scholarly journals Thermal Stability and Dynamic Mechanical Properties of Poly(ε-caprolactone)/Chitosan Composite Membranes

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5538
Author(s):  
Yanbo Zhang ◽  
Yaqi Wu ◽  
Ming Yang ◽  
Gang Zhang ◽  
Haiyan Ju
Keyword(s):  
Thermal Stability ◽  
Tissue Engineering ◽  
Composite Membranes ◽  
Dynamic Mechanical Properties ◽  
Decomposition Temperature ◽  
Scanning Calorimetry ◽  
Engineering Applications ◽  
Thermal Stabilities ◽  
Blend Ratio ◽  
Dynamic Mechanical

Poly (ε-caprolactone) (PCL) and chitosan (CS) are widely used as biodegradable and biocompatible polymers with desirable properties for tissue engineering applications. Composite membranes (CS–PCL) with various blend ratios (CS:PCL, w/w) of 0:100, 5:95, 10:90, 15:85, 20:80, and 100:0 were successfully prepared by lyophilization. The thermal stabilities of the CS–PCL membranes were systematically characterized by thermogravimetric analysis (TG), dynamic thermogravimetry (DTG), and differential scanning calorimetry (DSC). It was shown that the blend ratio of PCL and CS had a significant effect on the thermal stability, hydrophilicity, and dynamic mechanical viscoelasticity of the CS–PCL membranes. All the samples in the experimental range exhibited high elasticity at low temperature and high viscosity at high temperatures by dynamic mechanical thermal analysis (DMTA). The performances of the CS–PCL membranes were at optimum levels when the blend ratio (w/w) was 10:90. The glass transition temperature of the CS–PCL membranes increased from 64.8 °C to 76.6 °C compared to that of the pure PCL, and the initial thermal decomposition temperature reached 86.7 °C. The crystallinity and porosity went up to 29.97% and 85.61%, respectively, while the tensile strength and elongation at the breakage were 20.036 MPa and 198.72%, respectively. Therefore, the 10:90 (w/w) blend ratio of CS/PCL is recommended to prepare CS–PCL membranes for tissue engineering applications.

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.

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.

Thermal and dynamic mechanical analysis of hybrid jute/sisal fibre reinforced epoxy composite

2016 ◽  
Vol 232 (9) ◽  
pp. 743-748 ◽  
Author(s):  
MK Gupta
Keyword(s):  
Thermal Properties ◽  
Storage Modulus ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Decomposition Temperature ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Sisal Fibre ◽  
Dynamic Mechanical

The aim of the present study is to investigate the dynamic mechanical and thermal properties of hybrid jute/sisal fibre reinforced epoxy composites. The hybrid composites were prepared by hand layup technique having total fibre loading of 30% by weight with different weight ratios of jute and sisal fibres. Dynamic mechanical properties such as storage modulus ([Formula: see text]), loss modulus ([Formula: see text]) and damping ([Formula: see text]) were investigated in the temperature range of 30–200 ℃. The thermal stability of the prepared composites was studied using thermogravimetric analysis. Other thermal properties such as glass transition temperature ( Tg), crystallization temperature ( Tc) and decomposition temperature ( Td) were also obtained by differential scanning calorimetry. The results indicated a positive effect of hybridization in terms of increase in dynamic mechanical and thermal properties. Storage modulus, loss modulus and Tg were found to be higher for hybrid composite having a higher percentage of jute fibres.

Dynamic Mechanical Properties of Epoxy Resin with Multifunctional Polyamine Curing Agent

2015 ◽  
Vol 744-746 ◽  
pp. 1374-1377
Author(s):  
Xi Wang
Keyword(s):  
Thermal Stability ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Diglycidyl Ether ◽  
Curing Agent ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Dynamic Mechanical ◽  
Glass Relaxation ◽  
Thermal Stability Of

A nonlinear multifunctional polyamine N,N,N’,N’-tetra (3-aminopropyl)-1,6-diamino-hexane (TADH), was prepared and employed as a novel hardener for diglycidyl ether of bisphenol A (DGEBA). Nonisothermal reactions of DGEBA/TADH were systematically investigated with differential scanning calorimetry (DSC). In addition, analysis of thermal stability of the cured DGEBA/TADH with thermogravimetric analysis (TGA) revealed that it possessed quite good thermal stability and increased residual char content at 600◦C in nitrogen. Furthermore, dynamic mechanical analysis (DMA) of the DGEBA/TADH network showed its relaxations were characterized by localized motions of hydroxyl ether segments and cooperative motions of whole network chains (glass relaxation) at different temperature regions.

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 Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 700
Author(s):  
Muhamad Hasfanizam Mat Yazik ◽  
Mohamed Thariq Hameed Sultan ◽  
Mohammad Jawaid ◽  
Abd Rahim Abu Talib ◽  
Norkhairunnisa Mazlan ◽  
...  
Keyword(s):  
Shape Memory ◽  
High Performance ◽  
Loss Modulus ◽  
Decomposition Temperature ◽  
Hybrid Nanocomposites ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
Tan Δ

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

Synthesis and properties of phthalonitrile-based resins containing spirocycle acetal

2020 ◽  
pp. 095400832097759
Author(s):  
Ke Li ◽  
Hua Yin ◽  
Kun Yang ◽  
Pei Dai ◽  
Ling Han ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Room Temperature ◽  
Laser Desorption Ionization ◽  
Scanning Calorimetry ◽  
Rheological Analysis ◽  
Ionization Time ◽  
Dynamic Mechanical ◽  
Nmr Spectrometry ◽  
Current Context

Designing novel low-melting, high-rigidity phthalonitrile resin is of great significance in the current context of development. In this study, rigid spirocycle acetal structure was introduced into phthalonitrile to reduce the melting point and maintain their thermal stability. The chemical structure of resins was confirmed by nuclear magnetic resonance (NMR) spectrometry, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The curing behaviors were studied by differential scanning calorimetry (DSC). Thermal stability and mechanical properties of the cured resins were investigated by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The processability was studied by rheological analysis. The results indicated the three monomers had a low melting temperature, wide processing windows and low viscosities. These polymers did not exhibit Tg from room temperature to 400°C, exhibited superb dynamic mechanical property and thermal stability.

scholarly journals A Characteristic Study of Polylactic Acid/Organic Modified Montmorillonite (PLA/OMMT) Nanocomposite Materials after Hydrolyzing

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 376
Author(s):  
Su-Mei Huang ◽  
Jiunn-Jer Hwang ◽  
Hsin-Jiant Liu ◽  
An-Miao Zheng
Keyword(s):  
Thermal Stability ◽  
Polylactic Acid ◽  
Decomposition Temperature ◽  
Material Strength ◽  
Scanning Calorimetry ◽  
Hydrolysis Process ◽  
Twin Screw ◽  
Thermal Pressing ◽  
Organophilic Clay ◽  
Mmt Clay

In this study, the montmorillonite (MMT) clay was modified with NH4Cl, and then the structures were exfoliated or intercalated in a polylactic acid (PLA) matrix by a torque rheometer in the ratio of 0.5, 3.0, 5.0 and 8.0 wt%. X-ray diffraction (XRD) revealed that the organic modified-MMT(OMMT) was distributed successfully in the PLA matrix. After thermal pressing, the thermal stability of the mixed composites was measured by a TGA. The mixed composites were also blended with OMMT by a co-rotating twin screw extruder palletizing system, and then injected for the ASTM-D638 standard specimen by an injection machine for measuring the material strength by MTS. The experimental results showed that the mixture of organophilic clay and PLA would enhance the thermal stability. In the PLA mixed with 3 wt% OMMT nanocomposite, the TGA maximum decomposition temperature (Tmax) rose from 336.84 °C to 339.08 °C. In the PLA mixed with 5 wt% OMMT nanocomposite, the loss of temperature rose from 325.14 °C to 326.48 °C. In addition, the elongation rate increased from 4.46% to 10.19% with the maximum loading of 58 MPa. After the vibrating hydrolysis process, the PLA/OMMT nanocomposite was degraded through the measurement of differential scanning calorimetry (DSC) and its Tg, Tc, and Tm1 declined.

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.

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