氧化有机溶剂木质素基亲水性上浆剂的制备及其在聚丙烯中的应用

Preparation of Oxidized Organosolv Lignin-based Hydrophilic Sizing Agent and Its Application in Polypropylene

碳纤维(Carbon fiber,CF)复合材料的界面相容性是决定复合材料综合性能的关键性因素,上浆剂在碳纤维与基体树脂之间发挥不可或缺的作用,环保亲水性上浆剂的制备是亟待解决的研究热点问题。本文对亲水性木质素基上浆剂及碳纤维增强聚丙烯(Polypropylene,PP)复合材料进行了研究,首先将木质素氧化处理增加活性基团,再与环氧基团反应制备氧化木质素基环氧树脂,然后与醇胺和羧酸反应,获得亲水性木质素基上浆剂,进一步加入3-氨丙基三乙氧基硅烷(KH550),以平衡上浆剂的吸湿性,最终制备一种稳定性优异的环保亲水性木质素基上浆剂(OLBEDK)。通过质量分数2.5%的OLBEDK处理的CF,毛丝量仅为3.0 mg;复合材料的层间剪切强度(ILSS)、弯曲强度、弯曲模量和冲击强度与未上浆的CF增强PP复合材料相比,分别提高50.8%、34.2%、53.7%和127.8%,使CF/PP复合材料的综合性能显著提高。这归因于木质素的苯环与CF的碳六元环之间的π-π共轭作用,及KH550的烷基链与PP分子链之间发生物理缠绕,有效增强了CF与PP之间的界面相互作用。

The interfacial compatibility of carbon fiber(CF) reinforced composites is the key factor to determine the comprehensive properties of the composites. The sizing agent plays an indispensable role between carbon fibers and matrix resins. Environmentally friendly hydrophilic sizing agent is is a hot research issue to be solved. In this work,the hydrophilic lignin-based sizing agent and carbon fiber reinforced polypropylene(PP)composites are prepared and studied. The lignin is ozonized to increase the reactive group. The obtained lignin reacts with epoxy group to prepare the oxidized organic solvent lignin based epoxy resin(OLBE). OLBE reacts with alcohol amine and carboxylic acid to obtain the hydrophilic lignin-based sizing agent. KH550 is further added to balance the hygroscopicity of sizing agent. Finally,an oxidized organic solvent lignin-based hydrophilic sizing agent(OLBEDK)with excellent stability was prepared. The CF treated with 2. 5% solid content OLBEDK was only 3. 0 mg. The ILSS,Flexural strength,Flexural modulus and Impact strength of CF/PP composites are increased by 50. 8%,34. 2%,53. 7% and 127. 8%,respectively,compared with those of CF/PP composites without sizing. This is attributed to the π-π conjugation between the benzene ring of lignin and the carbon six-membered ring of CF,and the physical entanglement between the alkyl chain of KH550 and the molecular chain of PP,which enhances the interfacial interaction between CF and PP effectively.