丙烯酰胺在聚乙二醇水溶液中聚合产品的微观形态  

MICROSTRUCTURE OF THE LATEX PREPARED THROUGH AQUEOUS TWO-PHASE POLYMERIZATION OF ACRYLAMIDE IN AQUEOUS POLY(ETHYLENE GLYCOL) SOLUTION

作　　者：吕挺[1] 单国荣[1] 商宽祥[1] 

机构地区：[1]化学工程联合国家重点实验室(浙江大学)浙江大学化工系,杭州310027

出　　处：《高分子学报》2010年第6期647-652,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20776125;20876136);教育部新世纪优秀人才支持计划(项目号NCET-05-0512)资助项目

摘　　要：采用偶氮类水溶性引发剂2,2′-偶氮二异丙基咪唑啉二盐酸盐(VA044)引发丙烯酰胺(AM)在聚乙二醇(PEG)水溶液中的双水相聚合;研究了引发剂、单体、聚乙二醇浓度及温度对最终产品中聚丙烯酰胺(PAM)液滴形态、尺寸的影响.随着引发剂浓度的增加,液滴由球状变为细长条状;随着温度的上升,球状液滴逐渐趋于条状,然后又重新趋于球状;在初始单体浓度较低时,PAM液滴滴径分布较窄,当其浓度增加后,滴径呈多峰分布;随着PEG浓度的增加,聚合物液滴趋于球状。A latex of poly（acrylamide）（PAM） dispersed in a aqueous solution was successfully prepared through aqueous two-phase polymerization of acrylamide（AM） in aqueous poly（ethylene glycol）（PEG） solution with 2,2＇-azobis[2-（2-imidazolin-2-yl） propane ]-dihydrochloride（VA044） as the initiator.The effects of initiator,monomer and PEG concentrations,as well as the temperature,on the morphology and size of the droplets rich in PAM were systemically investigated.High initiator concentration leads to a high rate of polymer chains aggregation,which causes the small droplets separate from the continuous phase rapidly.The low viscosity in the earlier stage of polymerization could not prevent the coalescence of small droplets.At the same time,the high internal viscosity of the droplets is great enough to prevent easy diffusion of molecules between the coalescing droplets.Therefore,stripe shape droplets were generated.Since more monomer was consumed to generate small droplets because of high initial initiator concentration,less monomer polymerized inside the droplets.Thus,the stripe shape droplets can not become plump.The popcorn shape droplet was formed due to the aggregation between bigger droplets and small droplets.With temperature rising from 30℃ to 52.5℃,the rate of initiator decomposition accelerated,and the critical chain length of PAM separated from continuous phase shortened,both of which make the droplet morphology trend to stripe shape.However,monomer partition coefficient decreased with temperature rising meaning that more polymerization occurred inside droplets and the droplets formation was slowed.The former factor was inclined to form stripe shape droplets,and the latter trended to generate spherical droplets.Thus,the droplet shifted from round shape to stripe shape,and then formed round shape again.At low initial monomer concentration,the polymerization was very slow.However,higher monomer concentration causes the small droplets separate rapidly from continuous phase which leads t

关 键 词：双水相聚合 聚乙二醇 聚丙烯酰胺 液滴形态 

分 类 号：O631.3[理学—高分子化学]