Microwave Synthesis Of Hydrogenated Rosin-based Quaternary Ammonium Surfactants And Preparation Of Cationic Neutral Sizing Agent And Its Application

Hydrogenated rosin-based quaternary ammonium surfactants were synthesized by using microwave method, comparision of the effect of microwave irradiation method and conventional heating method on synthetic reaction was investigated. The structure and surface features were characterized. Meanwhile, preparation of cationic hydrogenated rosin sizing agents by compositing hydrogenated rosin-based quaternary ammonium surfactants and nonionic surfactants were investigated, and their application effect was discussed as well. The main experimental results are as follows:Hydrogenated rosin-based quaternary ammonium salt monomeric surfactant was synthesized by one-step means of microwave irradiation method using hydrogenated rosin, epichlorohydrin and triethylamine as raw materials (monomeric quaternary ammonium salt). Hydrogenated rosin-based quaternary ammonium salt gemini surfactant was synthesized by two-step means of microwave irradiation method using hydrogenated rosin, epichlorohydrin and tetramethylethylenediamine as raw materials (gemini quaternary ammonium salt). The effects of reaction conditions (reaction time, microwave power, reaction temperature, molar ratio) on esterification rate of monomeric quaternary ammonium salt were investigated by single-factor experiment, and then the suitable synthesis reaction conditions have been obtained as follows:reaction time of75min, microwave power of500W, reaction temperature of80℃and molar ratio of1:1:1. The suitable synthesis reaction conditions of gemini quaternary ammonium salt have been obtained by orthogonal experiment and single-factor experiment as follows:molar ratio between intermediate and tetramethylethylenediamine of3:1, microwave power of550W, reaction temperature of90℃and reaction time of1.5h. Compared with conventional heating method, results show that the reaction conditions of microwave irradiation method can be improved as well as the reaction time can be shortened dramatically.The structure of microwave synthesized products were characterized by FT-IR, and their surface features, such as critical micelle concentration(CMC), surface tension (ycMc), emulsifying property (with benzene), foaming property, Krafft poin and HLB value, were measured as well. Results show that ccmc value of2microwave synthesized products were9.83×10-4and6.32×10-4mol·L-1, respectively. The ccmc values were all up to10-5mol·L-1and the γCMC values were35.7and34.1mN·m-1, respectively.Composite emulsifier that compose of monomeric quaternary ammonium salt-Span60-Tween80with HLB value of14was obtained, and cationic hydrogenated rosin sizing agent (CRS-01) was prepared by using it. The average diameter of particles for CRS-01was537nm as well as its Zeta potential was+20.9mV. Composite emulsifier that compose of gemini quaternary ammonium salt-Span60-Triton X-100with HLB value of14was obtained, and cationic hydrogenated rosin sizing agent (CRS-02) was prepared by using it. The average diameter of particles for CRS-02was615nm as well as its Zeta potential was+23.4mV.Sizing performance of2cationic hydrogenated rosin sizing agents for pH from7.0to8.5was investigated by orthogonal experiment using technology of reverse sizing. Results show that CRS-01and CRS-02all can meet the neutral sizing requirements. Sizing value of CRS-01could reach to171s when it was applied to bleached eucalyptus pulp, and sizing value of CRS-02could reach to109s when it was applied to bleached bagasse pulp.