PAA/HA型高吸水性树脂的合成与性能

采用腐植酸钠溶液与丙烯酸共聚合成 PAA/ HA型高吸水性树脂 ,分析了反应机理和树脂的红外光谱及扫描电镜图 ,认为腐植酸钠与丙烯酸聚合生成高吸水性树脂时 ,首先是丙烯酸自聚 ,之后腐植酸与聚丙烯酸发生接枝共聚反应 ,最后聚丙烯酸侧链间进行交联 ,形成不溶于水的 PAA/HA网络结构 .红外光谱显示 ,PAA/ HA在 1 2 80 cm-1处出现了 PAA和 Na HA均没有的属于烷基芳基醚的吸收峰 ,而扫描电镜图说明腐植酸钠与丙烯酸生成了结构致密的不规则的网状结构 .文中比较了 p H值、离子种类与离子浓度对树脂吸水性能的影响 ,结果表明该树脂的水凝胶在酸性溶液中容易发生皱缩 ,在碱性溶液中则易发生膨胀 ;外部溶液中离子的存在会显著降低树脂的吸水性能 ,离子浓度越大 ,价数越高 ,吸水倍率降低的幅度越大 .该树脂对玉米生长效应和水分利用效率的影响测试表明 ,PAA/ HA型高吸水性树脂在保水的同时还能促进植物生长 .

Synthesis and properties of a high water absorbability resin

A high water absorbability resin is synthesized using sodium humate solution and acrylic acid. The mechanism of reaction, the IR spectra and SEM of the resin are analyzed, and it is held that alkylaryl may be formed during the polymerization reaction. An absorbing peak appears at 1280cm-1 of the IR spectra which exists only in IR spectra of alkylaryl ether, and SEM photographs show that the product has dense and irregular network structure. The effects of pH and ionic types and concentrations of reaction system on the water absorbability of the resin are discussed, and the results show that the hydrogel of the resin tends to contract in an acidic solution but expand in a basic solution. The positive ions in solution will make the water absorbability of the resin evidently decrease, and bivalent or trivalent ions will make the water absorbability low more than univalent ions do. The tests of maize indicate that the resin can not only absorb and hold more water but also accelerate the growth of plants.