Study on Synthesis and Characterization of Ferroelectric Side Chain Liquid Crystalline Polymers

1)示意图合成了多种具有末端链的聚甲基丙烯酸酯液晶，考察了末端链长度对其相变和近晶层结构的影响。在中间链链末端为烷氧基的聚甲基丙烯酸酯（SCLCPMs）中，当末端烷氧基长度(m)大于丁氧基长度（m=4）时，SCLCPMs形成具有多型层结构的近晶C相。终端链为m=4、5、6的sclcpm，倾斜角度为60 ~ 62，终端链为m=7、8的sclcpm，倾斜角度为50。然而，具有s-(-)-2-甲基丁氧基末端基团（对应长度m=4）的手性SCLCPM在手性近晶C^*相中形成了倾斜角度为42º的倾斜单层结构。这些结果表明，层的结构和倾斜角可以通过末端链的长度和结构来控制。2)制备了新型铁电侧链液晶聚合物，并对其自发极化进行了研究。具有手性基团的手性液晶聚酒石酸酯形成手性近晶C^*相，具有5 mc/m^2的大自发极化（PS）。在间隔单元中具有手性基团的手性液晶聚甲基丙烯酸酯也表现出Ps为1.2 mC/m^2A的手性近晶C^*相。手性非介形甲基丙烯酸酯与非手性介形甲基丙烯酸酯共聚制备手性液晶共聚甲基丙烯酸酯，形成手性近晶C^*相。

1) Various liquid crystalline polymethacrylates with terminal chains were schematically synthesized, and effects of terminal chain lengths for their phase transitions and smectic layer structures were examined.In the liquid crystalline polymethacrylates (SCLCPMs) having terminal alkoxy chains in the mesogenic pendant group, SCLCPMs form smectic C phases with polytype layer structures when the length (m) of the terminal alkoxy group is longer than butoxy group (m=4). In SCLCPMs having the terminal chains of m=4, 5, and 6, tilt angles are 60-62ﾟ, and in the case of m=7 and 8, the tilt angle is 50ﾟ. however, Chiral SCLCPM having s-(-)-2-methylbutoxy terminal group (corresponding to the length of m=4) forms a tilted monolayer structure with the tilt angle of 42ﾟ in a chiral smectic C^* phase.These results conclude that the layer structure and tilt angle can be con-trolled through the length and structure of the terminal chain.2) Novel ferroelectric side chain liquid crystalline polymers were prepared and their spontaneous polarizations were examined.A chiral liquid crystalline polytartrate which have chiral groups in a polymer backbone forms a chiral smectic C^* phase and has a large spontaneous polarization (PS) of 5 mc/m^2. A chiral liquid crystalline polymethacrylate having a chiral group in a spacer unit also exhibit a chiral smectic C^* phase with Ps of 1.2 mC/m^2A chiral group can be also introduced in the polymer skeleton through copolymerization. A chiral liquid crystalline copolymethacrylate prepared by copolymerization of chiral nonmesomorphic and achiral mesogenic methacrylates forms a chiral smectic C^* phase.