Monodomain hydrogels prepared by shear-induced orientation and subsequent gelation

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 95239-95245 ◽  
Author(s):  
Xiao Ying Lin ◽  
Zhi Jian Wang ◽  
Pengju Pan ◽  
Zi Liang Wu ◽  
Qiang Zheng
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystalline ◽  
Gelation Process

Shear-induced orientation of liquid crystalline hydroxypropylcellulose solution with reactants is frozen by subsequent polymerization and gelation process, resulting in monodomain hydrogel with anisotropic optical, swelling, and mechanical properties.

scholarly journals Fiber Formation and Structural Development of HBA/HNA Thermotropic Liquid Crystalline Polymer in High-Speed Melt Spinning

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Bo Seok Song ◽  
Jun Young Lee ◽  
Sun Hwa Jang ◽  
Wan-Gyu Hahm
Keyword(s):  
Mechanical Properties ◽  
Shear Rate ◽  
High Speed ◽  
Melt Spinning ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Fiber Formation ◽  
Structural Development ◽  
Thermotropic Liquid Crystalline Polymer

High-speed melt spinning of thermotropic liquid crystalline polymer (TLCP) resin composed of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-napthoic acid (HNA) monomers in a molar ratio of 73/27 was conducted to investigate the characteristic structure development of the fibers under industrial spinning conditions, and the obtained as-spun TLCP fibers were analyzed in detail. The tensile strength and modulus of the fibers increased with shear rate in nozzle hole, draft in spin-line and spinning temperature and exhibited the high values of approximately 1.1 and 63 GPa, respectively, comparable to those of industrial as-spun TLCP fibers, at a shear rate of 70,000 s−1 and a draft of 25. X-ray diffraction demonstrated that the mechanical properties of the fibers increased with the crystalline orientation factor (fc) and the fractions of highly oriented crystalline and non-crystalline anisotropic phases. The results of structure analysis indicated that a characteristic skin–core structure developed at high drafts (i.e., spinning velocity) and low spinning temperatures, which contributed to weakening the mechanical properties of the TLCP fibers. It is supposed that this heterogeneous structure in the cross-section of the fibers was induced by differences in the cooling rates of the skin and core of the fiber in the spin-line.

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

2015 ◽  
Vol 132 (40) ◽  
pp. n/a-n/a ◽  
Author(s):  
Huilong Guo ◽  
Yinwen Li ◽  
Jian Zheng ◽  
Jianqun Gan ◽  
Liyan Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Liquid Crystalline ◽  
Epoxy Composites ◽  
Liquid Crystalline Epoxy

scholarly journals A method for pet mechanical properties enhancement

2019 ◽  
Vol 10 (8) ◽  
pp. 1725
Author(s):  
Raffaella Aversa ◽  
Relly Victoria Virgil Petrescu ◽  
Antonio Apicella ◽  
Florian Ion Tiberiu Petrescu
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Molecular Structures ◽  
Reactive Blending ◽  
Scanning Calorimetry ◽  
Shear Transfer ◽  
Crystalline Polymers ◽  
Reactive Compatibilizer

A method for PET mechanical properties enhancement by reactive blending with HBA/HNA Liquid Crystalline Polymers for in situ highly fibrillar composites preparation is presented. LCP/PET blends were reactively extruded in presence of Pyromellitic Di-Anhydride (PMDA) and then characterized by Differential Scanning Calorimetry, Thermally Stimulated Currents and tensile mechanical properties. Moderate amounts of LCP in the PET (0.5 and 5%) and small amounts of thermo-active and reactive compatibilizer in the blend (0.3%) were found to significantly improve LCP melt dispersion, melts shear transfer and LCP fibril formation and adhesion. An unexpected improvement was probably due to the presence of two distinct phases’ supra-molecular structures involving PET-LCP and PMDA.

Structures and properties of side-chain liquid crystalline polynorbornenes containing an amide group: hydrogen bonding interactions and spacer length effects

2020 ◽  
Vol 11 (29) ◽  
pp. 4749-4759
Author(s):  
Dong Shi ◽  
Wen-Ying Chang ◽  
Xiang-Kui Ren ◽  
Shuang Yang ◽  
Er-Qiang Chen
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Liquid Crystalline ◽  
Amide Group ◽  
Self Organization ◽  
Side Chain ◽  
Hydrogen Bond Interaction ◽  
Spacer Length ◽  
Hydrogen Bonding Interactions ◽  
Structures And Properties

Side-chain liquid crystalline polynorbornenes based on benzanilide mesogens exhibit rich self-organization behaviours and enhanced mechanical properties owing to the lateral hydrogen bond interaction that can be tuned by the spacer length.

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