Effect of Ionic Content on the Properties and Structure of Viologen Elastomers

2000 ◽  
Vol 73 (5) ◽  
pp. 864-874 ◽  
Author(s):  
T. Murakami ◽  
S. Kohjiya ◽  
Y. Ikeda ◽  
H. Urakawa ◽  
K. Kajiwara
Keyword(s):  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Order Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Ionic Content ◽  
X Ray ◽  
Dynamic Mechanical ◽  
Before And After ◽  
Molecular Masses

Abstract Three viologen-type poly(tetramethylene oxide) (PTMO) ionenes with chloride anions (PTVs) were synthesized by living cationic polymerization, whose molecular masses of PTMO segments between the viologen units were 6100, 9800 and 12000 g/mol. The PTV films were elastomers and possessed the microphase-separated structure consisting of three phases, i.e., PTMO amorphous phase, PTMO crystalline phase and ionic aggregated phase. The effect of ionic content, i.e., the effect of molecular mass between the ionic segments on the higher-order structure and properties of the PTV films were investigated by differential scanning calorimetry, dynamic mechanical analysis, wide-angle X-ray diffraction and small-angle X-ray scattering (SAXS) measurements. The lower the ionic content was, the smaller the amorphous PTMO phase became and the more the long range-ordered structure of PTMO crystals of lamellae was regularly formed. This crystalline part significantly influenced the dynamic mechanical properties. The distance between the ionic domains became larger with the increase of the PTMO segments. The scattering peaks attributed to the crystalline phases and ionic domains were detected by SAXS for the PTV films whose molecular masses of PTMO segments were 9800 and 12000 g/mol. The distance between the ionic domains was changed little before and after the melting of PTMO crystals of PTV films.

Synthesis and thermal properties of high temperature phthalonitrile resins cured with self-catalytic amino-contanining phthalonitrle compounds

2016 ◽  
Vol 29 (10) ◽  
pp. 1209-1221 ◽  
Author(s):  
Xinggang Chen ◽  
Jiayu Liu ◽  
Zhenjie Xi ◽  
Shuyan Shan ◽  
Huili Ding ◽  
...  
Keyword(s):  
High Temperature ◽  
Catalytic Efficiency ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Dynamic Mechanical ◽  
Nucleophilic Displacement

A series of self-catalytic phthalonitrile compounds with o-, m-, and p- amino groups, namely, 4-(2-aminophenoxy)phthalonitrile (2-NH2-CN), 4-(3-aminophenoxy)phthalonitrile (3-NH2-CN), and 4-(4-aminophenoxy)phthalonitrile (4-NH2-CN), were synthesized via a facile nucleophilic displacement of a nitro-substituent with 4-nitrophthalonitrile. The phthalonitrile resins were prepared by curing 2-NH2-CN, 3-NH2-CN, and 4-NH2-CN with 1,3-bis(3,4-dicyanophenoxy) benzene ( m-BDB). The structures of these compounds were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and wide-angle X-ray diffraction. Curing behaviors of 2-NH2-CN, 3-NH2-CN, and 4-NH2-CN with m-BDB were recorded by differential scanning calorimetry. The results show that the processabilities of m-BDB with 4-NH2-CN are superior to those with 2-NH2-CN and 3-NH2-CN due to higher self-catalytic efficiency and broader processing windows. Thermal stabilities were evaluated by thermogravimetric analysis, and the polymers with all these self-catalytic compounds exhibit excellent thermal and thermal-oxidative stabilities. Dynamic mechanical analysis reveals that these polymers have high storage modulus and high glass transition temperatures. The polymers of 4-NH2-CN show more outstanding processability, thermal stability, and dynamic mechanical properties than those of 2-NH2-CN and 3-NH2-CN and can be considered as a good candidate as a self-catalytic curing agent for high-temperature phthalonitrile polymers.

scholarly journals Construction of Mechanically Reinforced Thermoplastic Polyurethane from Carbon Dioxide-Based Poly(ether carbonate) Polyols via Coordination Cross-Linking

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2765
Author(s):  
Gaosheng Gu ◽  
Jincheng Dong ◽  
Zhongyu Duan ◽  
Binyuan Liu
Keyword(s):  
Carbon Dioxide ◽  
Dynamic Mechanical Analysis ◽  
Thermoplastic Polyurethane ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dynamic Mechanical ◽  
Chemical Structures ◽  
Vis Spectroscopy

Using carbon dioxide-based poly(propylene ether carbonate) diol (PPCD), isophorone diisocyanate (IPDI), dimethylolbutyric acid (DMBA), ferric chloride (FeCl3), and ethylene glycol (EG) as the main raw materials, a novel thermoplastic polyurethane (TPU) is prepared through coordination of FeCl3 and DMBA to obtain TPU containing coordination enhancement directly. The Fourier transform infrared spectroscopy, 1H NMR, gel permeation chromatography, UV−Vis spectroscopy, tensile testing, dynamic mechanical analysis, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis were explored to characterize chemical structures and mechanical properties of as-prepared TPU. With the increasing addition of FeCl3, the tensile strength and modulus of TPU increase. Although the elongation at break decreases, it still maintains a high level. Dynamic mechanical analysis shows that the glass-transition temperature moves to a high temperature gradually along with the increasing addition of FeCl3. X-ray diffraction results indicate that TPUs reinforced with FeCl3 or not are amorphous polymers. That FeCl3 coordinates with DMBA first is an effective strategy of getting TPU, which is effective and convenient in the industry without the separation of intermediate products. This work confirms that such Lewis acids as FeCl3 can improve and adjust the properties of TPU contenting coordination structures with an in-situ reaction in a low addition amount, which expands their applications in industry and engineering areas.

scholarly journals Investigation of viscoelastic properties and thermal behavior of photocurable epoxy acrylate nanocomposites

2017 ◽  
Vol 24 (5) ◽  
pp. 691-697
Author(s):  
Behzad Shirkavand Hadavand ◽  
Hossein Hosseini
Keyword(s):  
Thermal Behavior ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Cuo Nanoparticles ◽  
Epoxy Acrylate ◽  
Silane Coupling Agents ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Acrylate Resin ◽  
Epoxy Acrylate Resin

AbstractIn this study, the dynamic-mechanical properties and thermal behavior of the nanocomposites of a photocurable epoxy-acrylate resin and CuO nanohybrid were determined. In order to improve the dispersion of CuO nanoparticles and prevention of nanoparticle migration to the surface coating, the surface of commercial nanoparticles was modified by triethoxymethylsilane (TEMS) and vinyltrimethoxysilane (VTMS) as silane-coupling agents. Dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) tests were then performed on CuO-filled epoxy-acrylate resins to identify the loading effect on the properties of material. The thermal stability of nanocomposites was affected slightly after incorporation of CuO nanoparticles. DMA studies revealed that filling the CuO nanoparticles into epoxy-acrylate resin can produce a significant enhancement in storage modulus, as well as a shift in the glass transition temperature. The films reinforced with the modified CuO exhibit the most significant enhancements in properties.

scholarly journals Microstructure Evolution and Performance Improvement of Hypereutectic Al–Mg2Si Metallic Composite with Ca or Sb

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nucleation Behavior ◽  
X Ray ◽  
Primary Mg2si ◽  
Before And After ◽  
And Performance ◽  
Hardness Values

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.

Thermal stability and dynamic mechanical behavior of functional multiphase boride ceramics/epoxy composites

2019 ◽  
Vol 39 (6) ◽  
pp. 508-514
Author(s):  
Yannan He ◽  
Zhiqiang Yu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Reaction Heat ◽  
Dynamic Mechanical

Abstract The thermal and dynamic mechanical properties of epoxy composites filled with zirconium diboride/nano-alumina (ZrB2/Al2O3) multiphase particles were investigated by means of differential scanning calorimetry, dynamic thermo-mechanical analysis, and numerical simulation. ZrB2/Al2O3 particles were surface organic functional modified by γ-glycidoxypropyltrimethoxysilane for the improvement of their dispersity in epoxy matrix. The results indicated that the curing exotherm of epoxy resin decreased significantly due to the addition of ZrB2/Al2O3 multiphase particles. In comparison to the composites filled with unmodified particles, the modified multiphase particles made the corresponding filling composites exhibit lower curing reaction heat, lower loss modulus, and higher storage modulus. Generally speaking, the composites filled with 5 wt% modified multiphase particles presented the best thermal stability and thermo-mechanical properties due to the better filler-matrix interfacial compatibility and the uniform dispersity of modified particles. Finite element analysis also suggested that the introduction of modified ZrB2/Al2O3 multiphase particles increased the stiffness of the corresponding composites.

Effects of Phenolic Oligomer on the Dynamic Mechanical Properties of Nitrile Butadiene Rubber

2011 ◽  
Vol 335-336 ◽  
pp. 120-123 ◽  
Author(s):  
Chang Su ◽  
Pan He ◽  
Li Huan Xu ◽  
Cheng Zhang
Keyword(s):  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Peak Position ◽  
Butadiene Rubber ◽  
Reaction Products ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Nitrile Butadiene Rubber ◽  
Tan Δ ◽  
Damping Peak

In this article, the damping mechanism of organic hybrids consisting of Nitrile Butadiene Rubber (NBR) and phenolic oligomer 4-methyl-pheno reaction products of both dicyclopentadiene and isobutylene (MPDI) were investigated by dynamic mechanical analysis (DMA). It was shown that NBR/MPDI blends exhibit only one damping peak, which shifted to higher temperature with the increase of MPDI content, and the maximum of tan δ peak decreased slightly when the ratio of NBR/MPDI was no more than 100/20, and then increased when the ratio rised from 100/20 to 100/80. Fourier transform infrared spectrum (FT-IR) showed that the hydrogen bond were formed between -OH of MPDI and a-H of NBR. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements indicated that MPDI exhibit amorphous features, which was compatible with the blends. These may imply that much more stable damping material with both higher tan δ peak and controllable damping peak position can be achieved.

Chain Structure and Dynamic Mechanical Property of the Vinylidenefluoride and Chlorotrifluoroethylene Copolymers

2014 ◽  
Vol 1049-1050 ◽  
pp. 123-128
Author(s):  
Guo Ping Zeng ◽  
Chun Bo Yue ◽  
Ya Qing Weng ◽  
Ming Yu Wang ◽  
Heng Feng Li
Keyword(s):  
Mechanical Properties ◽  
Random Distribution ◽  
Dynamic Mechanical Properties ◽  
Chain Structure ◽  
Radical Copolymerization ◽  
Dynamic Mechanical Property ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dynamic Mechanical

A series of vinylidenefluoride (VDF) and chlorotrifluoroethylene (CTFE) copolymers were prepared by radical copolymerization, the chain elements structures of the copolymers were gain with the elemental analysis, and the crystal regions with X-ray diffraction spectrum. The effect of chain elements structure on the crystallinity and dynamic mechanical properties was discussed with the DMA analysis. The result shows: the increasing of the CTFE content decreases the chain elements structure of VDF-VDF, the random distribution of VDF-CTFE structure has a great effect on the crystallization properties and the dynamic mechanical properties. The increasing of CTFE content improves the storage modulus and the damping of copolymers in the amorphous copolymers, while the distribution of chain segments’ length gets narrower.

scholarly journals Effect of Phenolic Resin Oligomer Motion Ability on Energy Dissipation of Poly (Butyl Methacrylate)/Phenolic Resins Composites

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 490
Author(s):  
Xing Huang ◽  
Songbo Chen ◽  
Songhan Wan ◽  
Ben Niu ◽  
Xianru He ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrogen Bonding ◽  
Glass Transition ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Butyl Methacrylate ◽  
Scanning Calorimetry ◽  
Phenolic Resins ◽  
Dynamic Mechanical ◽  
The Matrix

Poly (butyl methacrylate) (PBMA) was blended with a series of phenolic resins (PR) to study the effect of PR molecular weight on dynamic mechanical properties of PBMA/PR composites. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) found a similar variation of glass transition temperature (Tg). The maximum loss peak (tanδmax) improved in all PBMA/PR blends compared with the pure PBMA. However, tanδmax reduced as the molecular weight increased. This is because PR with higher molecular weight is more rigid in the glass transition zone of blends. The hydrogen bonding between PBMA and PR was characterized by Fourier transform infrared spectroscopy (FTIR). Lower molecular weight PR formed more hydrogen bonds with the matrix and it had weaker temperature dependence. Combined with the results from DMA, we studied how molecular weight affected hydrogen bonding and thus further affected tanδmax.

scholarly journals Amino-Functionalized Lead Phthalocyanine-Modified Benzoxazine Resin: Curing Kinetics, Thermal, and Mechanical Properties

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1855 ◽  
Author(s):  
Li-wu Zu ◽  
Bao-chang Gao ◽  
Zhong-cheng Pan ◽  
Jun Wang ◽  
Abdul Qadeer Dayo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Dynamic Mechanical

Phenol-diaminodiphenylmethane-based benzoxazine (P-ddm)/phthalocyanine copolymer was prepared by using P-ddm resin as matrix and 3,10,17,24-tetra-aminoethoxy lead phthalocyanine (APbPc) as additive. Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA) were used to investigate the curing behavior, curing kinetics, dynamic mechanical properties, thermal stability, and impact strength of the prepared copolymers. The kinetic parameters for the P-ddm/APbPc blend curing processes were examined by utilizing the iso-conversional, Flynn–Wall–Ozawa, and Málek methods. The P-ddm/APbPc blends exhibit two typical curing processes, and DSC results confirmed that the blending of APbPc monomer can effectively reduce the curing temperature of P-ddm resin. The autocatalytic models also described the non-isothermal curing reaction rate well, and the appropriate kinetic parameters of the curing process were obtained. The DMA and impact strength experiments proved that the blending of APbPc monomer can significantly improve the toughness and stiffness of P-ddm resin, the highest enhancements were observed on 25 wt.% addition of APbPc, the recorded values for the storage modulus and impact strength were 1003 MPa and 3.60 kJ/m2 higher, respectively, while a decline of 24.6 °C was observed in the glass transition temperature values. TGA curves indicated that the cured copolymers also exhibit excellent thermal stabilities.

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