蓖麻油改性环氧聚氨酯防腐蚀涂料的研制

介绍了一种蓖麻油改性的环氧聚氨酯防腐蚀涂料.以蓖麻油改性异氰酸酯预聚物和环氧树脂为基料,以价格较为低廉的滑石粉、钛白粉、沉淀硫酸钡为颜填料制备了成本较低,性能较为优异的防腐蚀涂料.检测了优化条件下制备的涂料的性能.以蓖麻油改性环氧聚氨酯防腐蚀涂料和未经蓖麻油改性的环氧聚氨酯防腐蚀涂料进行防腐蚀性能对比,蓖麻油改性环氧聚氨酯防腐蚀涂料的耐酸、碱、盐水等防腐蚀性能更好.     

环氧树脂蓖麻油双重改性水性聚氨酯皮革涂饰剂的合成与性能

以聚氧化丙烯二醇(PPG)和异佛尔酮二异氰酸酯(IPDI)为原料,蓖麻油(CO)和环氧树脂(E-44)为交联剂,采用预聚体分散法合成了一系列用于皮革涂饰的环氧树脂蓖麻油双重改性水性聚氨酯(ECOWPU)。采用FTIR、TEM、DSC、TGA对聚合物结构及膜的性能进行了分析。FTIR表明聚合物中引入了蓖麻油和环氧树脂,羟基和环氧基均参与反应。通过TEM可观察乳液颗粒呈球形,粒径较为均匀。DSC表明,改性后胶膜的微相分离程度增大。TGA表明,环氧树脂和蓖麻油的加入提高了聚氨酯的热稳定性。蓖麻油、E-44含量的增加,均使胶膜拉伸强度逐渐增大,断裂伸长率、吸水率降低。当蓖麻油添加量为4.9%,E-44添加量为7%时,胶膜的综合性能最佳。     

高铁机车专用环氧防腐底漆的制备

以腰果油改性聚酰胺为固化剂制备了一种环氧防腐底漆,并按铁道部标准TB／T2260-2001的规定对涂层的防腐性和机械性能进行了测试。结果表明,使用腰果油改性聚酰胺作为固化剂能明显提高涂层的耐盐雾性,对涂层的机械性能影响甚微,达到了铁道部标准要求。     

Progress on Epoxy/Polyamide and Inorganic Nanofiller-Based Hybrids: Introduction,Application, and Future Potential

An efficient method to obtain better properties of epoxy-based nanocomposites is to introduce thermoplastic polymer such as polyamide into thermosetting resin. Combined effect of both polymers provides extra-bonding sites for nanofiller dispersion. This review mainly covers inorganic nanofiller dispersed epoxy/polyamide nanocomposite and their applications. To understand interaction between thermoset epoxy and thermoplastic polyamide, knowledge of structure, synthesis, and categorization is worth important. Addition of inorganic nanofiller such as layered silicate and metal oxide results in enhanced thermomechanical, physiochemical, and anticorrosive properties of resultant nanocomposite. These nanocomposites have applications as protective coatings, adhesives, insulators in electrical devices, and in aerospace industries.     

环氧改性水性聚氨酯分散体的合成及应用

以环氧树脂E-51和蓖麻油为原料制备了环氧改性的水性聚氨酯分散体。试验结果表明：当环氧树脂用量为6％、蓖麻油用量为20％和n-NCO／n—OH为1．4时,所得涂膜具有优异的耐水性、硬度和抗划伤性,满足水性木器面漆的性能要求。     

Improvement of the interfacial shear strength of poly(p‐phenylene benzobisoxazole) fiber/epoxy resin composite via a novel surface coating agent

Poly(p‐phenylene benzobisoxazole) (PBO) fiber with a smooth surface exhibits limited interfacial interaction with resin matrix. One of the effective strategies to improve the adhesion between the fiber and resin matrix is through surface modification of the fiber. In this study, we have proposed a novel surface treatment agent based on phosphoester cross‐linked castor oil (PCCO) for effective surface treatment of PBO fibers. The surface treatment agent was prepared by a simple cross‐linking reaction between hydroxy phosphorylated castor oil (PCO) and epoxy resin, with alcohol as the solvent at 65°C. Once the PBO fiber was treated with this agent, the interfacial adhesion between the PBO fiber and the epoxy resin could then be improved. Systematic analyses suggest that the surface treatment with (PCO + epoxy)/alcohol solution improves the interaction of the PBO fiber with the epoxy resin matrix. The PCCO coated onto the surface of PBO fiber acts as a coupling agent, improving the interfacial shear strength (IFSS) of the PBO fiber/epoxy resin composite. Results indicate a 156% increase in IFSS without compromising the mechanical properties of the fiber. POLYM. COMPOS., 37:1198–1205, 2016. © 2014 Society of Plastics Engineers     

Influence of some vegetable oils on the photocrosslinking of coatings based on an o-cresol novolac epoxy resin and a bis-cycloaliphatic diepoxide

The influence of cashew nut shell oil (CNO), epoxidized soybean oil (ESO), castor oil (CO), and dioctyl phtalate (DOP) on the photocrosslinking kinetics of UV curable mixtures containing an o-cresol novolac epoxy resin (CNE), a bis-cycloaliphatic diepoxide monomer (BCDE), and a triarylsulfonium salt (TAS) as a cationic photoinitiator has been studied. The formulation with a weight ratio CNE/BCDE/TAS of 60/40/5 was found to have the highest cure rate and the greatest final conversion of epoxy groups upon UV exposure. The presence of an unsaturated oil or of DOP in the UV curable formulation, at a content ranging from 0.07 to 0.79 mol/kg, was shown to increase the initial polymerization rate of the epoxy groups from 12 up to 31 mol/kg s, and the epoxy conversion after 18 s UV exposure from 80 up to 95%. It was found that the UV cured coatings containing CNO or DOP at concentrations between 0.3 and 0.6 mol/kg and ESO at concentrations between 0.12 and 0.19 mol/kg exhibit the best performance. These results were explained by a number of competitive factors, mainly the effects of the chemical structure and content of the oils and of DOP on the polarity, viscosity, compatibility, and internal filter effect of the UV curable resins, as well as by the characteristics of the tridimensional polymer networks formed upon UV exposure. The materials produced under the optimal conditions determined in this study can be used as high performance decorative and protective coatings and also as adhesives in different sectors of applications.     

Experimental and numerical analysis of single lap bonded joints: Epoxy and castor oil PU-glass fibre composites

ABSTRACT

Currently, there is a growing concern for the environment. Several studies of new materials to reduce environmental impact have been carried out by different research groups, and many companies have replaced parts made of fossil sources by renewable materials. The use of polyurethane (PU) derived from castor oil as a matrix for composite materials and adhesives is one example. Hence, the present work aims to compare the numerical and experimental analyses of castor oil PU and epoxy resin not only as a matrix of composite materials, but also as an adhesive of bonded joints. The joint coupons were manufactured by using castor oil PU-glass fibre and epoxy-glass fibre as adherents, which were bonded by epoxy or castor oil PU. Thus, four combinations of adherents and adhesives were investigated. Specimens with identical geometry were used in all tests, which were based on guidelines for single lap bonded joints. Computational simulations via Finite Element Method were performed for predictions of the adhesive layer stresses and strength. In addition, a material model is proposed to predict the failure of the adhesive layer. The experimental and numerical results showed that PU derived from castor oil has good mechanical performance, making this material a feasible alternative for bonded joints, mostly nowadays when environment is a major concern.     

Flame-retardant compounds for polymeric materials from an abundantly available,renewable biosource,castor oil

Castor oil is a triglyceride extracted from the seed (castor bean) of the castor plant. This plant will thrive on relatively poor soil and in an arid climate. The oil is nonedible but is produced annually in large volume to be converted to biodiesel (largely for the European market). The oil contains both unsaturation and hydroxyl functionality that may be utilized for conversion to flame retarding materials. A series of phosphorus esters has been generated from castor oil. All display good flame retardancy in the diglycidyl ether of bisphenol A (DGEBA) epoxy resin. Introduction of bromine at the double bond generally enhances the flame retardancy of these esters.     

环氧树脂/马来海松酸酐聚酰胺的固化反应及产物性能研究

以马来海松酸酐为原料,通过与多元胺(二乙烯三胺、三乙烯四胺、四乙烯五胺)进行酰胺化反应,合成了3种环氧树脂固化剂马来海松酸酐聚酰胺,分别命名为聚酰胺样品Ⅰ、聚酰胺样品Ⅱ、聚酰胺样品Ⅲ。利用傅里叶红外光谱仪(FT-IR)、热重分析仪(DTA)、拉力机等分析测试手段,对环氧树脂/马来海松酸酐聚酰胺体系固化产物的特征性能进行了表征。结果表明,环氧树脂分别与3种聚酰胺样品按理论质量配比100:51、100:45、100:45混匀后,在室温放置6 h后再于80℃固化4 h,可完全固化,环氧树脂/聚酰胺样品Ⅰ剪切强度可达21.6 MPa,3种固化体系热分解温度均大于300℃,可望在对剪切强度、耐热等级要求较高的固化剂领域得到广泛应用。     

Cure kinetic of castor oil‐based polyurethane

This research presents the kinetic studies on the cure reactions of a new material, castor oil‐based polyurethane resin. Thermal analysis by isothermal differential scanning calorimetry was used, as a variety of factors affect its cure, including formulation and polymerization process. The kinetic reaction of this catalyzed system is described by nth order equation. Castor oil, a vegetable triglyceride, was reacted with methylene diphenyl 4,4′‐diisocyanate to produce an elastomeric matrix. The objective of this research is thermal characterization of new polyurethane that is less aggressive to humans and environment; therefore, castor oil used on the synthesis is derived from a natural and renewable resource. The activation energy measured for the castor oil‐based polyurethane resin studied in this work was about 56 kJ/mol. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Thiol modification of difunctional castor oil and its utility as room temperature setting elastomeric material

Difunctional castor oil has been reacted with thioglycolic acid for the synthesis of castor oil dithioglycolate (CODT). Elastomeric products have been obtained from CODT alone and in combination with liquid polysulfide polymer LP-33 by oxidative cure with manganese dioxide. Semireinforced (SRF) carbon black has been used as a filler. CODT has also been evaluated as a flexibilizer for liquid epoxy resin (Synpol 200).     

改性蓖麻油制备UV光固化涂料的研究

研究了改性蓖麻油制备UV光固化涂料。由蓖麻油、环氧丙烯酸树脂UVR6100、光引发剂UVI6990制得的涂料具有优良的光泽、良好的柔韧性、良好的附着力与硬度，且当改性蓖麻油含量为40％时，漆膜性能最为优良。     

A cost-effective high solids epoxy binder for protective coatings

Conclusion  From the foregoing it can be concluded that Epikote DX-874 can be used with a variety of curing agents for specific end-use requirements. A solids content of 85–90% by weight can be obtained by careful formulation of the paint. Performance equal to that of a traditional solvent-borne solid epoxy resin — polyamide curing agent binder system can be obtained when the incorporation of an aliphatic flexible part in the epoxy resin is compensated for by a part aromatic or cycloaliphatic component in the curing agent. By an example it is demonstrated that a lower cost can be obtained compared with that of traditional solvent-borne systems. Further cost savings in paint manufacturing, transport and application can be envisaged.     

Glass-reinforced interacting blends of epoxy/polyurethane based on castor oil: Synthesis and characterization. II

Mechanical and dielectric properties of rubber mixtures of epoxy/polyurethane based on castor oil loaded with glass fiber is of great interest from a technological point of view. Epoxy resin was prepared from bisphenol A and epichlorohydrin in alkaline medium. Polyurethane was prepared from the hydroxyl group of castor oil reacted with 2,4-toluene diisocyanate. Elemental analysis and infrared (IR) spectra are presented as evidence for the formation of these materials. A homogeneous solution of epoxy resin and polyurethane was prepared in acetone containing a curing agent 1,3-propane diamine. The glass-reinforced laminates were prepared by interacting polymer blends on the glass fiber through compression moulding. Chemical resistance to solvents, flexural strength, izod impact strength, and Rockwell hardness studies on a series of specimens were investigated. It was observed that they behave as tough materials. An attempt was made to study the effect of electrical conductivity by changing the compositions of rubber mixtures during reinforcement with glass fibers. The dielectric constant (E′) dielectric loss (E″), and loss tangent (tan δ) of the specimens and their dependence of temperature was studied.     

Cure behavior of epoxy resin containing castor oil and cashew nut shell liquid and its derivative

The cure behavior of epoxy resin with a conventional amide‐type hardener (HD) was investigated in the presence of castor oil (CO), cashew nut shell liquid (CNSL), and cashew nut shell liquid–formaldehyde resin (CFR) with dynamic differential scanning calorimetry (DSC). The activation energy of the curing reaction was also calculated on the basis of nonisothermal DSC thermograms at various heating rates. A one‐stage curing was noted in the case of epoxy resin filled with CO, whereas the epoxy resin with CNSL and CFR showed a two‐stage curing process. A competitive cure reaction was noted for the epoxy resin/CNSL(or CFR)/HD blends. In the absence of HD, CFR showed lower values of curing enthalpy than that of CNSL. The activation energy of epoxy resin curing increased with increasing CNSL and CFR loading. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Aging and Thermal Studies on Epoxy Resin Modified by Epoxidized Novolacs

Epoxy resins are thermosetting polymers widely used for polymer composites, adhesives, high performance coatings, potting and encapsulation, and numerous other applications. These resins have excellent mechanical and electrical properties, low cure shrinkage, and good adhesion to most substrates. This study is an attempt to improve the thermal and aging characteristics of epoxy resin by blending with other multifunctional epoxies such as EPN and ECN. Bis-phenol A epoxy resins containing 2.5 to 20 wt% of epoxy novolac were cured in the presence of a polyamide hardener and tested for thermal and mechanical properties, hardness, water absorption, etc. Blends containing 10 to 15 wt% of epoxy novolac show substantial improvement in properties such as tensile strength, elongation, and energy absorbed to break. The novolac derived from p-cresol was better than that based on phenol in enhancing the properties. TGA, DSC, and DMA were employed for studying the thermal properties of the modified resin. The study reveals that modification using epoxy phenol and p-cresol novolac resins (EPN and ECN, respectively) improves the aging characteristics of the epoxy resin in addition to overall improvement of the mechanical properties.     

Synthesis and characterization of epoxy resins containing arsenic acrylate

The properties of epoxy resins containing arsenic acrylate have been compared with that of a blank epoxy resin (DGEBA). The values of epoxide equivalent, hydroxyl content, hydrolyzable chlorine content, and specific gravity increased, whereas refractive index decreased in the epoxy resins containing arsenic acrylate (AsA₃). This is attributed to a complex formation between an As and an oxygen atom in the resin, as evidenced from IR spectroscopy. The reaction is first order (ER₃) with an activation energy of 53 kJ/mole. The epoxy resin with As cured with polyamide at 30°C, showed chemical resistance and excellent thermal stability compared with blank epoxy resin (epoxy resin without As).     

蓖麻油聚氨酯IPN黄变性能的研究

分别用2,4-甲苯二异氰酸酯(TDI)和六亚甲基二异氰酸酯(HDI)与蓖麻油反应制备出两种多异氰酸酯预聚体,再与交联剂(环氧树脂或烯类单体)反应制备出了不同的蓖麻油聚氨酯互穿网络型聚合物(IPN),通过黄色指数的测定,研究了体系组成对IPN黄变性能的影响。     

聚酰胺与腰果酚改性胺环氧固化剂的耐黄变性能比较

E-20环氧树脂分别与聚酰胺树脂和腰果酚改性酚醛胺固化,将漆膜曝晒,检测色差;用紫外线照射,检测漆膜性能。发现腰果酚改性酚醛胺比聚酰胺使环氧漆膜变黄的速率要快,紫外线对前者颜色影响更大,因而聚酰胺适合于作环氧面漆固化剂,腰果酚改性酚醛胺适合于作环氧底漆固化剂。