丙烯酸酯共聚物无皂水溶胶稳定性的研究

用溶液聚合法合成了四种AA含量不同的丙烯酸酯共聚物(MMA/BA/HEMA/AA)，通过中和AA使共聚物带有—COO~-能起自乳化作用分散于水中而成为无皂水溶胶．TEM观察表明水溶胶粒子呈球状，单分散性好，粒径随AA含量增加而变小，在30～90 nm范围．用电导滴定法测定水溶胶粒子中—COOH和—COO~-的分布，表明绝大部分—COO~-处于粒子表面，并且随AA含量增加，粒子表面的—COO~-增多，Zeta电位增大，这是导致水溶胶的抗电解质稳定性(以C.C.C.值反映)和贮存稳定性(以表现粘度反映)随AA含量增加而提高的主要原因。

Study on the Stability of Soap-free Water-Solubilized Polyacrylic Colloidal Dispersions

Four acrylic copolymers (MMA/BA/HEMA/AA) containing various amount of AA were prepared by solution polymerization. The soap-free water-solubilized colloidal dispersions were obtained by dispersing the copolymer in water through seif-emulsion of the partly neutralized AA in the copolymer. TEM showed that the particles of the colloidal dispersions are spherical and of monodispersion, and the particle size decreases with increasing AA content ranging from 30nm to 90nm. It was found by conductometric titration that most -COO- locates on the particle surface and the surface -COO- increases with increasing AA content, resulting in the enhancement of zeta-potential. An these results are consistent with the facts that the electrolyte-resistance (expressed as C.C.C.value) and the storage stability (expressed as apparent viscosity) of the conoidal dispersions increase with increasing AA content.