A series of novel side chain liquid crystalline polysiloxanes containing cyano‐ and cholesterol‐terminated substituents: Where will the structure‐dependence of terminal behavior of the side chain reappear?

Abstract

A series of polysiloxane side chain liquid crystal polymers with strong polarity cyano substitution‐terminated achiral side chains and cholesterol‐terminated chiral side chains was successfully synthesized via thiol‐ene click chemistry. 1H‐NMR, FT‐IR, and thermogravimetric analysis were used to confirm their chemical structures and thermal stabilities. Their phase transition behaviors and phase structures were systematically investigated by a combination of analysis methods such as differential scanning calorimetry, polarized optical microscopy, and X‐ray. Results revealed that attributing to the decisive role of the polarity interaction, all the polymers only developed a monolayer interdigitated SmA phase in which the period arrangement was determined by the cyano‐terminated side chains, the increased content of cholesterol‐terminated chiral side chains (Xchol) just expanded the distance between neighboring molecules within a layer. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1765–1772

Grafting of thermotropic fluorinated mesogens on polysiloxane to improve the processability of linear low-density polyethylene

“…No vinyl signals of the two monomers at 4.97 and 5.80 ppm were found in the 1 H-NMR spectrum of P6, which indicated that the excess monomers were completely removed and P6 was successfully obtained. 24 Based on the integral of typical peaks, the grafted ratio of two monomers in P6 also agreed with the feed ratio.…”

Design and Synthesis of Polysiloxane Based Side Chain Liquid Crystal Polymer for Improving the Processability and Toughness of Magnesium Hydrate/Linear Low-Density Polyethylene Composites

“…Besides, the initial melting temperature (T initial ) PSCTLCP is 173.6 • C. Figure 1b shows 1 H NMR spectra of M and PSCTLCP. The representative signals of the vinyl group in M at 5.28 and 6.0 ppm are not found in 1 H NMR spectrum of PSCTLCP, which further indicates that the excessive M is completely removed and PSCTLCP is successfully obtained [36]. DSC experiment is used to examine the phase transition of PSCTLCP.…”

“…NMR spectra of M and PSCTLCP. The representative signals of the vinyl group in M at 5.28 and 6.0 ppm are not found in 1 H NMR spectrum of PSCTLCP, which further indicates that the excessive M is completely removed and PSCTLCP is successfully obtained[36].…”

Polysiloxane-Based Side Chain Liquid Crystal Polymers: From Synthesis to Structure–Phase Transition Behavior Relationships

“…Special attention is paid to the effect of the heteroatom (such as O, S) in the spacers and their properties. In regard to the dependence of mesogenic units on phase structures and phase behaviors, in addition to the influence of diverse rigid structures [76,77,78]; the lateral substituents of the mesogenic side groups [79,80,81], the aliphatic tail length of the mesogenic groups [82,83,84,85], the chirality [86,87,88,89] and polarity [90] of the mesogenic groups, and the functionality of the mesogenic groups (such as photo-sensitive property [91,92,93,94], amphiphilic property [95,96], etc.) exerted a strong effect on mesomorphic properties.…”

“…By thiol-ene click chemistry, H. Yang et al designed and synthesized a series of PMMS-based PSCLCPs, the mesogenic units of which were cholesterol-terminated chiral unit with achiral substituted 4-methoxyphenyl 4-(allyloxy) benzoate unit [121], or cholesterol-terminated chiral unit with achiral substituted 4-cyanophenyl 4-(allyloxy) benzoate unit [90], respectively. The phase behaviors of PMMS-based polymers based on cholesterol-terminated chiral unit and achiral substituted 4-methoxyphenyl 4-(allyloxy) benzoate unit (abbreviation for PMMS-OCH 3 -based polymers) have been described in this paper above.…”