双(环氧四氢双环戊二烯)醚及其二醇醚的合成和固化

合成了双(环氧四氢双环戊二烯)醚(Ⅱ)、双(环氧四氢双环戊二烯)乙二醚(Ⅲ)及双(环氧四氢双环戊二烯)丁二醚(Ⅳ)。以酸酐和甘油为固化剂时,它们的凝胶速度的次序为(Ⅱ)>(Ⅲ)>(Ⅳ),测定了由它们所得铸塑料的温度形变曲线,(Ⅲ)与(Ⅳ)的热机性能相似,而(Ⅱ)则优于(Ⅲ)及(Ⅳ),而与双环氧化双环戊二烯接近,将(Ⅱ)与双环氧化双环戊二烯比较,则(Ⅱ)为液体,且具有较快的凝胶速度。     

双环戊二烯苯酚树脂的合成新工艺

以双环戊二烯（DCPD）和苯酚为原料,甲磺酸为催化剂,合成了双环戊二烯苯酚树脂。适宜工艺条件:苯酚与DCPD摩尔比为5、反应温度120 ℃、反应时间5 h、催化剂质量分数为1.5%,收率89%。所得的双环戊二烯苯酚树脂（DPR）经催化加氢法在H2气压力1.5 MPa、催化剂Pd/Al2O3用量为原料质量分数的0.5%、反应温度80 ℃条件下对树脂进行脱色处理。 得到浅黄色双环戊二烯苯酚树脂,收率89%,经IR和1H NMR表征分析其为目的产物,产物指标达到国际同类产品的质量标准。     

乙酰丙酮金属络合物对酸酐固化环氧树脂体系潜伏性促进作用的研究

酸酐固化环氧树脂体系比胺固化的体系具有更优异的力学和电气性能以及高温热稳定性能,但需要较高和较长的固化温度和时间。尽管在室温下有一定的使用期,为了节红能源和缩短生产周期,通常用叔胺类促进剂加快其固化反应速率,但此时体系的使用期较短。因此研制一种能用于酸酐固化环氧树脂体系的潜伏性促进剂是十分必要的。理想的潜伏性促进剂应使其在室温下的贮存使用期不受影响,且在一定的温度下具有较快的固化反应速率,此外,固化产物应具有良好的机电热性能。     

聚甲基二间苯二乙炔基硅烷改性二氧化双环戊二烯环氧树脂及其复合材料的性能

用聚甲基二间苯二乙炔基硅烷树脂（PSA）改性二氧化双环戊二烯（R-122环氧树脂）得到R-122/PSA树脂体系,并以该树脂为基体制备了玻璃纤维复合材料。通过FT-IR、DSC和TGA研究了R-122/PSA树脂的固化反应及其耐热性能,同时研究了R-122/PSA基复合材料的力学性能、耐热性能、介电性能和耐水性能。结果表明：改性树脂在高温下保持了良好的耐热性能,mPSA/mR-122=0.2的固化物在800°C下质量保留率比纯R-122树脂的提高了30%。所制备的复合材料常温下弯曲强度达到735 MPa,220°C下的弯曲强度达到418.4 MPa,不仅保留了良好的力学性能,而且耐热性能得到了很好的提升,同时其浸泡96 h后的吸水率仅为0.65%,耐水性能优异。     

前线聚合研究及应用进展(下)

综述了单体性质、压力、引发剂、反应容器等因素对前线聚合的影响,并对影响前线稳定性的诸多因素进行了讨论,简要介绍了光引发前线聚合近年来最新发展,综述了前线聚合在制作梯度材料、聚氨酯合成、不饱和聚酯及环氧固化、双环戊二烯开环异位聚合、互穿网络结构制备及微孔材料填充固化保护等方面的应用状况。     

金属有机化合物的分析 Ⅲ、双(烷基环戊二烯基)二芳氧基钛、锆、铪的薄层色谱研究

双环戊二烯基钛、锆、铪化合物的研究工作,近年来取得了迅速的进展。我国科学工作者合成了一系列双环戊二烯基二芳氧基钛、锆、铪化合物。目前,这类化合物的催化特性和抗癌作用已引起有关方面的重视,因此,它们的分离分析工作亟需进行。关于双环戊二烯基钛、锆、铪衍生物的薄层色谱工作,仅Howarth 研究了(C_5H_5)_2TiCl_2及C_5H_5TiCl_3二化合物的分离;谢珍珍报导了双环戊二烯基二芳氧基钛、     

DMF中脱除环戊二烯、双环戊二烯的新方法

在用二甲基甲酰胺(DMF)抽提蒸馏分离异戊二烯(ip)时,控制溶剂中环戊二烯(cpd)、双环戊二烯(dcpd)的浓度是制取聚合级ip 的关键所在。目前工业化流程中,为控制循环溶剂中cpd、dcpd 含量,使用了常压解析、减压解析和共沸蒸馏等三个塔。从我们以前的工作得知,经解析后的DMF 中cpd 含量主要由解析塔釜温度、dcpd 浓度及停留时间所决定。也即降低DMF 中cpd 含量既可用降低解析塔釜温度的方法(即上述常、减压解析流程),也可以用降低dcpd 浓度     

新型三官能团脂环族环氧化合物的合成、表征及其阳离子引发光固化活性研究

以双环戊二烯等为原料合成一种新型三官能团液体脂环族环氧树脂. 通过红外光谱、 核磁共振氢谱及质谱等对其中间体及环氧树脂的结构进行了表征. 所得脂环族环氧树脂采用阳离子引发 剂二甲苯基碘鎓六氟磷酸盐引发进行紫外光固化, 对其光固化活性进行了研究, 同时讨论了氧化剂过氧化苯甲酰对该光固化体系的增感作用. 研究结果表明, 新合成的脂环族环氧树脂采用二甲苯基碘鎓六氟磷酸盐引发可以进行光固化, 过氧化苯甲酰明显地加快了其光固化速度, 固化膜具有较好的热稳定性.     

高活性固载化三氯化铝催化合成金刚烷

首次用固载化AlCl3催化剂催化桥式四氢双环戊二烯异构化反应合成金刚烷.结果表明,以γ-Al2O3为载体的固载化AlCl3催化剂在较低的反应温度(140℃)下具有较高的催化活性和生成金刚烷的选择性,桥式四氢双环戊二烯的转化率达到100%,金刚烷的选择性为17.7%;而以Si O2作为载体制备的催化剂,几乎没有金刚烷生成.     

双环戊二烯

双环戊二烯是石油裂解 C_5馏分和煤焦油苯头馏分中一种重要的烯烃。来源丰富、价廉易得,被广泛地应用在聚合物材料和有机化学产品方面,作为一种新型有机化工原料和有机化学试剂具有广阔的发展前景。分子结构双环戊二烯(Dicyclopentadiene,简称 DCPD)系环戊二烯(Cyclopentadiene,简称 CPD)的二聚体,分子式 C_(10)H_(12),属降冰片烯类。     

Controlled shrinkage polymers: Characterization of epoxy resins cured with spirobislactones

The diglycidyl ether of bisphenol A (DGEBA) was cured with either an aliphatic or an aromatic spirobislactone using a tertiary amine catalyst. The products were characterized by FTIR, TGA, DSC, dilatometry, and single-fiber adhesion measurements, and their performance was compared to that of DGEBA cured with acid anhydrides. Both aliphatic and aromatic bislactones are effective curing agents for DGEBA. FTIR and dilatometry confirm that both lactone rings open early in the curing reaction and initially offset shrinkage caused by polymerization. After the bislactone has been consumed, oxirane reactions proceed in a normal fashion. The final shrinkage of cured DGEBA polymers, with or without addition of bislactones, is 3.0–3.5%. Bislactone-modified materials possess superior thermal properties, when compared to those of anhydride-cured materials.     

Mechanical relaxation mechanism of epoxide resins cured with acid anhydrides

The mechanism of low-temperature mechanical relaxation in epoxide resins cured with various acid anhydrides has been investigated by comparing dynamic mechanical properties and chemical structures of these networks. One mechanical relaxation, denoted as the β relaxation, is observed at about ?70°C. The β relaxation is affected by the chemical structure of the curing agents, but not by that of the epoxide resins. In addition, the strength of the relaxation increases linearly with increasing concentration of diester linkage introduced in the network by reaction with acid anhydrides. From these results, it is concluded that the β relaxation mechanism of the anhydride-cured systems involves the motion of diester segments included in the network structures.     

Studies on Surface Free Energy of an Anhydride-Epoxy Cured System: Effect of Side Alkenyl Chain Length of Hardener on Tensile and Impact Properties

Three kinds of alkenyl succinic anhydrides (ASA) with varying side chain lengths (2-octenyl, 2-dodecyl, and 2-hexadecynyl succinic anhydrides) for hardeners as epoxy curing agents are synthesized by the ene reaction. The curing effect of ASA on the mechanical tensile and impact properties of cured diglycidyl ether of bisphenol-A (DGEBA) epoxy resin is studied. It is observed that increasing the side alkenyl chain length of ASA leads to a decrease of tensile strength of the cured epoxy resin, probably due to the decreasing of cross-linking density. However, it is found that the impact properties of the casting specimens are increased as the side alkenyl chain length of the hardener increases. This is probably due to the effect of the nonpolar or London-dispersive component of the surface free energy of the ASA studied, resulting in improving of the toughness properties of the casting specimens. Copyright 2000 Academic Press.     

Cure reaction and phase behavior of liquid crystalline epoxides-anhydride systems

A series of novel liquid crystalline epoxides with lateral substituents were cured with anhydrides and the cure kinetics was investigated by non-isothermal DSC technique. The results showed that the lengths of lateral substituents have great effect on the value of Ea. The curing reaction became less active, when the liquid crystalline epoxides have long lateral substituents and were controlled by diffusion at the late stage of cure. A nematic structure was observed by POM and XRD.     

Network build-up and structure in curing of epoxy resins

The available branching theories and their application to curing of epoxy resins are reviewed. Special attention is paid to theoretical treatment and experimental results of curing with polyamines, polyetherification, and to curing with poly(carboxylic acid)s and cyclic anhydrides.     

Characterisation of cured alkyd paint binders using swollen state 13C-NMR

Swollen state ¹³C-NMR can be used to characterise commonly encountered air-dried alkyd paint binders. Deuterochloroform is the solvent of choice and a conventional Fourier transform spectrometer can be used. The polyol and aromatic acid present in the binder can be readily identified and some useful information on the drying oil fatty acids can be obtained. The study of partially cured materials leads to information concerning curing mechanisms. Modifiers present in the alkyds such as silicones, polyurethanes and styrenic materials can readily be identified. The presence of titanium dioxide pigment in the cured binder does not greatly alter the quality of the spectra obtained thus allowing full characterisation of the resin used.     

咪唑固化不同类型环氧树脂的固化特征、固化动力学及其反应活性

以咪唑为固化剂,对缩水甘油醚型、缩水甘油酯型环氧树脂(简称链型环氧树脂)及脂环环氧树脂的固化特征、固化动力学及反应活性进行了研究.DSC实验结果表明,固化过程均分两阶段进行,链型环氧树脂固化反应表观活化能低于脂环环氧树脂.各树脂第一阶段的表观反应活化能均低于第二阶段活化能.当脂环环氧树脂中混入不同比例的链型环氧树脂后,固化反应速率均较脂环环氧树脂单独固化时快,当链型环氧树脂量大于50％时,更为明显.     

基于松香酸酐的环氧树脂体系固化动力学及TTT图绘制

研制了基于松香酸酐固化剂的生物质环氧树脂体系,采用全动态DSC法研究了树脂体系的固化反应动力学,通过半经验的唯象模型拟合得到了固化反应参数,活化能Ea为59.68 kJ/g,指前因子A0为1.28×1015s-1,反应级数n为2.483,由此建立了体系固化温度/时间/固化度间的关系;采用恒温DSC及DMA方法测试玻璃化转变温度,应用DiBenedetto经验方程拟合得到了玻璃化转变温度与固化度间的关系.应用锥板旋转黏度计测试了树脂体系不同温度下的凝胶时间,通过线性回归分析得到了凝胶时间与温度之间的关系.由唯象模型和DiBenedetto方程分别计算得到凝胶时的固化度为0.386,玻璃化转变温度为26.22°C.由上述工作绘制了基于松香酸酐生物质树脂体系的TTT(time-temperature-transition diagram)固化图,可确定树脂体系在不同温度任意时间下的状态.     

环氧树脂／酚酞聚醚醚砜共混物的相行为

酚酞聚醚醚砜(PES-c)同未交联的双酚A二缩水甘油醚(DGEBA)环氧树脂的共混物呈单一的玻璃化转变温度,其相容性主要归因于混合熵的贡献。PES-C同交联的环氧树脂之间的相容性与所用的固化剂有关。以胺类作DGEBA的固化剂时,共混物不发生相分离;以酸酐作固化剂时,共混物发生相分离。     

Influence of Residual Polyesterification Catalysts on the Curing of Polyesters

 Unsaturated polyesters are synthesized by means of polyesterification, often with catalysts like strong acids, metal oxides and metal-organic salts. Most often, the catalysts used cannot be separated from the bulk of the polyester. Also, some organic or inorganic additives – called fillers – which are used with the polyester in order to decrease cost, affect the curing of the polyester. In this work the effect of residual catalyst on the curing of unsaturated polyester is studied. Unsaturated polyesters were prepared using propylene glycol with a 10% molar excess over stoichiometry and a mixture of dicarboxylic acids, namely maleic acid (unsaturated) adipic acid (saturated) and phthalic anhydride (saturated) at a molar ratio 1:2:2. Lead dioxide, p-toluenesulfonic acid and zinc acetate were used as catalysts, at 0.1% w/w. After the polyesterification, the polymers were diluted with styrene at a proportion of 100:30 w/w. The resins were cured by using MEKP (methylethylketone peroxide) as initiator and CoNp (cobalt naphthenate) as accelerator. Catalysts affect the final color of the polyester. The kinetics of curing of the resins was studied by DSC analysis based on the exothermic peak due to the double bonds breaking to give crosslinked macromolecules. The heat released ΔH is decreased by the presence of catalyst, while activation energy, the frequency factor and the order of reaction are increased.