表面处理对环氧树脂/PBO纤维界面剪切强度的影响

采用了磺化聚芳酰胺(SPA)和固化剂593分别对PBO纤维进行表面处理,用钢针将配好的环氧树脂基体溶液似微球状滴在固定在试样架上的PBO纤维上,考察了处理前后PBO纤维与环氧树脂界面剪切强度的变化。结果表明,两种表面处理对PBO纤维与环氧树脂基体的界面剪切强度都有贡献,其中固化剂处理能显著提高界面剪切强度,改变了界面破坏模式,使PBO纤维与环氧树脂基体的界面剪切强度最高可达19.41 MPa,比未处理时的界面剪切强度提高95%。     

Fatigue Crack Growth in Epoxy/Aluminum and Epoxy/Steel Joints

The fatigue crack growth rate within epoxy/aluminum and epoxy/steel joints was evaluated as a function of a) type of surface pretreatment, b) water soak, c) fatigue cycle rate (Hz), d) adhesive thickness and e) type of epoxy adhesive.

For both adherends, aluminum and steel, a significant improvement in the fatigue behavior was obtained by use of a mercaptoester coupling agent. After an 8-day, 57°C water soak, the metal surfaces which were pretreated with coupling agent (CA) or by phosphoric acid anodization (PAA) still resulted in cohesive failure, while the controls had higher crack growth rate and showed greater scatter. The room-temperature cure matrix with CA-treated aluminum showed a less dramatic improvement, probably because of a known difference in the application procedure. For the steel joints and room-temperature adhesive the improvement in the fatigue behavior of CA-treated samples was maintained after the 8-day hot water soak. No significant change was found in the fatigue crack growth rate over a frequency range of 1 to 5 Hz, but a significant change was found as a function of the bondline thickness. The room temperature curing adhesive evaluated herein exhibited a much lower fatigue resistance than a heat-cured commercial structural adhesive FM-73.     

硅烷偶联剂和固化温度对LY12铝合金／环氧树脂黏接强度的影响

研究了含硫硅烷偶联剂和固化温度对LY12铝合金／环氧树脂黏接剪切强度、拉伸位移的影响规律，并用扫描电镜观察分析了黏接试样的拉伸剪切断面形貌特征。结果表明，铝合金表面经过硅烷偶联剂处理后，80～180℃固化时，黏接剪切强度介于19.4～22.2MPa之间，明显高于铝合金表面未用硅烷偶联剂处理时的最大黏接强度17.5MPa，断面呈现被平行裂纹一层层掀开的破坏现象，表明硅烷偶联剂起到了明显的界面改性作用。低温固化条件下黏接强度低，断面较平整；在220℃以上高温固化时，界面相脆化，黏接性能快速下降，断面呈现脆性断裂特征。     

Fatigue Crack Growth in Epoxy/Aluminum and Epoxy/Steel Joints

The fatigue crack growth rate within epoxy/aluminum and epoxy/steel joints was evaluated as a function of a) type of surface pretreatment, b) water soak, c) fatigue cycle rate (Hz), d) adhesive thickness and e) type of epoxy adhesive.

For both adherends, aluminum and steel, a significant improvement in the fatigue behavior was obtained by use of a mercaptoester coupling agent. After an 8-day, 57°C water soak, the metal surfaces which were pretreated with coupling agent (CA) or by phosphoric acid anodization (PAA) still resulted in cohesive failure, while the controls had higher crack growth rate and showed greater scatter. The room-temperature cure matrix with CA-treated aluminum showed a less dramatic improvement, probably because of a known difference in the application procedure. For the steel joints and room-temperature adhesive the improvement in the fatigue behavior of CA-treated samples was maintained after the 8-day hot water soak. No significant change was found in the fatigue crack growth rate over a frequency range of 1 to 5 Hz, but a significant change was found as a function of the bondline thickness. The room temperature curing adhesive evaluated herein exhibited a much lower fatigue resistance than a heat-cured commercial structural adhesive FM-73.     

Investigation of Steel/Epoxy Adhesion Durability Using Polymeric Coupling Agents III. Influence of Coupling Agent Layer Thickness

Steel/epoxy peel specimens were prepared using ethylene-mercaptoester (EME) copolymer coupling agents (90 wt% mercaptoester units) applied in thickness ranging from 25 to 350 Å. An optimum thickness of approximately 140 Å, which corresponded to an over 200% increase in peel strength when compared to 50 Å thick samples, was determined from ellipsometry and 90° peel strength measurements. The corrosion protection obtained was essentially independent of coupling agent thickness.     

液液界面剪切黏度研究进展

界面剪切黏度是表征乳液油水界面膜性质的重要参数之一,界面剪切黏度反映了油/水界面膜的强度。该文回顾了液液界面剪切黏度的研究进展,并对液液界面的研究进行了展望。引用文献40篇。     

The Effects of Interphase Properties on Interfacial Shear Strength in Polymer Matrix Composites

The effects of interphase elastic modulus, glass transition temperature, and thickness on interfacial shear strength were investigated both experimentally and theoretically. Single fiber fragmentation tests were performed over a range of temperatures on samples with tailored interphases. Three different types of interphases were investigated: high modulus/high glass transition temperature, low modulus/low glass transition temperature and uncoated (no tailored interphase). A reduction in interfacial shear strength with temperature was observed for all three types of samples tested. The magnitude of this decrease was found to correlate with the glass transition temperature of the interphase. The low T_g interphase samples showed large reductions in IFSS, while samples with a higher T_g coating showed only a small decrease. A three-phase, axisymmetric elasticity solution was developed to predict the sensitivity of the stress state to the interphase material properties and temperatures used in the experimental studies. Predictions which incorporated the change in modulus of both the matrix and interphase with temperature were in good agreement with the experimental trends. Both the theoretical and experimental results supported the existence of an interphase with reduced glass transition in the uncoated samples.     

硅烷偶联剂及其水解物对环氧树脂拉伸剪切强度的影响

以双酚A和环氧氯丙烷为原料,通过缩聚反应制得环氧树脂;将硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)在酸催化下水解,得到水解物。探讨了KH-570及其水解物用量对环氧树脂胶黏剂拉伸剪切强度的影响。结果表明,不加KH-570及其水解物时,环氧树脂胶黏剂的拉伸剪切强度最大为2.47 MPa;只加KH-570水解物时,环氧树脂胶黏剂的拉伸剪切强度最大为3.28 MPa;只加入KH-570时,环氧树脂胶黏剂的拉伸剪切强度最大为5.23 MPa。在KH-570水解物与环氧树脂的质量比相同条件下,随着KH-570用量的增大,环氧树脂胶黏剂的剪切强度先增后减,在KH-570的用量为环氧树脂质量的15%时达到最大;相同KH-570用量下,随着KH-570水解物用量的增大,环氧树脂胶黏剂的剪切强度先增后减,在KH-570水解物和环氧树脂的质量比为5∶5时达到最大。当KH-570的用量为环氧树脂质量的15%、KH-570水解物与环氧树脂的质量比为5∶5时,环氧树脂胶黏剂的拉伸剪切强度达到9.36 MPa。     

硅烷偶联剂对热塑性聚氨酯及复合玻璃性能的影响

利用硅烷偶联剂KH550对热塑性聚氨酯胶膜(TPU)进行表面改性处理,通过红外光谱、表面接触角、可见光透过率、粘结强度等测试研究了偶联剂处理对TPU胶膜的结构和性能的影响.结果表明:改性后的TPU胶膜表面粗糙度增大,表面水接触角降低,由120.5°降至80.5°,胶膜表面活性、耐热稳定性和可见光透过率都有明显的提升.同时,胶膜对于复合玻璃(Glass/TPU/PC)的粘结强度有显著提高,当处理时间为5 min时效果最佳,粘结强度由改性前的2.02 MPa增大至5.63 MPa,提高了179％.     

Zinc Coated Steel/Epoxy Adhesive Systems: Investigation of the Interfacial Zone by FTIR Spectroscopy

The present study takes advantage of the ability of Fourier Transform Infrared Spectroscopy (FTIR) for the analysis of ultrathin organic films on metals. FTIR in the reflection mode (IRRAS) is used in order to study the interaction of ultrathin films of dicyandiamide (hardener of most one-pack epoxy resins) with various substrates, model ones such as gold or zinc and industrial ones such as steel and zinc-coated steels.

Pure zinc surfaces and, to a lesser extent, zinc-coated steels are shown to react with dicyandiamide after heating at 180°C, as evidenced by the frequency shift of the absorption band (at about 2200 cm^-1) characteristic for nitrile groups. As real systems consist of thick layers of a fully formulated adhesive cured onto a metallic substrate, the direct investigation of such a buried interphase is no longer possible by FTIR and by most of the known spectroscopies. Some mechanically tested specimens are then analysed, after failure, by FTIR microspectrometry. The spectra obtained, corresponding to the fracture initiation zone which is about 100 μm in diameter, advocate for the presence of an ultrathin layer of modified polymer still covering the substrate.     

环氧树脂/氮化铝复合材料冲击性能的研究

通过钛酸酯偶联剂处理氮化铝(AlN)粉末,采用机械分散和超声波分散相结合的方法,制得环氧树脂/AlN复合材料。实验表明,钛酸酯偶联剂能有效地改善AlN粉末的表面性能,偶联剂质量分数为6%时,改性效果最好;AlN填料质量分数为10%￣20%时,复合材料的冲击韧性较好。冲击断口形貌分析表明,河流状裂纹越窄,数量和分支越多,扩展路径越长,冲击韧性越好,A l N填料改性效果也越好。     

硫酸钙晶须对E-44环氧树脂的微结构与力学性能的影响

以E-44环氧树脂为基体,硫酸钙晶须（CSW）为增强材料制备了硫酸钙晶须／环氧树脂复合材料,研究了不同硫酸钙晶须含量对复合材料的拉伸强度、弯曲强度、磨损量及耐热温度的影响。结果表明,复合材料的力学性能、磨损量及耐热性均有所提高,拉伸强度和弯曲强度分别提高了25％、51％,磨损量降低了54％,耐热温度提高了7．9℃。由SEM表明,试样断面光滑,属于脆性断裂。     

环氧树脂改性水性聚氨酯的合成与性能研究

采用环氧树脂（EP）、聚酯二元醇、异佛尔酮二异氰酸酯（IPDI）、二羟甲基丙酸（DMPA）等制备了环氧树脂改性水性聚氨酯。实验选择环氧树脂E-51为改性剂,讨论了EP含量、NCO／OH比值、DMPA含量对体系耐水性、粘接性及力学性能的影响。实验结果表明：EP质量分数为6％～8％、NCO／OH比值为1．3～1．4、DMPA质量分数为6％时,水性聚氨酯样品的性能较好。     

不同改性方法对竹纤维增强环氧树脂复合材料性能的影响

采用碱/硅烷偶联剂(KH550)和碱/KH550/二苯甲基二异氰酸酯(MDI)对竹纤维进行表面改性,并制备了环氧树脂/竹纤维复合材料,研究了两种表面改性方法对复合材料的力学性能及热稳定性的影响.结果表明,竹纤维经改性后,复合材料的拉伸强度显著提升,两种改性方法制备的复合材料在拉伸强度上无较大区别,但与碱/KH550改性...     

偶联剂对环氧树脂戚式碳酸镁体系力学和分散性能的影响

利用扫描电镜（SEM）和力学拉伸实验,分析和对比了硅烷、钛酸酯和铝酸酯偶联剂处理过的环氧树脂／碱式碳酸镁体系的显微结构和拉伸强度。分别研究了这些偶联剂对环氧树脂,碱式碳酸铗体系的显微结构和拉伸强度的影响。结果表明,使用硅烷偶联剂时,环氧树脂／碱式碳酸镁体系的力学性能和分散性能最好。     

Effect of Plasma-Polymerized Primers on the Durability of Aluminum/Epoxy Adhesive Bonds

The durability of aluminum/epoxy adhesive joints prepared from substrates pretreated by plasma etching and then deposition of plasma-polymerized primers was determined using the wedge crack testing method. Plasma etching and polymerization were conducted using both direct current (DC) and microwave (2.45 GHz) driven plasma systems. Plasma-polymerized primers were deposited using trimethysilane (TMS) and hexa-methyldisiloxane (HMDSO) to form siloxane-like and silica-like films, respectively. Plasma etching with argon and argon/hydrogen plasmas was used as a substrate pre-treatment. In some cases etching with an oxygen plasma was used as a post-treatment to give a silica-like surface to siloxane-like films deposited from TMS. Adhesive joints were prepared using two different epoxy adhesives, Cytec FM-300 and FM-123-2. Differences in initial adhesion were observed for primer films with chemical differences. Siloxane-like primer films were not wetted by the adhesive and resulted in poor wedge test results. Silica-like primer films were not wetted by the adhesive and resulted in poor wedge test results. Silica-like primer films deposited onto aluminum substrates resulted in wedge specimens with good adhesion and durability. The initial crack was cohesive within the adhesive. However, crack growth occurred at the interface between the adhesive and silica-like primer. Durability of the wedge specimens was essentially invariant of the type of microwave plasma pretreatment for grit-blasted aluminum substrates that were coated with silica-like primers before bonding with FM-123-2.     

环氧树脂/玻璃布复合材料拉伸剪切性能研究

本文介绍了浸渍方法、浸渍参数、树脂粘度及层压板纤维体积含量对环氧树脂/玻璃布拉伸剪切性能的影响。     

硅烷偶联剂改性超强聚乙烯纤维的性能表征

为充分发挥超强聚乙烯纤维作为复合材料增强体的补强作用,提高纤维与基体之间弱的界面黏结强度,采用硅烷偶联剂KH-550对超强聚乙烯纤维进行了表面改性。全自动单一纤维接触角测量发现改性后超强聚乙烯纤维的接触角减小了30.03%;场发射扫描电镜发现改性后超强聚乙烯纤维的表面由光滑变为粗糙且凹槽深度加深;傅里叶变换红外光谱测试发现改性后的超强聚乙烯纤维出现伯胺基团的弯曲振动和Si-O的特征吸收峰;X射线衍射测试发现改性后超强聚乙烯纤维的衍射峰位置略微发生了变化,且纤维的结晶度增大;热重同步分析发现改性后纤维的残炭率提高了0.56%。     

玻纤浸润剂组分对环氧基复合材料界面性能的影响

通过测定复合材料NOL环层间剪切强度,研究了增强型玻纤浸润剂中常用的几类成膜剂、润滑剂对玻纤增强环氧基复合材料界面层剪性能的影响。聚酯、环氧、聚氨酯成膜剂种类中,用于玻璃纤维增强环氧树脂基复合材料时,环氧成膜剂的复合材料界面性能最佳;不论干润滑剂,还是湿润滑剂,其复合材料的界面性能均较成膜剂弱,阳离子酰胺类润滑剂相对其他润滑剂略好。     

Relationship Between Some Mechanical Strengths of CFRP and Interfacial Properties

The relationships between microscopic properties such as interfacial shear strength (IFSS) and macroscopic properties such as flexural strength were investigated for CFRP prepared from carbon fiber and epoxy resin. Flexural, tensile and impact strengths all went through maximum values when plotted against the surface treatment time of the carbon fiber. The flexural strength of CFRP as a function of the treatment time of the carbon fiber behaved similarly to the adhesive strength of the resin and carbon fiber. Also, the results indicated that the bahavior of tensile and impact strengths varied with the treatment time in much the same way as the interfacial shear strength did. The occurrence of these two types of macroscopic and microscopic property effects can be understood by taking into account the chemical activity and roughness of the carbon fiber surface.