(四川大學 材料科學與工程學院，成都 610064)
摘 要: 為了提高Al2O3超微粉在水介質(zhì)中的分散穩(wěn)定性，先采用硅烷偶聯(lián)劑KH570對Al2O3進行表面改性，再對Al2O3粒子錨固偶氮引發(fā)劑偶氮二異丁基脒鹽酸鹽(AIBA)，進而引發(fā)丙烯酰胺(AM)單體聚合而制備聚丙烯酰胺(PAM)/Al2O3復合粒子。利用XPS、FT-IR、激光粒度儀、微電泳儀、分光光度計、SEM及XRD等對Al2O3復合粒子結構及分散性能等進行表征。結果表明：在40 ℃下加入水溶性偶氮引發(fā)劑，可以得到在水介質(zhì)中分散穩(wěn)定性良好，以聚丙烯酰胺為殼，以Al2O3為核的復合磨粒。與未改性的Al2O3超微粉相比，經(jīng)AM接枝聚合改性后的顆粒表面團聚現(xiàn)象得到改善，顆粒的D50減小；接枝改性后Al2O3的等電點IEP發(fā)生遷移，在pH值為9時顆粒表面Zeta電位絕對值達到最大。
關鍵字: Al2O3超微粉；偶氮引發(fā)劑；分散性；表面改性；復合磨粒
（College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China）
Abstract:In order to enhance the dispersion stability of ultra-fine Al2O3 powder in aqueous medium, Al2O3 particles were modified with silane coupling agent KH570 at first, then 2,2′-azobis(2-amidinopropane) dihydrochloride (AIBA) was anchored onto the modified Al2O3 to initiate the graft polymerization of acrylamide monomer (AM), and PAM/Al2O3 composite particles were obtained finally. The structure and dispersion property of Al2O3 composite particles were characterized by XPS, FT-IR, laser particle size analyzer, micro electrophoresis apparatus, spectrophotometer and SEM as well as XRD. The results indicate that the attained composite abrasive shows good dispersion stability in aqueous medium with PAM as shell and Al2O3 as core when water-soluble azo initiator is added at 40 ℃. Compared with unmodified Al2O3, the reunion phenomenon of grafting polymerization modified Al2O3 powder is improved by AM, the D50 of the modified particles is reduced. The isoelectric point (IEP) of the grafting modified particles is migrated, and the Zeta potential of the modified particles reaches the maximum value when the pH value is 9.
Key words: Al2O3 ultrafine powders; azo initiator; dispersion; surface modification; composite abrasive
