MDI-50三聚反应动力学的研究

采用2,4,6-三(二甲胺基甲基)苯酚(DMP-30)三聚催化剂合成了二苯基甲烷二异氰酸酯(MDI-50)的三聚体,用傅里叶变换红外光谱(FT-IR)和凝胶色谱(GPC)对产物进行了表征,并用FT-IR跟踪方法研究了MDI-50三聚反应的反应动力学。结果表明,MDI-50三聚反应是一级反应,60℃时反应的速率常数Ka为0.00760min-1,平均活化能为79.33kJ/mol。     

聚氨酯快速(RIM)聚合的绝热反应动力学

用环氧乙烷封端的聚环氧丙烷聚醚二元醇与4,4’-二苯基甲烷二异氰酸酯(MDI)或液化改性的MDI(L-MDI)进行快速本体聚合,比较了二月桂酸二丁基锡(DBTDL)、辛酸亚锡(SnOct)、硫醇锡(UL-29)以及相应的几种锡/胺体系在绝热条件下的催化活性.用非线性优化方法求取了反应动力学参数值.结果表明,在绝热条件下本体聚合的反应活化能为130～170kJ/mol,每当量NCO官能团的反应热为61～72kJ.催化剂的活性顺序为:SnOct>DBTDL>UL-29和BDTDL/DABCO(三乙烯二胺)>UL-29/DABCO>Snoct/DABCO.反应总级数为2级,催化剂种类的变化对反应总级数基本上无影响.     

FT-IR法研究IPDI与GAP预聚及预聚物和NC的固化反应

用傅里叶变换红外光谱(FT-IR)对聚叠氮缩水甘油醚(GAP)-异佛尔酮二异氰酸酯(IPDI)预聚物以及-NCO基团封端的GAP预聚物/硝化棉(NC)体系固化反应动力学进行了研究。结果表明,两种体系的固化速率均随着温度的升高而加快;当固化催化剂T12的质量分数为0.025%时,两种体系固化反应的表观活化能分别为64.88kJ/mol和111.19kJ/mol,且均表现为二级动力学反应。     

二异氰酸酯封端聚酯多元醇型固化剂合成反应动力学的研究

以低分子聚酯多元醇与二异氰酸酯合成新型聚氨酯固化剂,分别研究了甲苯二异氰酸酯（TD I）、二苯基甲烷二异氰酸酯（MD I）与低分子聚酯多元醇的反应动力学。结果表明,TD I封端低分子聚酯多元醇的反应为二级反应,反应活化能为51.7 kJ/mol;MD I封端低分子聚酯多元醇的反应在反应温度低于70℃时也为二级反应,反应活化能为27.6 kJ/mol。     

双元固化剂IPDI/N100与HTPE催化反应动力学

采用傅里叶变换红外(FTIR)光谱法研究双元固化剂IPDI(异佛尔酮二异氰酸酯)/N100(多官能度异氰酸酯)与HTPE(端羟基环氧乙烷–四氢呋喃嵌段共聚醚)之间的反应动力学,并与TDI(甲苯二异氰酸酯)/HTPE、IPDI/HTPE体系进行了比较。结果表明:以TPB(三苯基铋)作催化剂时,IPDI/N100/HTPE、TDI/HTPE、IPDI/HTPE体系的固化反应近似为二级反应,IPDI/N100/HTPE体系的表观活化能为126.21 kJ/mol,相比TDI/HTPE和IPDI/HTPE体系,IPDI/N100/HTPE体系的表观活化能分别升高了52.12、17.46 kJ/mol。     

混合异氰酸酯固化剂对HTPB固化反应的影响研究

为了缩短以端羟基聚丁二烯(HTPB)为粘结剂组分的浇注高聚物粘结炸药(PBX)及固体推进剂的固化时间,研究了二苯基甲烷二异氰酸酯(MDI)、异佛尔酮二异氰酸酯(IPDI)及其不同比例混合物作为固化剂对反应的影响。结果表明,用IPDI/MDI摩尔比为3∶1的混合固化剂的适用期超过6 h,固化时间为4 d,较单独使用IPDI作为固化剂的固化时间短,可以满足生产要求,是较理想的固化剂。     

水性聚氨酯预聚反应的动力学参数分析

本文选择聚酯,聚醚多元醇,异佛尔酮二异氰酸酯(IPDI),二羟甲基丙酸(DMPA)为主要原料,合成了水性聚氨酯乳液。主要研究了温度对预聚反应的影响,计算了反应速率常数K0和活化能Ea,并比较了温度对聚酯聚醚混合型和聚酯型水性聚氨酯预聚反应影响的大小。结果表明:纯聚酯多元醇与IPDI反应的活化能为97.99KJ/mol,聚酯/聚醚混合型多元醇与IPDI反应的活化能为60.606KJ/mol,制备水性聚氨酯时聚酯/聚醚混合型预聚反应温度要低于聚酯型。     

封闭型异氰酸酯的解封动力学研究

分别以咪唑、3,5-二甲基吡唑作为封闭剂对异佛尔酮二异氰酸酯(IPDI)封闭,合成了2种封闭型异氰酸酯,采用傅里叶变换红外光谱(FT-IR)和核磁共振波谱分析了封闭产物的结构特征,通过热重分析(TGA)研究了封闭产物的热分解反应动力学。结果表明,两种封闭剂都对异氰酸酯实现了全封闭。通过Kissinger和FWO方程求得咪唑封闭型异氰酸酯的活化能分别为65.1 k J/mol和65.8 kJ/mol,3,5-二甲基吡唑封闭型异氰酸酯的活化能分别为84.3 kJ/mol和75.3 kJ/mol。咪唑、3,5-二甲基吡唑封闭异氰酸酯的初始解封温度分别为139.1℃、140.8℃。     

FT-IR法研究粒铸EMCDB推进剂的固化反应动力学

用傅里叶变换红外光谱(FT-IR)法对聚乙二醇(PEG)/异佛尔酮二异氰酸酯(IPDI)体系和IPDI封端的PEG预聚物/硝化棉(NC)体系固化反应动力学进行了研究,同时考察了复合燃烧催化剂(铅盐、铜盐和炭黑组成质量分数0.3%)对二体系的固化反应动力学的影响。实验结果表明:二体系均随温度升高,反应速率加快;相同温度下,催化剂的加入明显加快了固化反应速率,并降低了其表观活化能,但不改变固化反应级数(仍为二级反应)。     

IPDI及MDI型聚氨酯预聚体中游离二异氰酸酯含量测定

合成了异佛尔酮二异氰酸酯（IPDI）型及二苯基甲烷二异氰酸酯（MDI）型无溶剂聚氨酯（PU）预聚体。利用高效液相色谱仪，建立了IPDI型及MDI型PU预聚体中游离二异氰酸酯单体含量的检测方法，并用在所合成PU预聚体中游离二异氰酸酯单体测定。结果表明，该方法能定量测定出IPDI型及MDI型PU预聚体中游离二异氰酸酯的含量，且具有良好的稳定性和线性，相关性系数均达到0．9999。     

Preparation of segmented, high molecular weight, aliphatic poly(ether-urea) copolymers in isopropanol. In-situ FTIR studies and polymer synthesis

The use of isopropanol (IPA) as the reaction solvent for the preparation of high molecular weight segmented polyether-urea copolymers based on cycloaliphatic diisocyanates was investigated. Reactivity of IPA with bis(4-isocyanatohexyl)methane (HMDI) and isophorone diisocyanate (IPDI) was studied between 0 and 40 °C using in-situ FTIR spectroscopy. HMDI, which has secondary isocyanate groups, shows a very slow reaction with a large excess of IPA at 0 and 23 °C. Analysis of the kinetic data indicates an activation energy of 51 kJ/mol for the reaction between HMDI and IPA. As expected, IPDI, which has both a primary and a secondary isocyanate (NCO) group, reacts faster with IPA compared with HMDI, which only has secondary NCO groups. However, the rate of reaction of IPDI with IPA at 0 °C is extremely slow (approximately 1% consumption of isocyanate in 60 min) thus allowing the use of IPA as the reaction solvent for polyether-urea synthesis. Preparation of high molecular weight, high-strength HMDI and IPDI based polyether-urea segmented copolymers in IPA has been demonstrated. Thermal analysis and stress-strain analyses were used to characterize the products.     

A kinetic investigation of polyurethane polymerization for reactive extrusion purposes

The effects of the reaction conditions on the kinetics of two different polyurethane systems were investigated. To do so, three different kinetic methods were compared: adiabatic temperature rise (ATR), measurement kneader, and high‐temperature measurements. For the first polyurethane system, consisting of 4,4‐diphenylmethane diisocyanate (4,4‐MDI), butane diol, and a polyester polyol, the reaction conditions did not seem to matter; a kinetically controlled reaction was implicated for all reaction conditions. The reaction was second order in isocyanate concentration and 0.5th order in catalyst concentration and had an activation energy of 52 kJ/mol. The second polyurethane system consisted of a mixture of 2,4‐diphenylmethane diisocyanate and 4,4‐MDI, methyl propane diol, and a polyester polyol. For this system, each of the three measurement methods showed different behavior. Only at a low catalyst concentration did the ATR experiments show catalyst dependence; at higher catalyst levels and for the other two measurement methods, no catalyst dependence was present. Furthermore, the ATR experiments proceeded much faster. Presumably, for this system, the rapid diffusion interfacial of the species present was hindered by the presence of bulky oligomer molecules. The result was a diffusion limitation reaction at low conversions and an inhomogeneous distribution of species at higher conversions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 370–382, 2006     

Kinetic study of the urethane and urea reactions of isophorone diisocyanate

Kinetic studies of the catalyzed urethane reactions between isophorone diisocyanate (IPDI) and alcohols and of the urea reactions between an isocyanate‐terminated prepolymer [IPDI–PPG2000–IPDI, where PPG2000 is poly(propylene glycol) with a number‐average molecular weight of 2000 g/mol] and water in the bulk state were performed with Fourier transform infrared (FTIR) spectroscopy. Dibutyltin dilaurate was used as the catalyst for the urethane reaction, and various tertiary amines were used as catalysts for the urea reactions. The reactions were followed through the monitoring of the change in the intensity of the absorbance band for NCO stretching at 2270 cm^?1 in the FTIR spectra; the activation parameters were determined through the evaluation of the kinetic data obtained at various temperatures (within the range of 30–60°C). The kinetic data indicated that the catalyzed isocyanate/alcohol and isocyanate/water reactions both followed second‐order kinetics during their initial stages but later followed third‐order kinetics resulting from the autocatalytic effects of hydrogen bonding between the hydroxyl groups and the newly formed urethane and urea groups. Furthermore, activation energies of 64.88 and about 80 kJ/mol for the isocyanate/alcohol and isocyanate/water reactions, respectively, indicated that the urea‐forming reactions were more sensitive to the reaction temperature than the urethane‐forming reactions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

溴化丁基橡胶液体抗氧剂的热分析研究

用热失重法(TG)和差示扫描量热法(DSC)分别测定了添加4种新型液体抗氧剂的溴化丁基橡胶(BIIR)的热失重温度、氧化诱导时间和氧化诱导温度,综合考察了4种抗氧剂的热稳定性和抗氧化性能,评选出性能最好的抗氧剂及其最佳添加量,并分别计算了BIIR的等温和非等温(动态)热氧化反应的活化能。结果表明,4种抗氧剂的热稳定性和抗氧化效果差异较大,但均能不同程度改善BIIR热氧化稳定性。等温热氧化动力学实验结果表明,BIIR热氧化反应符合阿伦尼乌斯方程,抗氧剂添加前后BIIR等温氧化反应活化能分别为131.14kJ/mol、150.25kJ/mol;动态热氧化动力学实验得到抗氧剂加入前后BIIR的非等温氧化反应活化能分别为86.23kJ/mol和108.49kJ/mol。     

聚氨酯甲基丙烯酸酯预聚物合成及反应动力学研究

以甲苯二异氰酸酯（TDI）、PEG1000和甲基丙烯酸-B-羟乙酯（HEMA）为原料,通过分步法合成聚氨酯甲基丙烯酸酯（PUMA）预聚物并对合成工艺及动力学参数进行了研究,确认TDI与PEG、TDI聚氨酯中间体与HEMA这2步反应均为二级反应．反应活化能分别为34．533kJ／mol、87471kJ／mol;这2步反应的最佳反应温度为65℃、70℃,其相应的反应速率常数分别为2．578×10^-3L／（mol·s）、2．1889×10^-2L／（mol·s）。     

巯基-烯点击反应制备氟化水性聚氨酯分散体

采用聚醚二元醇N210、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸和封端剂三羟甲基丙烷三(2-巯基乙酸酯)为原料,合成了巯基封端的聚氨酯预聚物,再通过巯基-烯点击反应将甲基丙烯酸十二氟庚酯(G04)引入聚氨酯链段,制备了端基为氟化物的聚氨酯分散体(FPUD)并与巯基封端水性聚氨酯分散体进行比较。研究了三乙胺(TEA)催化引发、紫外光光引发、偶氮二异丁腈(AIBN)热引发3种不同的引发方式对含氟水分散体稳定性和涂膜性能的影响,并用FT-IR对氟化前后分散体的结构进行表征。结果表明,3种引发方式都可成功引发G04与巯基间的点击反应,其中紫外光引发和AIBN热引发所得水分散体稳定性较好,通过紫外光引发所制备FPUD膜与水的接触角为86.5°,表面自由能为24.67×10-3J/m,吸水率为18.6%。     

马来酸双十八酯的合成及宏观动力学

以对甲苯磺酸为催化剂、甲苯为带水剂,以马来酸酐和十八醇为原料合成马来酸双十八酯。考察了原料配比、催化剂用量、带水剂用量和反应时间等因素对反应过程的影响,并测定了动力学数据。通过实验得到了反应工艺条件：n（十八醇）：n（马来酸酐）=2.3：1,对甲苯磺酸用量为马来酸酐和十八醇总质量的0．5％,甲苯用量为马来酸酐和十八醇总质量的96％,反应温度≤130℃、反应时间为4．0h,在该条件下马来酸酐的转化率达到98．76％。合成马来酸单十八酯的反应为二级反应,速率方程中的指前因子为O．655152L／（mol·min）,活化能为17．82kJ／mol。合成马来酸双十八酯的反应为二级反应,速率方程中的指前因子为1．53951×1011L／（mol·min）,活化能为98．05kJ／mol。     

国内外特种异氰酸酯市场与供需

介绍了包括六亚甲基二异氰酸酯(HDI)、异佛尔酮二异氰酸酯(IPDI)、二环己基甲烷–4,4'–二异氰酸酯(H12MDI)等特种异氰酸酯的世界供需动向与中国发展进展。     

Synthesis and characterization of diethylene glycol monobutyl ether—Blocked diisocyanate crosslinkers

Typically blocked isocyanate systems are used to obtain the performance of two component polyurethane (PU) system in a one-component mixture. In this study four types of isocyanates namely, hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI) were blocked with diethylene glycol monobutyl ether (DEGMBE). Elimination of the isocyanate groups and the formation of urethane bonds were studied by FTIR spectroscopy and titration methods. Thermal dissociation of blocked diisocyanates was analyzed by DSC and TGA techniques.Deblocking temperature obtained by DSC and TGA techniques was compared. Based on DSC data, it was found that deblocking of blocked MDI and TDI starts at lower temperatures compared to that of the aliphatic one (HDI). Reactivity of the blocked IPDI is between blocked MDI and blocked TDI.In general, TGA results show the same trend as DSC except for IPDI which shows the lowest deblocking temperature. Deblocking temperature values obtained by TGA technique were lower than DSC values.