催化乳液合成可溶性超支化聚合物的IFIRP法研究

Catalytic emulsion polymerization for soluble hyperbranched polymers by IFIRP process

描述了可进行催化乳液聚合合成可溶性超支化聚合物的一种新的聚合物合成过程——引发剂残片嵌入自由基聚合(IFIRP,Initiator-Fragment Incorporation Radical Polymerization)。分别以高浓度的偶氮二异丁酸甲酯(MAIB)和α-甲基苯乙烯(α-MS)为引发剂及阻聚剂,在十二烷基磺酸钠(SDS)和水及苯形成的乳液中,通过IFIRP过程,在70～80℃条件下将单体二异丁烯酸乙二酯(EGDMA)聚合反应3 h即可得到可溶性的超支化聚二异丁烯酸乙二酯纳米粒子聚合物。研究发现,当EGDMA、MAIB和α-MS浓度分别为1.0、2.0和2.0 mol/L时,到80℃为止未见到凝聚现象发生,生成可溶性聚合物的产率为44%左右,相对分子质量分布在1.2～1.5之间。分析结果表明共聚物的成分为(质量分数):α-MS为57%,MAIB为24%,含双键的EGDMA为5%,不含双键的EGDMA为14%。

This paper described a novel polymerization process-initiator-fragment incorporation radical polymerization（IFIRP） that can be used for catalytic emulsion polymerization for the synthesis of a series of soluble hyperbranched PEGDMA nanoparticles polymers.In the emulsion solution formed by sodium dodecyl sulfate（SDS） in water and benzene,a high concentrated dimethyl 2,2′-azobisisobutyrate（MAIB） and α-methylstyrene（α-MS） were used as initiator and retardants,respectively,the catalytic polymerization of ethylene glycol dimethacrylate（EGDMA） was carried out at 70 ℃ and 80 ℃ for 3 hours.The hyperbranched polymers of EGDMA with nanoparticles were formted.It was found that with the concentrations of EGDMA,MAIB and α-MS of 1.0,2.0 and 2.0 mol·L-1,respectively,the copolymerization proceeded homogeneously with no gelation occurred up to 80 ℃.A soluble copolymer in a yield of 44% was formed.The molecular weight distribution（Mw/Mn） was 1.2~1.5.The copolymers also contained 57% of α-MS units,24% of MAIB units,5% of EGDMA units with intact double bond and 14% of EGDMA units without double bond.