相反轉工藝對環氧乳液穩定性的影響

程文*，王宇，魯錦偉

（內蒙古電力科學研究院，內蒙古 呼和浩特 010020）

相反轉工藝對環氧乳液穩定性的影響

程文*，王宇，魯錦偉

（內蒙古電力科學研究院，內蒙古 呼和浩特 010020）

采用自制大分子乳化劑 E-10000，以相反轉乳化法制備了環氧乳液，通過測定電導率來確定相反轉點。探討了乳化劑用量、乳化溫度、攪拌速率和乳化時間對乳液穩定性及固化膜性能的影響。結果表明，當乳化劑質量分數小于17%時，體系為不完全相反轉，大于17%時才為完全相反轉。所得最優制備工藝為：乳化劑質量是環氧樹脂質量的20%，乳化溫度78 °C，攪拌速率1200 r/min，乳化時間40 min。此時環氧乳液穩定性好，平均粒徑374 nm，且粒徑分布較窄。其固化膜的鉛筆硬度為2H，柔韌性2 mm，附著力0級，沖擊強度50 kg·cm，吸水率6.29%。

環氧樹脂；相反轉乳化；臨界水量；電導率；穩定性

Abstract:An epoxy emulsion was prepared via phase inversion emulsification with a home-made macromolecular emulsifier E-10000.The phase inversion point was determined by conductivity testing.The effects of emulsifier content,emulsification temperature, stirring rate and emulsification time on the stability of emulsion and properties of its cured film were studied.The results showed that the phase inversion will not be complete until the mass fraction of emulsifier is up to 17%.The optimal preparation conditions were obtained as follows: mass fraction of emulsifier 20% (with respect to the mass of epoxy resin), emulsification temperature 78 °C, stirring rate 1200 r/min, and emulsification time 40 min.The emulsion prepared thereunder has a good stability, an average particle size of 374 nm and a narrow particle size distribution.Its cured film has a pencil hardness of 2H, flexibility 2 mm, adhesion strength 0 grade, impact strength 50 kg·cm and water absorption rate 6.29%.

Keywords:epoxy resin; phase inversion emulsification; critical water content; conductivity; stability

First-author’s address:Inner Mongolia Electric Science Research Institute, Hohhot 010020, China

相反轉乳化法是一種環氧樹脂水性化的有效方法，原指多組分體系中連續相與分散相在一定條件下相互轉化的過程，如在油/水/乳化劑的三元體系中，連續相從油相(O)向水相(W)或由水相向油相轉變[1]。在相轉變區附近，體系的一些物理性質(如黏度、電導率、界面張力等)會發生突變，利用這一特點能夠制得粒徑小、穩定性好的乳液。楊振忠等[2-4]詳細研究了環氧樹脂相反轉過程中的相態變化、微粒形態、流變性能等，但未深入探討乳化工藝。周立新等[5]分析了環氧樹脂相反轉過程中的工藝參數，但因其采用的是小分子乳化劑，制備的環氧乳液的貯存穩定性有限，粒徑偏大。因此，要制備穩定且粒徑小的乳液，不僅需要采用適宜的乳化劑，而且必須嚴格控制乳化工藝?！?br>