【作者】 熊艳丽；

【导师】 王汝敏；

【作者基本信息】 西北工业大学 ， 材料学， 2006， 硕士

【摘要】 随着航空航天工业对耐热结构胶粘剂的迫切需求,双马来酰亚胺型结构胶粘剂成为研究的重点。本文从胶粘剂原料的选择、配方和工艺研究出发,并采用纳米氧化硅和晶须硅对胶粘剂体系进行了改性研究,得到的胶粘剂固化工艺良好,在200℃下粘接强度高,同时耐热性、韧性达到较好统一。 在配方和工艺研究方面,依据拉伸剪切强度数值确定最佳配比为N,N-4,4’-二苯甲烷型双马来酰亚胺树脂(BMI)/4,4’-二氨基二苯砜(DDS)=1:1.5(摩尔比),预聚体/双酚A环氧(EP)=60/40(质量比)。粘度和凝胶化时间表明该配方工艺性好;利用傅立叶变换红外光谱(FTIR)和差示扫描量热(DSC)分析了反应机理,并确定最佳固化工艺为150℃/2h+200℃/2h+220℃/1.5h,Kissinger法和Ozawa法计算了表观活化能ΔE、碰撞因子A和反应级数n等固化反应动力学参数。 研究发现基本配方的胶粘剂脆性较大,因此进行了纳米氧化硅和晶须硅两种无机填料对胶粘剂的改性研究,并且都添加了硅烷偶联剂KH-550对填料进行表面改性。激光粒度仪测试结果和透射电镜(TEM)照片显示偶联剂改性作用良好,使纳米氧化硅在基体中基本能够达到纳米级分散,使胶粘剂粘接性能提高。FTIR谱图证实KH-550有效地接枝到了纳米氧化硅和晶须硅表面,并考查了填料添加量和偶联剂用量对填料在基体中分散状况的影响,得到了其最佳值。 研究发现无机的纳米氧化硅和晶须硅的加入对胶粘剂耐热性和力学性能也有很大影响。动态力学能谱(DMA)和热失重分析(TGA)表征了改性胶粘剂的耐热性能,纳米氧化硅使玻璃化温度(T_g)和热分解温度分别提高到208℃和295℃,晶须硅使热分解温度提高到275℃。纳米氧化硅使弯曲和冲击强度最大分别提高了36.8%和6.2%,晶须硅也使之有相当程度的增加。 结合弯曲和冲击断面的扫描电镜(SEM)电镜照片,初步探讨了纳米氧化硅和晶须硅对胶粘剂的改性机理,为多种理论的复合作用,但是分散状况始终是影响性能的主要因素。更多还原

【Abstract】 With the urgently demanding of heat-resistant structural adhesive in aeronautics and astronautics, the type of bismaleimide has been the focus in research. In this article, we firstly researched the raw materials、 recipes and technics. Nano-SiO_x and whisker SiO₂ were used to modify the systems of adhesives, and we got the curing technics excellent, and the cohesive strength high, at the same time the heat-resistance and toughness assorted with each other well.In recipes and technics, according to tensile shear strength, we assured the optimal proportions were: bismaleimide （BMI）/ diamine diphenyl sulfone （DDS） =1:1.5（mol）, prepolymer/epoxy （EP） =60/40（quality）. Viscosity and the time to gel indicated that the adhesives had fine technics;Fourier transform infrared（FTIR） and differential scanning calorimetry （DSC） were used to analyze the reaction mechanisms, and confirm the best curing technics of 150℃/2h+200℃/2h+220℃ /1.5h. Finally the curing kinetics of BMI/ DDS / EP was studied. The apparent activation energy ΔE、 pre-exponential factor A and the curing reaction order n were calculated.Merely the BMI/DDS/EP adhesives were very brittle;the next step was to enhance the toughness. In practice, we added nano-SiO_x and whisker SiO₂ to the system, and necessary silane coupling agent gamma-chloropropyltriethoxy silane （KH-550） improved the performances of fillings’ surfaces. The test of laser granularity instrument and transmission electron microscope （TEM） pictures showed that coupling agent exerted modification effect, and nano-SiOx dispersed well in matrix. FTIR spectrums approved that the molecule of KH-550 effectively grafted to the surfaces of nano-SiO_x and whisker SiO₂. The dosages of fillings and coupling agent were examined via their affection on dispersion.For nano-SiO_x and whisker SiO₂ were organic, their additions played important roles in heat-resistance and mechanical properties. Dynamic mechanical analysis （DMA） and thermogravimetric analysis （TGA） charactered the heat-resistance of modified adhesives. Nano- SiO_x made glass transition temperature （T_g） and heat decomposition temperature separately improve to 208℃ and 295℃;Whisker SiO₂ made heat decomposition temperature reached 275℃。 Nano- SiO_x made bendingstrength and impacting strength increased 36.8% and 6.2% to the greatest extent;The addition of whisker Si(>2 also made contributions to mechanical properties in a certain degree.Combined with scanning electron microscope （SEM） pictures of sections after bending and impacting, the mechanisms of nano-SiOx and whisker SiO2 modifying the adhesives were discussed primarily. Several theories together acted on the last results, but the dispersion was the most important factor at all the time.更多还原