Rheology, morphology and mechanical properties of LLDPE/PS blends catalyzed by combined Lewis acids

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Yan-Long Liu ◽  
Li-Gang Yin ◽  
Zhuo Ke ◽  
Qiang Shi ◽  
Jing-Hua Yin
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Lewis Acids ◽  
Low Frequency ◽  
Complex Viscosity ◽  
Reactive Blending ◽  
Izod Impact ◽  
Rheological Experiments ◽  
And Storage

AbstractThe rheological, morphological and mechanical properties of LLDPE/PS blends with a combined catalyst, Me3SiCl and InCl3·4H2O, were studied in this work. The higher complex viscosity and storage modulus at low frequency were ascribed to the presence of graft copolymers, which were in situ formed during the mixing process. From the rheological experiments, the complex viscosity and storage modulus of reactive blends were higher than the physical blends. The dispersion of LLDPE particles of reactive blending becomes finer than that of physical blends, consistent with the rheological results. As a result of increased compatibility between LLDPE/PS, the mechanical properties of reactive blends show much higher tensile and Izod impact strength than those of physical blends.

scholarly journals Isothermal Crystallization and Rheology Properties of Isotactic Polypropylene/Bacterial Cellulose Composite

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1284 ◽  
Author(s):  
Bo Wang ◽  
Fu-hua Lin ◽  
Xiang-yang Li ◽  
Zhong-wei Zhang ◽  
Xiao-rong Xue ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Storage Modulus ◽  
Isotactic Polypropylene ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Complex Viscosity ◽  
Isothermal Crystallization Kinetics ◽  
Interfacial Compatibility ◽  
And Storage ◽  
Better Than

Bacterial cellulose (BC) is a new kind of cellulose with great potential in enhancing preparation of isotactic Polypropylene (iPP) composites, which have been found with excellent performance. However, the interface compatibility between BC and iPP is poor. In this study, iPP/BC composites were prepared by solution mixing. Esterification modified BC (CO) and Maleic anhydride grafted polypropylene (MAPP) added as a compatibilizer was both used to improve the interfacial compatibility of the iPP/BC composites. The rheology and isothermal crystallization behavior of the composites was tested and discussed. The result shows that the complex viscosity and storage modulus of the composite significantly increase in the rule iPP, iPP/BC2, iPP/CO2, and M-iPP/BC3, which indicates that the compatibility of the composite increases as this rule. According to the isothermal crystallization kinetics result, the crystal growth mode of iPP was not affected by the addition of BC and the interfacial compatibility. The spherulite growth rate of the iPP/BC composite increases with increasing crystallization temperature. Especially, the value decreases as the same rule with the complex viscosity and storage modulus of the composite at the same isothermal crystallization temperature. These results suggest that the interface compatibility of iPP/BC composites is greatly improved and the interface compatibility of the M-iPP/BC3 is better than the iPP/CO2.

scholarly journals A method for pet mechanical properties enhancement

2019 ◽  
Vol 10 (8) ◽  
pp. 1725
Author(s):  
Raffaella Aversa ◽  
Relly Victoria Virgil Petrescu ◽  
Antonio Apicella ◽  
Florian Ion Tiberiu Petrescu
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Molecular Structures ◽  
Reactive Blending ◽  
Scanning Calorimetry ◽  
Shear Transfer ◽  
Crystalline Polymers ◽  
Reactive Compatibilizer

A method for PET mechanical properties enhancement by reactive blending with HBA/HNA Liquid Crystalline Polymers for in situ highly fibrillar composites preparation is presented. LCP/PET blends were reactively extruded in presence of Pyromellitic Di-Anhydride (PMDA) and then characterized by Differential Scanning Calorimetry, Thermally Stimulated Currents and tensile mechanical properties. Moderate amounts of LCP in the PET (0.5 and 5%) and small amounts of thermo-active and reactive compatibilizer in the blend (0.3%) were found to significantly improve LCP melt dispersion, melts shear transfer and LCP fibril formation and adhesion. An unexpected improvement was probably due to the presence of two distinct phases’ supra-molecular structures involving PET-LCP and PMDA.

scholarly journals Melanocyte pigmentation stiffens murine cardiac tricuspid valve leaflet

2009 ◽  
Vol 6 (40) ◽  
pp. 1097-1102 ◽  
Author(s):  
Kantesh Balani ◽  
Flavia C. Brito ◽  
Lidia Kos ◽  
Arvind Agarwal
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Tricuspid Valve ◽  
Viscoelastic Properties ◽  
Mechanical Analysis ◽  
Current Work ◽  
Valve Leaflet ◽  
Stiffness Measurement ◽  
Proper Functioning

Pigmentation of murine cardiac tricuspid valve leaflet is associated with melanocyte concentration, which affects its stiffness. Owing to its biological and viscoelastic nature, estimation of the in situ stiffness measurement becomes a challenging task. Therefore, quasi-static and nanodynamic mechanical analysis of the leaflets of the mouse tricuspid valve is performed in the current work. The mechanical properties along the leaflet vary with the degree of pigmentation. Pigmented regions of the valve leaflet that contain melanocytes displayed higher storage modulus (7–10 GPa) than non-pigmented areas (2.5–4 GPa). These results suggest that the presence of melanocytes affects the viscoelastic properties of the mouse atrioventricular valves and are important for their proper functioning in the organism.

Evaluating the Effect of Carbon Black—A Short Carbon Fiber Hybrid Filler on the Electro-Activated Shape Memory Cyanate Ester/Epoxy Composites

2020 ◽  
Vol 12 (5) ◽  
pp. 652-658 ◽  
Author(s):  
Yong-Kun Wang ◽  
Liang-Chao Wang ◽  
Yu-Ting Zhang ◽  
Jun-Jie Ye ◽  
Yang Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Carbon Black ◽  
Shape Memory ◽  
Storage Modulus ◽  
Synergistic Effects ◽  
Cyanate Ester ◽  
Short Carbon Fiber ◽  
And Storage ◽  
Short Carbon

An electro-activated type shape memory cyanate ester-epoxy (CE-EP) composites containing short carbon fiber (SCF) and carbon black (CB) were fabricated, where SCF linked among CB particles to make the superior conductivity network in compositions. In the compositions, the content of CB was fixed at 5 wt%, while the amount of SCF was ranged from 0 to 0.9 wt%. The synergistic effects of SCF and CB on the mechanical properties test, electrical properties, SEM, DMA and the electro-activated type shape memory experiment was reviewed. The outcomes showed that when the parts of SCF is less than 0.9%, the mechanical properties and storage modulus of required compositions expand with the content of the SCF growth. But, when the SCF content reaches 0.9 wt%, the flexural strength and storage modulus of the compositions decrease slightly. With the growth of SCF content, the glass transformation temperature increases from 89 °C to 103 °C and the resistivity of the composites decreases gradually. The resistivity of the composites is only 7.37 Ω/cm with 0.9 wt% of SCF. Further, the thermal response speed and shape convalescence rate of the compositions increase greatly with the growth of SCF content.

Synergistic effect of carbon nanotubes and nano-hydroxyapatite on mechanical properties of polyetheretherketone based hybrid nanocomposites

2020 ◽  
pp. 096739112096950
Author(s):  
Manjeet Kumar ◽  
Rajesh Kumar ◽  
Sandeep Kumar
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Elastic Modulus ◽  
Storage Modulus ◽  
Fracture Resistance ◽  
Compression Molding ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanocomposite ◽  
And Storage

Hybrid nanocomposites utilize the benefits of properties of different fillers to enhance its desired properties. Polyetheretherketone (PEEK) based hybrid nanocomposites have immense potential applications in aerospace, automobile, high-temperature electrical applications, and medical and health care. The present work is an attempt to improve the elastic modulus, hardness, fracture resistance, and storage modulus simultaneously by reinforcing the PEEK matrix with multiwall carbon nanotubes (MWCNTs) filler and 30 wt.% nano hydroxyapatite (nHA)-MWCNT hybrid filler. The nanocomposites having 0,1,3,5 and 7 wt.% of MWCNTs were fabricated by the Ball Mixing and Compression Molding Method. Customized Die Heater setup was used to ensure uniform heating and cooling during compression molding. The morphology was examined by Field Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive X-ray Spectroscopy (EDS) and uniform distribution of nano-fillers was observed. The nanoindentation method was adopted to investigate the Static Mechanical Analysis (SMA) and Dynamic Mechanical Analysis (DMA) at varying frequencies of loading, of nanocomposites. At 5 wt.% of MWCNTs, the enhancements in elastic modulus, hardness, fracture resistance, and storage modulus were observed to be 80%, 36%, 32%, and 58% respectively in case of PEEK/(0–7%)MWCNT nanocomposite and 104%, 76%, 16%, and 80% respectively in case of PEEK/30%nHA-(0–7%)MWCNT hybrid nanocomposite. The decrements in loss factor indicated the improvement in elastic behavior of nanocomposites with increasing wt.% of MWCNTs. The elastic modulus of PEEK/30%nHA-5%MWCNT hybrid nanocomposite was observed to be 7.67 GPa, which falls within the range of elastic modulus of the human cortical bone. The results revealed that 5 wt.% of MWCNTs is optimum filler composition for improving the mechanical properties.

scholarly journals Enhanced Physical and Mechanical Properties of Flake–Shape/Vinyl-ester Nanocomposites Through Surface Modification of Graphene and Glass Flake: A Comparison with Simulated Data

2020 ◽  
Vol 11 (4) ◽  
pp. 11316-11337
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Flexural Strength ◽  
Water Absorption ◽  
Storage Modulus ◽  
Vinyl Ester ◽  
Graphene Nanosheets ◽  
Analytical Data ◽  
Physical And Mechanical Properties ◽  
And Storage

: The main goal of this work was to investigate the effects of silane-modified graphene nanosheets (MGNS) and modified nanoglass flakes (MNGF) on the physical and mechanical properties of vinyl-ester resin (VER) composites. The surface modification was evaluated about these composites' physical and mechanical behavior by techniques such as water absorption, tensile, three-point bending, and dynamic mechanical thermal analysis (DMTA). The analytical data revealed that the silane functionalized nanocomposites improved the interface between the nanosheets and vinyl-ester matrix. It was found that surface modification could significantly improve the dispersion and adhesion of GNS and nanoglass flakes (NGF) compared with those of neat vinyl-ester and unmodified composites. The presence functionalization of NGF and graphene nanosheets (GNS) in vinyl-ester formulation did affect the tensile and flexural strength and modulus, water absorption, and storage modulus. GNS/VER exhibited higher tensile and flexural strength and modulus than the original composite. DMTA results also showed incorporation of NGF and GNS decreased glass transition and increased storage modulus relative to neat composites. Nonetheless, the incorporation of functionalized graphene nanosheets and nano glass flakes represent higher Tg and storage modulus.

Effect of single-walled carbon nanotube on the physical, rheological and mechanical properties of thermoplastic elastomer based on PP/EPDM

2014 ◽  
Vol 21 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Amir Narimani ◽  
Mahmood Hemmati
Keyword(s):  
Mechanical Properties ◽  
Tensile Modulus ◽  
Thermoplastic Elastomer ◽  
Complex Viscosity ◽  
Scanning Calorimetry ◽  
Low Frequencies ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Izod Impact ◽  
Walled Carbon Nanotubes

AbstractThe effect of the incorporation of single-walled carbon nanotubes (SWNT) on the morphological, physical, rheological and mechanical properties of thermoplastic elastomer based polypropylene (PP)/ethylene propylene diene (EPDM) (80/20) is reported. The morphological study showed that the size of the dispersed phase decreased by the addition of SWNT, this effect being more appreciable with 0.5 wt.% of SWNT. The results of differential scanning calorimetry showed that the addition of SWNT increased the crystallinity of PP/EPDM/SWNT nanocomposites. This effect was not linearly dependent on SWNT content, particularly at high SWNT concentrations. The rheological results revealed that addition of SWNT increased the storage modulus and complex viscosity at low frequencies. The Izod impact strength and tensile strength improved when 0.5 wt.% of SWNT was used. Furthermore, the tensile modulus increased remarkably by increasing the SWNT content, but the elongation at break of the material decreased.

Talc Filled Thermoplastic Composites: Melt Rheological Properties

2003 ◽  
Vol 13 (6) ◽  
pp. 297-304 ◽  
Author(s):  
P. Mederic ◽  
M. Moan ◽  
M.-H. Klopffer ◽  
Y. Saint-Gerard
Keyword(s):  
Storage Modulus ◽  
Rheological Behavior ◽  
Volume Fraction ◽  
Flow Direction ◽  
Low Frequency ◽  
Complex Viscosity ◽  
Thermoplastic Composites ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Frequency Sweeps

Abstract The effects of composition and resulting morphology on the rheology of thermoplastics filled with different talc platelets were studied in the 0-22% range of volume fraction, Φ. The sufficiently filled polymer composites exhibit a rheological behavior which significantly differs from the pure polymers used in this work, a linear low density polyethylene, a low density polyethylene and a polyamide 12. The changes in the rheological behavior are influenced by the size, the concentration and the surface treatment of plate-like talc particles. They also depend on the chemical nature and viscous and elastic characteristics of the polymer matrix. In particular, the effect of platelet orientation on the viscoelastic properties of reinforced composites was pointed out. For sufficiently filled systems, a low frequency response indicative of a pseudo solid-like behavior is obtained only during the first frequency sweep. In fact, the low frequency storage modulus, G’, is constant. With repeated frequency sweeps, more platelets were aligned in the flow direction, thus the low frequency storage modulus gradually decreases and becomes dependent on frequency, ω. The low frequency complex viscosity η* also progressively decreases with repeated frequency sweeps. In addition, for these systems, the low shear viscosity η build up in an unbounded manner because of the existence of particle-particle interactions. There are stresses below which there is no flow indicating the existence of yield values. Steady shear elastic properties are also studied, especially in the case of systems showing an apparent yield stress.

scholarly journals Bone-Mimicking Injectable Gelatine/Hydroxyapatite Hydrogels

2019 ◽  
Vol 33 (3) ◽  
pp. 325-335
Author(s):  
Anamarija Rogina ◽  
Nikolina Šandrk ◽  
Laura Teruel-Biosca ◽  
Maja Antunović ◽  
Marica Ivanković ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Storage Modulus ◽  
Hek293 Cells ◽  
Injectable Hydrogels ◽  
Composite Hydrogels ◽  
Natural Bone ◽  
Hydroxyapatite Crystal ◽  
Prepared Composite

Bioactive synthetic hydrogels have emerged as promising materials because they<br /> can provide molecularly tailored biofunctions and adjustable mechanical properties. To<br /> mimic the mineralogical and organic components of the natural bone, hydroxyapatite and<br /> a tyramine conjugate of gelatine were combined in this study. The effect of various amounts of in situ synthesized hydroxyapatite in gelatine-tyramine on the morphology<br /> and physical properties of injectable hydrogels was investigated. Mineralogical identification confirmed successful precipitation of in situ formed hydroxyapatite. Better distribution of hydroxyapatite crystal agglomerates within modified gelatine was found at 5 % of hydroxyapatite, which could be responsible for increased storage modulus with respect to pure gelatine hydrogel. Prepared composite hydrogels are non-toxic and support<br /> the proliferation of Hek293 cells.

Synthesis and Properties Epoxy Resin/Mesoporous Silica-Sepiolite Nanocomposites

2010 ◽  
Vol 129-131 ◽  
pp. 1248-1251 ◽  
Author(s):  
Qing Ming Jia ◽  
Shao Yun Shan ◽  
Li Hong Jiang ◽  
Ya Ming Wang
Keyword(s):  
Mechanical Properties ◽  
Mesoporous Silica ◽  
Epoxy Resin ◽  
Mechanical Analysis ◽  
Test Results ◽  
Time Dynamic ◽  
In Situ Deposition ◽  
Ep Matrix ◽  
And Storage

Size, shape and processing of the inorganic fillers are important for improving properties of nanocomposites. In this paper, a novel nanofiller containing mesoporous silica(MS) and fibrous sepiolite(SE) was prepared by in situ deposition method. EP/MS-SE nanocomposite was obtained by adding MS-SE to epoxy resin(EP) matrix. Morphologies and mechanical properties of the new ternary nanocomposite were investigated. For purpose of comparison, the corresponding binary nanocomposites, i.e., EP modified with either MS or SE, were tested as well. The test results of mechanical properties show that MS improves the strength of EP and SE obviously enhances the toughness of EP, but oM-MS exhibits synergistic effect on toughening and reinforcing of EP at the same time. Dynamic mechanical analysis revealed that the glass transition temperature and storage modulus of the EP/MS-SE nanocomposite was higher than those of pure EP.

Sign in / Sign up

Export Citation Format

Share Document