scholarly journals Polyimide-Based Nanocomposites with Binary CeO2/Nanocarbon Fillers: Conjointly Enhanced Thermal and Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1952
Author(s):  
Alexandra L. Nikolaeva ◽  
Iosif V. Gofman ◽  
Alexander V. Yakimansky ◽  
Elena M. Ivan’kova ◽  
Ivan V. Abalov ◽  
...  

To design novel polymer materials with optimal properties relevant to industrial usage, it would seem logical to modify polymers with reportedly good functionality, such as polyimides (PIs). We have created a set of PI-based nanocomposites containing binary blends of CeO2 with carbon nanoparticles (nanocones/discs or nanofibres), to improve a number of functional characteristics of the PIs. The prime novelty of this study is in a search for a synergistic effect amidst the nanofiller moieties regarding the thermal and the mechanical properties of PIs. In this paper, we report on the structure, thermal, and mechanical characteristics of the PI-based nanocomposites with binary fillers. We have found that, with a certain composition, the functional performance of a material can be substantially improved. For example, a PI containing SO2-groups in its macrochains not only had its thermal stability enhanced (by ~20 °C, 10% weight loss up to 533 °C) but also had its stiffness increased by more than 10% (Young’s modulus as high as 2.9–3.0 GPa) in comparison with the matrix PI. In the case of a PI with no sulfonic groups, binary fillers increased stiffness of the polymer above its glass transition temperature, thereby widening its working temperature range. The mechanisms of these phenomena are discussed. Thus, this study could contribute to the design of new composite materials with controllable and improved functionality.

Author(s):  
M.O. Kaptakov

In this work, the mechanical properties of composite samples prepared using a conventional and nanomodified matrix were studied. The thickness of the monolayers in the samples was 0,2 μm. It was found in experiments, that the addition of fullerene soot as a nanomodifierled to an increase in the mechanical properties of the samples along the direction of reinforcement. At the same time, an improvement in the quality of the contact of the matrix with the fibers in the samples with the nanomodifier was observed: on the fracture surface, the nanomodified matrix envelops the fibers, while the usual matrix completely exfoliates. The obtained effects of changing the strength of composites can be associated, among other things, with a change in the level of residual stresses arising in composites during nanomodification. Analytical and numerical modeling methods are used to explain these effects.


1999 ◽  
Author(s):  
Y. Schmitt ◽  
C. Paulick ◽  
Y. Bour ◽  
F. X. Royer

Abstract The control of the quality of mixture based on very short carbon fibers and epoxyde resins leads to suitable mixture for molding of complex geometries. A gain in fluidity is obtained if the suspensions are treated by ultrasounds and simultaneously stirred under vacuum. Addition in a very small ratio of microbubbles in the mixture allows to obtain a viscosity less than those of the matrix alone. For many polymer materials the gain of fluidity can be of 20 to 25% with size and concentration of the microspheres thoroughly chosen. A certain number of new resins is developped to elaborate composite materials with specific mechanical properties close to standard aluminium. Tensile test an ultimate stress are used to quantify the improvements of the mechanical properties. Fillers concentrations up to 30 % are obtained.


RSC Advances ◽  
2019 ◽  
Vol 9 (61) ◽  
pp. 35532-35538 ◽  
Author(s):  
Dinghua Yu ◽  
Juan Zhao ◽  
Wenjuan Wang ◽  
Jingjie Qi ◽  
Yi Hu

With bio-based monoester of acrylated isosorbide as the comonomer, copolymerized poly(methyl methacrylate) showed improved thermal stability and mechanical properties.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3944 ◽  
Author(s):  
Zhen Gu ◽  
Zili Gao ◽  
Wenli Liu ◽  
Yongqiang Wen ◽  
Qi Gu

Natural tissues and organs have different requirements regarding the mechanical characteristics of response. It is still a challenge to achieve biomaterials with anisotropic mechanical properties using an extracellular matrix with biological activity. We have improved the ductility and modulus of the gelatin matrix using 3D printed gelatin microfibers with different concentrations and topologies and, at the same, time achieved anisotropic mechanical properties. We successfully printed flat microfibers using partially cross-linked gelatin. We modified the 10% (w/v) gelatin matrix with microfibers consisting of a gelatin concentration of 14% (w/v), increasing the modulus to about three times and the elongation at break by 39% in parallel with the fiber direction. At the same time, it is found that the microfiber topology can effectively change the matrix ductility, and changing the modulus of the gelatin used in the microfiber can effectively change the matrix modulus. These findings provide a simple method for obtaining active biological materials that are closer to a physiological environment.


2017 ◽  
Vol 30 (10) ◽  
pp. 1159-1168 ◽  
Author(s):  
Animesh Sinha ◽  
Nazrul Islam Khan ◽  
Subhankar Das ◽  
Jiawei Zhang ◽  
Sudipta Halder

The effect of reactive (polyethylene glycol) and non-reactive (toluene) diluents on thermal and mechanical properties (tensile strength, hardness and fracture toughness) of diglycidyl ether of bisphenol A epoxy resin (cured by triethylenetetramine) was investigated. The thermal stability and mechanical properties of the epoxy resin modified with reactive and non-reactive diluents at different wt% were investigated using thermo-gravimetric analyser, tensile test, hardness test and single-edge-notched bend test. A minor variation in thermal stability was observed for epoxy resin after addition of polyethylene glycol and toluene at 0.5 wt%; however, further addition of reactive and non-reactive diluents diminished the thermal stability. The addition of 10 wt% of polyethylene glycol in epoxy resin significantly enhances the tensile strength (∼12%), hardness (∼14%) and fracture toughness (∼24%) when compared to that of neat epoxy resin. In contrast, major drop in mechanical performance was observed after addition of toluene in epoxy. Furthermore, fracture surfaces were investigated under field emission scanning electron microscope to elucidate the failure mechanism.


e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Benghong Yang ◽  
Meng Li ◽  
Bangping Song ◽  
Yun Wu

AbstractA series of Inorganic/organic nanocomposites were prepared by blending cage-like carboxyl-bearing polyhedral oligomeric silsesquioxane (carboxyl-POSS) with polymethyl mathacrylate (PMMA) in THF solvent. FTIR and 29Si-NMR were employed to characterize the structures of the nanocomposites. SEM images showed that the as-prepared films were smooth and no aggregation of carboxyl-POSS was observed. TGA and DSC results showed that the incorporation of small amount of nanosize carboxyl-POSS enhanced the thermal stability of PMMA. When 1.0 wt% of carboxyl-POSS was incorporated into PMMA matrix, the Tg and Td increased by 16.9 °C and 21.0 °C, respectively. However, higher POSS contents (>1.0 wt%) would deteriorate the thermal and mechanical properties of the nanocomposites.


2014 ◽  
Vol 783-786 ◽  
pp. 1692-1697
Author(s):  
Je Deok Kim ◽  
Mun Suk Jun

Nafion-azole (benzimidazole, 1,2,4-triazole, 1,2,3-triazole) composite membranes were prepared by room temperature and autoclave solution processing for high temperature (above 100 °C) PEMFC. Among the various Nafion – azole composite membranes, Nafion – 1,2,3-triazole membrane showed excellent flexibility, thermal stability, and homogeneous structure. Nafion – 1,2,4-triazole composite membrane had high thermal and mechanical properties, and also showed high proton conductivity of 0.02 S/cm at the temperature of 160 °C under dry (N2) condition.


2013 ◽  
Vol 430 ◽  
pp. 222-229 ◽  
Author(s):  
Oana Suciu ◽  
Teodora Ioanovici ◽  
Liviu Bereteu

Hydroxyapatite is a biomaterial, more exactly a bioceramic, from a category of materials frequently used in bone implants. In order to improve mechanical properties, hydroxyapatite is doped with different chemical substitutes, among which the most used are: Mg2*, Zn 2*, La3*, Y3*, In3* Bi3* CO32-, Si and Mn. In the paper are presented the modality of obtaining hydroxyapatite doped with magnesium through wet precipitation method and also the determination of its main mechanical characteristics. There is also an analysis on the effects of magnesium on the following mechanical properties: density, hardness, longitudinal modulus of elasticity, conductibility and thermal stability.


Sign in / Sign up

Export Citation Format

Share Document