高取代度阳离子淀粉基苯丙乳液的合成和应用研究

Synthesis and Application of Highly Cationic Starch-based Styrene-acrylate Copolymeric Emulsion for Papermaking

关键词:  阳离子表面施胶剂  苯丙乳液  无皂聚合  高取代度阳离子淀粉

Key Words:cationic surface sizing agent  styrene-acrylate copolymeric emulsion  soap-free polymerization  highly cationic starch

摘要:以苯乙烯（St）、丙烯酸正丁酯（BA）、丙烯酸叔丁酯（tBA）为单体，H₂O₂-FeSO₄为引发体系，高取代度阳离子淀粉（HCS）为乳化剂，开展了苯丙表面施胶剂的无皂乳液聚合。探讨了HCS的用量、分子量（以特性黏度表示）、取代度对乳液聚合的影响，使用多种方法评价了乳液的理化性能与应用性能。所制备得的高取代度阳离子淀粉基苯丙乳液胶粒平均粒径小（126.2 nm）、正电性强（Zeta电位为25.8 mV）、贮存稳定性优良；将其应用在瓦楞原纸上，施胶纸张的Cobb值为21.6 g/m²，水滴接触角达121.6°，与低取代度阳离子淀粉基苯丙乳液相比，其应用效果具有明显优势。研究对其能赋予纸张更佳施胶效果的原因也提出了机理性的解释。

Abstract:Soap-free emulsion polymerizations of styrene-acrylate surface sizing agent for papermaking were carried out using styrene （St）， n-butyl acrylate （BA）， and tert-butyl acrylate （tBA） as monomers， H₂O₂-FeSO₄ as initiator， and a series of highly cationic starches （HCS） as emulsifiers. The effects of dosage， molecular weight （characterized by intrinsic viscosity）， and degree of substitution of the HCS on the emulsion polymerization were discussed. A variety of methods were used to evaluate the physical and chemical properties as well as the application performance of the emulsions. The prepared styrene-acrylate emulsion had a small average particle size of colloidal particles （126.2 nm）， and strong positive charge properties （Zeta potential was 25.8 mV） and had excellent storage stability， when it was applied to corrugated base paper， the Cobb value of the sized paper was 21.6 g/m²， and the water droplet contact angle reached 121.6°. A mechanistic explanation for the reason why it could give paper better surface sizing effects was also provided.