A Study on Composites from Casein Modified Melamine-Formaldehyde Resin

Amino resins are used for various applications such as decorative plastic plates, decorative wood boards, particle boards, leather tanning, foam, coating, and molding materials. In the present work, it was planned to prepare modified melamine-formaldehyde resin by incorporating casein. The intended melamine-formaldehyde-casein (MFC) resin samples were prepared under alkaline condition with an 1:3 melamine: formaldehyde ratio. Casein was incorporated in varying proportions (up to 25% w/w of melamine content) at 85–90°C. The samples were characterized by viscosity measurement and vapor pressure osmometry (VPO). The resin samples were cured isothermally at 60°C using ammonium chloride as well as hydroxylamine hydrochloride and at 120°C using hexamine as the curing agents. Jute fabric (JFRC) and glass fabric reinforced composites (GFRC) were produced by maintaining 60:40 and 40:60 proportion of resin to reinforcement materials, respectively. The laminates thus formed were characterized for their mechanical properties and chemical resistance.     

Modified Cyclohexanone-Formaldehyde Resin as an Epoxy Resin Curing Agent

Cyclohexanone-formaldehyde (CHF) resin was brominated and the brominated CHF (BCHF) was then reacted with excess aromatic diamines. The aminated CHF resins designated as ACHFs (modified ketone resin) were characterized and then applied as epoxy resin curing agents. Thus, the curing of the commercial epoxy resin diglycidil ether of bisphenol-A (DGEBA) by ACHFs was monitored by differential scanning calorimetric (DSC), based on the the DSC scans, the glass fiber-reinforced composites of DGEBA-ACHF systems were prepared and characterized by chemical resistivity and mechanical properties.     

氰酸酯树脂改性研究进展

氰酸酯树脂(CE)具有优异的介电性能、较高的玻璃化转变温度和强度、良好的耐化学腐蚀性和耐热性等优点,然而其固化物脆性较大,并且其韧性常常不能满足使用要求。从提高CE韧性角度,介绍了各种CE的改性方法(包括橡胶弹性体改性、热固性树脂改性、热塑性树脂改性和互穿聚合物网络改性等)及其应用研究进展。针对改性过程中存在的问题,提出了CE改性的未来发展方向。     

环氧改性有机硅树脂的制备及其性能研究

采用化学方法制备了环氧改性有机硅树脂。通过红外分析表明,环氧树脂与有机硅树脂发生了化学反应。研究发现：环氧改性有机硅树脂的水接触角、瓦均有变化,微观形态仍呈均相结构。研究还发现：随环氧树脂用量增大,改性有机硅树脂微观结构的粗糙度提高,水接触角增大。     

球形壳聚糖呋喃甲醛树脂的制备及吸附性能研究

采用物理和化学双重方法对壳聚糖进行改性,得到一种性能良好的吸附树脂。试验中先采用滴加成球法制备球形壳聚糖,然后用呋喃甲醛对其改性,合成了球形壳聚糖呋喃甲醛树脂。用均匀设计方法对最佳合成工艺条件进行了探讨,利用红外光谱、X射线衍射分析和电镜分析对树脂进行了表征,研究了树脂的基本结构性能和在酸中的稳定性、吸附动力学和吸附容量等性能。结果表明,树脂具有发达的微孔结构,较大的比表面积,在酸性环境中不流失等特点,树脂的吸附容量大,吸附速度快。     

Synthesis,Characterization and Glass/Carbon Reinforcement of Acetone-Formaldehyde-1,5-Dihydroxynaphthalene-Epoxy Resin System

Acetone-formaldehyde (AF) resin containing the methylol group (–CH₂OH) has been prepared and condensed with 1,5-dihydroxynaphthalene (DN) in the presence of an alcoholic alkali catalyst at varying ratios of AF:DN: 1:1, 1:1.5 and 1:2, respectively. The resultant AFDN resins were characterized by elemental analyses, IR spectral studies, and number average molecular weight determined by the nonaqueous conductometric titration method. Further reaction of the AFDN resins was carried out with different epoxy resins (i.e., DGEBA, DGEBC and DGEBF). The curing of these resins was monitored by differential scanning calorimeter (DSC) and their kinetic parameters have been evaluated. Based on DSC thermograms both glass and carbon fiber-reinforced composites have been laminated and characterized for chemical, mechanical and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA).     

Glass-Reinforced Composites Based on a Novel Oligoimide-Epoxy Resin System

A novel matrix resin system, oligoimide-epoxy resin, has been developed to prepare glass fiber reinforced composites. Benzidine bismaleimide-diaminodiphenyl methane (BBM-DDM) and ethyl-ene bismaieimide-diaminodiphenyl methane (EBM-DDM) oligo-mers having more —NH₂ groups were prepared through the Michael addition reaction. These oligoimides were used for curing of commercial epoxy resin (i.e., diglycidyl ether of bisphenol-A) at 120°–140°C to fabricate crosslinked oligoimide-epoxy resin glass fiber reinforced composites without the evolution of byproduct. The fabricated composites (i.e., laminates) were characterized by their chemical resistance and mechanical properties.     

透明粉末涂料用丙烯酸树脂的合成及性能研究

采用溶液聚合法合成带环氧基团的丙烯酸树脂,并对其结构进行了表征。研究了甲基丙烯酸缩水甘油酯(GMA)用量、引发剂类型对丙烯酸树脂及涂料性能的影响。通过选用夺氢能力较弱的引发剂以及聚合工艺的优化,合成出高流平、高耐候、耐腐蚀性佳的透明粉末涂料用丙烯酸树脂。     

Novel Interacting Blends of Unsaturated Polyester-s-Triazine and Epoxy Resin

2-(4-ethyl-1-piperazinylo)-4,6-bismaleatedethylamino-1,3,5-triazine (EBT) was prepared by the reaction of 2-(4-ethyl-1-piperazinylo)-4,6-bishydroxyethylamino-1,3,5-triazine and maleic anhydride. The EBT derivative was characterized by elemental analysis, acid value and spectral studies.

EBT was then polycondensed respectively with three commercial epoxy resins, namely diglycidyl ether of bisphenol-A (DGEBA), diglycidyl ether of bisphenol-F (DGEBF) and diglycidyl ether of bisphenol-C (DGEBC). The resultant polymers are designated as unsaturated polyester-s-triazine (UPETs) and were characterized by elemental analysis, spectral study, molecular weight determination, differential scanning calorimeter (DSC)and thermogravimetry. The interacting blends of UPETs with DGEBA epoxy resin was made at stoichiometric ratio. The blending of these systems was monitored on a differential scanning calorimeter (DSC), and based on DSC data the glass-reinforced composites (GRC_s) were prepared and characterized by physical and mechanical properties.     

环氧树脂的合成与应用研究概况

环氧树脂因具有优良的物理机械性能、化学稳定性、耐化学腐蚀性、耐热及粘接性能而得到广泛应用.其种类繁多且合成方法各异.文章以双酚A型环氧树脂为例对环氧树脂合成工艺及其在不同领域的几种应用形式分别进行了综述.     

木质素基聚酯型环氧树脂的制备及表征

以高沸醇木质素为原料合成聚酯型木质素基环氧树脂,用红外光谱对产物结构进行表征。讨论了预聚体——醇解木质素聚合酸(ALPA)含量和固化剂用量对所得木质素环氧树脂粘合强度及固化物的力学性能的影响,并用DSC和TGA对产物的热稳定性进行了测试。结果表明,随着ALPA含量的增加,木质素环氧树脂固化物的热稳定性能明显增强,粘合强度先增大后减小,最佳的ALPA投料比例为50%(质量),固化剂最佳用量为树脂质量的15%。     

腰果酚基环氧树脂的合成及其性能研究

设计合成了一种腰果酚基环氧树脂。首先,以羟乙基腰果酚醚(HCE)和三氯氧磷(POCl3)为原料,利用亲核取代反应合成了一种具有三臂结构的预聚体(PT-HCE)。采用双氧水/甲酸的均相催化法对PT-HCE进行了环氧化,合成了磷酸三羟乙基腰果酚醚环氧树脂(EPT-HCE),同时探究了甲酸的投料比对环氧值的影响。结果表明:当双键与甲酸的物质的量比为1∶0.4时,环氧值能达到最高值0.18 mol/(100 g)。通过傅里叶变换红外光谱仪(FT-IR)、核磁共振波谱仪(NMR)对PT-HCE和EPT-HCE的结构进行了表征,证明了环氧树脂被成功合成。此后,利用所合成的树脂制备了热固化涂料,研究了酸酐含量等对涂层附着力、铅笔硬度和耐冲击性等性能的影响,还将EPT-HCE与双酚A型环氧树脂E51进行了复配。结果表明:相比于纯E51环氧树脂制备的涂层,加入EPT-HCE树脂后的涂层柔韧性得到了提高。     

支化聚醚型环氧树脂／双酚A环氧树脂共混体系的研究

通过端基转换的方法合成了一种新型支化聚醚型环氧树脂，通过FTIR证实了环氧基团的存在，用化学分析法测定了环氧值。利用这种环氧树脂对E-44环氧树脂进行改性，大大提高了固化环氧树脂的冲击强度，同时弯曲强度和模量下降并不多；用扫描电镜观察改性的冲击断面发现有明显韧性断裂特征。     

胺类固化剂固化的双酚环氧树脂回收再利用的研究

双酚F型环氧树脂的耐酸性较低，在硝酸溶液中能够被安全分解。基于这一特性，本文探讨了一种环氧树脂化学回收再利用的方法。首先，用乙酸乙酯做溶液把该树脂的硝酸分解生成物从中性环境溶液中萃取出来，干燥后，替代部分环氧树脂，混入环氧树脂中，经固化剂固化后，制得再生树脂。并对原树脂和再生树脂的机械性能进行了比较。     

三聚氰胺树脂纤维的改性

概述了三聚氰胺树脂纤维的阻燃机制及改性方法,特别对化学改性方法以及化学改性剂的筛选要求进行了介绍,指出改性的目的是在保持其良好的耐高温和阻燃性能的前提下改善三聚氰胺树脂纤维的柔性,提高纤维强度。     

有机硅改性环氧树脂的制备及其性能研究

以3种有机氯硅烷单体水解制备有机硅单体,有机硅单体改性了环氧树脂,水解条件为温度35～40℃,时间1～1.5 h,用水量n(H2O)∶n(Cl)=(6～7)∶1。通过红外光谱分析表明,有机硅主要是与环氧树脂中羟基发生化学反应。对环氧树脂改性前后的力学性能、耐热性和防潮性进行测试,结果表明,当n(R)/n(Si)为1.5时,拉伸强度可达23.91 MPa,弯曲强度达到29.24 MPa,冲击强度达到10.02 kJ/m2,50%的质量热损失温度431℃,分别比改性前提高了3.86 MPa,9.49 MPa,6.18 kJ/m2,30℃;同时,改性后树脂防潮性能也得到了提高。     

溶剂法制备AES树脂及其性能研究

介绍了溶剂法合成丙烯腈/乙丙橡胶/苯乙烯共聚(物AES)的制备方法,探讨了一步法合成AES过程中反应体系发生的物理化学变化研,究了AES树脂双峰粒径分布的结构及其对树脂物理力学性能的影响。     

低表面能树脂的性能及固化研究

通过化学改性,合成了环氧树脂/有机硅复合树脂。探讨了不同固化剂及其复配方式对其固化性能的影响,并得到最佳的固化剂配方。通过红外光谱（IR）、扫描电子显微镜（SEM）、动态力学分析（DMA）以及接触角测试,研究并比较了改性前后有机硅树脂涂层的微观结构形貌、体系混溶性、表面性能（接触角）等的变化。研究结果表明：环氧树脂与有机硅树脂之间具有较好的微观混溶性;改性后,树脂表面的粗糙度增加,接触角增大,形成低表面能树脂。     

Synthesis,Characterization and Glass Reinforcement of Poly(Ester Amido Imide)s

Poly(ester amido imide)s (PEAI)s (IIIa–e) were prepared by the intermolecular Diels-Alder (DA) reaction of bismaleimide (II) having epoxy resin segment with various bisfurans (Ia–e) having amide bridge. The DA reaction was carried out with tetrahydrofuran as a solvent, as well as in bulk, followed by aromatization of DA polyadduct intermediates in the presence of acetic anhydride. All the resultant polymers, designated as poly(ester amido imide)s (PEAI)s, were characterized by elemental analysis, number average molecular weight, IR spectral studies and thermogravimetry. The PEAIs exhibit good thermal stability. Bismaleimide (II) and bisfurans (Ia–e) were polymerized (at 150 ± 10°C) by in situ DA intermolecular reaction into moderately thermally stable PEAIs. The glass fiber-reinforced composites (i.e., laminates) of all PEAIs were prepared and characterized by their chemical resistance and mechanical properties.