含氟丙烯酸酯改性水性硝化纤维乳液的制备及其性能

Preparation and Properties of Fluoroacrylate Modified Waterborne Nitrocellulose Emulsion

以硝化纤维(NC)、异佛尔酮二异氰酸酯(IPDI)、丙烯酸(AA)、丙烯酸羟乙酯(HEMA)、全氟辛基乙基丙烯酸酯(FA)、三乙胺(TEA)为主要原料,采用自乳化法制备含氟丙烯酸酯改性水性硝化纤维乳液(WNC)。通过傅里叶变换红外光谱(FTIR)、透射电子显微镜(TEM)、纳米粒度仪、动态流变仪以及视频光学接触角测定仪对所制乳液及薄膜进行了结构和性能表征,并考察了单体聚合温度、n(AA)∶n(HEMA)、含氟丙烯酸酯质量分数(占反应物AA、HEMA、NC、IPDI总质量的百分数)对乳液及其薄膜性能的影响。结果表明,所得WNC乳液性能稳定,乳液胶粒呈球形,具有核-壳结构。当单体聚合温度为60℃,n(AA)∶n(HEMA)=3∶1,含氟丙烯酸酯用量为1.0%时,所得乳液粒径较小且分布窄,平均粒径和分散系数分别是54 nm和0.023;改性后的乳液薄膜吸水率降低至2.0%,薄膜接触角增加至120°,相比较未改性的WNC乳液,改性后的WNC乳液薄膜具有优异的耐水性。

A waterborne nitrocellulose （WNC） emulsion modified by fluoroacrylate was prepared by selfemulsifieation with nitrocellulose （ NC ）, isophorone diisocyanate （ IPDI ）, acrylic acid （ AA ）, hydroxyethyl acrylate（HEMA） ,perfluoroalkyl ethyl acrylates（FA） and triethylamine（TEA） as main raw materials. The prepared emulsion and film were characterized by FTIR, TEM, nano particle size analyzer, dynamic rheometer and contact angle analyzer. The effects of polymerization temperature, mole ratio of AA to HEMA, and dosage of fluoroacrylate on the properties of emulsion and film were also studied. The results showed that the WNC emulsion was stable and the particles of emulsion were regularly spherical with a core-shell structure. When the polymerization temperature was 60 ℃, the mole ratio of AA to HEMA was 3：1 and the mass fraction of fluoroacrylate （based on the mass of the total reactant） was 1.0%, the WNC emulsion exhibited smaller particle size and narrow particle size distribution. The average particle size and polydispersity index （PD1） were 54 nm and 0. 023, respectively. The water absorption of modified WNC film reduced to 2. 0% and contact angle increased to 120 ℃, which indicated that the modified WNC film had better water resistance than the unmodified WNC film.