“可点击”丙烯酸酯聚合物的合成及其巯-炔光交联研究

Synthesis of “Clickable” Acrylate Polymers and Their Thiol-alkyne Photocrosslinking Reaction

通过丙烯酰氯和1-乙炔基1-环己醇的酯化反应,制备了乙炔基功能化的丙烯酸酯功能单体1-乙炔基环己基丙烯酯(ECA)。以该单体与丙烯酸甲酯(MA)进行自由基聚合反应,合成了乙炔基功能化均聚物(PECA)和共聚物(PMA-co-PECA),用1 HNMR、FT-IR、GPC等对其结构进行了表征。结果表明:在自由基聚合过程中,ECA中的乙炔基得以保留,所得到的乙炔基功能化聚合物可溶于普通有机溶剂,如氯仿、二甲基亚砜、四氢呋喃、丙酮等。实时红外跟踪了PMA-co-PECA与三羟甲基丙烷三巯基丙酸酯经光引发的巯-炔反应,得到交联的聚合物网络,凝胶分数大于90%,表明聚合物链上保留的乙炔基与巯基的加成反应有较高的活性,可以通过硫醇-炔点击反应实现快速功能化。

A acetylene functionalized acrylate monomer,1-ethynylcyclohexyl acrylate(ECA),was prepared by the esterification of acryloyl chloride with 1-ethynyl 1-cyclohexanol.Then the acetylene functionalized polyacrylates PECA and PMA-co-PECA were synthesized through the free radical homopolymerization of ECA and copolymerization of ECA with methyl acrylate(MA).The structure of PECA and PMA-co-PECA were characterized by 1HNMR,FTIR and GPC.The results suggest that the triple bonds were completely retained,and the resulting polymers were soluble in common solvents such as chloroform,dimethyl sulfoxide,tetrahydrofuran,acetone,etc.The thiol-yne reaction between PMA-co-PECA and trimethylolpropane tri(3-mercaptopropionate)(TMTP)was monitored by real-time IR,suggesting that the acetylene bearing polymers can be rapidly photocrosslinked and functionalized by thiol-alkyne reaction,and the bulk tertairy group does not affect the reactivity of the thiol-yne reaction.The gel fraction of the yeilding network was found to be more than 90%.