PHASE-BEHAVIOR OF BLENDS OF POLY(ETHYLENE GLYCOL) AND PARTIALLY NEUTRALIZED POLY(ACRYLIC ACID)
PHASE-BEHAVIOR OF BLENDS OF POLY(ETHYLENE GLYCOL) AND PARTIALLY NEUTRALIZED POLY(ACRYLIC ACID)
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DOI：
10.1021/ma00113a002
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发表时间：
1995-04-24
期刊：
影响因子：
5.5
通讯作者：
WEISS, RA
中科院分区：
文献类型：
--
作者：
LU, XY;WEISS, RA
由于酸和醚氧之间存在氢键，聚丙烯酸（PAA）和聚乙二醇（PEG）的混合物在整个组成范围内是可混溶的。红外分析表明，酸-醚络合物的形成优于由羧酸基团自缔合形成的环状酸二聚体。随着丙烯酸 (AA) 与锂盐 (LiA) 中和程度的增加，混溶性降低，并且对于用含有 0.1-0.4 摩尔分数 LiA 的 AA-LiA 共聚物制成的共混物观察到较低的临界溶解温度 (LCST)。根据平衡熔点降低数据和二元相互作用模型计算不同化学物质之间的成对相互作用能。 AA 和乙二醇 (EG) 之间的有利相互作用促进了混溶，而 LiA 和 EG 之间的不利相互作用则有利于分层。红外分析表明，酸的中和降低了酸-醚络合物的浓度，并促进了有利于相分离的酸环状二聚体的形成。
Blends of poly(acrylic acid), PAA, and poly(ethylene glycol), PEG, are miscible over the entire range of composition as a result of hydrogen-bonding between the acids and ether oxygens. Infrared analysis showed that the formation of acid-ether complexes is preferred over that of cyclic acid dimers formed from self-association of the carboxylic acid groups. Miscibility decreased as the extent of neutralization of acrylic acid (AA) to the lithium salt (LiA) increased, and lower critical solution temperatures (LCST) were observed for blends made with AA-LiA copolymers containing 0.1-0.4 mole fraction LiA. Pairwise interaction energies between the different chemical species were calculated from equilibrium melting point depression data and a binary interaction model. Favorable interactions between AA and ethylene glycol (EG) promoted miscibility, while an unfavorable interaction between LiA and EG favored demixing. Infrared analysis showed that neutralization of the acid reduced the concentration of acid-ether complexes and promoted formation of acid cyclic dimers that favored phase separation.