- An efficient, facile, and fast synthesis of 4-alkoxy-4′-hydroxybiphenyls
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A simple, fast and efficient method of synthesis of 4-alkoxy-4′-hydroxybiphenyls has been described. The reactions of 4,4′-dihydroxybiphenyl with appropriate alkyl halides were carried out over 3 h in DMSO in presence of solid powdered KOH.
- Orzeszko, Barbara,Melon-Ksyta, Dorota,Orzeszko, Andrzej
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- Synthesis and characterization of side chain polymer with helical PLLA segments containing mesogenic end group
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Series of mesogenic biphenol derivatives HO6OPPOn (n = 4,6,8) were prepared by asymmetric reaction and purified. Then HOLAxO6OPPOn were prepared with controlled molecular weights by adjusting the feed ratios of HO6OPPOn, SnOct2 catalyst and LLA
- Chen, Hongru,Xue, Qingbin,Li, Zhuohua,Sun, Lingmin,Zhang, Quanxuan
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- Influence of main-chain and molecular weight on the phase behaviors of side-chain liquid crystalline polymers without the spacer
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A series of end-on side-chain liquid crystalline polymers (SCLCPs) based on a biphenyl mesogen, poly(4,4′-alkoxybiphenyl acrylate) (PBiA-m, m = 1, 4, 6, 10, 18), were successfully synthesized by free radical polymerization or reversible addition fragmentation chain transfer (RAFT) polymerization. The chemical structures of the monomers were confirmed by 1H NMR and mass spectrometry. The phase structures and transition behaviors were studied using DSC, POM and 1D WAXD. The experimental results found that PBiA-m showed the bilayer smectic phase and a higher clearing point (Ti) compared with poly(4,4′-alkoxybiphenyl methacrylate) (PBiMA-m). In addition, poly(4,4′-hexyloxybiphenyl methacrylate) (PBiMA-6) and poly(4,4′-hexyloxybiphenyl acrylate) (PBiA-6) with different molecular weights (Mn) and low molecular weight distributions have been successfully synthesized via the RAFT polymerization. The results indicated that all the polymers exhibited a bilayer smectic phase and Ti increased as the Mn of PBiMA-6 and PBiA-6 increased. Moreover, PBiA-6 had a higher Ti compared with PBiMA-6 with a similar Mn value. All the results suggested that the main-chain (acrylate and methacrylate) and Mn had a great influence on the properties of SCLCPs without the spacer.
- Bin, Ni,Yongbin, Luo,Yujie, Liu,Sheng, Chen,Hailiang, Zhang
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- Self organization of main-chain/side-chain liquid crystalline polymer based on "jacketing" effect with different lengths of spacer: From smectic to hierarchically ordered structure
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A series of combined main-chain/side-chain liquid crystalline polymers (MCSCLCP) based on "jacketing" effect, poly{(2,5-bis[n-(4-butoxy-4′-oxybiphenyl)n-alkyl]oxycarbonyl}styrene) with different lengths of alkyl spacers (denoted as Pn, n represents the number of carbon atoms in the alkyl spacers, n = 2-10) have been successfully synthesized via atom transfer radical polymerization (ATRP). The chemical structures of Pns and the corresponding monomers were characterized using combined techniques with satisfactory analysis data. The phase structures and transitions of Pn were investigated using differential scanning calorimetry (DSC), polarized optical microscope (POM), and one- and two-dimensional wide-angle X-ray diffraction (1D and 2D WAXD). It has been identified that P2 and P4 with short alkyl spacers form typical smectic phase. For n ≥ 6, Pns exhibit similar hierarchical ordered structure at low temperatures, bearing double orderings on the nanometer and sub-nanometer scales. In the hierarchical structure, the main-chains based on "jacketing" effect form a 2D centered rectangular scaffold, and the side-chain biphenyl mesogens within the scaffold pack into a smectic E-like structure. The a dimension of rectangular lattice enlarges with n. When the temperature is increased, different from P6, P8 and P10 present the same phase behavior, forming smectic B-like packing of side chains and maintaining their main-chain scaffold until isotropization.
- Xie, He-Lou,Ni, Bin,Liu, Quan,Wang, Jun,Yang, Shuang,Zhang, Hai-Liang,Chen, Er-Qiang
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- Preparation and characterization of side-chain liquid crystal polymer/paraffin composites as form-stable phase change materials
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A series of side-chain liquid crystal polymers (SCLCPs), named poly[ω-(4′-n-alkyloxybiphenyl-4-oxy) hexyl methacrylates] (P6biCm, m = 1, 2, 4, 6, 8, 10, 12, 14, 16 and 18), have been synthesized. Novel SCLCP/paraffin composite form-stable phase change materials (FSPCMs) were prepared by introducing P6biCm into paraffin. The minimum gelation concentration (MGC) and gel-to-sol transition temperature (TGS) properties were tested by a tube-testing method . It was found that P6biCm (m = 1, 2, 4, 6, 8, 10) were insoluble in paraffin, while P6biCm (m = 12, 14, 16, 18) exhibited a low MGC (≤6 wt%) and high TGS (TGS of P6biC12/paraffin is 140 °C). The structure and morphology of FSPCMs were systematically investigated by FT-IR, POM, 1D WXAD and SEM. The experimental results revealed that paraffin was restricted in the three-dimensional P6biCm network, leading to the FSPCM without leakage even above its melting point. The thermal properties were studied by DSC and TG. The research showed that the P6biCm/paraffin exhibited excellent thermal stability and high heat storage density. The shape stability was assessed by rheological measurements, indicating that solid hard gel soft gel liquid was observed with the increase of temperature. This work is useful in comprehending the physical mechanism of shape stability and in the meanwhile provides a novel method for synthesis of FSPCMs.
- Wu, Dang,Ni, Bin,Liu, Yujie,Chen, Sheng,Zhang, Hailiang
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- Synthesis, liquid crystalline and gelation properties of 4-semifluoroalkoxybiphenyl derivatives
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4-Semifluoroalkoxybiphenyl derivatives 1 and 2(n) (n = 4–6, 8 and 10) were designed, synthesized and their physic-chemical properties were examined. The effects of chemical structure on liquid crystalline and gelation properties were investigated. The clear point for 2(n) declines as the carbon number of terminal alkoxyl chain enlarges from 4 to 10. The clear point for 2(4) is 172 °C while 2(10) is 135 °C. The gelation properties for 2(n) are superior to those for 1, where the linking group of gelators 2(n) between a perfluoroalkyl group and biphenyl core are longer than that of 1. In compounds 2(n), the longer alkoxyl chain at the terminal position, the better gelation properties. The phase selective property of compound 2(10) in THF solution is better than in toluene. 10 wt% 2(10) solution in THF can selectively gelatinize oils and amines from aqueous-organic biphasic mixtures. Interestingly, 10 wt% 2(10) solution in THF also selectively gelatinize organic compound from homogeneous aqueous-organic mixtures. Gels formed by compounds 2(n) as supramolecular gels were investigated their thermoreversible and rheological property.
- Cao, Ban-Peng,Shen, Chunyang,Xu, Yuan,Zhou, Qi,Morita, Yuki,Okamoto, Hiroaki,Xiao, Qiang
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- Gel for liquid organic matter, and preparation method and application thereof
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The invention discloses a gel for a liquid organic matter, and a preparation method and application thereof. The gel is obtained by introducing a perfluoroalkyl group onto a 4,4'-biphenol skeleton. The gel can solidify the liquid organic matter through a heating-cooling method; moreover, under the action of a cosolvent, a liquid with pungent odour can be solidified quickly; the volatility of the liquid organic matter is reduced.
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Paragraph 0017-0018
(2019/09/05)
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- Supramolecular side-chain functionalized polymers: Synthesis and self-assembly behavior of polynorbornenes bearing PdII SCS pincer complexes
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A new polynorbornene bearing palladated SCS pincer complexes at each repeat unit has been synthesized using ring-opening metathesis polymerization. Small mesogenic molecules possessing nitrile or pyridine-based anchoring units are instantaneously and quantitatively coordinated to the palladium center in one simple self-assembly step giving rise to a densely functionalized polymer. These results suggest that the coordination of mesogenic small molecules onto the polymer scaffold can provide a simple and efficient route to a variety of materials.
- Pollino, Joel M.,Weck, Marcus
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p. 1277 - 1285
(2007/10/03)
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