阳离子无皂含氟核壳苯丙乳液的制备及成核机理

在水溶性阳离子单体甲基丙烯酰氧基乙基三甲基氯化铵(DMC)存在下,以乙醇为助溶剂,通过种子半连续核壳乳液聚合法制备阳离子无皂含氟核壳苯丙乳液。考察了水溶性阳离子单体DMC和乙醇用量对乳液聚合过程的影响;用透射电镜(TEM)和X射线光电子能谱(XPS)对聚合物乳液乳胶粒形貌及涂膜化学组成进行表征,并讨论了无皂乳液聚合的成核机理和聚合过程。结果表明,采用种子半连续乳液聚合法,当DMC的质量分数为6.0%,乙醇的质量分数为7.5%(釜液)时,可以得到稳定的阳离子核壳结构含氟乳液,无皂乳液聚合的成核机理是先以均相成核方式后继续以低聚物成核方式进行,最终形成核壳结构。

Preparation of Cationic Soap-Free Fluorinated Styrene-Acrylate Latex with Core-Shell Sturcture and Its Nucleation Mechanism

Soap-free cationic fluorinated poly-styrene-acrylate latex particles with core-shell structure were synthesized by seeded semi-continues emulsion polymerization using ethanol as co-solvent in the presence of water soluble cationic monomer methacryloxyethyltrimethyl ammonium chloride(DMC).The effects of DMC dosage and ethanol content on the stability of polymerization were studied.The surface element composition of the prepared copolymer film was analyzed by X-ray photoelectron spectroscopy(XPS),and the micro-structure of the prepared latex particles were observed by transmission electron microscopy(TEM).The nucleation mechanism of emulsion polymerization was discussed based on the experimental results.The result shows that cationic soap-free fluorinated poly-styrene-acrylate emulsion with a core-shell structure can be prepared when the monomer DMC is 6.0% and the ethanol is 7.5%.The nucleation mechanism of emulsion polymerization is the combination of a homogeneous nucleation and micelle nucleation mechanism.