环氧胶粘剂增韧改性剂

介绍了三种典型的环氧树脂胶粘剂的增韧改性剂——丁腈橡胶、其它类弹性体和热塑性工程塑料,并对近年来环氧增韧改性剂的研究工作进行了综述。     

CTBN与ATBN改性环氧胶粘剂的研究

将端羧基丁腈橡胶(CTBN)接枝上环氧官能团进行改性,将改性后的CTBN添加到环氧胶粘剂的A组分中;将端氨基丁腈橡胶(ATBN)以不同的比例加入到环氧胶粘剂的固化剂即B组分中。考查胶粘剂的剪切、剥离强度和玻璃化转变温度以及2组分的配比对胶粘剂性能的影响。结果表明,将改性后的CTBN橡胶与ATBN配合使用比单独使用其中一种的综合性能更好,2者在A、B组分中分别占12质量份数左右时其增韧效果最显著。     

新型增韧改性环氧胶粘剂

天津城建学院与河北大学合作攻关，以丁腈-40液体橡胶为主料，对E-44双酚A环氧树脂／低分子质量聚酰胺树脂固化体系进行了增韧改性，研制出新型改性环氧树脂胶粘剂，该剂可以在室温下24h固化，室温剪切强度最高可达22．4MPa，     

环氧胶粘剂增韧改性研究进展

回顾了关于近些年环氧树脂及环氧胶粘剂增韧的研究进展情况，比较系统地介绍了环氧树脂增韧的方法及相关增韧机理，并在此基础上总结了环氧胶粘剂的增韧方法，指出了今后环氧胶粘剂增韧改性研究方向。     

环氧大豆油低聚物增韧环氧树脂胶粘剂

合成了三种环氧大豆油低聚物作为室温和高温固化环氧树脂增韧剂,对其增韧环氧体系的粘接性能和力学性能进行了考察。试验结果表明,环氧树脂低聚物对固化体系的初期粘度等性能没有影响,对固化体系粘接性能和力学性能等有较大影响。与未改性的环氧树脂相比,由顺丁烯二酸酐扩链的环氧大豆油低聚物改性的环氧树脂剪切强度提高了56.64%。     

环氧大豆油低聚物增韧环氧树脂胶粘剂

合成了三种环氧大豆油低聚物作为室温和高温固化环氧树脂增韧剂，对其增韧环氧体系的粘接性能和力学性能进行了考察。试验结果表明，环氧树脂低聚物对固化体系的初期粘度等性能没有影响，对固化体系粘接性能和力学性能等有较大影响。与未改性的环氧树脂相比，由顺丁烯二酸酐扩链的环氧大豆油低聚物改性的环氧树脂剪切强度提高了56．64％。     

环氧胶粘剂增韧改性研究进展

概述了关于近些年环氧树脂以及环氧树脂胶粘剂增韧改性的研究进展情况,简单地介绍了以无机刚性填料(颗粒)增韧改性环氧胶粘剂的情况,比较详细地叙述了以橡胶弹性体和热塑性树脂增韧改性环氧胶粘剂的一些重要研究情况及相关的增韧机理,指出了国内外之间环氧胶粘剂发展的差距,同时提出了环氧胶粘剂将来的重点和发展趋势。     

水溶性环氧胶粘剂的推广与应用

1前言随着船舶工业的发展，船舶建造中的装满要求也越来越高。因此，不论大小船舶的地板都采用了粘贴塑料方块或塑料地毯工艺。采用粘贴，必然要大量应用胶粘剂。选用什么样的胶粘剂，这是船舶系统一直研究和关注的问题。过去，大都采用202’、825＃、999＃等氯丁橡胶型胶粘剂，这些胶粘剂都有不可克服的缺点，如202＃胶、999#胶，其毒性大，且防火性差，在船舶施工中很不安全。825＃胶粘剂虽然改用了三氯乙烯作稀释剂，防火性能得到很大改善，但其毒性大，在各大船厂施工中均发生过程度不同的中毒现象。因此，研究出一种无毒或毒性小的胶粘…     

环氧-聚砜结构胶粘剂耐环境性能的研究

报导了SY-14环氧-聚砜胶粘剂体系的耐环境性能研究结果。在北京、南昌、广州和海口四个不同气候条件下的10年大气曝晒试验表明,各项胶接强度均末发生明显变化。含有抑制腐蚀底胶的胶接试板进行的10年室温盐水浸泡试验也取得了优良的试验结果。     

环氧胶粘剂增韧改性的研究开发现状

综述了环氧胶粘剂增韧改性的发展现状,主要对丁腈橡胶、其它类弹性体以及热塑性树脂增韧环氧胶粘剂的研究状况做了介绍,最后对环氧胶粘剂增韧改性的发展前景作了展望。     

核壳聚合物增韧环氧树脂的进展

核壳聚合物（CSP）现已用于增韧环境树脂，它具有许多优点：预先设计的CSP在环氧基体中的形态、大小和分散状态与固化规范无关；在提高环氧树脂韧性的同时不降低玻璃化温度。本文综述了CSP／环氧共混物的性能和增韧机理。主要的增韧机理是CSP粒子空穴化，释放裂缝附近的三轴度，继而产生膨胀形变和剪切屈服。     

Study of ionic polymer toughening epoxy resin

In this study, PEL [copolymer of poly(propylene) oxide (PPO) and poly(ethylene oxide) (PEO)] toughening epoxy resin with ionic charge was used to produce an interpenetrating action between the cross‐linking network structure of the epoxy resin and the PEL additive. Fourier transform infrared (FTIR) analysis of the toughening epoxy resin revealed that ? NCO disappeared at 2400 cm^?1, ? NH appeared at 3300 cm^?1, and ? C?O appeared at 1750 cm^?1. These results indicate that a urethane bond was produced. Dynamic mechanical analysis (DMA) and mechanical testing results indicated that as the level of PEL increased, the compatibility between the epoxy resin and PEL also increased. In addition, the compatibility was improved because the addition of cornate hardener produced a graft phenomenon. The tensile property, impact strength, and fracture toughness of PEL toughening epoxy resin all had a tendency to improve. The tensile strength, impact strength, and fracture toughness (K_IC value) were most improved when 30 phr cornate was added. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3740–3751, 2002     

The mechanisms and mechanics of the toughening of epoxy polymers modified with silica nanoparticles

The present paper considers the mechanical and fracture properties of four different epoxy polymers containing 0, 10 and 20 wt.% of well-dispersed silica nanoparticles. Firstly, it was found that, for any given epoxy polymer, their Young’s modulus steadily increased as the volume fraction, v_f, of the silica nanoparticles was increased. Modelling studies showed that the measured moduli of the different silica-nanoparticle filled epoxy polymers lay between upper-bound values set by the Halpin-Tsai and the Nielsen ‘no-slip’ models, and lower-bound values set by the Nielsen ‘slip’ model; with the last model being the more accurate at relatively high values of v_f. Secondly, the presence of silica nanoparticles always led to an increase in the toughness of the epoxy polymer. However, to what extent a given epoxy polymer could be so toughened was related to structure/property relationships which were governed by (a) the values of glass transition temperature, T_g, and molecular weight, M_c, between cross-links of the epoxy polymer, and (b) the adhesion acting at the silica nanoparticle/epoxy-polymer interface. Thirdly, the two toughening mechanisms which were operative in all the epoxy polymers containing silica nanoparticles were identified to be (a) localised shear bands initiated by the stress concentrations around the periphery of the silica nanoparticles, and (b) debonding of the silica nanoparticles followed by subsequent plastic void growth of the epoxy polymer. Finally, the toughening mechanisms have been quantitatively modelled and there was good agreement between the experimentally-measured values and the predicted values of the fracture energy, G_c, for all the epoxy polymers modified by the presence of silica nanoparticles. The modelling studies have emphasised the important roles of the stress versus strain behaviour of the epoxy polymer and the silica nanoparticle/epoxy-polymer interfacial adhesion in influencing the extent of the two toughening mechanisms, and hence the overall fracture energy, G_c, of the nanoparticle-filled polymers.     

Fracture and fatigue response of a self-healing epoxy adhesive

A self-healing epoxy adhesive for bonding steel substrates is demonstrated using encapsulated dicyclopentadiene (DCPD) monomer and bis(tricyclohexylphosphine)benzylidine ruthenium (IV) dichloride (Grubbs’ first generation) catalyst particles dispersed in a thin epoxy matrix. Both quasi-static fracture and fatigue performance are evaluated using the width-tapered-double-cantilever-beam specimen geometry. Recovery of 56% of the original fracture toughness under quasi-static fracture conditions occurs after 24 h healing at room temperature conditions. Complete crack arrest is demonstrated for fatigue test conditions that render neat resin and control samples failed. Inspection of fracture surfaces by electron microscopy reveals evidence of polymerized DCPD after healing. These results are the first mechanical assessment of self-healing for thin (ca. 360 μm) films typical of adhesives applications.     

基体种类对CTBN改性环氧树脂结构和性能的影响

研究了ＣＴＢＮ对不同种类的环氧树脂（Ｅ－５１、Ｆ－５１）力学性能的影响,通过扫描电镜观察了２种增韧体系的微观结构形态,并探讨了２种增韧体系的微观结构形态与力学性能间的关系。     

纳米增韧剂FORTEGRA 202增韧环氧胶粘剂的研究

阐述了环氧树脂的增韧方法和机理,对陶氏化学FORTEGRA 202环氧增韧剂在不同固化体系中的性能表现进行了研究。并与环氧胶粘剂中常用的端羧基丁腈橡胶（CTBN）或与环氧预聚的端羧基丁腈橡胶CTBN-Epoxy进行了性能对比。研究表明FORTEGRA 202环氧增韧剂除产品本身的低黏度所带来的配方调整空间更大的优势外,固化物还具有玻璃化转变温度高,拉剪强度更高,断裂韧性和透明度更好等优势。     

Comparison of fracture behavior between acrylic and epoxy adhesives

An experimental study was conducted on the strength of adhesively bonded steel joints, prepared epoxy and acrylic adhesives. At first, to obtain strength characteristics of these adhesives under uniform stress distributions in the adhesive layer, tensile tests for butt, scarf and torsional test for butt joints with thin-wall tube were conducted. Based on the above strength data, the fracture envelope in the normal stress-shear stress plane for the acrylic adhesive was compared with that for the epoxy adhesive. Furthermore, for the epoxy and acrylic adhesives, the effect of stress triaxiality parameter on the failure stress was also investigated. From those comparison, it was found that the effect of stress tri-axiality in the adhesive layer on the joint strength with the epoxy adhesive differed from that with the acrylic adhesive. Fracture toughness tests were then conducted under mode l loading using double cantilever beam (DCB) specimens with the epoxy and acrylic adhesives. The results of the fracture toughness tests revealed continuous crack propagation for the acrylic adhesive, whereas stick-slip type propagation for the epoxy one. Finally, lap shear tests were conducted using lap joints bonded by the epoxy and acrylic adhesives with several lap lengths. The results of the lap shear tests indicated that the shear strength with the epoxy adhesive rapidly decreases with increasing lap length, whereas the shear strength with the acrylic adhesive decreases gently with increasing the lap length.     

Toughness of syndiotactic polystyrene/epoxy polymer blends: microstructure and toughening mechanisms

Thermoplastic/epoxy blends were formed using an amine-cured epoxy polymer and a semi-crystalline thermoplastic: syndiotactic polystyrene (sPS). Complete phase-separation of the initially soluble sPS from the epoxy occurred via ‘reaction-induced phase-separation’ (RIPS) or via ‘crystallisation-induced phase-separation’ (CIPS), depending upon the thermal processing history employed. Dynamic mechanical thermal analysis showed that no sPS was retained dissolved in the epoxy polymer. For RIPS, at concentrations of sPS of up to 8 wt%, the sPS is present solely as spherical particles. However, macro phase-separation, giving a co-continuous microstructure, accompanied by local phase-inversion, dominates the RIPS blends containing more than 8 wt% sPS. In the CIPS blends, the sPS is present as spherulitic particles, and this microstructure does not change over the range of sPS concentrations employed, i.e. from 1 to 12 wt% sPS. The pure epoxy polymer was very brittle with a value of fracture energy, G_Ic, of about 175 J/m². However, the addition of the sPS significantly increases the value of G_Ic, though the toughness of the RIPS and CIPS blends differs markedly. For the RIPS blends, there is a steady increase in the toughness with increasing content of sPS and an apparent maximum value of G_Ic of about 810 J/m² is obtained for 8-10 wt% sPS. On the other hand, the measured toughness of the CIPS blends increases relatively slowly with the concentration of sPS, and a maximum plateau value of only about 350 J/m² was measured in the range of 8-12 wt% sPS. The relationships between the microstructure of the RIPS and CIPS sPS/epoxy blends and the measured fracture energies are discussed. Further, from scanning electron microscopy studies of the fracture surfaces and optical microscopy of the damage zone around the crack tip, the nature of the micromechanisms responsible for the increases in toughness of the blends are identified. For the RIPS blends, (i) debonding of the sPS particles, followed by (ii) plastic void growth of the epoxy matrix are the major toughening micromechanisms. The increase in toughness due to such micromechanisms is successfully predicted theoretically using an analytical model. In the case of the CIPS blends, the increase in the value of G_Ic results from (i) crack deflection and (ii) microcracking and crack bifurcation.     

Toughening epoxy adhesives with multi-walled carbon nanotubes

In this paper, the effect of adding multi-walled carbon nanotubes (MWCNTs) with an outer diameter of less than 8 nm to an epoxy adhesive was studied on the adhesive fracture resistance and damage behaviour. The fracture energies of the neat and toughened adhesives were measured by testing double-cantilever beam specimens. Moreover, a cohesive zone model (CZM) was used to numerically study the effect of MWCNTs on the damage behaviour of the toughened adhesives. The maximum improvement of 58.4% in the adhesive fracture energy was obtained when the adhesive was toughened with 0.3 wt% of MWCNTs. The fracture surfaces were analysed using the scanning electron microscopy (SEM) technique. It was found that the presence of MWCNTs in the toughened adhesives caused rougher fracture surfaces. Moreover, some fracture mechanisms including nanotube pull-out and de-bonding were observed in the fracture surfaces. The numerical analyses showed that the damage process zone length was also influenced by MWCNTs. The longest damage process zone was obtained for the toughened adhesive with 0.3 wt% of MWCNTs.