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

1)合成了不同端链结构的液晶聚甲基丙烯酸酯，考察了端链长度对其相变和近晶层结构的影响，发现端烷氧基长度(M)大于丁氧基长度(m=4)时，端烷氧基长度(M)大于丁氧基长度(m=4)时，液晶聚甲基丙烯酸酯(SCLCPMs)形成具有多型层结构的近晶C相。在具有m=4、5和6的端链的SCLCPM中，倾角为60-62ﾟ，并且在m=7和8的情况下，倾角为50ﾟ。然而，具有S-(-)-2-甲基丁氧基端基(对应于m=4的长度)的手性单层液晶聚合物在手性近晶C^*相中形成倾斜角为42ﾟ的单层结构。这些结果表明，层结构和倾斜角可以通过末端链的长度和结构来控制。2)合成了新型的铁电侧链液晶聚合物，并研究了它们的自发极化行为。在聚合物主链上带有手性基团的手性液晶聚酒石酸酯形成了手性近晶C^*相，并具有较大的自发极化(PS)为5 mC/m^2。含手性基团的手性液晶聚甲基丙烯酸酯也具有手性近晶C^*相，Ps为1.2mC/m^2A手性基团也可以通过共聚引入到聚合物骨架中。由手性非介晶甲基丙烯酸酯和非手性甲基丙烯酸酯共聚而成的手性液晶甲基丙烯酸酯形成了手性近晶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.