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。     

聚氨酯反应体系的固化和温度

采用n级反应动力表示式和热传导方程建立了描述聚氨酯反应模塑（RIM）体系固化和温度的方法,并进行了相应的理论计算,结果表明：催化剂浓度,模具温度对固化过程和体系最大温度均有明显影响;反应物料的温度对体系的最大温度有影响,但对体系固化时间影响不大。厚模具内部的温度场接近绝热性质,其历史可用来确定反应动力和热力的相关参量。     

软段对IPDI基透明聚氨酯弹性体微相结构与性能的影响

采用不同结构的软段、扩链剂l,4-丁二醇和异佛尔酮二异氰酸酯(IPDI)为主要原料合成了透明聚氨酯弹性体。研究了软段结构变化对聚氨酯弹性体的微相结构、力学性能、热稳定性及光学透明性的影响。结果表明,相对分子质量高的软段比相对分子质量低的软段更易结晶,耐低温性能更好;与聚氧四亚甲基二醇(PTMG)相比,聚酯型聚己二酸丁二醇酯二醇(PBAG)更易结晶。结晶尺寸在纳米级,材料的透明性可达85％以上。软段含量增加对软段区的结晶影响较小,但力学性能下降明显。混合多元醇的加入进一步提高了聚氨酯弹性体的微相分离程度,有利于软段结晶,在宏观上表现为拉伸强度和弹性模量明显增加。     

反应温度对DMTO装置产品选择性的影响

介绍了DMTO装置的基本工艺、反应再生部分的原理及影响DMTO反应的主要因素;以某工业装置数据为基础,分析了反应温度对工业级DMTO反应产物选择性的影响,为确定合理的反应温度、实现企业效益最大化提供了理论依据。     

扩链剂对IPDI基透明聚氨酯弹性体的影响

采用异佛尔酮二异氰酸酯(IPDI)和不同结构的扩链剂、多元醇合成了透明聚氨酯弹性体，通过DSC、TG、WAXD等研究了聚氨酯弹性体的形态结构和力学性能、热稳定性及光学透明性。结果表明，扩链剂结构对聚氨酯弹性体形态结构和力学性能、热稳定性及光学透明性有很大影响。降低扩链剂长度有利于微晶的长大、微相分离程度及力学性能的提高；增加扩链剂用量，聚氨酯弹性体的微相分离程度、微晶尺寸、力学性能及热稳定性能提高；硬段含量对聚氨酯弹性体光学透明性的影响不明显。     

乙二胺扩链剂对水性聚氨酯性能的影响

以聚醚220、异佛尔酮二异氰酸酯(IPDI)为主要原料,二羟甲基丙酸(DMPA)为亲水性扩链剂,丁二醇(BD)和乙二胺(EA)为小分子扩链剂,按不同配比合成了系列水性聚氨酯分散体。主要考察了乙二胺扩链剂用量对水性聚氨酯乳液的稳定性、乳液粒径、粘度以及膜吸水性和力学性能的影响。结果表明,随乙二胺扩链剂用量的增加,乳液粒径增大、分散稳定性变差、粘度减小、胶膜的拉伸强度增加、断裂伸长率减小、耐溶剂性增加、吸水率变化不明显、硬段相Tg升高,软硬段相分离程度增加。胶膜的ATR红外表现为PPG类聚醚型聚氨酯典型的红外光谱。     

硬段对聚碳酸酯二醇型水性聚氨酯性能的影响

以聚碳酸酯二醇(PCDL)为软段、二羟甲基丙酸(DMPA)为亲水扩链剂、异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,采用预聚体法合成了水性聚氨酯(WPU)。研究结果表明:随着n(HDI)∶n(IPDI)比例的增加,WPU的黏度、断裂伸长率增大,耐水性和耐乙醇性提高;当n(HDI)∶n(IPDI)=1.0∶1时,WPU的综合性能相对较好,其热稳定性和结晶性能得到明显改善。     

反应温度对吡唑硫醚衍生物选择性氧化的影响

在30％双氧水—乙酸体系中，严格控制反应温度可使3—甲硫基—4—乙氧羰基—5—氨基吡唑氧化成单一的3—甲砜基—4—乙氧羰基—5—氨基吡唑或3—甲亚砜基—4—乙氧羰基—5—氨基吡唑。     

反应温度对汽油催化裂解多产低碳烯烃的影响

利用自制的多产低碳烯烃催化剂在小型固定流化床装置上对催化裂化汽油、焦化汽油和直馏汽油的催化裂解性能进行了实验研究,考察了反应温度对催化裂解产物分布和低碳烃收率的影响.实验结果表明焦化汽油、催化汽油和直馏汽油最佳的催化裂解反应温度分别为580、600℃和680℃,随着反应物活性的降低而显著增加.乙烯的收率随着反应温度的升高呈抛物线增长;烯烃与正构烷烃有协同反应作用,烯烃能够加速正构链烷烃的反应速率;在烯烃存在下,芳烃会生成大量的焦炭;烯烃和链烷烃是生成低碳烯烃的主要来源,是催化裂解的理想组分;最佳催化裂解的反应物为催化汽油或者焦化汽油的轻馏分与直馏汽油的轻馏分的混合物.     

Selectivity of isophorone diisocyanate in the urethane reaction influence of temperature, catalysis, and reaction partners

In a model study of the selectivity of isophorone diisocyanate (IPDI) in the urethane reaction, the influence of the type of catalyst, temperature, and type of OH-group was demonstrated using primary and secondary butanol as reaction partners. In particular, the choice of catalyst has a dramatic effect on the composition of the final product mixture. The most important conclusions of the model study were confirmed in NCO-prepolymer synthesis. GFB LR-AT, D-45764 Marl, Germany. R. LOM?LDER received a Ph.D. Degree in Chemistry from the University of Münster, Germany. Dr. Lom?lder joined the research and development team for the coatings raw materials division of Hüls AG, Marl, Germany in 1989, where he worked with polyurethanes. Since 1992, Dr. Lom?lder has been working with IPDI and its derivatives in Hüls AG’s technical services department for polyurethane raw materials. FRIEDRICH PLOGMANN joined Veba Chemie’s technical services laboratory for polyurethane raw materials in 1976. In 1979, when Veba’s chemical activities were transferred to Hüls AG, Mr. Plogmann continued to work in the laboratory. PETER SPEIER joined the research and development department of Hüls AG in Marl, Germany in 1960, initially working with polybutadiene resins and later with saturated polyester resins. Since 1985, Mr. Speier has been working with polyurethanes raw materials in Hüls AG’s technical service laboratories in Marl.     

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     

Preparation and properties of polyurethane coatings based on acrylic polyols and trimer of isophorone diisocyanate

This paper presents a study on the effect of NCO/OH ratio and an increase in hydroxyl content of acrylic polyols on the properties of polyurethane (PU) coatings. Coating properties studied are gloss, scratch resistance, flexibility and adhesion, mechanical properties include tensile strength, modulus, percent elongation and Shore hardness, while physicochemical properties include chemical resistance and solvent absorption of coated PU samples. A series of acrylic polyols (copolymers) based on butyl acrylate (BA), methyl methacrylate (MMA), styrene and 2-hydroxy ethylacrylate (HEA) were prepared by selecting different percentage of hydroxyl content. Trimer of isophorone diisocyanate (IPDI) was also synthesized in the laboratory. This trimer has trifunctionality. Isocyanurate ring of trimer increases thermal properties of PU. Polyurethanes from these acrylic polyols (containing different percent hydroxyl) and trimer of IPDI were prepared with two different NCO/OH ratios viz, 1.1:1 and 1.2:1. Polyurethanes were coated on substrates for measuring coating properties. Mechanical properties were measured on cast films of the PUs. The experimental results revealed that all polyurethane coatings based on acrylic polyols and IPDI trimer showed good gloss, scratch resistance and excellent adhesion. Thermal stability of these PU samples was found to be better. Physicochemical properties reflected that these PU have excellent chemical and solvent resistance.     

Properties and paper sizing application of waterborne polyurethane emulsions synthesized with isophorone diisocyanate

In this work, a two-step synthesis methodology has been used to synthesize a series of waterborne polyurethane (WPU) emulsions with isophorone diisocyanate (IPDI), poly-caprolactone diol (PCL) and dimethylol propionic acid (DMPA) as monomers and ethylenediamine (EDA) as the chain extender, respectively. The influences of the NCO/OH molar ratio, DMPA content, chemicals-adding sequence, and acetone content on the physical properties of the resultant emulsions have been investigated in detail. The results show that the emulsion viscosity increases with an increase in the NCO/OH molar ratio or DMPA content whereas it declines sharply as the acetone amount increases. The emulsion particle size is seen to increase with the NCO/OH molar ratio but it decreases as the DMPA content increases. The chemicals-adding sequence is observed to strongly affect the particle size and viscosity of the resultant emulsions. For cast films, with an increase in the NCO/OH molar ratio, the elongation monotonically decreases while the tensile strength is seen to increase at first and then deceases. The film water absorption capacity is found to go up as the DMPA content increases. Furthermore, after sized with the emulsions, the paper water resistance is markedly improved and the 30s Cobb value is seen to decrease by 63% as compared to the unsized counterpart. The paper folding resistance and the tensile index are also improved to certain extents. For producing well-performed WPU emulsions for sizing paper sheets, an NCO/OH molar ratio of 1.6–1.8 and a DMPA content of 6.0–7.0 wt.% are preferably chosen.     

Polymerization kinetics in propellants of the hydroxyl-terminated polybutadiene–isophorone diisocyanate system

The copolymerization of a hydroxyl-terminated polybutadiene with isophorone diisocyanate in a propellant formulation has been studied. The kinetic rates for four different reaction temperatures have been measured both in gumstock and samples containing ammonium perchlorate. It is shown that the presence of ammonium perchlorate (up to 90% by weight) neither catalyzes nor retards the rate of binder polymerization. It is also shown that the polymerization follows an apparent second-order rate low with an activation energy of 9.8 kcal/mole.     

Role of isophorone diisocyanate in the optimization of adhesion tendency of polyurethane pressure sensitive adhesives

The present work describes the role of accurate selection of diisocyanate on the adhesion strength of polyurethanes (PUs). The concentration of diisocyanate induces the hard segment (HS) in the main architecture of PUs which decides the viscoelastic properties of the polymers. A balanced ratio of viscoelastic properties ultimately determines the adhesion strength. The composition of the polymers consists of a blend of macrodiol of hydroxyl-terminated polybutadiene and polypropylene glycol with different molecular weights. Isophorone diisocyanate (IPDI) is used to develop the urethane linkages by maintaining its contribution from 28 to 67% as HS contents. It determines the adhesion strength of the final product. The adhesion strength is evaluated by texture analyzer and 180° peel test. The probe tack analysis shows maximum adhesion energy of 156.2 J cm⁻² and 180° peel test shows 18.80 N/25 mm peel force. The glass-transition (T _g) values obtained through differential scanning calorimetry are in good agreement with theoretically calculated Flory–Fox temperature. The proportion of the loss tangent to the storage modulus (tan δ/E′) shows the optimum value of 2.80 MPa⁻¹. The ideal concentration of IPDI results to achieve better adhesion properties of PU pressure sensitive adhesives. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47124.     

Thermal and fire behavior of isophorone diisocyanate based polyurethane foams containing conventional flame retardants

This work reports on the fire behavior of isophorone diisocyanate‐based polyurethane foams containing different conventional flame retardants (FRs) such as melamine, ammonium polyphosphate, aluminum hydroxide, expandable graphite, and their combinations. The foams were obtained in a laboratory scale and characterized in terms of their morphology, density, thermal stability, and fire behavior. According to atomic force microscopy, the incorporation of FRs decreased the phase separated domain size. The cellular structure of the foams was examined qualitatively by scanning electron microscopy while the quantitative analysis of the surrounding skin was performed by optical microscopy and Image J. The FR containing foams showed more and smaller cells. The thermogravimetric analysis showed that the FRs had no influence in the initial degradation temperature of the foams. However, the obtained residue values were higher than the theoretical ones, indicating that there was some type of interaction between the FRs and the foams. The fire behavior of polyurethane foams was studied by the cone calorimeter and the data showed that the introduction of expandable graphite and combinations of ammonium polyphosphate/melamine to the reference foam gave rise to a significant reduction in the total heat release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45944.     

Evaluation of hydroxyl terminated polybutadiene‐isophorone diisocyanate gel formation during crosslinking process

Crosslinking reaction of hydroxyl‐terminated polybutadiene (HTPB)/isophorone di‐isocyanate (IPDI) was monitored by infrared spectroscopy, dynamic mechanical analysis (DMA), swelling measurements, and by relaxation time (T₂) measurements obtained by low‐field NMR technique. Chemical reaction monitored by FTIR shows that urethane bonds were predominantly formed throughout the whole reaction period while DMA and swelling became only effective once the three‐dimensional network was formed. NMR results allow differentiating between relaxation‐processes associated with different fractions of the reactants in the mixture prior to the network formation. The most important finding in this study is that two of the relaxation processes were found to decline whereas a new fraction with a short relaxation time which emerged specifically at an early stage of reaction and progressed along with advancement of the reaction. All results pointed out to a change in the mixture behavior around 30 h of crosslinking reaction at 60°C, reflecting an important restriction in molecules diffusion and mobilities which were attributed to the gel point formation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Polyurethanes based on isophorone diisocyanate trimer and polypropylene glycol crosslinked by thermal reversible diels alder reactions

Crosslinked self‐healing polyurethanes based on Diels–Alder (DA) reaction were synthesized from a trifunctionalized isophorone diisocyanate (IPDI) and polypropyleneglycol prepolymer with furfuryl alcohol and a commercial bismaleimide. The DA reaction was followed by FTIR spectroscopy at different temperatures. From the infrared results the kinetic rate constants as well as the DA reaction reversibility were established. The retro DA reaction (rDA) and its reversibility was monitored by DSC according to the enthalpy involved in the process. The obtained polymers exhibited thermosetting properties at room temperature, although they showed thermoplastic behavior at high temperatures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44543.     

Evaluation of isophorone diisocyanate crosslinked gelatin as a carrier for controlled delivery of drugs

The high solubility of gelatin in neutral, basic, and acidic biofluids may not promote a controlled drug delivery as a drug carrier. The present study reports the modification of the solubility and swellability of gelatin by crosslinking with hitherto uninvestigated isophorone diisocyanate to achieve controlled drug release characteristics. The crosslinked gelatin was insoluble and swellable in biofluids and analyzed by FT-IR and proton NMR, thermal analysis, swellability and biodegradability in simulated biofluids, X-ray diffraction, biocompatibility, and in vitro drug release kinetics and mechanism with 5-Fluorouracil as model drug. Crosslinking decreased the biodegradability and solubility, and enhanced the amorphous character of gelatin. The mild decrease in thermal stability of crosslinked gelatin was attributed to the urea linkage introduced. Drug release predominately occurred via anomalous transport mechanism with mild degradative diffusion. The observed results demonstrated that crosslinked gelatin can be used as a potential carrier to achieve controlled drug release.