【作者】 杨盛华；

【导师】 余剑英；

【作者基本信息】 武汉理工大学 ， 复合材料学， 2011， 硕士

【摘要】 遇水膨胀橡胶(WSR)是一种具有优良弹性和吸水性能的新型特种橡胶,在密封防水等多领域有着广泛的应用前景。但是,由于WSR长期使用后力学性能和吸水膨胀性能会大幅下降,且近年来多次在地下工程中检出硫化氢(H2S)气体,其强腐蚀性易导致WSR性能劣化。因此,提高WSR的耐久性和耐H2S腐蚀性具有非常重要的意义。本文将钠基蒙脱土进行有机化处理,通过熔融插层法制备了不同掺量的有机蒙脱土(OMMT)改性WSR,采用X射线衍射仪(XRD)对其微观结构进行了表征,研究了OMMT对WSR力学性能、吸水膨胀性能、气体阻隔性能、耐H2S腐蚀性能和耐久性的影响。主要研究结论如下：(1)XRD测试结果表明,当OMMT的掺量在10phr以内时,OMMT改性WSR呈剥离型结构。(2) OMMT可以有效提高WSR的拉伸强度、体积膨胀倍率,同时使WSR具有较好的保水性,而仅仅导致扯断伸长率略有减小。(3)采用OMMT改性后,WSR的气体渗透系数显著降低,当OMMT掺量为10phr时,降低幅度达34.5%。(4) OMMT能显著提高WSR的耐H2S腐蚀性,且随着OMMT掺量的增加,其耐腐蚀效果逐渐增强。10phrOMMT改性WSR在10%H2S气体中腐蚀20d后的拉伸强度保留率、扯断伸长率保留率和体积膨胀倍率保留率均比普通WSR提高10%以上,而在0.04%的H2S溶液腐蚀20d后,其上述性能的保留率比普通WSR提高20%左右。(5)反复浸水实验和热氧老化实验结果表明,与普通WSR相比,OMMT改性WSR具有较好的耐久性。反复浸水20个周期后,10phrOMMT改性WSR的拉伸强度保留率、扯断伸长率保留率和体积膨胀倍率保留率较普通WSR分别提高了10.1%、6.2%和12%,热氧老化条件为70℃×28d时,提高幅度则分别为10.8%、7.8%和11%。(6)采用加速热氧老化实验和阿累尼乌斯方程图对OMMT改性前后WSR的寿命预测结果显示,OMMT可以显著延长WSR的静态使用寿命。当OMMT掺量为10phr时,改性WSR常温下的静态使用寿命比普通WSR提高58.5%。(7) OMMT对WSR性能的改善作用可归因于OMMT与橡胶基体形成了剥离型结构,从而使改性WSR的力学性能和阻隔性能得到提高。更多还原

【Abstract】 Water swelling rubber (WSR) is a kind of a new special rubber with excellent elasticity and absorptivity. It can be used widely as caulking, sealing of gap and water-prove materials. However, the mechanical properties and water swelling properties of WSR will markedly decrease after long-term use, and H2S gas which was detected several times in the underground engineerings in recent years may cause WSR seal failure in the short term due to its strong corrosiveness. Consequently, it is of great importance to improve the durability and H2S resistance of WSR.In this paper, the Na-montmorillonite was organically modified, and organic montmorillonite (OMMT) modified WSR which contained different contents of OMMT were prepared by melt intercalation. The microstructure of OMMT modified WSR were characterized via X-ray diffraction (XRD), and their mechanical properties, water swelling properties, gas barrier properties, H2S corrosion resistance and durability was investigated. The following conclusions can be drawn in the paper.(1) XRD results indicated that OMMT layers were stripped off and formed exfoliated nanocomposites with rubber matrix when the OMMT content was within 10phr.(2) The addition of OMMT can improve the tensile strength, volume expansion ratio and water retention of WSR effectively, but only cause a slight decrease of the elongation at break.(3) The gas permeability coefficient of OMMT modified WSR was smaller than common WSR. When the OMMT content increased to 10phr, the lower rate was up to 34.5%.(4) The H2S corrosion resistance of WSR was improved by addition of OMMT and the improvement was gradually heightened with the increase of OMMT content. The retentions of tensile strength, elongation at break and expansion rate in volume of WSR modified by 10phr OMMT increased by 10% in comparison with unmodified WSR. After corroded in H2S solution (0.04%) for 20 days, the retention of mechanical properties enhances by 20% for OMMT modified WSR.(5) Compared with common WSR, OMMT modified WSR showed better durability. The retentions of tensile strength, elongation at break and expansion rate in volume of OMMT modified WSR (10phr) increased by 10.1%,6.2% and 12% than unmodified WSR after 20 cycles of alternate immersion in water, while those increased by 10.8%,7.5% and 11% after the samples aged at 70℃for 28 days.(6) Accelerated thermal aging experiment and Arrhenius’equation figure was used to predict the life of WSR. The results showed that the static service life of WSR was prolonged by introducing OMMT. When the OMMT content was 10phr, the static service life of WSR was increased 58.5% in room temperature.(7) The improvement of OMMT on WSR performance can be attributed to the formation of exfoliated structure between OMMT and rubber matrix, which enhances the mechanical properties and barrier ability of WSR.更多还原