Cure Kinetics and Mechanical Properties of Liquid Crystalline Epoxides with Long Lateral Substituents Cured with Anhydride

Liang, Liyan; Ren, Shaoping; Zheng, Yang; Lan, Ya‐Qian; Lu, Mangeng

doi:10.1295/polymj.pj2006219

Cited by 4 publications

(5 citation statements)

References 26 publications

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“…As was reported by our group, the cross‐linking density of LCE network decreased with increase of the length of the lateral substituents. The cross‐linking density of LCE network acted an important role in shape memory effects.…”

Section: Resultssupporting

confidence: 92%

Reinforcement in the mechanical properties of shape memory liquid crystalline epoxy composites

Guo

Zheng

et al. 2015

J of Applied Polymer Sci

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In this work, novel thermoresponsive shape memory composites based on glass fiber and nanosilica‐modified liquid crystalline epoxies (LCEs) with lateral substituent were prepared and characterized. According to the comprehensive analysis of polarized optical microscopy, wide‐angle X‐ray diffraction measurements, and tan δ data, the orientation of mesogen units were hindered by the introduction of nanosilica and lateral substituents of liquid crystalline epoxies, so that additional physical cross‐links except for similar chemical cross‐links emerged with the introduction of surface‐treated nanosilica. And the increased cross‐links could enhance the shape memory properties of the composites which could recover to their original state quickly in a time shorter than 30 s with high shape fixing ratios (>96%) and high shape recovery ratios (>98%), which indicated the composites could be applied into self‐deployable structural materials. Moreover, the reinforcement in the dynamic storage moduli, tensile modulus, and the tensile strength and shape memory properties indicated that glass fiber and nanosilica‐modified shape memory liquid crystalline epoxy composites could be high‐performance composites and could be used as new candidates for aerospace smart materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42616.

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Section: Resultssupporting

confidence: 92%

Reinforcement in the mechanical properties of shape memory liquid crystalline epoxy composites

Guo

Zheng

et al. 2015

J of Applied Polymer Sci

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“…Accordingly, the loss modulus of PLA/J1 and PLA/J2 showed an improvement of 19.37% and 28.48%, respectively, compared to neat PLA, as shown from the peaks at temperatures of 50-55 • C. The tangent δ represents the ratio between the dissipated energy and the elastically stored energy, which is given by the relationship E /E . It measures the energy used to bend the PLA and PLA/J specimens during DMA testing and is dissipated directly into heat [59]. The glass transition temperature (T g ) can be deduced from the peak of the tanδ curve and is a function of temperature as seen in Figure 10c.…”

Section: Dynamic Mechanical Analysis (Dma)mentioning

confidence: 99%

Influence of Reactive Chain Extension on the Properties of 3D Printed Poly(Lactic Acid) Constructs

et al. 2021

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Fused deposition modeling (FDM) is currently the most popular 3D printing method, where thermoplastic polymers are predominantly used. Among them, the biobased poly(lactic acid) (PLA) governs the FDM filament market, with demand higher than supply, since not all grades of PLA are suitable for FDM filament production. In this work, the effect of a food grade chain extender (Joncryl ADR® 4400) on the physicochemical properties and printability of PLA marketed for injection molding was examined. All samples were characterized in terms of their mechanical and thermal properties. The microstructure of the filaments and 3D-printed fractured surfaces following tensile testing were examined with optical and scanning electron microscopy, respectively. Molecular weight and complex viscosity increased, while the melt flow index decreased after the incorporation of Joncryl, which resulted in filaments of improved quality and 3D-printed constructs with enhanced mechanical properties. Dielectric spectroscopy revealed that the bulk properties of PLA with respect to molecular mobility, both local and segmental, were, interestingly, not affected by the modifier. Indirectly, this may suggest that the major effects of the extender are on chain length, without inducing chain branching, at least not to a significant extent.

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“…The mechanical properties, including tensile strength, Young's modulus and elongation at break, decrease as increase of the length of lateral substituent. Larger substituents lead to decreased cross‐linking densities of the LC networks . Therefore, we synthesized LCE6 as matrix of the composites, for the better comprehensive performance of LCE6 like better toughness than LCE2 and LCE4, better mechanical properties than LCE8, LCE10 and LCE12.…”

Section: Methodsmentioning

confidence: 85%

Enhancement in the thermal and dynamic mechanical properties of high performance liquid crystalline epoxy composites through uniaxial orientation of mesogenic on carbon fiber

Guo

Liang

et al. 2014

J of Applied Polymer Sci

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In this work, a high performance liquid crystalline epoxy composite was prepared and the effect of the alignment of LCE with long lateral substituent on the carbon fiber surface curing at low temperature on fracture toughness, dynamic mechanical, and thermal properties of liquid crystalline epoxy with lateral substituent (LCE6) was investigated by polarized optical microscopy (POM), wide angle X‐ray diffraction measurements (WAXS), dynamic mechanical analysis (DMA), thermogravimetric (TGA), and scanning electron microscopy (SEM). Curing degree of the composite was observed by FTIR. The experimental results indicate that the fracture toughness, glass transition temperature (Tg), thermal stability, degradation kinetics are associated with the alignment of LCE6 along long axis of carbon fiber. The alignment of LCE6 on carbon fiber surface can increase mesogen network density, which leads to higher fracture toughness, higher thermal stability, increase of the activation energies and higher Tg of the composite. The dynamic mechanical analysis shows that the compoaite possesses extremely higher dynamic storage moduli, which indicates that this LCE6/DDM/CF composite can be a high performance composite. Thus, the compoaite can be a potential candidate for advanced composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40363.

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Cure Kinetics and Mechanical Properties of Liquid Crystalline Epoxides with Long Lateral Substituents Cured with Anhydride

Cited by 4 publications

References 26 publications

Reinforcement in the mechanical properties of shape memory liquid crystalline epoxy composites

Reinforcement in the mechanical properties of shape memory liquid crystalline epoxy composites

Influence of Reactive Chain Extension on the Properties of 3D Printed Poly(Lactic Acid) Constructs

Enhancement in the thermal and dynamic mechanical properties of high performance liquid crystalline epoxy composites through uniaxial orientation of mesogenic on carbon fiber

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