Graft copolymerization of crude lignosulfonates with acrylic monomers was investigated, its mechanism wasreviewed, and the occurrence of polymerization was confirmed by IR determination. Differing from pure lignosulfo-nates, graft copolymerization of crude lignosulfonates with acrylic monomers could be initiated solely by hydroperoxideat 1.5% - 2.0% ( mass ratio) of dry lignosulfonates. With sufficient initiator in the reaction solution,the influence ofreaction temperature and time on viscosity of products was not apparent. Viscosity of final products was increasedfollowing the increase of monomers dosage. At the same dosage, products modified with acrylamide(AM) had higherviscosity than those with acrylic acid( AA), because amide groups on AM polymers is less hydrophilic than carboxylicgroups on AA polymers.%研究了木质素磺酸盐粗产品与丙烯酸类单体的接枝共聚反应,对其反应机理进行了评述,并采用红外光谱分析证实了聚合反应的发生.与现有的对纯化木质素磺酸盐的研究结果不同,粗产品的接枝共聚反应可以单纯由过氧化氢引发,原因可能是粗产品中含有的还原性物质起到了亚铁离子的作用.研究表明,合适的引发剂用量应该是木质素磺酸盐干重的1.5%～2.0%,当反应体系中引发剂用量充分时,反应温度和时间对产物粘度的影响不明显.产物的粘度随丙烯酸类单体用量的增加而提高,在相同单体用量下,丙烯酰胺改性产物的粘度高于丙烯酸改性产物,原因是丙烯酰胺聚合物上酰胺基的亲水性比丙烯酸聚合物上羧酸基的亲水性低.
展开▼
