【摘要】 以4,4′-(α,ω-烷亚甲基二酰氧)二苯甲醛和二氨基二苯并-18-冠-6为单体,采用溶液缩聚方法,首次合成了一类新的席夫碱型高分子液晶冠醚。单体的结构通过元素分析、IR、1H-NMR和MS等方法确证,聚合物的性质采用GPC、DSC、TG、WAXD和POM等方法进行了研究。发现所有的聚合物加热到各自的熔融温度(Tm)以上都能形成液晶态,在液晶态可以观察到向列相的纹影织构和近晶相的焦锥织构。聚合物的熔融温度和各向同性温度(Ti)随聚合物分子中柔性间隔基的变化而变化,它们有较高的清亮点温度。更多还原

【Abstract】 A novel series of Schiff base type polymer liquid crystalline crown ethers was synthesized for the first time by solution polycondensation from 4,4′-（alkylene dioyloxy）dibenzaldyhyde （M₁） , cis-4,4′-diaminodibenzo-18-crown-6 （M₂） and trans-4,4′diaminodibenzo-18-crown-6 （M₃） as the monomers. The monomers structures were identified by using elementary analysis, IR, （）¹H-NMR and MS etc. The properties of polymers were investigated by using GPC, DSC, TG, WAXD and POM. It is found that all the polymers go into liquid crystal phase when heated to their melting temperature （T_m）. The typical nematic Schlieren texture, and smectic phase focal-conics texture can be observed. The melting temperature and isotropization temperature （T_i） change with varing of the flexible spacer unit in the polymers, all the polymers have higher cleaning points.更多还原