scholarly journals Thermal Mechanical Properties of Graphene Nano-Composites with Kevlar-Nomex Copolymer: A Comparison of the Physical and Chemical Interactions

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2740 ◽  
Author(s):  
Jessy Shiju ◽  
Fakhreia Al-Sagheer ◽  
Zahoor Ahmad
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Composite Films ◽  
Nano Composites ◽  
Electron Microscopies ◽  
Atomic Force ◽  
The Matrix ◽  
Physical And Chemical ◽  
And Storage

This paper reports the preparation of Kevlar-Nomex copolymer nano-composites with exfoliated pristine and functionalized graphene sheets (Grs). The graphene oxide (GrO) platelets were amidized by the reaction of amine-terminated aramid (Ar) with the functional groups present on the GrO surface to prepare the nano-composites films with different loadings of GrO. Chemical changes involved during the oxidation and subsequent amidation were monitored by Raman, FTIR and XP spectroscopic analyses. Morphology of the composite films was studied by atomic force and scanning electron microscopies. Viscoelastic properties of the hybrid films were studied for their glass transition temperature (Tg) and storage modulus by dynamical mechanical thermal analysis (DMTA). A higher shift in glass transition temperature was obtained by chemically binding the aramid copolymer chains on the functionalized Gr sheets. The increase in tensile strength and modulus at various loadings of GrO are compared with the composites using pristine Gr. The effect of interfacial interactions between the matrix chains and the reinforcement on the properties of these hybrids have been explained.

scholarly journals On the Combined Effect of Both the Reinforcement and a Waste Based Interfacial Modifier on the Matrix Glass Transition in iPP/a-PP-pPBMA/Mica Composites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2606
Author(s):  
Jesús-María García-Martínez ◽  
Emilia P. Collar
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Atactic Polypropylene ◽  
Complex Character ◽  
The Matrix ◽  
Maleamic Acid ◽  
Interfacial Modifier ◽  
Key Parameter

This work deals with the changes of the glass transition temperature (Tg) of the polymer in polypropylene/mica composites due to the combined and synergistic effect of the reinforcement and the interfacial modifier. In our case, we studied the effect on Tg of platy mica and an interfacial modifier with p-phenylen-bis-maleamic acid (pPBMA) grafted groups onto atactic polypropylene (aPP-pPBMA). This one contains 5.0 × 10−4 g·mol−1 (15% w/w) grafted pPBMA and was previously obtained by the author’s labs by using industrial polymerization wastes (aPP). The objective of the article must be perceived as two-fold. On one hand, the determination of the changes in the glass transition temperature of the isotactic polypropylene phase (iPP) due to both the reinforcement and the agent as determined form the damp factor in DMA analysis. On the other hand, forecasting the variation of this parameter (Tg) as a function of both the interfacial agent and reinforcement content. For such purposes, and by assuming the complex character of the iPP/aPP-pPBMA/Mica system, wherein interaction between the components will define the final behaviour, a Box–Wilson experimental design considering the amount of mica particles and of interface agent as the independent variables, and the Tg as the dependent one, has been used. By taking in mind that the glass transition is a design threshold for the ultimate properties of parts based in this type of organic–inorganic hybrid materials, the final purpose of the work is the prediction and interpretation of the effect of both variables on this key parameter.

PREPARATION AND PROPERTIES OF A NOVEL EPOXIDIZED CASTOR OIL/CLAY NANOCOMPOSITES

2004 ◽  
Vol 03 (04n05) ◽  
pp. 663-669 ◽  
Author(s):  
S.-J. PARK ◽  
F.-L. JIN ◽  
J.-R. LEE
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mechanical Analysis ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tearing Energy ◽  
And Storage ◽  
Epoxidized Castor Oil

A novel nanocomposites of modified clay in a glassy epoxy were prepared using a direct melt intercalation technique. The contents of oganoclay were varied with 0, 1, 2, and 3 wt% and N-benzylpyrazinium hexafluoroantimonate (BPH) was used for curing of epoxy matrix as a cationic latent catalyst. Dynamic mechanical analysis (DMA) measurement was performed to examine the glass transition temperature of the nanocomposites. As a result, X-ray diffraction indicated the intercalation of the epoxy chains happening inside the gallery of clay. The nanocomposites showed a higher glass transition temperature and storage modulus than those of the pristine epoxy. The mechanical interfacial properties of the nanocomposites were also investigated and the improvement in tearing energy of 160% over pristine epoxy was obtained.

INFLUENCE OF MULTIPLE CURING ON MECHANICAL PROPERTIES OF EPOXY MATRIX AND ITS ADHESION TO FIBERS

2021 ◽  
pp. 12-19
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mechanical Behavior ◽  
Adhesive Strength ◽  
Epoxy Matrix ◽  
Steel Wire ◽  
Curing Temperature ◽  
The Matrix

Adhesive strength of «epoxy binder-steel wire» joints and the mechanical behavior of the binder during multiple repeated curing have been investigated. It is shown that when the curing temperature is considerably higher than the glass transition temperature of the binder, the adhesive strength decreases monotonically with an increase in the number of curing cycles. In this case the mechanical properties of the matrix also decrease. Possible mechanisms of the observed changes are discussed.

Vinylpyridinium ionomers. III. Influence of the matrix glass transition temperature on the dynamic mechanical properties of random acrylate-based systems

1990 ◽  
Vol 68 (7) ◽  
pp. 1228-1232 ◽  
Author(s):  
Denis Duchesne ◽  
Adi Eisenberg
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Butyl Acrylate ◽  
Matrix Material ◽  
Ethyl Acrylate ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
The Matrix

The thermal and dynamic mechanical properties of random butyl acrylate- and plasticized ethyl acrylate-based vinylpyridinium ionomers have been investigated. The properties of the ionomers were found to be dependent on the glass transition temperature of the matrix material. Ionomers having a glass transition temperature lower than ca. 25 °C exhibited all the features associated with the presence of phase-separated microdomains or clusters while the materials with higher glass transition temperatures were not. It was also observed that the dispersion associated with the vinylpyridinium clusters for a butyl acrylate-based ionomer with 12 mol% of ionic units occurs at ca. 25 °C. This value is very close to that observed previously by Otocka and Eirich in their study of a butadiene-based vinylpyridinium ionomer with the same ion content. Keywords: ionomers, plasticization, clustering, glass transition, dynamic mechanical properties.

Silica-Polymer Core-Shell Particles for Fabrication of Poly(methyl methacrylate) Composite Materials

2012 ◽  
Vol 531 ◽  
pp. 153-156
Author(s):  
Ren Gui Peng ◽  
Cheng En He ◽  
Wei Tang ◽  
Yue E Liu ◽  
Ying Kui Yang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Composite Materials ◽  
Glass Transition Temperature ◽  
Methyl Methacrylate ◽  
Interfacial Adhesion ◽  
Core Shell ◽  
Poly Methyl Methacrylate ◽  
The Matrix ◽  
Shell Particles

Poly(n-butyl acrylate) grafted silica nanoparticles were compounded with poly(methyl methacrylate) to yield silica/polymer composites with the improved dispersion of silica and interfacial adhesion with the matrix, thus showing increases in storage modulus and glass transition temperature.

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