【作者】 夏开胜；

【导师】 沈上越；

【作者基本信息】 中国地质大学 ， 材料学， 2005， 硕士

【摘要】 高吸水保水材料是一种吸水能力特别强，而且保水能力也非常好的特殊功能高分子材料。该材料在国民经济的众多领域得到了应用。但是，传统高吸水保水材料由于生产成本高、抗盐性能和保水性能较差、凝胶强度低等原因，其应用范围受到很大限制，推广应用缓慢。 本研究主要针对我国北方旱作农区降雨少且集中、土壤有机质含量低、保水性差的现状，以降低生产成本、简化生产工艺、提高抗盐性和保水性为出发点，采用湖北宜昌煤系煅烧高岭土超细粉体与高分子复合的技术路线，研制得到煅烧高岭土／聚丙烯酸钠高吸水保水复合材料。实验过程表明，材料制备工艺简单、周期短，实验便于控制。 本论文研究了丙烯酰胺用量、引发剂用量、交联剂用量和中和度四个因素对煅烧高岭土／聚丙烯酸钠高吸水保水复合材料吸水性能的影响。研究表明，丙烯酰胺最佳用量为15％，引发剂最佳用量为0.25％，交联剂最佳用量为0.08％，中和度为80％时最佳。 通过固定上述四因素为最佳配比，研究了煅烧高岭土添加量对煅烧高岭土／聚丙烯酸钠高吸水保水复合材料吸水性能、保水性能、凝胶强度、重复使用性能和原料成本的影响，在满足项目要求的前提下综合评价得到，最佳煅烧高岭土添加量为60％。此时复合材料吸蒸馏水倍率达646g／g，吸自来水倍率达248g／g，生理盐水倍率达56g／g；保水率在离心60min后为94.5％，常温放置15天后为61.5％，50℃放置6h后为87.1％，80℃放置6h后为80.0％，较不添加矿物时均有提高；此时复合材料凝胶强度为121g／cm~2，提高了43％，重复使用三次后吸水倍率达到首次的74％，原料成本降低了约5000元／吨。 采用XRD分析、IR分析和ESEM分析对煅烧高岭土／聚丙烯酸钠高吸水保水复合材料进行了表征。结果表明，复合材料为煅烧高岭土、丙烯酸钠和丙烯酰胺三者的复合体，在复合过程中，煅烧高岭土没有发生结构变化，而是以片状形态均匀分散于高分子基体中，且当煅烧高岭土添加量为60％时，复合效果最好。 结合高吸水保水材料的吸水理论，初步探讨了煅烧高岭土／聚丙烯酸钠高吸水保水复合材料的吸水机理。研究表明，煅烧高岭土因可能与高分子在复合过程中发生表面接枝聚合而粘附在高分子网络结构上，复合材料在吸水时受渗透压和网络弹性张力的共同作用，最终达到吸水平衡。更多还原

【Abstract】 Superabsorbents can absorb a large amount of water compared with general water absorbing materials in which the absorbed water is hardly removable even under some pressure. Because of their excellent characteristics, superabsorbents are widely used in health, agriculture and horticulture applications.The study is regard to the current situation in the north of china such as little rainfall, low soil organic content, and poor water holding capacity. To reduce the production cost, simplify the production technology and improve the salt-resisting and water-holding, the research adopt the compound of calcined kaolin ultra powder in Yichang, Hubei and high polymer, and at last get calcined kaolin/sodium polyacrylate super absorbent composite. The experiment shows that it is easy to control with simple process and short cycle.The influences of acylamide content, initiator content, cross linker content and neutralization degree (all in term of the quality of acrylic acid) on the composite was studied. It shows that the optimization preparation process was determined as the content of acylamide, initiator, cross linkers and the extent of neutralization of 15%, 0.25%, 0.08%, and 80% respectively.Under the best match of previous factors, the influences of calcined kaolin addition content on water-absorbing and water-holding performance, gel intensity, repeatability and cost were studied. When the calcined kaolin addition content is 60%, the water absorption performance is the best that distilled water absorbency is 646g/g, tap water absorbency 248g/g, and physiological saline absorbency 56g/g. Compared with the composite without mineral, the retention rate is increased to 94.5% after centrifugation for 60 minutes, 61.5% after stay for 15 days in room temperature, 87.1% after stay for 6 hours in 50℃, 80.0% after stay for 6 hours in 80℃. The gel intensity is 121 g/cm~2 enhanced 43%. The water absorbency rate can reach 74% after used three times. The production cost is reduced by 5000yuan/ton.The analysis of XRD, IR and ESEM shows that the composite is composed of calcined kaolin, sodium polyacrylate, and acylamide, there is no structural change in calcined kaolin and it is dispersed homogeneously as flaky grains in polymer, and when the addition content of calcined kaolin is 60%, the compound is best.With water absorption theories of superabsorbent, water-absorbing mechanics of the composite was preliminarily researched. The result shows that calcined kaolin adheres to更多还原