用多官能团引发剂合成超支化聚苯乙烯及其C60衍生物

通过α-溴丙酰溴与Z5(季戊四醇与2,2-二羟甲基丙酸缩聚的产物)酯化反应制得超支化原子转移自由基聚合(ATRP)引发剂Z5-B(约含19个引发点).在100℃及CuCl/N,N,N,N",N"-五甲基二亚乙基三胺催化下,用Z5-B引发苯乙烯的ATRP聚合(环己酮为溶剂,体积分数为50%),得到超支化的聚苯乙烯,将溴端基叠氮化后与C60反应,获得超支化聚苯乙烯C60衍生物.该超支化C60衍生物可用于光限制材料.

Synthesis of Hyperbranched Polystyrene and Its Fullerene End-capped Derivatives with Multifunctional Atom Transfer Radical Polymerization Initiator

A novel multifunctional ATRP initiator was synthesized by esterfication of a hyperbranched polyester Z5[from pentaerythritol and 2,2-bis(hydroxymethyl)propionic acid]. The macroinitiator contained approximately 19 initiating sites per molecule. It was used for the ATRP of styrene mediated by CuCl and N,N,N,N",N"-pentamethyldiethylenetriamine(PMDETA) in cyclohexanone at 100 ℃. The molar ratio of monomer to initiator was 100/1, 200/1, 300/1, respectively. Through hydrolysis of hyperbranched polymer, the arm chain length of the hyperbranched polystyrene was detected by GPC, the results showed that ATRP process under these conditions was well controlled. The hyperbranched PS was further reacted with sodium azide in dimethyl formamide at room temperature to yield an azide end-functional hyperbranched polymer. Then a covalently bonded C60-hyperbranched polymeric derivative was achieved by reacting C60 with the sodium azide end-capped hyperbranched polymer in 1,2-dichlobenzene solution at 130 ℃. In the hyperbranched polymeric derivatives, the mass fraction of the fullerene was about 1%—2.5%.