纳米两性聚乙烯铵-丙烯酸钠膜的制备与表征

为研究一种新型两性聚电解质渗透汽化膜分离材料,利用沸腾、高速搅拌的无皂乳液聚合法合成纳米聚丙烯酰胺-丙烯酸,经Hoffman降解制备纳米聚乙烯铵-丙烯酸钠。利用红外光谱、扫描电镜和激光粒度分析仪对纳米聚乙烯铵-丙烯酸钠进行结构表征,测试不同pH值时聚乙烯铵-丙烯酸钠膜的耐水性。对不同浓度、不同有机物-水体系中的溶胀度和吸水速率进行测试。结果表明:聚乙烯铵-丙烯酸钠粒径在24 nm左右、pH≈5(接近等电点)时,聚乙烯铵-丙烯酸钠膜的耐水性最好,适合乙醇、丙酮中水的分离。

Preparation and Characterization of Nano-scaled Polyethylene Ammonium Sodium Acrylate Polyampholite Membrane

In order to develop a new type of polyamphoteric electrolyte pervaporation membrane materials,nano-sized polyacrylamide-acrylic acid(PAM-AA) particles were prepared using the soap-free emulsion polymerization method and boiling at high temperature and became nano-sized polyethylene ammonium-sodium acrylate(PVAM-SA) particles by Hoffman degradation reaction.The structure of PAM-SA was characterized using Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM) and laser particle size analysis.The water-resistant properties of the PVAM-SA polyampholite membrane under defferent pH values were studied.The degree of swelling and water-absorbent rate of the PVAM-SA polyampholite membrane were tested in defferent organic-water system,with a series of concentrations.The results showed that the size of PVAM-SA particles were about 24 nm.The water-resistant properties of the PVAM-SA polyampholite membrane were better for ethanol-water system and acetone-water system at pH≈5(near the isoelectric point).