓝色即为终点,回收率在99．3％～102．9％之间,相对标准偏差为2．57％。     

进样量和进样方式对聚酯多元醇水分含量测定的影响

使用METTLER TOLED DL32水分测定仪,对聚酯多元醇水分含量测定的进样量和进样方式做了比较分析。试验结果表明采用滴管进样,进样量在0.1 g左右,一次进样即有很好的准确性和精确性,可不必重复进样。本测定方法具有测试速度快,分析时间短的特点。     

聚酯多元醇中水分测定

对标准测定方法进行了改进,减少 K.F 试剂中的甲醇用量,以减缓或防止缩羰化合物的生成,从而使聚酯多元醇中的微量水分的滴定终点清晰,测定的相对误差小于10%。     

ICP-AES法测定芳烃聚酯多元醇中金属离子含量

采用微波消解制样,建立了电感耦合等离子体发射光谱(ICP-AES)法测定芳烃聚酯多元醇中Ti、Mn、Fe、Co、Zn、Sn等金属离子含量的方法.结果表明,测定方法的检出限为0.0206～0.303 μg/mL,回收率为96.8%～100.5%,方法的相对标准偏差小于4.62%,该法准确、快速、简便,应用于芳烃聚酯多元醇中金属元素的测定,结果满意.     

Preparation of polyester polyols from unsaturated fatty acid

Oleic acid is a typical unsaturated fatty acid that is found widely in vegetable oils. The objective of this investigation was to produce a new type of oleic‐based polyol from oleic acid. Possible advantages of this approach include the production of high‐performance polyurethane materials from renewable resources and value‐added research for oleic acid. Oleic‐based polyols were synthesized by a three‐step process consisting of epoxidation and ring‐opening reaction, followed by esterification. The synthesized polyols appeared as a viscous liquid at room temperature with hydroxyl numbers from 307 to 425 mg KOH/g. Preparation of polyurethane foams using oleic‐based polyols and isocyanate was studied. An environmentally friendly blowing agent, HCFC‐141b, together with a small amount of water, was used. The synthesized foams were characterized by FTIR, SEM, and TG/DSC. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

混合苯二甲酸共聚酯的研制及其性能研究

使用300 L通用聚合反应器,以对苯二甲酸(PTA)和间苯二甲酸(PIA)为原料,按照一定混合比例与乙二醇进行酯化和缩聚反应,制得聚混合苯二甲酸乙二醇酯(PETI);探讨了PETI的热性能及加工性能,并以PETI为原料,分别使用小釜反应器和Mucell发泡仪进行发泡实验。结果表明:随着PIA含量的增加,PETI的玻璃化转变温度降低(均为60~70℃),吸水率降低;PIA质量分数为28%时,PETI有少量结晶,同时具有较好的微孔发泡加工性能。     

醋酸酐室温酰化法测定聚酯多元醇中羟值的含量

本文介绍了利用醋酸酐室温酰化法测定聚酯多元醇中的羟值含量.讨论了水含量、称样量、酰化温度的控制、滴加速度等对测定结果的影响.严格按照实验条件做,此法是一种既简便又快速的测定方法.     

The physical and mechanical properties of polyurethanes from oleic acid polyols

Three different polyester polyols, with various oleic acid content, were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40, and Alk65, in which 28, 40, and 65 represent the percentage of oleic acid of the polyol formulations. These polyester polyols were reacted with aromatic diisocyanate [toluene diisocyanate (TDI)] to form PUR coatings. The acid value, hydroxyl value, molecular weight, and viscosity of the polyols have been determined. The reaction between the polyols and TDI was studied by Fourier Transform Infrared spectroscopy and X‐ray diffraction (XRD). The effects of varying NCO/OH ratio and oleic acid content of polyols on physical and mechanical properties of PUR films were studied. XRD results indicate that the samples are amorphous. PURs, made with Alk28, have the best mechanical properties followed by Alk40 and Alk65. The mechanical properties of the samples have increased as the NCO/OH ratio was increased from 1.2 to 1.6. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

癸二酸系聚酯多元醇的合成

采用癸二酸,对苯二甲酸与乙二醇,丁二醇,己二醇,新戊二醇进行缩聚反应,以二氯内化剂,在１４０－２００℃下反应５－７ｈ,合成了癸二酸系聚酯多元醇。实验结果表明,当醇酸摩尔比大于１．２０：１,催化剂用量为５＊１０＾－３ｍｏｌ／ｍｏｌ时,可得到酸值小于２．０ｍｇ／ｇ,羟值（ＫＯＨ）大于５０ｍｇ／ｇ,相对分子质量为１５００－２０００的聚酯多元醇。讨论了聚酯的化学组成对聚醌多元醇结构的影响,考察了催化剂的种     

Preparation of polyurethane wood adhesives by polyols formulated with polyester polyols based on castor oil

The aim of this work was the synthesis of polyester polyols from renewable sources as one of the important compounds of polymeric polyurethane (PU) adhesives. The polyester polyols were synthesized by condensation polymerization of different dicarboxylic acids with castor oil and the reaction conditions were in agreement with green chemistry principles. The preparation of PU wood adhesives was carried out by the reaction of each obtained polyester polyol with 4, 4′-diphenylmethane diisocyanate (MDI). The adhesive performance was improved by mixing the obtained polyester polyols with polypropylene glycol (PPG 400) and butanediol (BD). Different NCO/OH ratios were used to obtain adhesives with appropriate properties. The structures of the synthesized polyesters and adhesives were characterized by FTIR, thermogravimetric analysis (TGA) and lap shear strength values were also determined in various conditions such as cold water, hot water, acid and alkali solutions.     

透明聚酯型水性聚氨酯的制备与性能研究

聚酯型WPU(水性聚氨酯)具有较高的力学强度和粘接强度,但是其较高的结晶性会导致胶膜透明性较差。以聚丙二醇(PPG)、聚己二酸丁二醇酯二醇(PBA)、异佛尔酮二异氰酸酯(IPDI)、2,2′-二羟甲基丙酸(DMPA)和1,4-丁二醇(BDO)等为原料,制备PPG改性聚酯型WPU。研究结果表明:PPG改性聚酯型WPU的黏度适中,储存稳定性良好;随着PPG含量的不断增加,WPU胶膜的透明性因结晶受阻程度增大而变好,相应胶粘剂的T型剥离强度和拉伸强度下降,而断裂伸长率升高;当w(PPG)=10%～20%时,相应WPU胶粘剂的透明性、T型剥离强度(≥1.97 N/mm)、拉伸强度(≥14.7 MPa)和断裂伸长率(≥421%)俱佳。     

DMSO as solvent on the synthesis of flame-retardant polyether polyols

Polyether polyols with flame-retardant properties are synthesized using glycerol phosphate disodium salt as an initiator and dimethyl sulfoxide (DMSO) as a solvent. The molecular weight of the polyol decreased when higher solvent to initiator ratios were used, revealing that a larger amount of salt was activated. In addition, the larger the amount of activated salt was, the higher the percentage of phosphorous was in the final polyol. Glycerol phosphate disodium salt was still partially insoluble in the studied proportions of DMSO. Thus, the recovery and reuse of this part of the salt for the synthesis of new flame-retardant polyols were evaluated. The recovered salt promoted a shorter induction period because it presented a larger amount of deprotonated hydroxyl groups. In addition, there were no differences between both synthesized polyols, indicating that it is possible to use the recovered salt in the same way as it is used commercially with the advantage of a shorter induction period for polymerization. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47042.     

用二聚酸聚酯二元醇制备高固体物含量聚氨酯分散体

以二聚酸聚酯二元醇、二羟甲基丙酸、三羟甲基丙烷及异佛尔酮二异氰酸酯等为原料,用预聚法合成了固体物质量分数50%以上的聚氨酯分散体(PUD).PUD的平均粒径在90～150 nm,12 r/min搅拌速率下的剪切黏度绝大多数在500 mPa·s以下.透射电镜分析显示PUD呈现胶粒间大小和形状互不相同的多分散体系.动态力学分析表明试样胶膜的玻璃化转变温度在-40～-35℃,NCO/OH(摩尔比)的增大使PUD胶膜的玻璃化转变温度升高.热重分析显示PUD胶膜在280℃开始分解,其拉伸强度为14.1～25.0 MPa,扯断伸长率为508%～716%,吸水率为2.44%～4.56%.