scholarly journals Characteristics of Thermosetting Polymer Nanocomposites: Siloxane-Imide-Containing Benzoxazine with Silsesquioxane Epoxy Resins

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2510
Author(s):  
Chih-Hao Lin ◽  
Wen-Bin Chen ◽  
Wha-Tzong Whang ◽  
Chun-Hua Chen
Keyword(s):  
Thermal Expansion ◽  
Storage Modulus ◽  
Polymer Nanocomposites ◽  
Epoxy Resins ◽  
Coefficient Of Thermal Expansion ◽  
Dynamic Mechanical ◽  
Double Decker ◽  
The Matrix ◽  
Thermosetting Polymer ◽  
Oligomeric Silsesquioxane

A series of innovative thermosetting polymer nanocomposites comprising of polysiloxane-imide-containing benzoxazine (PSiBZ) as the matrix and double-decker silsesquioxane (DDSQ) epoxy or polyhedral oligomeric silsesquioxane (POSS) epoxy were prepared for improving thermosetting performance. Thermomechanical and dynamic mechanical characterizations indicated that both DDSQ and POSS could effectively lower the coefficient of thermal expansion by up to approximately 34% and considerably increase the storage modulus (up to 183%). Therefore, DDSQ and POSS are promising materials for low-stress encapsulation for electronic packaging applications.

Thermal expansion and dynamic mechanical analysis of epoxy matrix–borosilicate glass hollow particle syntactic foams

2017 ◽  
Vol 54 (3) ◽  
pp. 463-481 ◽  
Author(s):  
Steven Eric Zeltmann ◽  
Brian Chen ◽  
Nikhil Gupta
Keyword(s):  
Thermal Expansion ◽  
Dynamic Mechanical Analysis ◽  
Borosilicate Glass ◽  
Coefficient Of Thermal Expansion ◽  
Hollow Microsphere ◽  
Mechanical Analysis ◽  
Syntactic Foams ◽  
Matrix Resin ◽  
Dynamic Mechanical ◽  
The Matrix

Syntactic foams are commonly fabricated with sodalime–borosilicate glass hollow microsphere fillers, which are susceptible to degradation after long-term or high temperature moisture exposure. In comparison, borosilicate glass hollow particles offer higher degradation resistance to moisture, lower thermal expansion, and higher softening temperature. This work explores borosilicate glass hollow microspheres for use as fillers in syntactic foams and studies their thermophysical properties. The coefficient of thermal expansion over the temperature range 35–90℃ was observed to decrease from 62.4 μ/K for the matrix resin to a minimum of 24.3 μ/K for syntactic foams, representing higher thermophysical stability of syntactic foams. Theoretical models are used to conduct parametric studies and understand the correlation between material parameters and coefficient of thermal expansion of syntactic foams. The dynamic mechanical analysis results show that the storage modulus of syntactic foams increases with increasing glass hollow microsphere wall thickness and with decreasing glass hollow microsphere volume fraction in the glassy region at 40℃. The β-relaxation of the matrix resin found at 66.1 ± 2.0℃ was suppressed in the majority of syntactic foams, further improving the stability around typical application temperatures.

scholarly journals Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 125
Author(s):  
Seyed Kiomars Moheimani ◽  
Mehran Dadkhah ◽  
Mohammad Hossein Mosallanejad ◽  
Abdollah Saboori
Keyword(s):  
Thermal Expansion ◽  
Mechanical Strength ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Structural Effect ◽  
Metal Matrix Nanocomposites ◽  
Mechanical Stirring ◽  
Specific Strength ◽  
The Matrix ◽  
Matrix Nanocomposites

Metal matrix nanocomposites (MMNCs) with high specific strength have been of interest for numerous researchers. In the current study, Mg matrix nanocomposites reinforced with AlN nanoparticles were produced using the mechanical stirring-assisted casting method. Microstructure, hardness, physical, thermal and electrical properties of the produced composites were characterized in this work. According to the microstructural evaluations, the ceramic nanoparticles were uniformly dispersed within the matrix by applying a mechanical stirring. At higher AlN contents, however, some agglomerates were observed as a consequence of a particle-pushing mechanism during the solidification. Microhardness results showed a slight improvement in the mechanical strength of the nanocomposites following the addition of AlN nanoparticles. Interestingly, nanocomposite samples were featured with higher electrical and thermal conductivities, which can be attributed to the structural effect of nanoparticles within the matrix. Moreover, thermal expansion analysis of the nanocomposites indicated that the presence of nanoparticles lowered the Coefficient of Thermal Expansion (CTE) in the case of nanocomposites. All in all, this combination of properties, including high mechanical strength, thermal and electrical conductivity, together with low CTE, make these new nanocomposites very promising materials for electro packaging applications.

Thermal Shrinkage Behavior of Battery Separator

2018 ◽  
Author(s):  
Shutian Yan ◽  
Jie Deng ◽  
Chulheung Bae ◽  
Xinran Xiao
Keyword(s):  
Thermal Expansion ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Porous Membrane ◽  
Thermal Shrinkage ◽  
Dynamic Mechanical Analyzer ◽  
Free Standing ◽  
Dynamic Mechanical ◽  
Battery Separator ◽  
Shrinkage Behavior

Battery separators are thin, porous membrane of 20∼30 microns thickness. Polymer separators display a significant amount of shrinkage at elevated temperatures. It is difficult to quantitatively characterize the large shrinkage behavior with a free standing separator sample. This paper examines the use of a dynamic mechanical analyzer under tensile mode in measuring the coefficient of thermal expansion (CTE) of three commonly used separators.

scholarly journals Effects of added SiO2 nanoparticles on the thermal expansion behavior of shape memory polymer nanocomposites

2018 ◽  
Vol 30 (1) ◽  
pp. 32-44 ◽  
Author(s):  
Mohammad Javad Mahmoodi ◽  
Mohammad Kazem Hassanzadeh-Aghdam ◽  
Reza Ansari
Keyword(s):  
Thermal Expansion ◽  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Shape Memory Polymer ◽  
Polymer Nanocomposite ◽  
Thermal Expansion Behavior ◽  
Interphase Region ◽  
Expansion Behavior

In this study, a unit cell–based micromechanical approach is proposed to analyze the coefficient of thermal expansion of shape memory polymer nanocomposites containing SiO2 nanoparticles. The interphase region created due to the interaction between the SiO2 nanoparticles and shape memory polymer is modeled as the third phase in the nanocomposite representative volume element. The influences of the temperature, volume fraction, and diameter of the SiO2 nanoparticles on the thermal expansion behavior of shape memory polymer nanocomposite are explored. It is observed that the coefficient of thermal expansion of shape memory polymer nanocomposite decreases with the increase in the volume fraction up to 12%. Also, the results reveal that with the increase in temperature, the shape memory polymer nanocomposite coefficient of thermal expansion linearly increases. The role of interphase region on the thermal expansion response of the shape memory polymer nanocomposite is found to be very important. In the presence of interphase, the reduction in nanoparticle diameter leads to lower coefficient of thermal expansion for shape memory polymer nanocomposite, while the variation of nanoparticles diameter does not affect the coefficient of thermal expansion in the absence of interphase. Based on the simulation results, the shape memory polymer nanocomposite coefficient of thermal expansion decreases as the interphase thickness increases. In addition, the contribution of interphase coefficient of thermal expansion to the shape memory polymer nanocomposite coefficient of thermal expansion is more significant than that of interphase elastic modulus.

Development of nanocomposite coatings with improved mechanical, thermal, and corrosion protection properties

2017 ◽  
Vol 52 (8) ◽  
pp. 1045-1060 ◽  
Author(s):  
Majid TabkhPaz ◽  
Dong-Yeob Park ◽  
Patrick C Lee ◽  
Ron Hugo ◽  
Simon S Park
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Composite Coatings ◽  
Scratch Resistance ◽  
Gas Permeation ◽  
Graphene Nanoplatelets ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this study, new composite coatings are fabricated and investigated for their applications as the metal coating. The studied coatings consist of two-layered composites with various nanoparticulates as fillers in a polymeric matrix (styrene acrylic). The first layer bonded to the steel plate uses a combination of zinc particles, multi-walled carbon nanotubes, and graphene nanoplatelets. For the second layer, hexagonal boron nitride with high electrical insulation properties is added to the matrix. The morphology of the nanoparticulates is conducted using a scanning electron microscope. The coefficient of thermal expansion, cathodic disbondment resistance, gas penetration, and scratch resistance of the coatings are evaluated. The corroded area on the cathodic disbondment test specimens reduced down up to 90% for the composite with zinc (20 wt%), multi-walled carbon nanotubes (2 wt%), and graphene nanoplatelets (2 wt%), compared to a specimen coated with a pure polymer. It is seen that the presence of nanoparticulates decreased gas permeation and thermal expansion of the matrix by 75% and 65%, respectively. The addition of nanoparticulates also enhanced scratch resistance of the coating composites.

Design and study on the tailorable directional thermal expansion of dual-material planar metamaterial

2019 ◽  
Vol 234 (3) ◽  
pp. 837-846
Author(s):  
Rui Yang ◽  
Qing Yang ◽  
Bin Niu
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Rectangular Lattice ◽  
Design Calculation ◽  
Theoretical Derivation ◽  
Rectangular Cell ◽  
Lattice Materials ◽  
The Matrix ◽  
Simulation And Experiment ◽  
Dual Material

Current studies on tailoring the coefficient of thermal expansion of metamaterials focused on either complex bending-dominated lattice or the stretching-dominated lattice which transforms the spaces of triangle and tetrahedron. This paper proposes a kind of dual-material rectangular cell of tailorable thermal expansion, which reduces the complexities of design, calculation, and manufacture of lattice materials. The theoretical derivation using the matrix displacement method is adopted to study the thermal expansion properties of rectangular cell in the direction of height, the analytical expressions of coefficient of thermal expansion and optimization model are used to design the sizes of rectangular cell, and experimental verification is carried out. It is found that the middle cell of lattice had the same thermal expansion law as that of the unit cell. The rectangular cells of negative coefficient of thermal expansion −7 ppm/℃, zero coefficient of thermal expansion, and large positive coefficient of thermal expansion 36.2 ppm/℃ in the direction of height were realized, respectively. The consistency of theory, simulation, and experiment verifies that rectangular lattice material made of two kinds of common materials with a different coefficient of thermal expansions can achieve the design of coefficient of thermal expansion in the direction of height by choosing different material distribution and geometric parameters.

DYNAMIC MECHANICAL PROPERTIES OF NANOCOMPOSITES WITH POLY (VINYL BUTYRAL) MATRIX

2010 ◽  
Vol 24 (06n07) ◽  
pp. 805-812 ◽  
Author(s):  
A. M. TORKI ◽  
I. ŽIVKOVIĆ ◽  
V. R. RADMILOVIĆ ◽  
D. B. STOJANOVIĆ ◽  
V. J. RADOJEVIĆ ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Dynamic Mechanical Properties ◽  
Titania Nanoparticles ◽  
Mixing Process ◽  
Melt Mixing ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
Silica And Titania ◽  
Vinyl Butyral

This work reports the preparation of SiO 2 and TiO 2/poly (vinyl butyral) nanocomposites with enhanced dynamic mechanical properties. Silica and titania nanoparticles were introduced in the matrix as the neat powder and as colloidal sol using the melt mixing process. Composites reinforced with colloidal sol silica and titania showed higher mechanical properties than the ones reinforced with as-received particles. When sol TiO 2 particles are used, the highest increase of storage modulus of about 54% is obtained for 5 wt% loading, while for sol SiO 2, the storage modulus increases with the addition of nanosilica with the largest increase of about 99% for 7 wt% loading. In addition, nanocomposites were introduced within Kevlar/PVB composites. The addition of 5 wt% silica and titania colloidal sol lead to the remarkable increase of the storage modulus for about 98 and 65%, respectively. Largest contribution of nanoreinforcements in lowering the glass transition temperature is observed for 7 wt% loading of TiO 2 and SiO 2 colloidal sol.

Microstructure Modeling for Prediction of Thermal Expansion Coefficient of Plain Weave C/SiC Considering Manufacturing Porosities

2011 ◽  
Vol 399-401 ◽  
pp. 315-319 ◽  
Author(s):  
Sheng Li Lv ◽  
Qing Na Zeng ◽  
Lei Jiang Yao ◽  
Xiao Yan Tong
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Fibre Bundles ◽  
Plain Weave ◽  
Microstructure Modeling ◽  
Crack Volume ◽  
The Matrix

The aim of this paper is to propose a microstructure modeling for prediction of thermal conductivity of plain weave C/SiC fibre bundles considering manufacturing flaws. Utilizing photomicrographs taken by scanning electron microscope (SEM), we established an accurate sub representative volume element (sub-RVE) model for carbon fiber bundles and RVE for the plain weave C/SiC composite with consideration of four classes of manufacturing porosity. The thermal expansion coefficient of carbon fibre bundles on axial and transverse coefficient of thermal expansion is calculated, respectively. Based on which thermal expansion coefficient of plain weave C/SiC is obtained with the value of 2.71×10-6 in-plain, which has a good correlation with experimental value. The influences of different manufacturing flaws on material’s thermal expansion coefficient are studied. The study shows that as the matrix porosity or crack volume fraction is increasing, thermal expansion coefficient of plain weave C/SiC is decreasing correspondingly while the speed gradually slows.

Coefficient of Thermal Expansion Measurement of Metal Matrix Composites by Thermo Mechanical Analyser

2011 ◽  
Vol 264-265 ◽  
pp. 663-668 ◽  
Author(s):  
B. Karthikeyan ◽  
S. Ramanathan ◽  
V. Ramakrishnan
Keyword(s):  
Thermal Expansion ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Stir Casting ◽  
Matrix Composites ◽  
Aerospace Materials ◽  
Casting Technique ◽  
Actual Use ◽  
The Matrix

The demand of today’s and future spacecrafts for a stable platform for critical payloads is the driving force behind the coefficient of thermal expansion (CTE) measurement of different aerospace materials. The CTE of a composite is different from that given by a simple rule of mixtures. This is because of the presence of reinforcement. The expansion coefficient of reinforcement is less than that of the matrix which introduces a mechanical constraint on the matrix. The degree of constraint is also dependent on the nature of the reinforcement. It is important to point out that interface can exert some influence on the value of CTE, especially for very small particle size. In addition to the interface, the CTE of particle reinforced metal matrix composites (MMCs) is affected by several other factors. To cater the needs of various requirements in a spacecraft making, a wide variety of materials are used. Besides, the indigenization efforts and development of new materials for space-use emphasizes the measurement of CTE before their actual use. Stir casting technique was used to fabricate composites containing Si Cp as reinforcements and special thermo physical properties of the material are found. CTE of the composites are measured by TMA. The experiments have been carried out in the temperature range -1400 C to 5750 C.

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