光引发1,1-二苯基乙烯法合成聚甲基丙烯酸甲酯-b-聚丙烯酸丁酯嵌段共聚物

Synthesis of Poly(Methyl Methacrylate)-b-Poly(Butyl Acrylate)by 1,1-Diphenylethylene Method with Ultraviolet Light

在紫外光(UV)照射下,以1,1-二苯基乙烯(DPE)为自由基控制剂,2-羟基-2-甲基-1-苯基-1-丙基酮(1173)为光引发剂,在室温引发甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)共聚,合成了聚甲基丙烯酸甲酯-b-聚丙烯酸丁酯嵌段共聚物。用红外光谱、核磁共振谱、紫外光谱及凝胶渗透色谱-多角度激光散射技术对聚合物结构进行了表征,同时分析了聚合机理。研究表明,在室温UV照射及DPE存在下,1173能引发MMA聚合,生成具有可控相对分子质量及较窄相对分子质量分布的聚甲基丙烯酸甲酯,且DPE以一种半醌式结构存在于所生成的聚合物链中。该聚合物链可作为一种大分子引发剂,引发BA聚合,生成PMMA-b-PBA嵌段共聚物。

Poly( methyl methacrylate)-b-poly( butyl acrylate) was synthesized via ultraviolet light( UV)-initiated copolymerization of methyl methacrylate and butyl acrylate using 1,1- diphenylethylene( DPE) as control agent of free radical. The block polymer obtained was characterized by infrared spectroscopy( IR),nuclear magnetic resonance( NMR),and size-exclusion chromatography with multi-angle laser light scattering( SEC-MALLS). The polymerization mechanism was also studied. It is found that DPE could control the UV-initiated polymerization of methyl methacrylate and exist as semi-quinoid structure in poly( methyl methacrylate) with controlled molecular weight and narrow molecular weight distribution. The DPE-containing poly( methyl methacrylate) could initiate polymerization of butyl acrylate,and formed poly( methyl methacrylate)-b-poly( butyl acrylate) under UV irradiation.