线形-枝状碳硅两亲嵌段聚合物的合成与表面性能

Synthesis and Surface Properties of Amphiphilic Linear-Dendritic Carbosilane Block Copolymers

通过对聚乙二醇端羟基烯丙基化及硅氢化加成反应,将疏水性有机硅基团接枝到亲水的聚乙二醇链段两端,得到有机硅接枝单元数量不同的两种线形-枝状两亲聚合物,用NMR、FTIR对其结构进行了表征,并评价了其表面活性。两种聚合物具有良好的表面活性,其临界聚集浓度(CAC)值分别为5.13×10-4mol/L和4.83×10-5mol/L,γCAC值分别为32.48 m N/m和32.21 m N/m。此外,该聚合物水溶液的表面张力-浓度曲线呈现"两段式"变化,说明聚合物分子在空气/水表面上有构象变换过程,而聚合物PEG链段、含硅枝状结构将显著影响吸附层中聚合物的分子构象。

Based on allylation of hydroxyl-terminated PEG and hydrosilylation of the allylic double bonds,two kinds of linear-dendritic amphiphilic block copolymers with carbosilane hydrophobic head groups attached to PEG hydrophilic bridging chain were synthesized. The molecular structures of the copolymers were characterized by means of NMR and FTIR, and their surface properties were evaluated. The two copolymers show good surface activities,the CAC values are 5.13 × 10-4 and 4. 83 × 10-5 mol/L, and the TcAc values are 32. 48 and 32. 21 mN/m respectively. Moreover, two breaks were observed in the surface tension vs concentration curve for the two copolymers, which is believed to originate from rearrangement of the copolymer molecules on the air/water surface, and the molecular architecture of the copolymers at the surface layer was affected by the PEG segments and carbosilane branched blocks of the copolymers.