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首先使氯甲基聚苯乙烯交联微球(CCMPSt)在有机相中充分溶脹,然后通过相转移催化剂(季铵盐)的作用,将水相中对羟基苯甲醛所产生的负氧离子转移至有机相,使之与CCMPSt微球表面的苄氯基团发生亲核取代反应,从而将CCMPSt微球转变为侧链带有醛基的聚苯乙烯交联微球(Aldehyde-CPSt).本研究重点考察了各种因素对液-液-固三相体系中相转移催化过程及取代反应的影响规律,较深入地探讨了反应机理.研究结果表明,通过相转移催化剂的作用,可将亲核取代试剂对羟基苯甲醛负氧离子不断地从水相转移至有机相,在有机相与交联微球CCMPSt的界面发生取代反应,从而将CCMPSt微球顺利地转变为功能微球Aldehyde-CPSt.有机溶剂的极性越强,对CCMPSt微球的溶脹性能越好,取代反应速率越快;相转移催化剂季铵离子上的碳链对称性越好及碳链越长,相转移催化的效果越好;有机相与水相的比例对相转移催化效果也有较大的影响.
First, chloromethyl polystyrene cross-linked microspheres (CCMPSt) fully swollen in the organic phase, and then by phase-transfer catalyst (quaternary ammonium salt), the aqueous phase of hydroxybenzaldehyde generated negative oxygen ions transfer To the organic phase so that the nucleophilic substitution reaction with the benzyl chloride group on the surface of the CCMPSt microspheres transforms the CCMPSt microspheres into Aldehyde-CPSt with aldehyde groups on the side chains The research focuses on the influence of various factors on the phase-transfer catalysis process and the substitution reaction in the liquid-liquid-solid three-phase system, and the reaction mechanism is discussed in depth.The results show that by the action of phase transfer catalyst, The nucleophilic substitution reagent p-hydroxybenzaldehyde negative oxygen ions are continuously transferred from the aqueous phase to the organic phase, and the substitution reaction occurs at the interface of the organic phase and the crosslinked microspheres CCMPSt, so that the CCMPSt microspheres are successfully transformed into the functional microspheres Aldehyde-CPSt .The stronger the polarity of organic solvent, the better the swelling property of CCMPSt microspheres, the faster the substitution reaction rate.The better the carbon chain symmetry of the quaternary ammonium ion of the phase transfer catalyst and the longer the carbon chain, the effect of phase transfer catalysis The better; ratio of organic phase to aqueous phase Also have a greater influence on the phase transfer catalysis effect.