scholarly journals Roles of Small Polyetherimide Moieties on Thermal Stability and Fracture Toughness of Epoxy Blends

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3310
Author(s):  
Seul-Yi Lee ◽  
Min-Joo Kang ◽  
Seong-Hwang Kim ◽  
Kyong Yop Rhee ◽  
Jong-Hoon Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Polymer Networks ◽  
Strain Energy Release ◽  
Critical Stress Intensity Factor ◽  
Diglycidyl Ether ◽  
Interpenetrating Polymer Networks ◽  
Test Machine ◽  
Epoxy Blends

Bisphenol A diglycidyl ether (DGEBA) was blended with polyetherimide (PEI) as a thermoplastic toughener for thermal stability and mechanical properties as a function of PEI contents. The thermal stability and mechanical properties were investigated using a thermogravimetric analyzer (TGA) and a universal test machine, respectively. The TGA results indicate that PEI addition enhanced the thermal stability of the epoxy resins in terms of the integral procedural decomposition temperature (IPDT) and pyrolysis activation energy (Et). The IPDT and Et values of the DGEBA/PEI blends containing 2 wt% of PEI increased by 2% and 22%, respectively, compared to those of neat DGEBA. Moreover, the critical stress intensity factor and critical strain energy release rate for the DGEBA/PEI blends containing 2 wt% of PEI increased by 83% and 194%, respectively, compared to those of neat DGEBA. These results demonstrate that PEI plays a key role in enhancing the flexural strength and fracture toughness of epoxy blends. This can be attributed to the newly formed semi-interpenetrating polymer networks (semi-IPNs) composed of the epoxy network and linear PEI.

scholarly journals Thermal Properties and Fracture Toughness of Epoxy Nanocomposites Loaded with Hyperbranched-Polymers-Based Core/Shell Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 418 ◽  
Author(s):  
Aldobenedetto Zotti ◽  
Simona Zuppolini ◽  
Anna Borriello ◽  
Mauro Zarrelli
Keyword(s):  
Thermal Stability ◽  
Fracture Toughness ◽  
Thermal Properties ◽  
Strain Energy Release ◽  
Critical Stress Intensity Factor ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Maximum Increase ◽  
Core Diameter ◽  
Core Shell Nanoparticles

Synthesized silicon oxide (silica) nanoparticles were functionalized with a hyperbranched polymer (HBP) achieving a core/shell nanoparticles (CSNPs) morphology. CSNPs were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), and Thermogravimetric Analysis (TGA). A core diameter of about 250 nm with a 15 nm thick shell was revealed using TEM images. An aeronautical epoxy resin was loaded with the synthesized CSNPs at different percentages and thermal properties, such as thermal stability and dynamic mechanical properties, were investigated with the use of different techniques. Although the incorporation of 2.5 wt% of CSNPs induces a ~4 °C reduction of the hosting matrix glass transition temperature, a slight increase of the storage modulus of about ~10% was also measured. The Kissinger Method was employed in order to study the thermal stability of the nanocomposites; the degradation activation energies that resulted were higher for the sample loaded with low filler content with a maximum increase of both degradation step energies of about ~77% and ~20%, respectively. Finally, fracture toughness analysis revealed that both the critical stress intensity factor (KIC) and critical strain energy release rate (GIC) increased with the CSNPs content, reporting an increase of about 32% and 74%, respectively, for the higher filler loading.

Studies on Nanostructured Polyurethane/Clay Interpenetrating Polymer Networks

2005 ◽  
Vol 475-479 ◽  
pp. 1001-1004
Author(s):  
Ninglin Zhou ◽  
Xiao Xian Xia ◽  
Li Li ◽  
Shao Hua Wei ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Polymer Networks ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Interpenetrating Polymer Networks ◽  
Absorption Properties ◽  
Tensile Testing Machine ◽  
Swelling Agent ◽  
Silicate Layers ◽  
Polyurethane Matrix

A novel exfoliated polyurethane (PU)/clay Interpenetrating Polymer Networks (IPNs) nanocomposite has been synthesized with polyurethane and organoclay. MTPAC is used as swelling agent to treat Na-montmorillonite for forming organoclay. The results indicate that there is very good compatibility between organoclay and PU. Nanoscale silicate dispersion was analyzed by XRD. The mechanical properties of the nanocomposites have been measured by tensile testing machine. The nanocomposites show obviously improved physical and mechanical properties when compared with the pure polymer. Additionally, PU /MTPAC- clay shows lower water absorption properties than pure PU do. In addition, the reinforcing and intercalating mechanism of silicate layers in polyurethane matrix are discussed.

Effect of Cellulose Functionalization on Thermal and Mechanical Properties of Epoxy Resin

2017 ◽  
Vol 757 ◽  
pp. 62-67 ◽  
Author(s):  
Kritsanachai Leelachai ◽  
Supissara Ruksanak ◽  
Tarakol Hongkeab ◽  
Supakeat Kambutong ◽  
Raymond A. Pearson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Diglycidyl Ether ◽  
Cellulose Content ◽  
Thermal And Mechanical Properties ◽  
Chemical Surface ◽  
Pull Out ◽  
Fiber Bridging ◽  
Surface Modified ◽  
Modified Epoxy

In this study, diglycidyl ether of bisphenol A (DGEBA) cured cycloaliphatic polyamine was modified with functionalized celluloses for improved thermal and mechanical properties. Three different types of surface-modified cellulose, polyacrylamide-g-cellulose (PGC), aminopropoxysilane-g-cellulose (SGC), and carboxymethyl cellulose (CMC), were investigated and used as reinforcing agents in epoxy resins. The storage modulus of these modified epoxy systems was found to significantly increase with addition of cellulose fillers (up to 1 wt. % cellulose content). An improved fracture toughness (KIC) was also observed with increasing cellulose loading content with PGC and SGC. Among the surface-modified celluloses, epoxy modified with SGC was found to have the highest fracture toughness followed by PGC and CMC at 1.0 wt.% cellulose addition due to the chemical surface compatibility. The toughening mechanisms of the cellulose/epoxy composites, measured by scanning electron microscopy (SEM), revealed that fiber-debonding, fiber-bridging, and fiber-pull out were responsible for increased toughness.

Influence of Polyacrylate on the Compatibility in P(MMA/EA)/PU Semi-IPNs

2012 ◽  
Vol 627 ◽  
pp. 873-877
Author(s):  
Xiao Xia Jian ◽  
Le Qin Xiao ◽  
Wei Liang Zhou ◽  
Hai Qin Ding
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Polymer Networks ◽  
Thermoplastic Elastomer ◽  
Ethyl Acrylate ◽  
Interpenetrating Polymer Networks ◽  
Structure And Properties ◽  
Infrared Spectrometer ◽  
Nuclear Magnetic Resonance Spectrometry ◽  
Magnetic Resonance Spectrometry

The Semi-Interpenetrating Polymer Networks(Semi-IPNs) of poly(methyl methyacrylate/ethyl acrylate)(P(MMA/EA)) and polyurethane thermoplastic elastomer (PU) were synthesized by PU and copolymer of methyl methacrylate and ethyl acrylate to improve the compatibility of polymethyl methacrylate(PMMA) and PU Semi-IPNs . The structure and properties were investigated by Fourier transform infrared spectrometer, Solid nuclear magnetic resonance spectrometry, Dynamic mechanical thermal analysis and Mechanical properties. The tensile stress of (P(MMA/EA)/PU)( P(MMA/EA):PU=3:7) can get to 9.6MPa, the additional physical crosslinks and entanglement for Semi-IPNs are the reasons.

Sign in / Sign up

Export Citation Format

Share Document