核壳乳液的合成及对蔗渣纤维的疏水化改性

Preparation of Cationic Latex with Core-shell Structre for Hydrophobic Modification of Bagasse Fibers

摘要:

本文采用半连续种子乳液聚合法，以苯乙烯（St）、丙烯酸丁酯（BA）、甲基丙烯酸缩水甘油酯（GMA）为单体，十六烷基三甲基氯化铵（CTAC）为阳离子乳化剂，二甲基丙烯酸乙二醇酯（EGDMA）为交联剂，2,2-偶氮二（2-甲基丙基咪）二盐酸盐（AIBA）为阳离子引发剂，制备阳离子乳液。研究了乳化剂用量、引发剂用量、保温时间以及反应温度等条件对乳液性能的影响。在反应温度80 ℃，乳化剂用量为单体质量的6 %，引发剂用量为单体质量的0.5 %，保温时间为2 h时单体转化率达到98.03 %，核壳结构由透射电镜、纳米激光粒度仪表征，乳胶粒子的平均粒径为57.21 nm且粒径分布窄（PDI=0.051），乳液的Zeta 电位为+47.62 mV。利用该乳液对蔗渣纤维进行表面疏水改性，并进行亲水性测试，结果表明，改性后蔗渣纤维接触角由0 °提高至98 °，疏水改性效果明显。

Abstract:

Cationic polymer latex, poly(styrene/butyl acrylate-co- glycidyl methacrylate) [P(St/BA-co-GMA)], with core–shell structure was synthesized by a two-step semi-batch emulsion polymerization with styrene (St), butyl acrylate (BA) and glycidyl methacrylate (GMA) as monomers, cetyl trimethyl ammonium chloride (CTAC) as cationic surfactant, ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, 2,2＇-azobis(2-methylpropionamidine) dihydrochloride (AIBA) as cationic initiator. The influence of surfactant dosage, initiator dosage, reaction temperature and time on the properties of latex were investigated. The monomer conversion of cationic latex reached 98.03% when the reaction proceeded under the following conditions: surfactant dosage of 6 %, initiator dosage of 0.5%, and 2 h reaction time at 80 ℃. The mean particle size and zeta potential of the resulted latex particles were 57.21 nm and +47.62 mV, respectively. The core-shell structure of latex was confirmed by Transmission Electron Microscope (TEM) and laser particle size analyzer. The latex was applied for hydrophobic modification of bagasse fibers. The water contact angle of the modified fiber was increased from 0°to 98°, compared with the untreated fiber, which indicated that the modified bagasse fibers were rendered hydrophobic by the cationic latex nanoparticles.