大豆分离蛋白纸张表面施胶剂的制备及性能

Preparation and Properties of Soy Isolate Protein Based Surface Sizing Agents for Papermaking

摘要:

以大豆分离蛋白(SPI)为原料、烯基琥珀酸酐(ASA)为疏水改性剂，控制ASA与SPI伯氨基的摩尔比合成四种不同酰化度的疏水大豆分离蛋白ASAn-SPI (下标n表示摩尔比，n=0.5，1，1.5和2)。通过伯氨基含量、FT-IR、UV-vis、荧光光谱、疏水指数等测定方法对ASAn-SPI的结构和性能进行表征。结果表明：长链疏水基团成功引入到SPI骨架上，ASAn-SPI的酰化度和疏水指数随着n的增加而增大，当n达到1.5后趋于稳定。ASA1.5-SPI的施胶量为0.77 g/m2时，施胶纸的初始水接触角可达132?，水滴保留时间可达53 min。XPS和SEM分析证实ASA1.5-SPI在纸纤维表面形成一层粗糙的疏水薄膜。此外，纸张力学性能测试表明，ASA1.5-SPI施胶纸的抗张强度由未施胶纸的0.6 kN/m提升至0.67 kN/m。

Abstract:

Using soy isolate protein (SPI) as raw material and alkenyl succinic anhydride (ASA) as hydrophobic modifier, four kinds of hydrophobic soy isolate protein (ASAn-SPI, the subscript n represented the molar rate of ASA to primary amino group of SPI, n=0.5, 1, 1.5 and 2) with different acylation degree were prepared through controlling the molar rate of ASA to primary amino group of SPI. The structures and properties of ASAn-SPI were characterized by means of primary amino content, FT-IR, UV-vis, fluorescence spectrum and hydrophobic index. The results indicated that long hydrophobic chain was successfully introduced into the SPI molecular framework, the acylation degree and hydrophobic index of ASAn-SPI increased with n and tended to be stable when n exceeded 1.5. Subsequently, ASA1.5-SPI was used in surface sizing of paper and the sizing amount was 0.77 g/m2. It was found that the initial water contact angle of ASA1.5-SPI sized paper was 132?, the retention time of water drop was 53 min. XPS and SEM analysis revealed that ASA1.5-SPI formed a rough hydrophobic layer on paper fiber surface. In addition, mechanical property tests indicated that the tensile strength of ASA1.5-SPI sized paper was increased from 0.6 kN/m to 0.67 kN/m compared with that of base paper.