摘要
用激光光散射技术研究了丙烯酰胺 丙烯酸共聚物 (简称P(AM AA) )的溶液行为 .结果表明 ,纯水中P(AM AA)分子的流体力学半径Rh的分布存在 10 0～ 5 0 0nm的范围 ,与溶液中的网状结构对应 .当加入NaCl后 ,Rh 分布变窄 ,集中在 10 0nm以下的范围内 ,10 0～ 5 0 0nm这一范围消失 ,说明P(AM AA)在纯水溶液中主要以网状结构存在 ,小分子盐如NaCl的加入会破坏这种网状结构 .网状结构的破坏导致溶液稳定性下降 ,在0 1mol LNaCl溶液中 ,当c <c (≈ 1 34× 10 - 3g mL)时 ,溶液稳定 ,长时间放置不会出现沉淀 ;当c >c 时 ,放置一段时间后 ,溶液中出现白色絮状沉淀 .
Poly (acrylamide-co-acrylic acid) [P(AM-AA)] has attracted many researchers for its special properties and potential applications in enhanced oil recovery (EOR). The network-structure of P ( AM-AA) in aqueous solutions and the behavior in 0.1 mol/L NaCl aqueous solutions were investigated by a combination of static and dynamic laser light scattering techniques. In the hydrodynamic radius ( Rh) distribution of P(AM-AA) molecules in aqueous solutions, a size range of 100 similar to 500 nm, which is coincident with the network-structure, is dominant. With the addition of NaCl., the width of hydrodynamic radius distribution decreases, and the radii concentrate in a range below 100 nm. These results provide strong evidence of the existence of network-structure in aqueous solutions of P(AM-AA) The network-structure will be destroyed with the addition of a small amount Of salts, such as NaCl, and then the stability of the solution decreases due to the destruction of the network-structure. In 0.1 mol/L NaCl aqueous solutions, there exists a critical concentration c * (approximate to1.34 x 10(-3) g/mL) : when c < c *, the solution of P( AM-AA) is stable and without precipitation for long time; when c > c * white flocculent precipitates appear after a period of time.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2003年第4期500-504,共5页
Acta Polymerica Sinica
基金
高分子材料工程国家重点实验室资助项目
