本文選題：丁苯橡膠 + 碳納米管　； 參考：《北京化工大學》2015年碩士論文

【摘要】：橡膠制品的裂紋尖端應變分布及其與準靜態(tài)裂紋擴展、動態(tài)疲勞破壞性能的關系近年來受到了廣泛的關注。本文的研究重點在于考察填料種類和用量對丁苯橡膠復合材料裂紋尖端應變分布的影響,進而評價材料的抗裂紋萌生和擴展性能。研究的填料體系包括純炭黑體系、純碳納米管體系、碳納米管等量替代炭黑體系以及碳納米管非等量替代炭黑體系。首先考察了炭黑粒徑的變化對其填充丁苯橡膠得到復合材料的抗裂紋性能的影響。采用數(shù)字圖像相關法對材料裂紋尖端附近區(qū)域的應變分布情況進行測定。結果表明,裂紋最尖端一點應變放大程度最強,距離尖端越遠應變放大效應越弱；同一材料裂紋尖端最大應變隨整體應變呈線性增加；裂紋尖端應變放大效應的作用區(qū)域均隨炭黑粒徑增加而減小。綜合填料網絡結構和準靜態(tài)裂紋萌生及擴展測試的結果,發(fā)現(xiàn)炭黑N234填充丁苯橡膠抗裂紋性能最好而炭黑N990最差的規(guī)律并進行了解釋。同時采用有限元分析法對與炭黑填充丁苯橡膠有著同樣單軸拉伸應力應變性質的試樣表面進行了應變分布的模擬,由于Ogden方程在計算時忽略了材料實際的滯后特性,模擬結果在試樣整體應變大于30%時與數(shù)字圖像相關法實驗結果存在較大偏差。然后研究了碳納米管以1：1的比例部分替代炭黑N234填充丁苯橡膠準靜態(tài)下的抗裂紋表現(xiàn)。采用1至3份碳納米管分別替換相同份數(shù)的炭黑N234,結果表明,隨著碳納米管用量增加,過強的填料網絡結構不利于分擔裂紋尖端橡膠分子鏈承受的應力集中效應,反而強化了應變放大程度,不利于得到抗裂紋性能較好的復合材料。為了探討碳納米管作為填料部分替代炭黑的合理比例,對比研究了5份碳納米管、20份及40份炭黑N234填充丁苯橡膠的填料網絡結構和局部應變分布對其抗裂紋萌生及擴展性能的影響。雖然5份碳納米管具有和40份炭黑N234相近的形成填料網絡結構的能力,但受到碳納米管與橡膠基體作用較弱的特性的影響,在力學性能和抗裂紋性能方面5份碳納米管卻接近20份炭黑填充后的丁苯橡膠。若使碳納米管與炭黑共同形成的填料網絡結構與純炭黑接近,碳納米管特殊的幾何形貌對阻礙裂紋擴展的作用似乎會更明顯,因此選用1份對應4份的比例,繼續(xù)碳納米管部分替代炭黑填充丁苯橡膠的實驗。靜態(tài)裂紋萌生及擴展實驗和表面應變分布分析結果表明：3份碳納米管替代12份炭黑N234加入丁苯橡膠后得到的材料具有較純炭黑填充更低的裂紋尖端應變放大效應且更多的分子鏈參與均化應力集中的過程,宏觀上表現(xiàn)出最好的抗裂紋性能。
[Abstract]:The strain distribution at the crack tip of rubber products and its relationship with quasi-static crack propagation and dynamic fatigue failure properties have attracted extensive attention in recent years. The emphasis of this paper is to investigate the effect of filler type and content on the strain distribution at crack tip of SBR composites, and to evaluate the crack initiation and propagation properties of the materials. The filler system includes pure carbon black system, pure carbon nanotube system, carbon nanotube substitution carbon black system and carbon nanotube alternative carbon black system. The effect of the particle size of carbon black on the crack resistance of the composites filled with SBR was investigated. The strain distribution near the crack tip of materials was measured by digital image correlation method. The results show that the maximum strain amplification at the tip of the crack is the strongest, and the strain amplification effect is weaker when the crack tip is farther away from the crack tip, and the maximum strain at the crack tip of the same material increases linearly with the overall strain. The effect of strain amplification at crack tip decreases with the increase of carbon black particle size. Based on the network structure of filler and the results of quasi static crack initiation and propagation test, it is found that carbon black N234 filled SBR has the best crack resistance and the carbon black N990 is the worst. At the same time, the finite element analysis method was used to simulate the strain distribution on the surface of the sample with the same uniaxial tensile stress-strain property as the carbon black filled styrene-butadiene rubber. The Ogden equation neglects the actual hysteresis of the material. When the total strain of the sample is greater than 30, there is a big deviation between the simulated results and the experimental results of digital image correlation method. The crack resistance of N234 filled butadiene rubber filled with carbon black N234 at 1:1 was studied. The carbon black N234 with the same number of carbon black was replaced by 1 to 3 phr carbon nanotubes respectively. The results show that with the increase of carbon nanotube content, too strong packing network structure is not conducive to sharing the stress concentration effect of the crack tip rubber molecular chain. On the contrary, the strain amplification degree is strengthened, which is not conducive to obtaining the composites with better crack resistance. In order to study the reasonable proportion of carbon black partially replaced by carbon nanotubes as filler, The effects of filler network structure and local strain distribution on crack initiation and propagation of 5 carbon nanotubes (CNTs) 20 and 40 carbon black N234 filled styrene-butadiene rubber (SBR) were studied. Although 5 carbon nanotubes have the ability to form filler network similar to 40 carbon black N234, they are affected by the weak interaction between carbon nanotubes and rubber matrix. In terms of mechanical properties and crack resistance, 5 phr carbon nanotubes were found to be close to 20 phr carbon black filled styrene-butadiene rubber. If the network structure of the filler formed by carbon nanotubes and carbon black is close to that of pure carbon black, the effect of the special geometry of carbon nanotubes on the crack growth appears to be more obvious. The experiment of partially replacing carbon black with styrene-butadiene rubber by carbon nanotubes was carried out. The static crack initiation and propagation experiment and surface strain distribution analysis showed that the strain amplification effect at crack tip was lower after adding 12 phr carbon black N234 instead of 12 phr carbon black N234. The results showed that the strain amplification effect at crack tip was lower than that filled with pure carbon black. And more molecular chains participate in the process of homogenizing stress concentration, Macroscopically, it shows the best crack resistance.
【學位授予單位】：北京化工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TQ333.1;TB33

【參考文獻】

相關期刊論文 前1條

1 孫霞容;栗付平;王力;蔣洪罡;;納米氧化鋅對天然橡膠疲勞性能的影響[J];特種橡膠制品;2009年05期

相關博士學位論文 前1條

1 徐敏;納米碳管的化學改性以及與高分子的復合[D];華東師范大學;2003年

相關碩士學位論文 前1條

1 黃舟;不同填料/炭黑/丁苯橡膠復合材料的疲勞破壞性能及機理[D];北京化工大學;2013年

，

本文編號：1906746