【作者】 李秀辉；

【导师】 吴江渝；

【作者基本信息】 武汉工程大学 ， 材料学， 2010， 硕士

【摘要】 吸水膨胀橡胶(WSR)是一种具有优良弹性和吸水膨胀性能的新型功能性止水密封橡胶材料。由于其施工方便、材料有效利用率高且工程造价低,在防水密封等诸多领域有着广阔的应用前景和巨大的市场需求。一般可以通过物理共混法和化学接枝法制备WSR,由于考虑到制品质量、工艺和成本等因素,工业上一般都是将橡胶等弹性基体和高吸水树脂(SAR)通过比较容易大规模工业化的物理机械共混法制备WSR。SAR的吸水膨胀性能,基体材料的弹性、力学性能以及二者的共混性能等对WSR的综合应用性能有着重要的影响。目前,在实际工程应用中发现共混型WSR仍然存在着一些较突出的问题:SAR与疏水性橡胶基体的相容性差、耐盐性差以及WSR(尤其是是大型制品)的吸水膨胀速率较慢,这些缺点都将在很大程度上制约着WSR的大规模推广和应用。本文主要研究了聚丙烯酸类SAR的合成工艺、SAR的疏水改性工艺、NBR基WSR的制备工艺,并对制备的吸水膨胀橡胶材料的力学性能和吸水膨胀性能进行了考察。本文以AA、AMPS、DMDAAC为功能单体,以过硫酸钾(KPS)为引发剂,聚乙二醇双丙烯酸酯(PEGDA(M_w = 258))为交联剂,利用反相悬浮法合成了两性离子型高吸水树脂,研究了油水比、引发剂用量、交联剂量、AA中和度和单体配比高吸水树脂吸水性能的影响。实验表明,合成高吸水树脂的的适宜工艺条件:油水比为:4:1,交联剂用量为0.55%,引发剂用量为0.8%,AA中和度为80%,单体配比为:AA/AMPS/DMDAAC = 67.4:29:3.6,反应温度为70℃。合成得到的高吸水树脂吸收蒸馏水和自来水的倍率高达分别达到1170 g/g和405 g/g。采用FT-IR对合成的高吸水树脂的结构进行了分析,证实了不同亲水功能单体的共聚;利用SEM分析了SAR的形貌为微米级的球形结构,且粒子间易团聚;TG分析表明SAR具有较好的热稳定性。实验还研究了SAR的吸水速率和在不同盐溶液中的吸水性能。为了改善基体材料NBR与亲水组分SAR间的相容性,本实验对SAR进行了疏水性互穿网络结构改性研究。将丙烯酸丁酯(BA)、丙烯酸(AA)、交联剂、引发剂与SAR混合,使SAR充分溶胀后引发BA和AA进行原位聚合,得到疏水改性高吸水树脂(m-SAR)。实验分别采用FT-IR和TG进行了结构分析和热稳定性分析。以m-SAR、白炭黑及各种橡胶助剂与丁腈橡胶(NBR)机械共混制备了吸水膨胀橡胶(WSR)。研究了不同改性组分含量、SAR含量等对WSR的吸水前后的机械力学性能和吸水膨胀性能分别进行了讨论,还利用SEM和TG对WSR进行了微观结构和热稳定性分析。结果表明:SAR改性后,WSR的流失率得到了降低,相容性在一定程度上得到了改善;WSR的吸水速率较快,能在较短时间内达到吸水平衡。通过吸水性能测试研究了环境温度和电解质环境对WSR的吸水膨胀性能的影响。结果表明,随温度升高,WSR平衡吸水倍率有所下降,质量流失率有所增大。随阳离子和浓度电荷数增加,WSR的吸水膨胀倍率均明显降低。更多还原

【Abstract】 Water-swellable rubber(WSR)is a novel functional material with excellent properties of elastic and swelling. Due to the efficiency, convenience, stuff saving and low-price, WSR hold good applicable prospect and huge market demand. Preparation methods of WSR are mainly blending and grafting. Generally, regards for quality, process and cost, blending, which can be industrialized widely, is the most popular. The elastic, mechanical property of matrix material and compatibility between SAR and matrix material have vital influence on comprehensive performance. Currently, blending bring serious problems, such as bad compatibility, poor salt-resistant, low swelling rate and so on, which will restrict the application area of WSR.In the paper, the synthesis process of SAR, hydrophobic modification of SAR, preparation of WSR and its mechanical and swelling properties were investigated.In the thesis, acrylic acid(AA), 2-acrylamide-2-methylpropanesulfonic acid(AMPS)and diallyldimethylammonium chloride(DMDAAC)as functional monomers, potassium persulfate as initiator, Poly(ethylene glycol) diacrylate(PEGDA(Mw = 258))as cross-linking agent, a new amphoteric ionic super absorbent resin(SAR)based on inverse suspension copolymerization was synthesised successful. The effects of oil/water ratio, cross-linking agent, initiator, neutralization, comonomer ratio on the swelling property of SAR were studied. It showed that the preferable conditions were oil/water ratio was 4, WPEGDA = 0.55%, WKPS = 0.8%, neutralization of AA was 80%, WAA/WAMPS/WDMDAAC = 67.4: 29: 3.6, and the temperature of copolymerization was 70℃. The absorbent capability of SAR reaches up to 1170 g/g in distilled water and 405 g/g in tap water. The FT-IR, SEM and TG analysis respectively showed that the SAR was a sphere copolymer at micron scale and have excellent thermal stability.For the purpose of improvement of compatibility between SAR and NBR, hydrophobic interpenetrating polymer network(IPN)modification of SAR was researched in the experiments. BA, AA, initiator and cross-linking agent were mixed with SAR, and polymerized in situ after swelling adequately, modified SAR(m-SAR)was prepared. The impacts of modified content on swelling compatibility were studied. The structure and thermal stability were investigated by FT-IR and DSC respectively.WSR was prepared by NBR, m-SAR, white carbon black(WCB)and all other addition agents blended. The effects of content of modified constituents and SAR on the mechanical and swelling capabilities were studied separately. Furthermore, the microcosmic structure was studied by SEM, thermal stability were investigated by DSC too. The results showed that after modification, the mass loss of WSR was lower, compatibility was improved to some degree. Besides, the WSR swelled quickly and could achieve equilibrium in much short time. The swelling capability of WSR at various environmental temperatures and in different salt solutions was investigated. The test result indicated that the swelling capabilities of WSR at the equilibrium lowered and the mass loss decreased with the rising of the environmental temperatures. similarly, the equilibrium swelling capabilities of WSR decreased with the concentration and valency of cation rised.更多还原