降解方式及引发剂对淀粉接枝共聚水煤浆分散剂性能的影响

Effects of Degradation Mode and Initiator on Properties of Starch Grafted Copolymer as Dispersant for Coal Water Slurry

以降解淀粉为原料,在最佳引发剂下接枝不同单体,合成两种淀粉接枝共聚物,并对比其性能。加入丙烯酸羟乙酯(HEA)和苯乙烯(ST),制备出淀粉-丙烯酸羟乙酯-苯乙烯接枝共聚物(简称HSS);加入丙烯酸(AA)、苯乙烯磺酸钠(SSS),制备出淀粉-丙烯酸-苯乙烯磺酸钠接枝共聚物(简称SAS)。研究了淀粉经氧化和酸解不同降解方式处理后对水煤浆的分散效果,考察了不同引发剂对淀粉接枝共聚反应的影响。结果表明:氧化降解处理后的淀粉降黏作用增强,接枝效率高。NaHSO3-K2S2O8是淀粉接枝共聚反应中理想的引发剂。SAS分散剂在神华煤颗粒表面的60 s接触角为-50.39°,HSS分散剂在神华煤颗粒表面的60 s接触角为-54.83°,SAS分散剂体现出更佳的润湿性能。HSS分散剂在煤颗粒表面的饱和吸附量为2.43 mg/g,SAS分散剂的饱和吸附量为2.97 mg/g。SAS分散剂既有淀粉的结构特点,也显示了优良的聚羧酸分散剂优势。

Two kinds of graft copolymers were synthesized by grafting different monomers onto degraded starch with the best initiator.Hydroxyethyl acrylate(HEA)and styrene(ST)were added as graft copolymers to prepare starch hydroxyethyl acrylate styrene graft copolymers(HSS),and acrylic acid(AA)and sodium phenylene sulfonate(SSS)were added as graft copolymers to prepare starch acrylic acid sodium phenylene sulfonate graft copolymers(SAS).The effects of different treatments of starch degradation,such as oxidation and acidolysis,on the dispersion and graft copolymerization were investigated.The results show that the starch treated by oxidative degradation shows a stronger viscosity reducing effect and a higher grafting efficiency.NaHSO3-K2S2O8 is an ideal initiator in the starch graft copolymerization.The contact angle of SAS on the surface of Shenhua coal particles is-50.39°after 60 s,which is lower than that of HSS,indicating a better wettability of SAS.The saturated adsorption capacity of HSS on the surface of coal particles is 2.43 mg/g,and that of SAS dispersant is 2.97 mg/g.The hydrophilic groups such as carboxyl group and sulfonic acid group in the structure of the SAS dispersant can effectively be adsorbed on the surface of Shenhua coal particles to form hydrophilic composite coal particles,which is more conducive to the stability of coal water slurry.