【作者】 林海琳；

【导师】 崔英德；

【作者基本信息】 广东工业大学 ， 材料学， 2005， 博士

【摘要】 海藻作为一种丰富的海洋资源,产量大,价值低,再生能力强,将它应用于吸水材料领域,可望为材料领域增加一种新的功能性海洋生物可降解吸水树脂。天然海藻酸钠树脂的吸水性能和力学性能较差,达不到实际使用要求。本文运用分子设计原理,对海藻酸钠进行醚化改性,提高其相容性和化学稳定性并选择烯类与酰胺类单体与之通过接枝、聚合、交联、互穿等方式,采用水溶液聚合法,制备了海藻酸钠系列高吸水树脂。探讨了单体类型,单体浓度、溶剂、反应温度等因素对吸水树脂性能影响。着重研究了吸水树脂的吸水性能、表面形态结构、热稳定性、微生物降解性能、树脂对土壤持水性状的影响及生物学效应,为海藻酸钠系列吸水树脂的开发和应用开辟了一条新的技术路线。 研究表明,对海藻酸钠(SA)进行醚化改性(ESA),最佳醚化度Ds在0.2～0.5之间,醚化提高了(SA)的相容性和化学稳定性,,当醚化海藻酸钠占总单体的质量分数小于20%时,接枝效果较理想,吸去离子水和吸盐水倍率最高分别达到450g/g和69g/g。网络中引入适量的非离子单体丙烯酰胺提高了树脂的吸盐水倍率。 研究了ESA高吸水树脂体系组分间的相容性。IR,DSC和SEM分析初步表明,相界面的大分子在互穿的同时还引入了化学键,使微区间变得更加融合,微区变小,材料单体间具有较好的相容性。体系组分的相容性与相区尺寸的大小和组成有关,当m(ESA/AA):m(PVA)=88:12,m(ESA/AA):mP(AM)=92:8,w(PVA+P(AM))=10%,且m(PVA):m(P(AM))=70∶30时,树脂ESA/AA/PVA、ESA/AA/P(AM)、ESA/AA/PVA/P(AM)的界面呈均匀分布状态。 对凝胶的力学性能分析表明,柔性大分子PVA、P(AM)等引入ESA/AA网络大分子后,凝胶的韧性增加,这是因为它们降低了体系的电荷密度,削弱了分子链间的静电作用,虽然增加了氢键的作用,但分子间总的作用力降低,因而韧性增加。 研究了ESA吸水树脂的热稳定性。TG-DTG分析表明,所制备的ESA树脂的热分解温度均在200℃以上,热稳定性较好。对吸水树脂的耐热性的研究更多还原

【Abstract】 As an abundant ocean resource, algae has the characteristic of strong revegetate and biodegradable ability. It is expected that it could be used as a new resin in material field. Sodium alginate resins are used commercially in the form of ionic gels crosslinked with mutivalet metal cation. However, Sodium alginate resins show low water absorbencies and poor mechanical property due to their own properties and high crosslink desity of the gels. In this dissertation, sodium alginate is etherificated in order to meliorate its compatible performance and chemical stability. By polymer molecular design, a series of complex superabsorbent resins based on etherificated sodium algiate (ESA) are prepared. The effects of various factors including monomer types, monomer concentration, solution media and crosslink temperature on water absorbency and mechanical strength of resins are studied. The surface configuration, thermal stability, degradation behavior, swelling stability and moisture retention properties in soil are also studied. The research proposes a new technical approach for the application of ESA superabsorbent in material field.The result of the experiments shows that viscosity is degraded and chemical stability is enhanced for sodium alginate by etherificate, and the best etherificate degree (Ds) is within 0.2-0.5 while the optimized ESA content is within 20%. Under the optimized reaction condition, Grafting ratio is high and ESA/AA and ESA/AA/AM resins have higher water and saline absorbency.Polymer network with different compositions is synthesized, characterization result with IR, DSC and SEM proves that there are physical intertwises and chemical bonds among molecule chains on polymer surfaces. SEM analysis indicates that with the composition ratio, m(ESA/AA):m(PVA)=88 : 12 , m(ESA/AA): mP (AM) =92: 8 and w (PVA+P (AM)) =10%, m (PVA): m[P (AM) ]= 70:30, the ESA/AA/PVA, ESA/AA/P(AM), ESA/AA/PVA/P(AM) resins更多还原