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Amphiphilic copolymers Pn (n = 1–3) with mPEG as hydrophilic segment and aliphatic polycarbonate as hydrophobic segment were designed and synthesized successfully, and the results of POM, XRD and DSC showed that only P3 showed liquid crystalline (LC) phase. Due to the carboxyl and cholesteric LC groups in the side chain of the polycarbonate, the micelles prepared in this study were endowed with pH and temperature dual response. The effects of different conditions such as selective solvents, copolymer concentration, pH, temperature, the structure and LC mesophase on the self-assembly behavior and drug loading properties of the copolymer micelles were explored. It was found that the critical water concentration for self-assembly, the particle size and morphology of the micelles could be effectively controlled by changing the above conditions. Moreover, introducing LC properties into the copolymer could effectively decrease the critical water concentration for self-assembly and elevate the drug loading content. The DOX was conjugated to the copolymers by hydrogen bonds, and the copolymer P3 could form regular fusiform micelles after loading with DOX. Moreover, P3-DOX micelles could be endocytosed into cells and the drug release behavior could be triggered by the weak acid condition and elevated temperature. Therefore, the P3-DOX micelles could achieve a pH-triggered rapid drug release under weakly acidic conditions of the tumor cells. This kind of controllable micelles will have a potential application as drug-carriers in drug delivery.

A series of copolymers [P (TMC-co-DTC)] with different molecular weights based on trimethylene carbonate (TMC) and 2, 2-dimethyltrimethylene carbonate (DTC) were synthesized via ring-opening copolymerization, by adjusting the amount of Sn(Oct)2. The thermal performance showed that the Tg and Td of the obtained amorphous copolymer rose with the increase of molecular weight from 118 to 213 kDa. Then the in vitro enzymatic experiment was carried out in lipase solutions, it could be concluded that the higher the molecular weight, the faster the degradation rate of the P (TMC-co-DTC), which may be related to the stronger hydrophobicity of the high molecular weight sample. Furthermore, the degradation mechanism of P (TMC-co-DTC) was determined to be the surface erosion, due to the result of the unchanged molecular weight during the degradation period. The fact that polycarbonate copolymer produces no acidic compounds in the process of enzymatic degradation had also been confirmed. This study provides confirmation for adjusting the degradation behavior performance of polycarbonate materials by molecular weight to meet the needs of more abundant clinical applications.

A series of symmetric and asymmetric three-arm liquid crystals (TALCs) of which the molecular structure with a central core of 1, 2, 4-butanetriol attached by three rod-like mesogenic moieties have successfully been synthesized. The rod-like mesogenic side arms are 4′-(4-(trifluoromethyl) benzoyloxy) biphenyl-4-carboxylic acid (TFBA) and 4′-(4-(allyloxy) benzoyloxy) biphenyl-4-carboxylic acid (AOBA), respectively. BTA0 and BTA3 are symmetric TALCs with three TFBA or three AOBA as LC side arms, respectively. BTA1 is an asymmetric TALC with one AOBA and two TFBA as side arms. BTA2 is an asymmetric TALC with two AOBA and one TFBA as side arms. The chemical structures and LC properties of the LC side arms and TALCs were characterised by FTIR, 1H NMR, elemental analysis, DSC, TG, POM and X-ray diffractometer. TFBA displayed smectic B (SmB) phase, AOBA exhibited nematic (N) phase. The TALCs all displayed chiral mesophase properties. BTA0 displayed chiral smectic C (SmC∗) mesophase. BTA1, BTA2 and BTA3 exhibited cholesteric (ch) mesophase. In addition, a chiral smectic A (SmA∗) mesophase was observed for BTA1. The results indicated that the 1, 2, 4-butanetriol is vital in inducing chiral mesophase of the TALCs. The side arms also played an important role in the mesophase type and mesogenic region. The TALCs displayed cholesteric mesophase when nematic LC side arm AOBA was introduced into the chiral core. The mesogenic region of the TALCs increased with the content of the wide-mesophase-region LC side arm AOBA introduced into the TALCs increasing. The melting temperature and the clear temperature of the TALCs were lower than those of the LC side arms (TFBA and AOBA). The mesophase regions of the TALCs were wider than those of the LC side arms.

Four new liquid crystalline thiophene compounds (M1−M4) with a long flexible spacer were prepared. Their structures were characterized by Fourier transform infrared and proton nuclear magnetic resonance. The mesomorphism and thermal stability were investigated with differential scanning calorimetry, polarizing optical microscopy, and thermogravimetric analysis. The photo-physical properties were evaluated using ultraviolet/visible spectroscopy and photoluminescence. M1−M4 all showed thermotropic mesogenic properties with excellent thermal stability, and exhibited nematic threaded texture, droplet texture, and Schlieren texture on heating and cooling cycles. The effect of flexible spacer and terminal groups on mesomorphic and spectroscopic property is discussed. The experimental results demonstrated that the tendency toward melting temperature (Tm) decreased, while isotropic temperature (Ti) increased with increasing the flexible spacer length. In CHCl3 solution, these thiophene compounds displayed...

Poly(amic acid) composite films with the thermotropic liquid crystal, 10-cholesteroxy-10-oxocaproic acid (COOA) were developed. The composites could still show liquid crystal behavior at low COOA loading (as low as 3 wt%) due to the phase separation under the induction of temperature. The synergistic reaction of the interaction of PAA with COOA and the arrangement of COOA endowed the films with strong fluorescence and a higher temperature shifted liquid crystal phase. Even more, the dielectric constant of the composites was enhanced. The composites were multifunctional optical-electric materials.

A new side chain liquid crystal aliphatic polycarbonate bearing side-functionalized diosgenyl mesogen, well-defined amphiphilic block copolymer mPEG 43 - b -P(MCC-DHO) 11 was synthesized through the ring-opening polymerization and coupling reaction. The chemical structures and average molecular weights of the monomers and copolymers obtained in this study were characterized using Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR) spectrum, and gel permeation chromatographic (GPC) measurement. Their mesomorphism was investigated with differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and variable-temperature x-ray diffraction (XRD) measurement. As a result, the monomer DHO and copolymer mPEG 43 - b -P(MCC-DHO) 11 all exhibited fan-shaped texture of a smectic A (SmA) phase on heating and cooling cycles. Furthermore, mPEG 43 - b -P(MCC-DHO) 11 revealed a LC state at body temperature. In addition, XRD suggested that mPEG 43 - b -P(MCC-DHO) 11 showed a SmAd phase and exhibited interdigitated packing of side chains.

A new cholesterol side-functionalised polycarbonate was synthesised through a coupling reaction between the terminal carboxyl group of the monomer 6-cholesteroxy-6-oxocaproic acid (COHA) and side hydroxyl group of the polycarbonate (PHTMC). The chemical structures of the intermediate compounds, monomers and polymers obtained in this study were characterised with FT-IR and 1H NMR spectrum. Their phase behaviour and thermal stability were investigated using polarising optical microscopy, differential scanning calorimetry, X-ray diffraction and thermogravimetric analysis. The monomer COHA showed a cholesteric phase, while the corresponding cholesterol side-functionalised polycarbonate P(TMC-g-COHA) revealed a smectic A phase. This behaviour was attributed to an increased density of the mesogenic units in side chain and hence an ordered organisation into the mesophase. Furthermore, P(TMC-g-COHA) could exhibit a liquid crystalline state below body temperature (≈37°C). This fact indicated it could be us...

New amphiphilic liquid crystal (LC) polycarbonate block copolymers containing side-chain cholesteryl units were synthesized. Their structure, thermal stability, and LC phase behavior were characterized with Fourier transform infrared (FT-IR) spectrum, 1H NMR, gel permeation chromatographic (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarizing optical microscope (POM), and XRD methods. The results demonstrated that the LC copolymers showed a double molecular arrangement of a smectic A phase at room temperature. With the elevating of LC unit content in such LC copolymers, the corresponding properties including decomposition temperature (Td), glass temperature (Tg), and isotropic temperature (Ti) increased. The LC copolymers showed pH-responsive self-assembly behavior under the weakly acidic condition, and with more side-chain LC units, the self-assembly process was faster, and the formed particle size was smaller. It indicated that the self-assembly driving force was derived from the orientational ability of LC. The particle size and morphologies of self-assembled microspheres loaded with doxorubicin (DOX), together with drug release tracking, were evaluated by dynamic light scattering (DLS), SEM, and UV–vis spectroscopy. The results showed that DOX could be quickly released in a weakly acidic environment due to the pH response of the self-assembled microspheres. This would offer a new strategy for drug delivery in clinic applications.

Fig.S1 shows the UV-Vis spectra of the different concentrations of DBP solution; Fig.S2 shows the relationship between the mass concentration of DBP solution and the absorbance; Figs.S3-S13 show the GC/MS of DBP and main degradation intermediates

The phthalate ester compounds in industrial wastewater, as kinds of environmental toxic organic pollutants, may interfere with the body's endocrine system, resulting in great harm to humans. In this work, the photocatalytic degradation properties of dibutyl phthalate (DBP) were investigated using α-Fe2O3 nanoparticles and H2O2 in aqueous solution system. The optimal parameters and mechanism of degradation were discussed by changing the morphology and usage amount of catalysts, the dosage of H2O2, pH value and the initial concentration of DBP. Hollow α-Fe2O3 nanoparticles showed the highest degradation efficiency when 30 mg of catalyst and 50 µl of H2O2 were used in the DBP solution with the initial concentration of 13 mg l−1 at pH = 6.5. When the reaction time was 90 min, DBP was degraded 93% for the above optimal parameters. The photocatalytic degradation mechanism of DBP was studied by the gas chromatography–mass spectrometry technique. The result showed that the main degradation intermediates of DBP were ortho-phthalate monobutyl ester, methyl benzoic acid, benzoic acid, benzaldehyde, and heptyl aldehyde when the reaction time was 2 h. DBP and its intermediates were almost completely degraded to CO2 and H2O in 12 h in the α-Fe2O3/ H2O2/UV system.

The morphological control of polymer micellar aggregates is an important issue in applications such as nanomedicine and material science. Stimuli responsive soft materials have attracted significant attention for their well-controlled morphologies. However, despite extensive studies, it is still a challenge to prepare nanoscale assemblies with responsive behaviors. Herein, a new chiral liquid crystal (LC) aliphatic polycarbonate with side chain bearing diosgenyl mesogen, named mPEG43-PMCC25-P(MCC-DHO)15, was synthesized through the ring-opening polymerization and coupling reaction. The self-assembled behavior of the LC copolymer was explored. In aqueous solution, the functionalized copolymer could self-organize into different nanostructures with changing pH value, such as nanospheres and nanofibers. This would offer new possibilities in the design of nanostructured organic materials.

It is difficult to deal with the industrial wastewater from printing and dyeing due to the high concentration of organics, complex composition, deep chrominance and variable water quality. Herein, this work aimed to design a kind of photocatalyst based on Fe2O3 nanoparticle doped with In2O3, which was used to degrade rhodamine B. The degradation performance of the prepared catalyst for rhodamine B was explored under different conditions including the doped amount of In2O3, photocatalyst dosage, H2O2 content and pH. The degradation efficiency could reach 94% under optimal conditions. In addition, the degradation mechanism of rhodamine B was investigated by analyzing intermediate products obtained with high performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC–MS). Obviously, this study offers a new possibility for effectively treating large quantities of organic pollutants in the printing and dyeing industry.

The synthesis of four new chiral mesogenic monomers (M1–M4) and side chain ferroelectric liquid crystalline polymers containing (2S, 3S)-2-chloro-3-methylpentanoate is described. The chemical structures and phase behaviour of the monomers and polymers obtained in this study were characterised by Fourier transform infrared, proton nuclear magnetic resonance, polarising optical microscopy, differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction. The selective reflection of light was investigated with ultraviolet/visible (UV/Vis). Their structure–mesomorphism relationships were discussed. M1 and P1 all showed a chiral smectic C (SmC*) phase. M2 and M3 revealed a SmC* phase and cholesteric phase, while their corresponding polymers P2 and P3 revealed a SmC* phase and smectic A (SmA) phase. M4 only exhibited a cholesteric phase, whereas the corresponding polymers P4 showed a SmA phase. Moreover, the selective reflection of light shifted to the long-wavelength region at the SmC* phase...

The toxic Hg(II) being released excessively into the water body from various sources has threatened the environment and human health. The aim of this study is to design a rapid and selective adsorbent, and propose an alternative way to dispose the spent adsorbent. To this end, a new material (MAP) was designed by inducing the polymerization of m-aminothiophenol onto MCM-41 (Mobil Composition of Matter) surface obtained using cheap diatomite as a silica source and modified by APTES ((3-aminopropyl) triethoxysilane), and the spent adsorbent was further converted into an active catalyst for acetophenone synthesis. The adsorption properties of the MAP were systematically explored under different parameters, and the corresponding results were analyzed based on different adsorption kinetic and isotherm models. The study found the removal rate and adsorption capacity of the MAP could reach 96.56% and 242.42 mg/g within 15 min. The coexisting cations showed little competition effect on the removal of Hg(II), and the adsorption capacities after five cycles did not obviously decrease. Kinetic study indicated that the adsorption data were well fitted to the pseudo-second-order model, and the adsorption equilibrium data followed the Langmuir model. After adsorption studies, the Hg(II)-MAP was used as a catalyst in the reaction of phenylacetylene to acetophenone with high yield of 97.01%. This work not only provides a rapid and selective adsorbent for removal of Hg(II) ions, but also opens a novel avenue for reusing the toxic spent adsorbent for catalytic application.

A series of new chiral monomers (M1–M4) and the corresponding siloxane polymers (P1–P4) containing menthyl groups were synthesised to establish the relationship between their structure and liquid crystalline properties. The effect of the mesogenic core rigidity and the spacer length on the phase behaviour of the monomers and polymers obtained in this study was discussed. The selective reflection of light for the chiral monomers was studied with UV-Vis spectrometer. Polarising optical microscopy, differential scanning calorimetry, X-ray diffraction and thermogravimetric analysis were used to characterise the phase behaviour and thermal stabilities. It was found that these chiral monomers and polymers were beneficial for the formation of the mesophases when a flexible spacer was inserted between the mesogenic core and terminal menthyl groups. M1–M3 showed enantiotropic chiral smectic C phase and cholesteric phase, and monotropic cubic blue phase on cooling cycle. M4 only showed cholesteric phase. P1–P4 show...

To investigate liquid crystalline properties and structure relationships of chiral compounds based on menthol, a series of new chiral monomers derived from menthol derivatives, a mesogenic crosslinking agent, the corresponding side chain homopolymers with siloxane backbone, and cholesteric elastomers were synthesized. The structures and purity of these chiral compounds obtained in this study were characterized using FTIR, 1H NMR, and elemental analyses. The mesomorphism and thermal stabilities were investigated using differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analysis, and X-ray diffraction. The selective reflection of light for the chiral monomers was studied with UV/visible/near IR. The effect of the crosslinking agent content on the phase transition temperatures of the elastomers was discussed. It was found that these chiral monomers seemed beneficial for the formation of the mesophases when a flexible spacer was inserted between the mesogenic core and the terminal menthyl groups. All obtained chiral monomers showed a cholesteric phase, chiral smectic C phase, and cubic blue phase. The crosslinking agent exhibited a smectic A (SA) phase and nematic phase. However, their corresponding homopolymers with siloxane chains tended to form a lower order SA phase. With an increase of the mesogenic rigidity, the melting temperatures, glass transition temperatures (Tg), and isotropic temperatures (Ti) of chiral monomers or homopolymers all increased. For the elastomers, general tendency was toward increased Tg and Ti with increasing the crosslinking agent content.

The synthesis of new chiral monomers (M1 −M3 ) based on menthol and the corresponding polyacrylates (P1 −P3 ) is described. The chemical structures, formula and phase behaviour of the obtained monomers and polymers were characterised with FT-IR, 1H-NMR, elemental analyses, differential scanning calorimetry (DSC), polarising optical microscopy (POM) and X-ray diffraction (XRD). The effect of the mesogenic core rigidity, spacer length and menthyl steric effect on the phase behaviour of M1 −M3 and P1 −P3 is discussed. The expected mesophase of the compounds based on menthol can be obtained by inserting a flexible spacer between the mesogenic core and the terminal groups. For the chiral monomers and polyacrylates, their corresponding melting temperature (T m), glass transition temperature (T g) and clearing temperature (T i) increased with an increase of the mesogenic core rigidity; while the T m, T g and T i decreased with increasing the spacer length. M1 and P1 showed no mesophase, while M2 and M3 all revea...

A nematic liquid crystalline polysiloxane has been found to be a novel nucleating agent (LCP-NA2) to induce the formation of β-crystals in isotactic polypropylene (iPP). Wide angle X-ray diffraction, differential scanning calorimetry, and polarized optical microscopy were used to evaluate the nucleating activity of LCP-NA2. The effect of LCP-NA2 content, crystallization temperature, and time on the crystallization structure, morphology, and thermal behavior of the iPP was discussed. The results indicated that the nucleating activity mainly depended on LCP-NA2 content and thermal history of processing. The addition of LCP-NA2 could provide a large number of nuclei and lead to a more uniform morphology, along with a change in the nucleation and crystal growth mechanism. The relative content of β-crystal increased with increasing LCP-NA2 content or crystallization temperature, reached a maximum value of 70 % when LCP-NA2 content and crystallization temperature were 1.0 wt% and 125 °C, and then decreased with a further increase of LCP-NA2 content or crystallization temperature. In addition, a different polymorphic behavior had been observed between pure iPP and LCP-NA2/iPP blends under the same thermal treatment.

The nucleating activity of side-chain liquid–crystalline copolymer, as new β-nucleating agent (LCP-NA3), towards isotactic polypropylene (iPP) was investigated by differential scanning calorimetry, wide-angle X-ray diffraction, and polarized optical microscopy. The effect of LCP-NA3 content, crystallization temperature, and time on the phase behavior of the iPP has been discussed. The results indicate that the relative content of β-crystal mainly depends on LCP-NA3 content, crystallization temperature, and time. A high content of β-crystal can be obtained by the combined effect of the optimum LCP-NA3 concentration, crystallization temperature, and time. The maximum content of β-crystal reaches 0.63 when the LCP-NA3 content, crystallization temperature, and time are 0.8 wt%, 130 °C, and 1 h, respectively. In addition, LCP-NA3 is identified to have dual nucleating ability for α- and β-crystals under appropriate kinetic conditions.

The synthesis of new chiral monomer 4-(menthyloxyacetoxy- benzoyloxy)biphenyl-4′-(2-(undec-10-e noyloxy)ethoxy)benzoate (ML), crosslinking agent 4-(undec-10-enoyloxy)biphenyl-4′-(2-(undec-10-enoyloxy)ethoxy)benzoate (CA), and liquid crystal polymer networks (E1−E5) containing menthyl group is presented. Their chemical structures and phase behavior were characterized with Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), elemental analyses, polarizing optical microscopy, differential scanning calorimetry, thermogravimetric analysis (TGA), and X-ray diffraction. The selective reflection of light for ML was investigated with ultraviolet/visible/near infrared (UV/Visible/NIR). By inserting a flexible spacer between the mesogenic core and the terminal menthyl groups, MLcould form mesophase and show a chiral smectic C phase, cholesteric phase and cubic blue phase. CA displayed a smectic A phase and nematic phase. The polymer networks containing less than 12 mol% of the crosslinking units showed reversible cholesteric phase transition, wide mesophase temperature range, and excellent thermal stability. With increasing the content of crosslinking unit, the corresponding Tg increased, the Ti decreased, and the mesophase temperature range narrowed for E1−E5. TGA showed that the Td(5%) was greater than 330°C for E1−E5.

A new chiral mesogenic monomer (MLC) based on menthyl groups and the corresponding cholesteric elastomers (LCE1–LCE3) were prepared. Their chemical structures and purity were characterized by Fourier transform infrared, nuclear magnetic resonance and elemental analyses. The liquid crystalline properties were investigated by differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analysis and X-ray diffraction. The selective reflection of light for MLC was characterized with ultraviolet/visible/near infrared. The effect of the content of crosslinking units on the liquid crystalline behaviour of LCE1–LCE3 is discussed. The experimental results show that the chiral monomer and the corresponding elastomers containing menthyl groups can show mesomorphism when a flexible linkage chain is inserted between the mesogenic core and the bulky terminal menthyl fragments to reduce the steric effect. MLC exhibited a chiral smectic C phase, a cholesteric phase and a cubic blue phase. LCE1–LCE3 with a low content of crosslinking units showed a cholesteric phase because of the introduction of the nematic crosslinking unit. With increasing content of crosslinking units, the corresponding glass transition temperature increased, while the clearing temperature decreased. Thermogravimetric analysis showed that LCE1–LCE3 have good thermal stability. Copyright © 2012 Society of Chemical Industry

The synthesis of a new cholesteric monomer (MLC) containing menthyl groups and a series of cholesteric elastomers (LCE1−LCE4) is described. Their chemical structures and purity were characterized by FTIR, 1H-NMR, and elemental analyses. The phase behavior and thermal stability were investigated by differential scanning calorimetry, polarizing optical microscopy, X-ray diffraction, and thermogravimetric analysis. By inserting a flexible spacer between the mesogenic core and the terminal menthyl groups, mesomorphism of MLC was realized. LCE1−LCE4 with low content of crosslinking unit exhibited cholesteric phase because of the introduction of the nematic crosslinking unit. This indicates that low levels of chemical crosslinking do not significantly affect the phase behavior and mesomorphism of the elastomers, and reversible mesophase transitions can be observed. In addition, with increasing the content of crosslinking unit, the corresponding Tg decreased for LCE1−LCE4, whereas their Ti did not remarkable change. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

The synthesis of new chiral liquid crystal monomers (M1 −M4 ) derived from menthyl groups, the corresponding smectic polymers (P1 −P4 ), and cholesteric elastomers (E1 −E4 ) based on M2 and crosslinking agent (CA ) is presented. The chemical structures and purity were characterised by Fourier transform infrared, 1H nuclear magnetic and elemental analyses. The phase behaviour and mesomorphism were investigated by differential scanning calorimetry, polarising optical microscopy, thermal gravimetric analysis and X-ray diffraction. The selective reflection of light for M1 −M4 was characterised with ultraviolet/visible/near infrared. The structure–property relationships of M1 −M4 and P1 −P4 were studied. The effect of the content of mesogenic crosslinking units on phase behaviour and mesomorphism of E1 −E4 was discussed. By inserting a flexible spacer between the mesogenic core and the terminal menthyl groups, M1 −M4 all showed strong mesomorphism and exhibited an oily streak and focal conic textures of the ch...

Chiral monomer (M1 ), mesogenic and non-mesogenic crosslinking agents (C1 and C2 ), and the corresponding liquid crystalline elastomers (P1 and P2 series), have been synthesised. Their chemical structures have been characterised by Fourier transform infrared or 1H nuclear magnetic resonance and their phase behaviour investigated by differential scanning calorimetry, polarising optical miscoscopy, thermo-gravimetric analysis (TGA) and X-ray diffraction. The effect of the crosslinking unit on the phase behaviour of the elastomers has been studied. M1 showed a cholesteric oily streak and focal conic texture. C2 exhibited a nematic enantiotropic thread-like and schlieren texture, and a monotropic fan-shaped texture in the SA phase. Due to the introduction of the mesogenic crosslinking unit, elastomers, P2-1 −P2-5 , exhibited a cholesteric phase, while elastomers, P1-1 −P1-4 , derived from a non-mesogenic crosslinking unit, exhibit a SA phase. As the content of the crosslinking unit increased, the T g of the P...

The synthesis of five new cholesteryl-based monomers (M-1−M-5) and the corresponding smectic comb-like polymers containing cholesteryl groups (P-1−P-5) is presented. The chemical structures were characterised by FT-IR, 1H NMR and elemental analyses. The specific optical rotations were evaluated with a polarimeter. The phase behaviour was investigated by polarising optical microscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction. The specific optical rotation values of these monomers and polymers with the same number of phenyl rings and terminal groups were nearly equal; however, they decreased with increasing the aryl numbers in the mesogenic core. The monomers M-1−M-5 showed oily streak and focal conic optical textures, or finger print textures characteristic of the chiral nematic phase. The polymers P-1−P-5 showed the smectic A phase. The melting, clearing, and glass transition temperatures increased, and the mesophase temperature ranges widened with increasing th...

The synthesis of two cholesteric monomers (M1 and M2), nematic crosslinking agent (C1 and C2), and the corresponding side-chain elastomers containing menthyl groups (P1 and P2 series) is described. The mesomorphism was investigated by differential scanning calorimetry, polarizing optical microscopy, X-ray diffraction, and thermogravimetric analysis. The effect of the content of the different nematic crosslinking unit on the mesomorphism of the elastomers was discussed. M1 and M2 showed cholesteric and blue phases; C1 and C2 showed nematic phase. Because of the introduction of the nematic crosslinking unit, elastomers P1-1−P1-5 and P2-1−P2-5 exhibited cholesteric phase. With increasing the content of nematic crosslinking unit, T g of the obtained elastomers revealed an increased tendency, and T i of P1 series firstly increased then decreased, while T i of P2 series decreased the mesomorphism of the corresponding elastomers when the content of nematic crosslinking unit was 12 mol.%.

Seven new cholesteric monomers (M-1−M-7) and the corresponding smectic comblike polymers containing cholesteryl groups (P-1−P-7) were synthesized. The chemical structures and purity were characterized by FT-IR, 1H NMR, and elemental analyses. The specific optical rotations were evaluated with a polarimeter. The mesomorphism was investigated by polarizing optical microscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction. The specific optical rotation values of these monomers and polymers with the same numbers of phenyl ring and terminal groups were nearly equal, however, they decreased with increasing the aryl numbers in the mesogenic core. M-1−M-7 showed oily streak texture and focal conic texture, or fingerprint texture, or spiral texture of cholesteric phase. P-1−P-7 showed the smectic A phase. The melting, clearing, and glass transition temperatures increased, and the mesophase temperature ranges widened with increasing the aryl number in the mesogenic core. Surprisingly, although the molecular structures of M-6 and M-7 were similar to those of M-4, namely the mesogenic cores contained three phenyl rings, their phase behavior had a considerable difference, and Tm and Ti of M-6 and M-7 were less than those of M-4. In addition, M-6 and M-7 also showed an obvious glass transition. TGA showed that all the polymers had good thermal stabilities.

The synthesis of new chiral monomers (M1−M5) and the corresponding smectic homopolymers (P1−P5) containing menthyl groups is described. The chemical structures and purity were characterized by FT-IR, 1H NMR and elemental analyses. The specific optical rotations were evaluated with a polarimeter. The phase behavior and mesomorphism were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction. The selective reflection property of light was studied with UV/visible/NIR. The monomers M2−M5 formed a chiral smectic C ( S C ∗ ) , and cholesteric or blue phase when a flexible linkage chain was inserted between the mesogenic core and the terminal menthyl groups by reducing the steric effect. M1 showed no mesomorphism, while M2−M5 showed enantiotropic S C ∗ and cholesteric phases. Moreover, M5 also exhibited a cubic blue phase on cooling. With increasing temperature, the selective reflection of light shifted to the long wavelength region at the S C ∗ phase range, and to the short wavelength region at the cholesteric phase range, respectively. The homopolymers P1−P5 all exhibited the batonnet textures of a smectic A phase. The melting, clearing, and glass transition temperatures increased, and the mesophase temperature ranges widened with increasing the aryl number in the mesogenic core.

Six new chiral monomers (M1–M6), and their corresponding side chain polymers (P1–P6) containing menthyl groups were synthesized. The chemical structures of M1–M6 were characterized with FTIR and 1H NMR. The structure–property relationships of the monomers and polymers obtained are discussed. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. Some compounds containing menthyl groups formed mesophase when a flexible spacer was inserted between the mesogenic core and the menthyl groups by reducing the steric hindered effect. The monomers M1, M4, and M5 did not reveal mesomorphic properties because of the weaker rigid core or the longer flexible terminal groups, whereas M2, M3, and M6 all revealed cholesteric phase. Except P4 and P5, the homopolymers P1–P3 and P6 showed a smectic A phase. In addition, melting, glass transition temperature, or clearing temperature increased, and the mesophase temperature range widened with increasing the rigidity of mesogenic core or decreasing the length of the flexible spacer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

New cholesteric monomers (M2−M5) and the corresponding smectic homopolymers (P2−P5) based on menthyl groups were synthesized. The chemical structures were characterized by Fourier transform infrared and 1H NMR. The specific optical rotations were evaluated with a polarimeter. The structure–property relationships of the new compounds are discussed. The mesomorphism was investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction. The selective reflection property of light was studied with UV/Visible/NIR. The monomers M2−M5 formed the cholesteric or blue phase when a flexible link chain was inserted between the mesogenic core and the terminal menthyl groups by reducing the steric effect. M1 showed no mesomorphism, while M2−M5 revealed enantiotropic cholesteric phase. In addition, M2 and M3 also showed a cubic blue phase on cooling. The selective reflection of light for M2−M5 shifted to the short reciprocal wavelength region with increasing the temperature or intramolecular spacer length. P2−P5 exhibited the smectic A phase. The melting, clearing, and glass transition temperatures increased when increasing the aryl number in the mesogenic core or decreasing the intramolecular spacer length.

The synthesis is described of four new chiral liquid crystalline monomers (M2–M5 ) and their corresponding side‐chain homopolysiloxanes (P2–P5 ) containing menthyl groups. Chemical structures were characterised using FT‐IR or 1H NMR spectra, and specific optical rotations were evaluated with a polarimeter. The phase behaviour and mesomorphic properties of the new compounds were investigated by differential scanning calorimetry, thermogravimetric analysis, polarising optical microscopy, UV/visible/NIR spectrocopy and X‐ray diffraction. The monomers and homopolymers with more aryl segments showed noticeably lower specific optical rotation value. The monomers M2–M5 formed a cholesteric or blue phase when a flexible spacer was inserted between the rigid mesogenic core and the terminal menthyl groups by reducing the steric effect. M2–M5 revealed enantiotropic cholesteric phase. Moreover, M2 also exhibited a monotropic smectic A (SmA) phase, and M4 also exhibited a cubic blue phase on cooling. The selective ref...

The synthesis of a new chiral mesogenic monomer (M1), a nematic monomer (M2), and a series of side chain cholesteric copolymers (P2–P6) containing the mesogenic menthyl groups is described. The chemical structures of the compounds were confirmed by FTIR and 1H NMR. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry, thermogravimetric analysis, and polarizing optical microscopy. M1 showed an enantiotropic cholesteric phase, and M2 revealed a nematic phase. The homopolymers P1 and P7, respectively, displayed a chiral smectic A (SA) phase and a nematic phase, while the copolymers P2–P6 exhibited the Grandjean texture of the cholesteric phase. Tg, Ti, and ΔT of P1–P7 increased with increasing the concentration of M2 in the polymers. All of the obtained polymers displayed very good thermal stability and the wide mesophase temperature range. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

A series of new chiral side-chain liquid-crystalline polymers were prepared containing smectic-nematic monomer and nonmesogenic chiral monomer. All polymers were synthesized by graft polymerization using polymethylhydrosiloxane as backbone. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analyses, and X-ray diffraction measurements. The chemical structures of the monomers and polymers obtained were confirmed by Fourier transform infrared, proton nuclear magnetic resonance spectra (1H NMR). M1 showed smectic (SB, SC) and nematic phase on the heating and the cooling cycle. Polymers P0–P2 were in chiral smectic A phase, while P3–P5 were in cholesteric phase, P6 has bad LC properties, and P7 has no LC properties. Experimental results demonstrated that nonmesogenic chiral moiety and LC mesogenic with long carbochain offered the possibility of application because of its lower glass transition temperature, and the glass transition temperatures and isotropization temperatures and the ranges of the mesophase temperature reduced with increasing the contents of chiral agent. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

New liquid crystalline monomer 4-(4-ethoxybenzoyloxy)biphenyl-4′-[(10-undecylen-1-yloxy)-4′-ethoxy]benzoate (M 1 ), chiral crosslinking agent isosorbide di-(10-undecylen-1-yloxybenzoate) (M 2 ), and the corresponding elastomers were prepared. The chemical structures of M 1 and M 2 were characterized by Fourier transform infrared and 1H-nuclear magnetic resonance. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. M 1 exhibited typical threaded texture and droplet texture of nematic phase. The use of chiral crosslinking agent in the polymer networks could induce cholesteric phase. The elastomers containing less than 10 mol% of the chiral crosslinking units showed elasticity, reversible phase transition, wide mesophase temperature ranges, and high thermal stability. For the elastomers P 2 –P 4 , the glass transition temperature (T g) increased; clearing temperature (T i) and mesophase temperature range (ΔT) decreased with increasing content of the crosslinking unit.

The synthesis of five chiral liquid crystalline monomers (M1–M5), and their corresponding side-chain polymers (P1–P5) based on (S)-(+)-2-methyl-1-butanol derivatives is described. The chemical structures of the monomers were confirmed by FT-IR, 1H NMR, and elemental analyses. The structure-property relationships of the monomers and polymers obtained are discussed. The mesomorphic properties were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), polarizing optical microscopy (POM), and X-ray diffraction (XRD) measurements. All monomers showed a cholesteric phase. For M2, M3, and M5, besides a cholesteric phase and a smectic A (SA) phase, M2 also revealed an enantiotropic chiral smectic C ( S C ∗ ) phase and a monotropic smectic B (SB) phase, and M3 also showed a SB phase. The polymers P1–P5 exhibited a SA phase, moreover, P2, P3 and P5 also revealed a S C ∗ phase. The experimental results demonstrated that a flexible siloxane backbone and a long flexible spacer tended to exhibit a low glass transition temperature, high thermal stability, and wide mesophase temperature range.

Six chiral monomers (M1−M6), and their corresponding polymers (P1, P4) and elastomers (P2, P3, P5, P6) derived from chiral mesogenic crosslinking agent were synthesized. The chemical structures of M1−M6 were confirmed by FTIR and 1H NMR spectroscopy. The structure-property relationships of M1−M6 and P1−P6 were discussed. Their mesomorphic properties and phase behavior were investigated by differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), polarizing optical microscopy (POM), and X-ray diffractometer (XRD) measurements. All monomers obtained, except M2 and M5, showed typical oily streaks texture and focal conic texture of cholesteric phase on heating and cooling cycles. The selective reflection of cholesteric monomers and elastomers shifted to the short wavelength region with increasing temperature. The elastomers P2 and P5 did not reveal the mesomorphic properties, and P3 and P6 showed cholesteric phase. TGA showed that P1−P6 had a high thermal stability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The synthesis of new side-chain cholesteric elastomers derived from a cholesteric monomer and mesogenic crosslinking agent is presented. The chemical structures of the monomers obtained were confirmed by elemental analyses, FT-IR, 1H NMR, and 13C NMR. The mesomorphic properties and thermal stability were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), polarizing optical microscopy (POM), and X-ray diffraction (XRD) measurements. M1 showed cholesteric phase, and M2 displayed enantiotropic nematic phase and monotropic smectic phase. The elastomers containing less than 12 mol% of the crosslinking units revealed reversible mesomorphic phase transition, wide mesophase temperature ranges, and high thermal stability.

A series of new cholesteric liquid-crystalline polysiloxanes (P1–P5) derived from menthyl groups were synthesized. The chemical structures of the monomers and polymers were characterized with Fourier transform infrared, 1H-NMR, 13C-NMR, and elemental analyses. The mesomorphic properties and thermal behavior were investigated with differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analysis, and X-ray diffraction measurements. The influence of the polymer structure on the thermal behavior was discussed. The monomer diosgeninyl 4-allyloxybenzoate exhibited a typical cholesteric oily-streak texture and a focal-conic texture. Polymers P1–P5 showed thermotropic liquid-crystalline properties. P1 displayed a smectic fan-shaped texture, P2–P5 showed a cholesteric Grandjean texture, and P6 and P7 did not show mesomorphic properties. The experimental results demonstrated that the glass-transition temperature and the clearing temperature decreased, and the mesomorphic properties weakened with an increasing concentration of menthyl units. Moreover, P1–P5 exhibited wide mesophase temperature ranges and high thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5559–5565, 2006

The synthesis of the new chiral monomer 4-(10-undecylen-1-yloxy)biphenyl-4′-[(S)-2-methyl-1-bu- toxy]benzoate (M1), the nematic crosslinking agent biphenyl 4,4′-bis(10-undecylen-1-yloxybenzoate) (M2), and the corresponding liquid-crystalline elastomer is described. The chemical structures of the chiral monomer and crosslinking agent have been characterized with Fourier transform infrared, elemental analyses, and proton and carbon-13 nuclear magnetic resonance spectra. The mesomorphic properties have been investigated with differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. Monomer M1 shows different smectic phases (smectic A, chiral smectic C, and smectic B) and a cholesteric phase, and M2 exhibits a nematic phase. The liquid-crystalline elastomer shows smectic A and chiral smectic C phases. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4234–4239, 2006

A series of new side-chain cholesteric liquid-crystalline elastomers derived from 4-(10-undecylen-1-yloxy)-4′-(4-ethoxybenzoyloxy)biphenyl and isosorbide di-(10-undecylen-1-ylenate) were synthesized. The chemical structures of the monomers obtained were confirmed by element analyses, FT-IR, 1H NMR and 13C NMR. The mesomorphic properties and thermal stability were investigated by polarizing optical microscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction measurements. The influence of the content of the crosslinking unit on the phase behavior of the elastomers was discussed. Monomer M1 showed nematic and different smectic (SA, SC, SB) phase on cooling cycle. Elastomers containing less than 27 mol% of the crosslinking units revealed elasticity, reversible mesomorphic phase transition, wide mesophase temperature ranges, and high thermal stability. Experimental results demonstrated that the glass transition temperature, melting temperatures, clearing temperature and mesophase temperature ranges decreased with increasing the content of the crosslinking unit.

New monomer cholesteryl 4-(10-undecylen-1-yloxybenzoyloxy)-4′-ethoxybenzoate (M1), crosslinking agent biphenyl 4,4′-bis(10-undecylen-1-yloxybenzoyloxy-p-ethoxybenzoate) (M2) and a series of side-chain cholesteric elastomers were prepared. The chemical structures of the monomers and elastomers obtained were confirmed by element analyses, FT-IR, and 1H NMR. The mesomorphic properties and thermal stability were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. The influence of the content of the crosslinking unit on the phase behavior of the elastomers was examined. M 1 showed cholesteric phase, and M 2 displayed nematic phase. The elastomers containing less than 12 mol% of the crosslinking units revealed reversible mesomorphic phase transition, wide mesophase temperature ranges, and high thermal stability.

A series of liquid crystalline (LC) polysiloxanes containing diosgeninyl and menthyl groups (from monomers M 1 and M 2, respectively) were synthesized. The chemical structures of the monomers and polymers obtained were confirmed by elemental analysis, Fourier transform infrared spectroscopy, proton NMR and carbon‐13 NMR. The LC properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X‐ray diffraction. Monomer M 1 showed cholesteric oily‐streak and spiral textures. Copolymers P 2–P 5 exhibited cholesteric phases. With increasing concentration of M 2 units, the glass transition and clearing temperatures decreased. Experimental results demonstrated that a flexible polymer backbone and a long flexible spacer tended to favour a lower glass transition temperature, higher thermal stability, and wider mesophase temperature range.

In this work we prepared a nematic monomer (4′‐allyloxybiphenyl 4′‐ethoxybenzoate, M1 ), a chiral crosslinking agent (isosorbide 4‐allyloxybenzoyl bisate, M2 ) and a series of new side chain cholesteric liquid crystalline elastomers derived from M1 and M2 . The chemical structures of the monomers and polymers were confirmed by FTIR and 1H NMR spectroscopy. The mesomorphic properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy and X‐ray diffraction. The effect of the content of the crosslinking unit on phase behaviour of the elastomers is discussed. Polymer P1 showed a nematic phase, P2 –P7 showed a cholesteric phase; P6 formed a blue Grandjean texture over a broad temperature range 145–209.6°C, with no changed on the cooling. Polymers P4 –P7 , with more than 6 mol % of chiral crosslinking agent, gave rise to selective reflection. Elastomers containing less than 15 mol % of the crosslinking units displayed elasticity, reversible phase tr...

A series of new side-chain cholesteric elastomers derived from cholesteryl 4-(10-undecylen-1-yloxy)-4′-ethoxybenzoate and phenyl 4,4′-bis(10-undecylen-1-yloxybenzoyloxy-p-ethoxybenzoate) was synthesized. The chemical structures of the monomers were confirmed by elemental analyses, Fourier transform infrared, and 1H NMR and 13C NMR spectra. The mesomorphic properties of elastomers were investigated with differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. The influence of the content of the crosslinking unit on the phase behavior of the elastomers was examined. Monomer M1 showed a cholesteric phase, and M2 displayed smectic and nematic phases. The elastomers containing

A series of new cholesteric liquid-crystalline polysiloxanes derived from steroid substituents were synthesized. The chemical structures of the monomers or polymers obtained were characterized by FTIR, element analyses, 1H NMR, and 13C NMR. Their mesogenic properties and thermal stability were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. Monomers exhibited typical cholesteric focal-conic or spiral texture. The polymers P1P6 showed cholesteric phase and P7 displayed smectic phase. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006

A series of new thermochromic side-chain liquid–crystalline polymers were prepared. The chemical structures of the resulting monomers and polymers were characterized by element analyses, FTIR, 1H-NMR, and 13C-NMR. Their mesogenic properties were investigated by differential scanning calorimetry, thermogravimetric analyses, polarizing optical microscopy, and X-ray diffraction measurements. The influence of the content of dye groups on phase behavior of the polymers was discussed. The polymers P1–P3 showed smectic phase, and P4–P7 revealed cholesteric phase. The polymers containing less than 30 mol % of the dye groups showed good solubility, reversible phase transition, wider mesophase temperature ranges, and higher thermal stability. Experimental results demonstrated that the clearing temperature and mesophase temperature ranges decreased with increasing the concentration of the dye groups. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 329–335, 2005

Four bisacrylate mesogenic monomers and the corresponding liquid-crystalline thermosets were synthesized. The chemical structures of the intermediate compounds and monomers obtained were confirmed by elemental analyses, Fourier transform infrared, and 1H NMR and 13C NMR spectra. The mesomorphic properties and thermal stability were investigated with differential scanning calorimetry, thermogravimetric analysis, polarized optical microscopy, and X-ray diffraction measurements. The influence of the curing temperatures and time on the phase behavior and thermal stability of the thermosets was discussed. All the monomers and thermosets exhibited a nematic schlieren texture. However, the monomers only showed the melting transition, and the thermosets displayed the glass transition. The experimental results demonstrated that the monomer structures strongly affected the phase behavior and the curing reaction rate, and the glass-transition temperatures and thermal stability of the thermosets increased with the curing temperature and time. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4478–4485, 2005

A series of liquid crystalline homopolysiloxanes and copolysiloxanes were synthesized. The chemical structures of the monomers M1 –M7 were confirmed by FTIR and 1H NMR spectroscopy. The structure–property relationships of the monomers and polymers are discussed; their phase behaviour and optical properties were investigated by differential scanning calorimetry, thermogravimetric analysis, and polarizing optical microscopy. All the monomers, except M2 and M7 showed smectic and nematic phases; the copolymers P8 –P15 displayed cholesteric phases. The homopolymers P1 –P7 exhibited smectic phases. The selective reflection of cholesteric monomers and copolymers shifted to longer wavelengths with increasing length of the rigid mesogenic core, with decreasing length of the flexible spacer, or with increasing content of nematic units. Experimental results demonstrated that a flexible polymer backbone, a rigid mesogenic core and a long flexible spacer tended to produce a lower glass transition temperature, higher t...

New side-chain liquid-crystalline polymers containing both cholesteric and thermochromic side groups were synthesized. Their chemical structures were confirmed with elemental analyses and Fourier transform infrared, proton nuclear magnetic resonance, and carbon-13 nuclear magnetic resonance spectra. The mesogenic properties and phase behavior were investigated with differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. The effect of the concentration of dye side groups on the phase behavior of the polymers was examined. The polymers showed smectic or cholesteric phases. Those polymers containing less than 20 mol % dye groups had good solubility, reversible phase transitions, wider mesophase temperature ranges, and higher thermal stability. The experimental results demonstrated that the isotropization temperature and mesophase temperature ranges decreased with an increasing concentration of dye groups. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3870–3878, 2004