以含缩醛官能团的有机锂为引发剂,将甲基丙烯酸甲酯(MMA)与含氟硅氧烷单体1,3,5-三甲基-1,3,5-三(3′,3′,3′-三氟丙基)环三硅氧烷(F3)阴离子嵌段共聚,获得了窄分子量分布的聚甲基丙烯酸甲酯-b-聚[甲基(3,3,3-三氟丙基)硅氧烷](PMMA-b-PMTFPS)嵌段共聚物,并用GPC,1H NMR,FTIR和DSC对嵌段共聚物进行了表征.研究结果表明,在THF中利用PMMA-OLi对F3进行阴离子开环聚合时,单体F3浓度的选择对提高嵌段共聚物产率至关重要。
The anionic block copolymerization of methyl methacrylate(MMA) and 1,3,5-trimethyl-1,3,5-tris (3',3',3'-trifluoropropyl) eyelotrisiloxane (F3 ) was earried out with an aeetal-funetionalized alkyllithium as the initiator, and poly ( methyl methaerylate )-b-poly [ methyl ( 3,3,3-trifluoropropyl ) siloxane ] ( PMMA-b-PMTFPS) dibloek eopolymers with a narrow moleeular weight distribution were synthesized. The bloek eopolymers were eharacterized by gel permeation ehromatography(GPC), proton nuelear magnetie resonanee speetroseopy ( ^1H NMR), Fourier transform infrared speetroseopy ( FFIR ) and differential seanning ealorimetry ( DSC ). The results show that the seleetion of the eoneentration of F3 was very important for obtaining PMMA-b-PMTFPS dibloek eopolymers with high yield when the terminal lithium alkoxide functional poly (methyl methaerylate) (PMMA-OLi) was served as the maeroinitiator of anionie ring-opening polymerization (ROP) of F3. Additionally, DSC results show that the glass transition behaviors of PMMA-b-PMTFPS dibloek eopolymers were dependent on the eontent of PMTFPS bloeks. The glass transition temperature of PMTFPS bloeks is about -69——-70℃, and the glass transition temperature of PMMA bloeks is about 128——130℃.