Reseach on Development of Functional Microspheres by Plasma-Graft Polymerization

本课题探讨了等离子体接枝聚合的最佳条件，建立了一种独特的微球表面改性方法，并对改性表面的功能进行了评价，为制备功能化微球开辟了一种新的实用方法。衬底材料为聚苯乙烯（10-260 μ m）和二氧化硅（70 μ m）微球。以甲基丙烯酸缩水甘油酯（GMA）、丙烯酰胺（AAM）和n -异丙基丙烯酰胺（NIPAM）为单体进行接枝聚合。利用等离子体辐照部分和聚合后部分组成的反应装置，在不同的操作条件下将聚合物层接枝到微球表面。采用1,1-二苯基-2-吡啶酰肼（DPPH）和乙胺分别测定自由基位点和聚合聚（GMA）的含量。结果表明，最佳氩等离子体处理条件为：聚苯乙烯为50W，300s；二氧化硅为200W，60s。接枝层的数量和结构受单体浓度和聚合后时间的影响。将含环氧基团的接枝聚丙烯酸甲酯（GMA）与亚氨基乙酸二钠（DSIA）作为质子给体化合物反应，得到表面保留羰基的功能微球。这些dsim改性微球对金属离子有定量的吸附能力，但对稀土金属离子没有自适应选择性。聚（NIPAM）层具有独特的温敏功能，在32°C以上和低于32°C时分别重复收缩和膨胀。通过温度上下摆动，将nipam修饰的微球固定化酶如脂肪酶。固定化脂肪酶对蓖麻油水解反应具有生物催化作用，转化率达82%，产率达40%。

In this reseach project, the optimum conditions of plasma-graft polymerization were discussed to establish the unique method for the surface modification of microspheres, and the functions of the modified surfaces were evaluated to develop a new practical method for preparation of functionalized microspheres. The substrate materials were polystirene (10-260 mu m) and silica (70 mu m) microspheres. Glycidilmethacrylate (GMA), acrylamide (AAM) and N-isopropylacrylamide (NIPAM) were used as the monomer for graft polymerization. The polymeric layr was grafted onto the surface of microspheres using the reaction apparatus consisted of plasma irradiation part and post polymerization part under various operating conditions. The amount of radical site and greafted poly (GMA) were determined by using 1,1-diphenyl-2- picrylhydrazyl (DPPH) and ethylamine, respectively. From these results, the optimum Ar plasma treatment condition to initiate graft-polymeerization were 50W,300seconds for polystirene and 200W,60seconds for silica. The amount and structure of grafted leyer were controlled with monomer concentration and post polymerization time. The grafted poly (GMA) including epoxide groups were reacted with disodium iminoacetate (DSIA) as the proton donor compound to from the functional microspheres keeping carbonyl groups on the surface. These DSIM-modified microspheres had quantitative adsobability for metal ions but no adsoptive selectivity in cace of rare-earth metal ions. Poly (NIPAM) layr have the unique temperature-sencitive function to repeat shrinking and swelling above and below 32 ﾟC,respectively. By temperature up and down swing, NIPAM-modified microspheres immobilized enzyme such as lipase inclusively. Immobilized lipase had the function as bio-catalyst for hydrolysis reaction of castor oil to 82% conversion and 40% yield of recinoleic acid.