POLY(N-ISOPROPYLACRYLAMIDE) LATICES PREPARED WITH SODIUM DODECYL-SULFATE
POLY(N-ISOPROPYLACRYLAMIDE) LATICES PREPARED WITH SODIUM DODECYL-SULFATE
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DOI：
10.1006/jcis.1993.1075
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发表时间：
1993-03-01
影响因子：
9.9
通讯作者：
PELTON, R
中科院分区：
文献类型：
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作者：
MCPHEE, W;TAM, KC;PELTON, R
以N-异丙基丙烯酰胺(NIPAM)和亚甲基双丙烯酰胺(BA)为单体，在十二烷基硫酸钠(十二烷基硫酸钠)存在下，通过水分散共聚合制备了稳定的交联型聚N-异丙基丙烯酰胺(NIPAM)水性胶体分散体。在32℃以下，颗粒随水高度膨胀，平均直径在400-800 nm之间。在32℃以上，平均直径减小了2倍。随着交联剂密度、甲醇的存在和尿素的存在，溶胀呈现出预期的趋势。在聚合过程中，随着十二烷基硫酸钠浓度的增加，平均粒径也出现了预期的减小。根据肿胀数据估计Floryχ值。出乎意料的是，在1×10-5MKCl中，25°C下清洁胶乳的平均直径和电泳迁移率比在较高电解液浓度下更大。同样出乎意料的是，观察到在没有BA的情况下获得了胶体颗粒。用链缠结的方法解释了聚NIPAM分子链中粒子的存在，而不是孤立的线型聚NIPAM链的存在。
Stable aqueous colloidal dispersions of cross-linked poly(N-isopropylacrylamide), polyNIPAM, were prepared by aqueous dispersion copolymerization of NIPAM with methylenebisacrylamide, BA, in the presence of sodium dodecyl sulfate, SDS. Below 32°C the particles were highly swollen with water and had average diameters in the range 400-800 nm. Above 32°C the average diameters decreased by a factor of 2. Swelling showed the expected trends with cross-linker density, the presence of methanol, and the presence of urea. Also observed was the expected decrease in average particle size with increasing SDS concentration during the polymerization. Flory χ values were estimated from the swelling data. Unexpectedly, the average diameter at 25°C and the electrophoretic mobility of a cleaned latex were greater in 1 × 10-5MKCl than in higher electrolyte concentrations. Also unexpected was the observation that colloidal particles were obtained without BA. The presence of particles rather than isolated linear polyNIPAM chains was explained by chain entanglement.