食品包装用无硅无氟苯丙乳液的制备及应用

Preparation and application of silicone-free fluorine-free styrene-acrylic emulsion for food packaging

关键词:  食品包装纸  防水防油  无硅无氟  丙烯酸酯乳液

Key Words:Food wrapping paper  chemical composition  fiber morphology  physical strength

摘要:本研究以MMA为硬单体,BA为软单体,采用预乳化种子乳液聚合法制备了无氟无硅“内硬外软”的核壳型丙烯酸酯乳液,利用St改善乳液防水性能,再通过NMA/MAA交联提升乳胶膜致密性从而进一步提高乳液防水防油性能。FTIR光谱证实了MMA、BA、St、NMA、MAA均参与了共聚,NMA与MAA发生交联,且成功接枝于乳液主链结构。TEM表明乳胶粒呈现核壳结构,且粒径分布均匀,粒径约为111nm,与激光粒度仪的测试结果一致。将所制备的交联改性核壳型苯丙乳液涂料涂覆在阻隔纸上,涂布纸具有良好的拒水性,Cobb1800s吸水值为8.6 g/m2^,比未改性下降约48.5%,并且具有优异的拒油性,kit等级达到10/12,比未改性升高1级。此外,涂层样品表现出优异的力学性能、热稳定性以及热封性。

Abstract:In this study, MMA was used as the hard monomer and BA as the soft monomer to prepare a fluorine-free and silicone-free "core-shell" acrylic emulsion with an "inner-hard, outer-soft" structure using the pre-emulsion seed emulsion polymerization method. The water resistance of the emulsion was improved by using St, and the latex film"s compactness was enhanced through NMA/MAA crosslinking, thereby further improving the emulsion"s water and oil resistance. FTIR spectra confirmed that MMA, BA, St, NMA, and MAA all participated in the copolymerization, with NMA and MAA undergoing crosslinking and successfully grafting onto the main chain structure of the emulsion. TEM images showed that the latex particles exhibited a core-shell structure, with a uniform particle size distribution of approximately 111 nm, consistent with the results from the laser particle size analyzer. The crosslinked modified core-shell phenylpropyl emulsion coating was applied to barrier paper, which exhibited excellent water resistance with a Cobb1800s water absorption value of 8.6 g/m2, approximately 48.5% lower than that of the unmodified paper. Additionally, the paper displayed outstanding oil resistance, with a kit rating of 10/12, which is one level higher than that of the unmodified paper. Furthermore, the coated samples demonstrated excellent mechanical properties, thermal stability, and heat seal ability.