氟化硅氧烷改性环氧树脂的制备与性能

首先,以全氟(2-甲基-3-氧杂己基)氟化物(六氟环氧丙烷二聚体)和N-(β-氨乙基)-γ-氨丙基三甲氧基硅烷(KH792)为原料制备一种氟化硅氧烷,用FTIR和1HNMR表征其结构.然后,将氟化硅氧烷与聚醚胺共同固化环氧树脂DGEBA(双酚A型二缩水甘油醚),测试了改性环氧树脂复合材料的性能.结果表明,与未改性环氧树...     

含氟环氧树脂的合成与性能研究

采用十二氟庚醇与双酚A环氧树脂接枝合成了侧链含氟环氧树脂。采用了力学性能测试、红外光谱(FTIR)、X-射线光电子能谱(XPS)、动态热机械分析(DMTA)及交流阻抗分析(EIS)研究了含氟环氧树脂固化物的力学性能、表面性能及电化学性能等。结果表明,含氟环氧树脂固化后氟元素在表面富集,其断裂延伸率和冲击强度较双酚A环氧树脂分别提高41%和26.8%,交流阻抗提高2个数量级以上。含氟环氧树脂的韧性和电性能显著提高。     

环氧基POSS改性环氧树脂的研制与性能研究

以苯基三乙氧基硅烷(PTES)和β-3,4-环氧环己基乙基三甲氧基硅烷(A186)为原料,甲醇、乙醇混合溶液为溶剂,酸性条件下水解制得含有Si—H键的环氧基低聚倍半硅氧烷(EP-POSS),通过傅里叶红外光谱(FT-IR)、核磁共振氢谱(¹H NMR)、核磁共振硅谱(²⁹Si NMR)等手段对其结构进行表征。用制备的EP-POSS对环氧树脂进行改性,分析了EP-POSS用量对树脂涂层附着力、耐冲击性、疏水性、耐热稳定性的影响。结果表明:当EP-POSS加入量为5%时,环氧树脂涂层附着力达到1级,耐冲击性达到50 cm,对水的接触角为90°,热稳定性大幅提升。     

乙烯基MQ硅树脂改性环氧树脂的研究

通过前期制备的乙烯基MQ硅树脂来对环氧树脂E44进行改性。根据对改性后产物的红外光谱分析、相对分子质量及分布的测定、环氧值测定,结果表明,乙烯基MQ硅树脂能与环氧树脂中的羟基发生反应,产物中大部分为环氧树脂的低聚物。通过对改性物的力学性能和耐热性能分析可知,与物理共混改性方法相比,化学共聚改性方法得到的产物具有相对较好的力学性能和较佳的耐热性能。当m(E-44)∶m(MQ)=50∶5时,经化学共聚改性后产物的拉伸强度达60.4 MPa、断裂伸长率达11.9%。当m(E-44)∶m(MQ)=50∶5时,改性后产物的玻璃化温度由改性前的153.0℃增加到168.5℃,玻璃化温度的提高,表明经化学共聚改性的环氧树脂耐热性能提高。     

乙烯基MQ硅树脂改性环氧树脂的研究

通过前期制备的乙烯基MQ硅树脂来对环氧树脂E44进行改性。根据对改性后产物的红外光谱分析、相对分子质量及分布的测定、环氧值测定,结果表明,乙烯基MQ硅树脂能与环氧树脂中的羟基发生反应,产物中大部分为环氧树脂的低聚物。通过对改性物的力学性能和耐热性能分析可知,与物理共混改性方法相比,化学共聚改性方法得到的产物具有相对较好的力学性能和较佳的耐热性能。当m(E-44)∶m(MQ)=50∶5时,经化学共聚改性后产物的拉伸强度达60.4 MPa、断裂伸长率达11.9%。当m(E-44)∶m(MQ)=50∶5时,改性后产物的玻璃化温度由改性前的153.0℃增加到168.5℃,玻璃化温度的提高,表明经化学共聚改性的环氧树脂耐热性能提高。     

液晶环氧树脂改性普通环氧树脂的研究

合成了一种液晶环氧树脂,并使之与普通环氧树脂共混固化,共混固化物的力学性能和热稳定性比普通环氧树脂固化物有明显的提高。     

环氧树脂改性水性聚氨酯消光树脂性能的研究

以环氧树脂(EP)作为自乳化PU(聚氨酯)的交联改性剂,合成了一系列改性WPU(水性聚氨酯)消光树脂。采用FT-IR(红外光谱)法、TGA(热失重分析)法和水接触角法对共聚物的结构和热性能进行了表征,并对其消光性能和耐水性进行了测定。研究结果表明:EP的环氧基和羟基都参与了交联反应,EP的引入可提高WPU的热稳定性和疏水性;当w(EP)=5.0%(相对于WPU预聚体质量而言)时,相应消光树脂的耐水性、耐热性俱佳。     

环氧有机硅油改性丙烯酸树脂的合成及性能

以偶氮二异丁腈为引发剂,通过丙烯酰氧基硅油与丙烯酸酯类单体的自由基共聚合反应,同时环氧828与丙烯酸共聚侧链羧基进行开环反应,合成以乙醇为主要溶剂的单相均匀牛顿型环氧有机硅油改性丙烯酸树脂。并对树脂涂膜的稳定性及硬度、耐水煮性,附着力等性能进行了研究。得到的树脂具有良好的热储稳定性,颜料广泛润湿性。环氧有机硅油改性丙烯酸树脂涂膜具有光泽高、硬度好、丰满度高、玻璃附着力强、耐水煮性好与透明性高等优异性能,适用于高档玻璃烤漆。     

A study on the properties of epoxy resin toughened by a liquid crystal‐type oligomer

A series of novel reactive toughening agents (LCEU_PPG) containing both a flexible spacer and rigid liquid crystalline unit were synthesized to modify the bisphenol epoxy resin/dicyandiamide curing system. The curing reactivity, apparent activation energy, curing mechanism, dynamic mechanical behavior, and impact strength of the modified system were systematically studied. Compared with the unmodified system, the results indicate that LCEU_PPG have greatly accelerated the curing reaction between epoxy resin and dicyandiamide, reduced the apparent activation energy of the curing reaction, enhanced the impact strength 3–7 times, and maintained high dynamic modulus and good thermal properties. In addition, SEM observation of the fracture surfaces showed a two‐phase microstructure in the modified systems. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 177–184, 1999     

环氧改性苯丙乳液的合成及性能

采用反应性乳化剂通过种子乳液聚合法制备木器涂料用环氧树脂改性苯乙烯-丙烯酸酯微乳液.研究了乳化剂的选择与用量、环氧树脂的用量和功能单体的用量对改性苯丙乳液综合性能的影响,并用傅立叶变换红外光谱仪(FT-IR)对乳液组成进行表征.研究发现反应型乳化剂可制备纳米级乳液,且m(DSB)m(DNS-86)=31时,乳液具有好的稳定性,涂膜有较好的耐水性;得到环氧树脂以及丙烯酸的最佳添加量;性能测试表明合成的环氧树脂改性苯丙乳液具有较好的成膜性能和优异的物理机械性能.     

含氟环氧树脂的研究进展

有机氟改性环氧树脂兼具环氧树脂与氟元素二者优点,已经成为近年来的研究热点,并已有不少学者研究制备出了具备高性能和应用价值的含氟环氧树脂。本文综述了含氟环氧树脂的研究及应用现状,详细介绍了含氟环氧树脂的合成方法以及在相关领域的应用,最后对含氟环氧树脂的前景进行了展望。     

Preparation and properties of cyanate ester modified by epoxy resin and phenolic resin

Stiff and brittle cyanate ester (CE) resin was modified by copolymerizing it with epoxy resin (ER) and phenolic resin (PR) to improve its toughness and flexibility. The cure process of the modified CE resin was characterized by gel time curves and differential scanning calorimetry curves. The Fourier transform infrared spectra of the modified CE resin showed its chemical structure during the curing process. The mechanical properties, thermal behavior, dielectric properties, and morphology of the modified CE resins were investigated. The results showed that an increase in epoxy and phenolic resins resulted in improved flexibility while maintaining thermal stability. When the mass ratio of CE/ER/PR was 70 : 15 : 15 (w/w), flexural strength and impact strength of the modified CE resin increased from 113.6 MPa and 5.2 kJ/m² to 134.5 MPa and 16.7 kJ/m², respectively. Little of the thermal stabilityand dielectric properties was sacrificed in the modification of the CE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3150–3156, 2007     

Mechanical properties of glass fiber composites with an epoxy resin modified by a liquid crystalline epoxy

The effect of liquid crystalline networks on epoxy + glass fiber composites is investigated. The matrix obtained from in‐situ curing of liquid crystalline (LC) diglycidyl ether of 4,4‐dihydroxybiphenol (DGE‐DHBP) with diglycidyl ether of bisphenol F (DGEBP‐F) by anhydride curing agent was used as the matrix for polymer composites. Impact, tensile, and flexural testing results are compared between the unmodified and modified systems. The interlaminar fracture toughness of commposites in the shear mode was determined by end notch flexure (ENF) tests. Scanning electron microscopy is used to study the fracture surfaces to understand the mechanism of fracture and interphase formation between the fiber and the matrix.     

端羧基丁腈橡胶改性环氧树脂的结构与性能

以液体端羧基丁腈橡胶(CTBN)作为环氧树脂(EP)的增韧改性剂,制备了CTBN/EP预聚体和共混物。采用红外光谱(FT-IR)法对两者的结构进行了表征,并着重探讨了CTBN含量对预聚体和共混物力学性能的影响。研究结果表明:预聚体中EP的环氧基开环,并与CTBN反应,生成了酯键;随着CTBN含量的不断增加,CTBN/EP预聚体和共混物的杨氏模量、拉伸强度降低,冲击强度和断裂伸长率呈先升后降态势,说明适量CTBN的引入对EP具有良好的增韧效果;当固化温度较低时,CTBN/EP预聚体的冲击强度明显优于CTBN/EP共混物,而固化温度较高时两者的冲击强度无明显差异。     

Cure behavior and properties of an epoxy resin modified with a bismaleimide resin

A bismaleimide (BMI) resin was added to an epoxy system composed of N,N′-tetraglycidyldiaminodiphenyl methane (TGDDM) and diaminodiphenyl methane (DDM). Cure behavior of the BMI modified epoxy resins was studied by a dynamic differential scanning calorimetry (DSC) method. Dynamic DSC thermograms of the BMI modified epoxy resins indicated unimodal reaction exothermic peaks. The overall heat of reaction per unit mass decreased with BMI composition. The residual heat of reactions of the epoxy blends cured at 180°C for 3 h increased with BMI composition. Thermal stability of the epoxy system improved by incorporating BMI resin. Flexural strength and modulus increased with BMI composition.     

环氧改性水性醇酸树脂的制备及其性能

将亚麻油酸与环氧树脂E-51进行开环反应制得了环氧酯,然后将其替代部分多元醇参与水性醇酸树脂的制备,并利用红外光谱对产物结构进行了表征。重点考察了环氧酯的合成工艺及环氧酯用量对树脂、漆膜各项性能的影响。结果表明,环氧酯最优合成工艺条件为:反应温度110℃,反应时间4 h,四丁基溴化铵用量为反应物总质量的1%,在该条件下,合成树脂的酸值为10.3 mg KOH/g;当环氧酯用量为醇酸树脂总质量的10%时,树脂及其漆膜的综合性能最优,且通过TG测试表明,环氧改性后水性醇酸树脂漆膜的热稳定性得到明显改善。     

Synthesis and properties of fluorinated biphenyl‐type epoxy resin

A novel fluorinated biphenyl‐type epoxy resin (FBE) was synthesized by epoxidation of a fluorinated biphenyl‐type phenolic resin, which was prepared by the condensation of 3‐trifluoromethylphenol and 4,4′‐bismethoxymethylbiphenyl catalyzed in the presence of strong Lewis acid. Resin blends mixed by FBE with phenolic resin as curing agent showed low melt viscosity (1.3–2.5 Pa s) at 120–122°C. Experimental results indicated that the cured fluorinated epoxy resins possess good thermal stability with 5% weight loss under 409–415°C, high glass‐transition temperature of 139–151°C (determined by dynamic mechanical analysis), and outstanding mechanical properties with flexural strength of 117–121 MPa as well as tensile strength of 71–72 MPa. The thermally cured fluorinated biphenyl‐type epoxy resin also showed good electrical insulation properties with volume resistivity of 0.5–0.8 × 10¹⁷ Ω cm and surface resistivity of 0.8–4.6 × 10¹⁶ Ω. The measured dielectric constants at 1 MHz were in the range of 3.8–4.1 and the measured dielectric dissipation factors (tan δ) were in the range of 3.6–3.8 × 10^?3. It was found that the fluorinated epoxy resins have improved dielectric properties, lower moisture adsorption, as well as better flame‐retardant properties compared with the corresponding commercial biphenyl‐type epoxy resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚氨酯改性环氧树脂的合成及性能研究

以聚氨酯(PU)作为环氧树脂(EP)的增韧改性剂,考察了m(EP):m(PU)比例、活性稀释剂等对PU改性EP性能的影响.结果表明:当m(EP):m(PU)=80:20时,改性EP的韧性和强度同时提高,并且其耐热性最佳;活性稀释剂的加入能在一定程度上增韧、增强纯EP及改性EP,但两者的耐热性有所降低.     

环氧基硅烷改性氰酸酯树脂的性能研究

采用环氧基硅烷(ESi)对双酚A型二氰酸酯树脂(BCE)进行改性,研究了ESi用量对ESi/BCE体系力学性能和动态力学性能等影响。结果表明:适量的ESi可以明显提高BCE的韧性和强度;当w(ESi)=6%时,ESi/BCE改性体系的力学性能最好,其冲击强度和弯曲强度分别从10.1 kJ/m2、94.11 MPa提高到14.49 kJ/m2、110.94 MPa;ESi/BCE体系的交联密度降至适度是其韧性提高的主要原因,并且其玻璃化转变温度(Tg)低于纯BCE体系(但降幅不大)。