涂料用玉米淀粉-苯乙烯接枝共聚乳液的制备与性能

以过硫酸钾为引发剂,在乳化剂OP存在下,玉米淀粉与苯乙烯接枝聚合制备了涂料用淀粉-苯乙烯乳液,经红外光谱确认了共聚物。研究了工艺条件对乳液聚合的影响,确定了较佳的乳液制备工艺:玉米淀粉于85℃糊化酸降解1 h,加入聚乙烯醇和乳化剂,按m(苯乙烯)∶m(淀粉)∶m(过硫酸钾)=20∶8∶0.28,在80~85℃接枝共聚3 h。引发剂分3个阶段加入:苯乙烯单体加入前先加入引发剂质量的20%,然后在2 h内均匀加入全部单体和引发剂质量的60%,最后加入剩余的20%引发剂反应1 h。以此乳液为成膜物质复配成的乳胶涂料的性能达到或超过GB/T9756—2001合格产品的指标:耐水性≥96 h,耐洗刷性≥500次,耐碱性24 h无异常。

Preparation and Performance of Starch-Styrene Graft Copolymerization Emulsion for Coating

Starch-styrene emulsion for coating was prepared by grafting copolymerization of corn starch with styrene using K_2S_2O_8 as initiator in the presence of emulsifier OP.The product was identified by IR.Thus,at 85 ℃,corn starch was pasted and degraded by acid for 1h,then grafted and copolymerized with styrene(m(styrene)∶m(starch)∶m(K_2S_2O_8)=20∶8∶0.28) at 80~85 ℃ for 3 h in the presence of polyethylene alcohol and emulsifier.The initiator was added in three periods:20% initiator was added before addition of monomer,60% of the initiator was added with the monomer during 2 h,and the remainder 20% was added at last and reacted further for 1 h.Starch-styrene coating was made up with water resistance over 96 h,wash and brush resistance over 500 times and normal base-resistance attaining or exceeding the quality requirement of GB/T9756-2001.