腐植酸与苯乙烯的接枝共聚改性

MODIFICATION OF HUMIC ACID BY GRAFT COPOLYMERIZATION WITH STYRENE

研究了腐植酸(HA)与苯乙烯(St)以H_2O_2-FeCl_2为引发体系的接枝共聚。结果表明,HA对St聚合有阻聚及滞聚作用。接枝度在H_2O_2/FeCl_2=3(摩尔比)时有极大值,提高聚合温度可使接枝效率和接枝度同时增加、增加St-HA的用量比可使接枝度增加,但接枝效率降低,接枝比基本不变。由接枝共聚物的红外光谱分析得出HA与PSt是以C-O-C连接的。接枝共聚物的磺化产物在水和酸性介质中均能溶解。

Graft copolymerization of styrene. (St) onto humic acid (HA), using H_2O_2- FeCl_2redox system as initiator in DMOSmedium was investigated.It was found that HA had dis-tinct inhibiting and retarding effect on the polymerization of St,and the ratio of H_2O_2-FeCl_2 was an important factor influencing the graft copolymerization.With increase of theH_2O_2-FeCl_2 ratio,the rate of polymerization increased,while the grafting cfficiency decrea-sed, the grafting degree approched a maximal value when the H_2O_2-FeCl_2 ratio was 3(mol/mol).The grafting efficiency and grafting degree increased with increase of polym-erization temperature The ratio of St to HA also had a direct influence on the graftingefficiency and grafting degree but not on the grafting ratio. The appearance of a newadsorption band (1120cm^(-l)) in the IR spectrum of copolymer was attributed to C-O-Clink formed in the HA-g-PSt molecule during the polymerization. The product obtainedby further sulfonation of graft copolymer is readily Soluble in water, acid and alkalisolution.