Influence of the side-chain structure and molecular weight on the re-entrant behaviors of mesogen-jacketed liquid crystalline polymers

摘要: Three series of mesogen-jacketed liquid crystalline polymers (MJLCPs) containing different terminal groups (phenmethyl, diphenylmethyl and triphenylmethyl) in the side chains, abbreviated as Pv-m-Bn, Pv-m-DPM, Pv-m-Tr (m = 2, 4, 6, 8, 10, 12, which are number methylene units between terephthalate core chains), were designed successfully synthesized via free-radical polymerization. Molecular characterization was performed by 1H NMR, GPC TG analysis. The phase structures transitions investigated a combination techniques including DSC, POM 1D/2D WAXD. experimental results revealed that all exhibited excellent thermal stabilities re-entrant behaviors MJLCPs found to be strongly dependent on structure side-chain, i.e., spacer length increased with volume when isotropic phase. On other hand, MJLCPs, poly{2,5-bis[(diphenylmethoxy-ethyl)oxycarbonyl]-styrenes} (Pv-2-DPMs), molecular weights (Mn) narrow Mn distributions have been ATRP. indicated below 1.73 × 104 g mol−1, only observed. When 3.40 mol−1 8.48 formed at low temperatures columnar nematic high temperatures. By further increasing exceed 9.71 stable developed. This work provides two effective ways design synthesize behaviors; moreover, it is meaningful deeply understand structure–property relationships MJLCPs.