CHEMISTRY OF MATERIALS
·
2025
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IF 7
Panpan Yang,Sheng Lu,Yuemiao Zhang,Xiaoting Lu,Pengfei Huang,Kun Wu,Jun Shi,Yi Fu
The production of degradable polymer materials with high thermal conductivity is urgently needed to reduce plastic pollution from electronic waste. This research prepared a series of intrinsically thermally conductive polyesters (L-LCPs) by the melt polycondensation reaction of biphenyl diol with three different dicarboxylic acids, which are dl-tartaric acid, dl-malic acid, and diethanolic acid. The thermal conductivity and hydrolysis behavior of these were investigated. Biphenyl group π–π stacking enhances the interchain interactions and endows the polyester with high thermal conductivity. The thermal conductivity of L-LCP3 reaches 0.716 W/(m·K), showing a significant improvement of 168.8% compared to L-LCP1, which is 3.5 times higher than polyethylene terephthalate (PET). The differential scanning calorimetry (DSC) results of the cooling process and the polarizing optical microscopy (POM) pictures showed that all of the L-LCPs are bidirectional thermotropic liquid crystal polymers. Meanwhile, the L-LCPs were efficiently hydrolyzed to valuable raw materials by using the mixed solvents tetrahydrofuran (THF) and H2O. The notable merits of the solvent system are the fragmentation effect of tetrahydrofuran and the enhancement of the catalyst NaOH activity by H2O. The L-LCPs are transformed into oligomers or monomers as the hydrolysis reaction proceeds. The residue weights of L-LCP3 were reduced to 67.2% in the THF–H2O solvent system. The T5%, Tmax, and residual carbon of L-LCP3 were 375.1 °C, 430.4 °C, and 6.2% at 800 °C, respectively, indicating that it has good thermal stability.
研究领域:
材料科学
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高分子化学
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热工学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2010
·Vol. 48
·期 24
·5679-5692
·
IF 3.971
Hongxia Peng,Yiwang Chen,Lie Chen,Xiaohui He,Fan Li
Mesogen jacketed liquid crystalline poly(1-alkyne) and poly(1-phenyl-1-alkyne) linked pendants of terphenyl mesogens with hexyloxy tails at the waist position ( {RCC [(CH 2 ) 3 OOC-terpheyl-(OC 6 H 13 ) 2 ]} n , where RH, PHATP(OC6)2 ; RC 6 H 5 , PPATP(OC6)2 ) were synthesized. The influences of structural variations on the thermal, mesomorphic, and luminescent properties were investigated. Polymerizations of all monomers are carried out by WCl 6 -Ph 4 Sn catalysts successfully. The polymers are stable ( T d ≥ 340 °C) and soluble in common solvents. The monomers and polymers show enantiotropic SmA phases in the heating and cooling processes, and the lateral side chains of the mesogenic units are perpendicular to the main chain. The “jacket effect” of chromophoric terphenyl core “shell” around the main chain also contributes to polymers with high photoluminescence, and the pendant-to-backbone energy transfer path is involved in the luminescence process of this polymers. In comparison with monosubstituted polyacetylene PHATP(OC6)2 , the disubstituted polyacetylene PPATP(OC6)2 shows better photoluminescence in both THF solution and film, and exhibited about 40 nm red-shifted than PHATP(OC6)2 , indicating that the “jacket effect” of terphenyl mesogens forces poly(1-phenyl-1-alkyne) backbone to extend in a more planar conformation with a better conjugation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2022
·
IF 2.676
Xiang-Yu Ma,Qiu-Cheng Li,Cheng-Han Song,Hong-Shuang Zhang,Yuan-Sen Zhi,Xiao-Zhi He
Fluorescent liquid crystal polymers have attracted much attention because of the combination of fluorescence, liquid crystallinity and processability. In this study, we designed and synthesised two series of photoluminescent cholesteric liquid crystal polysiloxanes, which contained cholesterol mesogens and fluorescein methyl ester with different side chain lengths. The chemical structures and liquid crystal properties of the polymers were investigated by the usual methods. The photoluminescent property were characterised by fluorescence spectroscopy. At the same time, the effects of the lengths of the fluorescent group chains on the liquid crystal and fluorescence properties of the polymers were studied. The results showed that the synthesised polymers possessing very good fluorescent and liquid crystal properties, which may has certain practical value and application prospect.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE FORUM
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2015
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IF 0
Wei Xing Chen,Xiao Long Zhang,Chun Yan Luo,Ai Jie Ma,Yong Qiang Gu
In order to study the infrared spectral characteristics of side-chain liquid crystal polymer, an infrared monomer containing a permanent dipole azobenzene group spaced from the methacryloyl moiety by a polymethylene segment was synthesized in three steps starting from 4-cyanoaniline. The monomer was polymerized with a push-pull azobenzene monomer, (-)-menthy1 methacrylate in the presence of azobisisobutyronitrile (AIBN) as the radical initiator. Structurally similar amphiphilic polymers were obtained by polymerization of analogous methacrylates in which the polymethylene spacers was replaced by oligo (oxyethy1ene) segments. The obtained polymer was characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectro photometry (UV-vis), Hot Stage Polarized Microscopy (HS-POM), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analyzer (TGA). Its infrared emissivity at different temperatures was tested by Bruker-V70 infrared analyzer. The results showed that the azobenzene poly (methyl methacrylate) (azo-PMMA) has high glass transition temperature(about 40°C), good thermal stability(divied in 294°C) and low infrared emission under 70%.
研究领域:
材料科学
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化学
✓ 已验证
DOI
CHINESE JOURNAL OF POLYMER SCIENCE
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2015
·Vol. 33
·期 10
·1431-1441
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IF 1.835
Zhao Wen,Lin Bao-ping,Zhang Xue-qin,Sun Ying,Yang Hong
We describe in this work an alkyne-hydrosilylation approach to synthesize a series of novel polysiloxane side-chain LCPs attaching end-on or side-on mesogenic side groups. Their properties are characterized by NMR, FTIR, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, polarized optical microscopy and small-angle X-ray scattering. These obtained alkenylsilane linked novel LCPs exhibit higher glass transition temperatures and clearing points, and especially display the tendency of forming smectic phases, in strong contrast with the nematic phases of their comparative conventional alkylsilane linked analogues, which manifests more rigid features of the alkenylsilane linkages and their significant influence on the mesomorphic properties.
研究领域:
高分子化学
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材料科学
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液晶材料
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有机合成
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 25
·e53951
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IF 3
Yifei Wu,Kun Wu,Fei Xiao,Enxiang Jiao,Jun Shi,Mangeng Lu
High thermal conductivity liquid crystal polymer has become a hot topic in electronic device research. Herein, we introduce a series of thermotropic liquid crystals synthesized by diphenyl diol, m-phthalic acid, and 5-hydroxyisophthalic acid. The intermolecular forces are tuned by adjusting the ratio (0, 20%, 40%, 60%, 80%, 100%) of monomers containing hydrogen bond donors in copolymers. The formation and dissociation of hydrogen bonds are analyzed from the red shift and blue shift of infrared spectra at variable temperatures. The thermal conductivity is increased to 0.31 Wm −1 k −1 . Meanwhile, its mechanical properties and thermal stability have improved significantly. A sharp increment of 2120% in tensile strength was observed, the maximum tensile strength is 17.39 MPa. While Young's modulus increased from 0.26 to 1.224 GPa. The increase in intermolecular forces is the main reason for this result. Moreover, X-ray single-crystal diffraction, polarizing microscope, differential scanning calorimetry, and thermogravimetric analysis (TGA) were also analyzed to further explore the thermal conduction mechanism. The formation of hydrogen bonds makes the linear polymer chain segments undergo reversible cross-linking, which affects their crystallization behavior and provides more thermal conduction pathways. By controlling the number of hydrogen bond donors to control the cross-linking density, the thermal conductivity and mechanical properties can be greatly improved.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
RSC Advances
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2020
·Vol. 10
·期 7
·3726-3733
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IF 3.119
Jing Wang,Qian Jiang,Xingtian Hao,Hongchao Yan,Haiyan Peng,Bijin Xiong,Yonggui Liao,Xiaolin Xie
Stimuli-responsive supramolecular gels have been widely investigated, but the construction of a liquid crystalline gel with a high mechanical property and reversible photo-response still remains a challenge. This is due to the difficulty of designing gelators with liquid crystal properties and gelation abilities in organic solvents simultaneously. In this study, an azobenzene-containing main-chain polyester (Azo-mLCP) with a pendant amide group was synthesized. The organogel of Azo-mLCP via a hydrogen bond in dioxane possessed reversible thermal- and photo-responsive behaviours. The organogel exhibited a good self-supporting ability when the concentration of the gelator was more than 7.5 wt%. The rapid trans-to-cis isomerization of Azo-mLCP in solution was studied via UV-Vis absorption spectra. In addition, the gel-to-sol transition of the organogel could be triggered efficiently by an incomplete trans-to-cis conversion strategy. This study opens a way for the main-chain liquid crystalline polymers to serve in potential applications in photo-responsive robust actuators, electro-optical devices, and so on.
研究领域:
材料科学
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高分子化学
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光化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2025
·
IF 2.2
Fei Chen,Guojun Huang,Tianyong Zhang,Yufeng Xu
Chiral nematic liquid crystal polymers, which exhibit reversible dynamic structural colours and fluorescence emissions in response to external stimuli, are highly secure and reliable materials for optical anti-counterfeiting. In this article, the chiral nematic liquid crystal polymers were synthesised through graft copolymerisation using polymethylhydrosiloxane (PMHS) as the main chain, chiral liquid crystal monomer M1, nematic liquid crystal monomer M2, and organic fluorescent anthracene compound M3 as side chains. The chiral nematic liquid crystal polymer (CLCP7）possesses a chiral helical structure that allows for selective reflection based on temperature changes, resulting in dynamic and reversible colour variations. Additionally, the discrete anthryl chromophoric segments within the CLCP7 matrix facilitate tunable photoluminescence which can be adjusted by manipulating the temperature. Furthermore, the CLCP7 exhibits highly sensitive photoluminescence response. The dynamic and reversible characteristics of structural colour and fluorescence emission make the CLCP7 an ideal candidate for intelligent optical anti-counterfeiting materials development with potential applications spanning information security and anti-counterfeiting domains.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Peng Wei,Hejuan Lou,Jinfei Yan,Longlong Li,Yifeng Zhang,Yumin Xia,Yanping Wang,Yimin Wang
In order to obtain thermotropic liquid crystal polymers (TLCP) with excellent comprehensive performance, naphthalene monomers (amount exceeding 50 mol%) of 6-hydroxy-2-naphthoic acid (HNA) and 2,6-naphthalene dicarboxylic acid (NDA) were used to prepare wholly aromatic TLCP with strong molecular interaction via “one-pot” melt polymerization method in this work. The structure and properties of the copolyesters were fully investigated by experimental measurements and molecular simulation . The simulation results indicated that the naphthalene TLCPs had less chain mobility and stronger molecular interactions, and resulted in a linear rigid chain conformation, endowing the copolyesters with superior properties. As compared with the control copolyester M without naphthalene units, the resulted copolyesters had higher glass transition and melting temperature, higher melt tension, better thermal stability and fiber mechanical property. Overall, the rigidity, molecular interaction and properties of the obtained copolyesters could be efficiently improved after incorporation of the naphthalene units, which is beneficial for its processing and application.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2015
·Vol. 58
·期 6
·1021-1026
·
IF 1.695
Chai Chunpeng,Yin Fangfang,Li Guoping,Luo Yunjun
The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate) (PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A (DGEBA) epoxy resin were investigated by impact test, tensile test and thermogravimetric analysis (TGA). The mechanism underlying the enhancement of mechanical properties of epoxy resin was studied using 1D wide-angle X-ray diffraction (WAXD) and scanning electron microscope (SEM). It was found that the mechanical properties of 1 wt%–5 wt% PDPVT/DGEBA composites were significantly improved compared to neat epoxy resin. Especially, the epoxy resin with 3 wt% PDPVT had the greatest increase in mechanical properties, with the impact strength, tensile strength and elongation while breaking increased by 87%, 59% and 174%, respectively. The increased mechanical strength was due to the fact that PDPVT maintained liquid crystalline phase in cured PDPVT/DGEBA composites, which would blunt the crack tip and prevent crack propagation. Moreover, PDPVT had slight effect on the thermal stability properties of epoxy resin.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2020
·
IF 2.908
Weiwei Tie,Surjya Sarathi Bhattacharyya,Zhi Zheng,Kyung Jun Cho,Tae Hyung Kim,Young Jin Lim,Seung Hee Lee
To develop stable polymer films which had high orientational ordering of carbon nanotube for polarization-dependent light modulator, we present a new concept for electric-field induced alignment of mesogenic carbon nanotubes (m-CNTs) in reactive mesogen host (RMS) fixed by ultraviolet (UV) polymerization. Covalent modification of m-CNTs was performed using structure-tailored mesogenic units [4-(6-hydroxyhexanolxy)-4’-carbonitrile, PCNOH] in esterification reaction based on 100–500 nm long CNTs shortened by acid oxidation cutting, confirmed through 1H NMR, FT-IR, Raman and XPS spectroscopy. Dynamic orientation of m-CNTs in soft m-CNT/RMS composite without aggregates was observed on a large scale by polarized optical microscopy, in which m-CNTs aligns along the electric field direction. It was reasonable the mesogenic segments introduced onto m-CNTs weakened van der walls interactions between the nanotubes by increasing steric repulsion, and then effectively improved the favourable affinity of m-CNTs with RMS molecules. Direct UV-induced polymerization of RMS molecules stabilized the orientational ordering of m-CNTs confirmed by Raman spectroscopy, and the obtained film also exhibited anisotropic light absorption depending on the polarization direction of an incident light. The facile methodology described in this study to generate oriented films of m-CNTs-in-RMS broadened the scope of potential applications of modulator devices and versatile functional composites with anisotropic physical properties.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
Communications Materials
·
2024
·Vol. 5
·期 1
·1-9
·
IF 7.5
Li Maohua,Gong Ping,Zhang Zhenbang,Li Linhong,Chen Yapeng,Qin Yue,Guo Yingying,Yang Rongjie,Zhang Jianxiang,Zhou Yiwei,Xu Kang,Wang Yandong,Do Hainam,Jia Xiaofei,Cai Tao,Lin Cheng-Te,Jiang Nan,Yu Jinhong
High thermal conductive polymers have become more important because equipment requires high performance, high-energy density, and high integration. There are different strategies to make high thermal conductive polymers, among which is the synthesis of polymers in the liquid crystal phase. However, the thermal conductivity of such material is rarely beyond 1 W m −1 K −1 because of the disordered molecular directionality. The disordered directionality between crystal zones limits the thermal conductivity in a specific direction. Here, we show a method for unifying the direction of crystal zones by applying an external electric field on the liquid crystal monomers. Meanwhile, by exposing the transparent equipment and specially designed photopolymerisable monomer in UV light, the liquid crystal monomer is in situ polymerised into a liquid crystal polymer with a high intrinsic thermal conductivity of 1.02 W m −1 K −1 . The molecular alignment was characterised and resulted in the resultant high conductivity.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）