共 18 条
Effect of water on internal aggregate structure in zinc-neutralized ionomers
被引:23
作者:
Welty, A
[1
]
Ooi, S
[1
]
Grady, BP
[1
]
机构:
[1] Univ Oklahoma, Sch Chem Engn & Mat Sci, Norman, OK 73019 USA
关键词:
D O I:
10.1021/ma981678q
中图分类号:
O63 [高分子化学(高聚物)];
学科分类号:
070305 ;
080501 ;
081704 ;
摘要:
The effect of water on zinc-neutralized ethylene-methacrylic acid (E-MAA) ionomers and sulfonated polystyrene (SPS) ionomers was studied. The change in weight after soaking in water was quantified as a function of zinc content and correlated to changes in spectra from zinc-edge extended X-ray absorption fine structure spectroscopy (EXAFS). EXAFS patterns for the fully dried ionomers were characteristic of zinc surrounded by four oxygen atoms. E-MAA ionomers absorbed much less water per zinc atom than SPS ionomers. Addition of water changed the EXAFS pattern in E-MAA ionomers, but the pattern was still characteristic of zinc coordinated to four oxygen atoms. This change was consistent with water replacing chelating carboxylate anions coordinated to zinc at the edges of aggregates or coordinated to isolated zinc ions. A new interpretation of the v(a)(COO-) infrared vibration was developed from this work. In SPS, addition of water caused zinc to become 6-fold coordinated to oxygen, which is suggestive of zinc totally solvated by water.
引用
收藏
页码:2989 / 2995
页数:7
相关论文