玻璃纤维增强复合材料的Ⅰ型层间断裂韧性

介绍了玻璃纤维增强复合材料Ⅰ型层间断裂韧性“RoundRobinTest”的结果随着偶联剂浓度的改变，Ⅰ型裂纹的扩展方式从稳态向非稳态转变这类断裂韧性强烈地依赖界面性能关键词##4界面性能;;Ⅰ型断裂韧性;;裂纹扩展;;稳态;;非稳态     

一种新型酚醛SMC的增稠机理和固化行为研究

讨论了一种新型酚醛SMC的增稠机理和固化行为.结果表明,增稠剂、填料和硅烷偶联剂对酚醛树脂糊的初期粘度有较大影响,当单独用氢氧化钙作增稠剂时增稠速度快,单独用氧化镁作增稠剂时增稠速度慢;当单独用滑石粉作填料时增稠速度快,单独用粘土作填料时增稠速度慢;通过调整增稠剂和填料各组份的比例可以得到粘度适合的酚醛树脂糊.另外,硅烷偶联剂能够催化酚醛SMC的硬化和固化,这已由DSC和凝胶时间数据所证实.这些研究结果为生产优质的酚醛SMC提供了理论依据.     

环氧树脂复合材料的制备及力学性能

通过配方设计,以硅烷偶联剂改性的空心玻璃微珠(HGB)为填料,端羧基液体丁腈橡胶(CTBN)为增稠剂和增韧剂,环氧树脂(EP)为基体,经变温分段固化技术制备环氧树脂/端羧基丁腈橡胶/空心玻璃微珠(EP/CTBN/HGB)三元泡沫复合材料并研究其力学和流变性能。结果表明,CTBN使得复合材料由脆性断裂变为韧性断裂;CTBN劣化了复合材料模量而HGB弥补了复合材料模量;当CTBN、HGB含量分别为12%(质量分数)和30%(体积分数)时,三元复合材料的冲击、弯曲、拉伸强度及弯曲模量均优于纯EP。另外,纯环氧树脂和EP/CTBN共混物的黏度呈现出牛顿流体的流变行为,而三元共混物的黏度表现出明显的剪切变稀现象。     

碳纳米管加入方式对碳纤维/环氧树脂复合材料层间性能的影响

针对碳纤维/环氧树脂预浸料,对比了直接在树脂中加入碳纳米管(CNTs)后制备预浸料以及将CNTs喷涂在预浸料表面2种CNTs加入方式对CNTs-碳纤维/环氧树脂复合材料层合板I型与II型层间断裂韧性及层间剪切强度的影响。通过对树脂黏度、固化反应以及玻璃化转变温度的考察,分析了CNTs含量对树脂性能的影响,考察了添加方法对CNTs长度与形态的影响。分析了2种CNTs加入方式对CNTs-碳纤维/环氧树脂层合板断裂韧性及层间剪切强度的改善效果与作用规律。结果表明:CNTs的加入使树脂的黏度提高,固化反应程度下降;2种分散方法对CNTs的长度与形态无明显影响;直接在树脂中加入CNTs对CNTs-碳纤维/环氧树脂复合材料I型与II型层间断裂韧性的提高效果低于在碳纤维/环氧树脂预浸料表面喷涂CNTs的方式,后者的CNTs利用率较高;由于CNTs团聚及对树脂固化反应的影响,CNTs含量过高会使得其对CNTs-碳纤维/环氧树脂层合板的增韧效果下降。     

酸刻蚀对玄武岩纤维表面偶联剂吸附量及纤维/环氧树脂复合材料力学性能的影响

纤维与树脂的复合需要有一个良好的界面相,以便能将载荷从基体有效地传递给增强纤维,纤维表面改性处理是达到这一要求的主要方法。采用盐酸刻蚀法对玄武岩纤维（BF）表面进行处理,讨论了酸刻蚀对纤维单丝拉伸性能、表面硅烷偶联剂吸附量的影响以及盐酸浓度对BF/环氧树脂复合材料力学性能的影响。结果表明：纤维的单丝拉伸强度随着盐酸浓度的升高呈加速下降趋势;1 mol/L盐酸处理后的纤维表面对硅烷偶联剂KH550的吸附量最大;1 mol/L盐酸刻蚀后再经硅烷偶联剂KH550处理的纤维制成的BF-KH550/环氧树脂复合材料的弯曲性能、拉伸性能和层间剪切强度最优。     

热熔法预浸料用氰酸酯树脂的性能

采用聚醚砜(PES)对氰酸酯树脂改性,制备出PM915树脂。对PM915树脂的工艺性能和固化物性能进行了系统研究,该树脂成膜性和贮存稳定性良好,适用于热熔法预浸料工艺。研究了PM915树脂的流变性能及凝胶时间,树脂在70℃时的黏度为20 Pa·s左右,在120℃条件下可保持黏度稳定时间达115 min,160℃时凝胶时间为40 min。PM915树脂制备过程中部分反应热已释放,其拥有较低的固化放热焓,固化温度为220℃。通过引入热塑性组分PES,PM915树脂的固化收缩率低至0.16%。PM915树脂固化物具有优良的热性能,热失重5%时的温度T_d5=423℃,玻璃化转变温度T_g=276℃,热膨胀系数为4.4×10?5/℃。通过热塑性树脂的改性,引入了柔性基团,进而提高了树脂固化物的韧性,PM915树脂固化物的弯曲强度和弯曲模量分别为139.3 MPa和4.2 GPa,拉伸强度和拉伸模量分别为75.8 MPa和3.8 GPa;扫描电子显微镜（SEM）表征显示PM915树脂固化物为韧性断裂。结果表明,PM915树脂是一种适用于热熔法预浸料的氰酸酯树脂基体,且具有低固化收缩率、高尺寸稳定性和优良耐热性,可应用于卫星等航天器结构件。      

管道翻衬修复技术用聚氨酯树脂体系配方的研究

利用等当量粒子反应原理,对聚氨酯树脂体系的主剂与固化剂的配比进行了计算。计算结果表明,聚氨酯树脂体系的主剂与固化剂的配比在100 ∶(20～26) 范围内。通过DSC 分析、动态黏度、恒温黏度分析及25 ℃凝胶时间的测试,确定了固化工艺与黏度符合管道翻衬修复技术的树脂最佳配比为100 ∶20 。为了验证其使用性能,进行了树脂与管壁剥离强度的模拟测试。结果表明,配比为100 ∶20 的聚氨酯树脂粘结强度较高,可满足管道翻衬修复技术的要求。      

硅烷改性聚氨酯的合成

以氨基硅烷偶联剂为基础,对以异氰酸酯基为端基的聚氨酯预聚体进行再封端,合成了一系列不同硅烷封端率的单组分湿固化聚氨酯。测试结果表明:硅烷偶联剂成功接枝在聚氨酯预聚体上,产物的表干时间、粘接强度、耐湿热都得到很大改善,力学强度在一定封端率下保持较好,在聚氨酯密封胶、弹性体等领域有很好的应用前景。     

正交试验法优化乙烯基酯树脂增韧体系的研究

采用正交试验设计方法研究了固化体系的用量、乙烯基酯树脂的用量、增韧体系的内部配比,3个因素对乙烯基酯树脂力学性能的影响。通过测试树脂的凝胶时间和黏度特性,研究了树脂体系的反应性和流变性,制定树脂固化成型工艺。制作树脂浇注体,测试各个组分的冲击、弯曲性能。综合各种因素,优化选出了冲击韧性最好的一组配方,其冲击强度达到12.27kJ/m2,约为未改性树脂(冲击强度为3.11kJ/m2)的4倍。     

功能化纳米SiO2-聚醚砜/BMI-酚醛环氧树脂复合材料的固化动力学与性能

以4,4’-二氨基二苯甲烷（DDM）为固化剂、双马来酰亚胺（BMI）和酚醛环氧树脂（F51）为基体、聚醚砜（PES）为增韧剂、硅烷偶联剂KH560功能化纳米SiO₂（KH-SiO₂）为改性剂,采用原位聚合法制备了KH-SiO₂-PES/BMI-F51复合材料,并通过非等温DSC确定了复合材料的固化工艺及固化反应动力学。根据Kissinger方程和Ozawa方程求得体系的表观活化能分别为96.03 kJ/mol和99.18 kJ/mol。FTIR测试结果表明:KH-SiO₂改性效果良好,不饱和双键和环氧基特征峰消失,BMI中C=C双键和F51中环氧基在DDM作用下参与了体系的固化反应。SEM结果表明:PES树脂和KH-SiO₂含量适当时,PES树脂和KH-SiO₂在树脂基体中分散均匀,断裂纹不规则杂乱发展,KH-SiO₂-PES/BMI-F51复合材料呈韧性断裂。力学性能测试和热失重测试表明:当PES含量为4wt%,KH-SiO₂含量为1.5wt%时,KH-SiO₂-PES/BMI-F51复合材料的弯曲强度、弯曲模量和冲击强度分别为156.23 MPa、4.18 GPa和20.89 kJ/m2,较BMI-F51基体分别提高了49.7%、29.4%和82.8%;KH-SiO₂-PES/BMI-F51复合材料的热分解温度为393.1℃,残重率为50%时,分解温度高达523.1℃,耐热性十分优异。KH-SiO₂-PES/BMI-F51复合材料的力学性能和耐热性有了较大提高,为拓展F51及BMI的应用范围提供了一定的理论数据。      

Mechanical behavior of bioactive composite cements consisting of resin and glass-ceramic powder in a simulated body fluid: Effect of silane coupling agent

Time-dependent strength behavior was investigated for bisphenol-a-glycidyl methacrylate/triethylene glycol dimethacrylate (Bis-GMA/TEGDMA) resin cements combined with glass-ceramic A-W filler treated with various kinds of silane coupling agents. The fracture strength of the composite resin cements was measured by three-point bending as a function of stressing rate in a simulated body fluid (SBF), and thereby the stress-corrosion susceptibility constant was evaluated. The fracture strength was found to depend on the kind of coupling agent used. For the present Bis-GMA/TEGDMA resin, the silane coupling agents without hydrophilic amine groups can be used to obtain good adhesion between resin and A-W filler owing to their nature of co-polymerizing with the resin. On the other hand, all the composite resin cements showed nearly the same degree of stress-corrosion susceptibility whether the A-W fillers were treated or untreated with silane coupling agents. This means that the stress-corrosion susceptibility of the present composite cements is predominantly affected by that of the matrix resin. Thus, the microcrack formation and growth at the resin matrix near particle - resin interface were thought to determine overall time-dependent strength behavior of the composite cements.     

固化剂对环氧树脂砂浆修补材料性能的影响

主要探讨了固化剂的掺量、存贮时间及环境因素对环氧树脂砂浆性能的影响.研究结果表明,固化剂掺量为30份/100份环氧树脂时,环氧树脂砂浆早期强度发展很快,3d抗折强度为7.2MPa,抗压强度为24.4MPa;后期强度发展稍慢,90d抗压强度为53.1MPa.固化剂掺量为10份/100份环氧树脂时,后期强度很大,90d抗压强度为96.9MPa,但早期强度发展较慢,固化时间长.40℃环氧树脂砂浆固化迅速,3d抗折强度即高于12.5MPa,抗压强度可达48.1MPa.     

硅烷偶联剂对铸造用碱酚醛树脂黏结强度的影响

通过黏结强度的测定和SEM分析,研究了硅烷偶联剂对碱酚醛树脂性能的影响.试验结果表明,硅烷偶联剂可以改善黏结剂与砂粒表面的接触状态,极大地提高碱酚醛树脂砂的黏结强度.     

Influence of adsorption behaviour of a silane coupling agent on interlaminar fracture in glass fibre fabric-reinforced unsaturated polyester laminates

The relationship between the interphase consisting of physisorbed and chemisorbed silane on glass fibres and the resultant composite Mode I delamination fracture toughness in glass fibre fabric laminate, was studied. The Mode I interlaminar fracture toughness of the laminate specimen was obtained by using a double cantilever beam (DCB) specimen. The delamination resistance of the laminate specimen finished with two silane concentrations and washed in methanol solvent, is discussed on the basis of the interlaminar fracture toughness. In order to determine the amount of physisorbed and chemisorbed silane on the glass fibre, the amount of total carbon was determined using an analysis instrument. The physisorbed silane migrated into the resin matrix and influenced the mechanical properties and interlaminar fracture of the laminate specimen. The amount of unsaturated polyester resin blended with a silane coupling agent was measured using dynamic mechanical spectroscopy, and a DCB specimen for mechanical properties and fracture toughness.     

New environmentally friendly composite laminates with epoxidized linseed oil (ELO) and slate fiber fabrics

This work focuses on the development of new composite laminates based on the use of epoxidized linseed oil (ELO) as matrix and reinforcement fabrics from slate fibers with different silane treatments. The curing behavior of the ELO resin is followed by differential scanning calorimetry (DSC) and the gelation is studied by oscillatory rheometry and gel-time. Composite laminates of ELO matrix and slate fabrics are manufactured by Resin Transfer Molding (RTM) and the mechanical properties of the composite laminates are tested in tensile, flexural and impact conditions. The effects of different silane coupling agents on fiber-matrix interface phenomena are studied by scanning electron microscopy (SEM). As in other siliceous fibers, silane treatment leads to improved mechanical performance but glycidyl silane treatment produces the optimum results as the interactions between silanized slate fiber and epoxidized linseed oil are remarkably improved as observed by scanning electron microscopy (SEM).     

三维编织碳复合材料的制备及其力学性能研究

采用真空辅助RTM工艺制备了三维编织碳纤维增强环氧树脂(C3D/EP)复合材料,通过对树脂的粘度特性和固化特性的分析,确定了最佳的工艺参数.金相显微镜对复合材料微观结构的观察表明树脂对纤维的浸润良好.同时,还研究了该工艺制备的C3D/EP复合材料的力学性能,结果表明随着纤维体积比的增加,复合材料的硬度、弯曲强度和冲击强度均提高,断口的扫描电镜观察表明复合材料的破坏方式是以脆性断裂为主.     

Influence of post-curing and coupling agents on polyurethane based copper filled electrically conductive adhesives

Effects of post curing and silane coupling agents with different functional groups such as epoxy, isocyanate and ureide on the electrical and mechanical properties of copper (Cu) filled electrically conductive adhesives (ECAs) were studied. Micron-sized Cu particles were used as conductive fillers and polyurethane resin was applied as the adhesive material. Significant differences could be observed on the as cured electrical resistivity and shear strength of the Cu filled ECAs joints prepared with different silane coupling agents. Silane coupling agents functionalized with epoxy groups yielded the lowest electrical resistivity and highest shear strength among the ECAs in this study. Besides, effect of post-curing at 170 °C for 1 h on the ECAs was also investigated. Results showed that ECAs after post-curing exhibited enhanced electrical conductivity and shear strength compared to the as cured ECAs.     

废胶粉的表面处理及在天然橡胶中的应用

采用硅烷偶联剂KH550对废胶粉进行表面处理,并将处理后的废胶粉与天然橡胶复合制备WRP/NR复合材料。借助L16(45)正交试验及单因素试验,探讨了废胶粉目数、废胶粉用量、硅烷偶联剂KH550用量对复合材料力学性能的影响;对处理后的废胶粉表面和橡胶拉伸试样断裂面进行了扫描电镜(SEM)观察;并通过热重分析研究了天然橡胶和复合材料的热降解性能。结果表明:当废胶粉目数为80目,废胶粉用量为10%,硅烷偶联剂KH550用量为1.5%时,复合材料的力学性能最优,拉伸强度为27.89MPa。SEM结果表明废胶粉表面粗糙度增大,比表面积增大,与NR基体的相容性得到了提高。而热重分析表明改性废胶粉的加入对天然橡胶的热稳定性能影响不大。     

端羧基液体丁腈橡胶改性海因环氧树脂性能研究

目的 采用端羧基液体丁腈橡胶(CTBN)对海因环氧树脂进行增韧改性。方法 通过热熔法将不同份数的CTBN添加到海因环氧树脂中，以4,4''–二氨基二苯甲烷为固化剂制备了改性环氧树脂，通过固化动力学研究确定了其固化工艺，考察CTBN用量对改性树脂体系的反应活性、力学性能、热性能以及断面微观形貌的影响。结果 随着CTBN的加入，改性树脂的固化放热峰向高温方向偏移。CTBN可显著提高树脂体系的断裂伸长率和冲击强度，其热性能基本保持不变。改性树脂的断面呈现两相“海岛”结构。结论 CTBN对海因环氧树脂有明显的增韧作用，制备的改性树脂体系可用于金属防腐涂料和胶黏剂等材料。     

多壁碳纳米管改性环氧树脂胶黏剂实验研究

将一种环氧树脂和表面羟基化的多壁碳纳米管(MWCNTs)按照质量比100∶0.1进行配比, 以超声波分散法制备MWCNTs/环氧树脂胶黏剂, 考察了两种硅烷偶联剂KH550和KH560对MWCNTs改性效果的影响。采用FTIR、 DSC、 DMA、 流变仪研究了MWCNTs对胶黏剂固化行为和流变特性的影响, 并结合断口形貌观察, 测试分析了MWCNTs对胶黏剂拉伸剪切强度和冲击强度的影响。结果表明: 硅烷偶联剂能与MWCNTs表面的羟基发生缩合反应, 增强了MWCNTs与环氧树脂基体的亲和性, 从而影响胶黏剂固化反应及黏度-剪切速率曲线; 经KH550改性的MWCNTs明显提高了胶黏剂与金属的界面粘结性, Al-Al拉伸剪切强度较无MWCNTs的胶黏剂提高了46.4%; 添加MWCNTs使胶黏剂的冲击断面更为粗糙, 开裂面积更大; 添加MWCNTs+KH550的胶黏剂冲击强度提高了44.1%, 说明MWCNTs/环氧树脂间界面性能对发挥MWCNTs的增韧效果非常重要。