Chloromethylation And Functionalization Research Of Highly Crosslinking Macrpoprous Absorption Resin D101

As a potentially powerful separation material, MAR possesses adsorption and sieving properties, has been extensively used pharmaceutical (antibiotics, vitamin, Chinese traditional medicine, biological pesticide), medical treatment, environmental protection, analysis in many fields and supported as key technology for realizing Chinese traditional medicine the modernization and internationalization in national long-term development outline of 2002. However, due to the special preparation process and complex structure characteristics of MAR, even adopting the same synthetic process, the structural parameters of MAR with functional group, such as the types and number of functional groups, the pore size and the distribution of the pore size, the specific surface area and the pore volume, can hardly keep near. These will block badly applications and theory research of MAR, limiting largely the application range of MAR. Therefore, overcoming the difficulties and studying MAR adsorption theory, especially adsorption selectivity research were currently key subjects of MAR technology. In this work, the chloromethylation research of highly crosslinking non-polarity macroporous absorption resin D101 was performed by using self-made1,4-bis(chloromethoxyl)butane(BCMB) and monochloromethyl ether(ME) as the chloromethylation reagent, respectively, then the functionalization of chloromethylated D101 with high chloromethylation degree was conducted adopting sulfanilic acid(SA) and para aminobenzoic acid(PAA) based on the structural similarity. The influences of reaction conditions on the modified reaction were examined, so the optimum reaction conditions were obtained, and the structural parameters: the specific surface area, the pore volume and the pore size of the unmodified and modified D101 were determined, making the following results:1. The chloromethylation of highly crosslinking polymer was the first the problem we faced, and therefore, in this work the chloromethylation research of highly crosslinking non-polarity macroporous absorption resin D101 was performed and reaction conditions were investigated and optimized, the optimal conditions at 50 oC for 14 h in Lewis acid(ZnCl₂) catalyst for chloromethylation of resin were found as follows: m(D101) : m(BCMB) : m(CCl₄)=1 : 4 : 18.6, swelling time 12 h, the chloromethylation degree of D101-Cl was 1.13 mmol/g, realizing the higher chloromethylation of highly crosslinking resin and having a certain value. In our above reaction conditions, to further increase chloromethylation degree of D101-Cl, therefore, reaction system was in ultrasonic environment, D101-Cl with chloromethylation degree of 2.28 mmol/g was obtained by adopting smaller ME.2. The functionalization of chloromethylated D101-Cl of 2.28 mmol/g was conducted adopting SA and PAA with similar structure, realizing the high effective functionalization modification of MAR. The optimal conditions for functionalization of resin were found as follows: m (D101-Cl) : m (SA) : m (DMF) : m (NaOH) = 1 : 0.5 : 1.27 : 0.33, reaction temperature 60 oC, reaction time 48 h, functionalization degree 1.78 mmol/g; m (D101-Cl) : m (PAA) : m (DMF) : m (NaOH) = 1 : 0.5 : 1.27 : 0.5, reaction temperature 55 oC, reaction time 48 h, functionalization degree 1.54 mmol/g.To investigate the changes of the structural parameters of unmodified and modified D101, the structural parameters: pore size, specific surface area and pore volume of D101, D101 with high chloromethylation degree and high functionalization degree were characterized, finding that the thermal stability, pore size and the distribution of pore size, specific surface area, pore volume of the modified resin have changed obviously. Modified D101-SO₃^- and D101-CO₂^- with the same functionalization degree were also characterized, finding that pore size and the distribution of pore size, specific surface area, pore volume remained at the same level, which satisfied the requirements on MAR theory research, and provided necessary conditions for the law research of adsorption selectivity for MAR.