Rheology, morphology and mechanical properties of compatibilized poly(vinylidene fluoride) (PVDF)/thermoplastic polyurethane (TPU) blends

Compatibilized blends of poly(vinylidene fluoride) (PVDF) and thermoplastic polyurethane (TPU) were developed using maleated PVDF (PVDF-g-MA). Excellent compatibilization between PVDF and TPU was demonstrated by theological, morphological, and mechanical measurements. The introduction of PVDF-g-MA into the PVDF/TPU blends caused an increase in viscosity and storage modulus. Much finer morphology was clearly observed by SEM. The tensile tests showed that the tensile strength and ultimate elongation achieved a significant improvement with addition of PVDF-g-MA.

Age hardening and mechanical properties of Mg-Gd-Er alloy

The Mg-8Gd-0.6Zr-xEr (x = 1, 3 and 5 mass%) alloys were prepared by casting technology, and the microstructures, age hardening behaviors and mechanical properties of alloys have been investigated. Microstructures of the alloys are characterized by the presence of rosette-shaped equiaxed grains. The age hardening behaviors and the tensile properties are enhanced by adding Er element. The maximum aged hardness of Mg-8Gd-0.6Zr-5Er alloy is 97, it is nearly 1.24 times higher than that of Er-free alloy.

Effect of Nd on the microstructure, mechanical properties and corrosion behavior of die-cast Mg-4Al-based alloy

Die-cast Mg-4Al-0.4Mn-xNd(x = 0, 1, 2, 4 and 6 wt.%) magnesium alloys were prepared successfully and influences of Nd on the microstructure, mechanical properties and corrosion behavior of the Mg-4Al-0.4Mn alloy have been investigated. The results showed that with the addition of Nd binary Al2Nd phase and Al11Nd3 phase. which mainly aggregated along the grain boundaries, were formed, and the relative ratio of above two phases was in correlation with the Nd content in the alloy. Meanwhile, the grain sizes were greatly reduced with the increasing Nd content. It was found that due to the addition of Nd both the tensile properties and corrosion resistance were improved substantially.

Effect of Y for enhanced age hardening response and mechanical properties of Mg-Ho-Y-Zr alloys

In this study, compositional dependence of age hardening characteristics and tensile properties were investigated for Mg-4Ho-xY-0.6Zr alloys (x = 0, 3 5, and 7 wt%). The result showed that with increasing Y content, the hardness of the alloys increased in the as-quenched and aged-peak conditions. Considerable age hardening response was recognized for the alloys. When the alloy containing 7% Y showed the most remarkable age hardening response at aging temperature of 250 degrees C.

Thermal and mechanical properties of poly(butylene terephthalate)/epoxy blends

In this study, melt blends of poly(butylene terephthalate) (PBT) with epoxy resin were characterized by dynamic mechanical analysis, differential scanning calorimetry, tensile testing, Fourier transform infrared spectroscopy, and wide-angle X-ray diffraction. The results indicate that the presence of epoxy resin influenced either the mechanical properties of the PBT/epoxy blends or the crystallization of PBT. The epoxy resin was completely miscible with the PBT matrix. This was beneficial to the improvement of the impact performance of the PBT/epoxy blends.

The microstructures and mechanical properties of cast Mg-Zn-Al-RE alloys

The microstructures and mechanical properties of cast Mg-Zn-Al-RE alloys with 4 wt.% RE and variable Zn and At contents were investigated. The results show that the alloys mainly consist of alpha-Mg, Al2REZn2, Al4RE and tau-Mg-32(Al,Zn)(49) phases. and a little amount of the beta-Mg17Al12 phase will also be formed with certain Zn and At contents. When increasing the Zn or At content, the distribution of the Al2REZn2 and Al4RE phases will be changed from cluster to dispersed, and the content of tau-Mg-32(Al,Zn)(49) phase increased gradually. The distribution of the Al2REZn2 and Al4RE phases, and the content of beta- or tau-phase are critical to the mechanical properties of Mg-Zn-Al-RE alloys.

Microstructure and mechanical properties of high performance Mg-Gd based alloys

The Mg-12Gd-4Y-2Nd-0.3Zn-0.6Zr (wt.%) alloy was prepared by casting technology, and the structure, age hardening behavior and mechanical properties of the alloy have been investigated. The results demonstrated that the alloy was composed of alpha-Mg matrix, a lot of dispersed Mg24RE5 (RE = Gd/Y/Nd) and Mg5RE precipitates in the as-cast and the T6 state alloys. The alloy exhibited remarkable age hardening response and excellent mechanical properties from room temperature (RT) to 300 degrees C by optimum solid solution and aging conditions. The ultimate tensile strength.

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF TI-BASED METALLIC GLASS MATRIX COMPOSITES

Ti40Cu40Ni10Zr10-xScx (x = 0.5 and 1, at%) alloys were prepared by copper mould casting method. Microstructures of the phi 3 mm rod alloys were investigated by XRD and SEM. The results showed that the phi 3 mm rods were glassy matrix with TiCu crystalline phase. Mechanical properties were studied by compressive test. Ti40Cu40Ni10Zr9Sc1 alloy exhibited good compressive strength over 2200 MPa and superior compressive deformation is about 7.9%.

Combination of Carbon Nanotubes with Ni2O3 for Simultaneously Improving the Flame Retardancy and Mechanical Properties of Polyethylene

Effects of multiwalled carbon nanotubes (MWCNTs) and Ni2O3 on the flame retardancy of linear low density polyethylene (LLDPE) have been studied. A combination of MWCNTs and Ni2O3 showed a synergistic effect in improving the flame retardancy of LLDPE compared with LLDPE composites containing MWCNTs or Ni2O3 alone. As a result, the peak value of heat release rate measured by cone calorimeter was obviously decreased in the LLDPE/MWCNTs/Ni2O3 Composites. According to the results from rheological tests, carbonization experiments, and structural characterization of residual char, the improved flame retardancy was partially attributed to the formation of a networklike structure due to the good dispersion of MWCNTs in LLDPE matrix, and partially to the carbonization of degradation products of LLDPE catalyzed by Ni catalyst originated from Ni2O3, More importantly, both viscoelastic characteristics and catalytic carbonization behavior of LLDPE/MWCNTs/Ni2O3 composites acted in concert to result in a synergistic effect in improving the flame retardancy.

Ab initio study on the electronic and mechanical properties of ReB and ReC

The structural, electronic, and mechanical properties of ReB and ReC have been studied by use of the density functional theory. For each compound, six structures are considered, i.e., hexagonal WC, NiAs, wurtzite, cubic NaCl, CsCl, and zinc-blende type structures. The results indicate that for ReB and ReC, WC type structure is energetically the most stable among the considered structures, followed by NiAs type structure. ReB-WC (i.e., ReB in WC type structure) and ReB-NiAs are both thermodynamically and mechanically stable. ReC-WC and ReC-NiAs are mechanically stable and becomes thermodynamically stable above 35 and 55 GPa, respectively. The estimated hardness from shear modulus is 34 GPa for ReB-WC, 28GPa for ReB-NiAs, 35GPa for ReC-WC and 37GPa for ReC-NiAs, indicating that they are potential candidates to be ultra-incompressible and hard materials.

Influence of Annealing on Microstructure and Mechanical Properties of Isotactic Polypropylene with beta-Phase Nucleating Agent

The microstructure and mechanical properties of beta-nucleated iPP before and after being annealed at different temperatures (90-160 degrees C) have been analyzed, Annealing induced different degrees of variation in fracture toughness of beta-nucleated iPP samples. namely, slight enhancement at relatively low annealing temperatures (< 110 degrees C) and great improvement at moderate temperatures (120-130 degrees C), whereas dramatic deterioration at relatively high temperatures ( > 140 degrees C) has been observed. The variation of fracture toughness of beta-nucleated iPP is observed to be dependent on the content of beta-NA. Experiments, including scanning electronic microscope (SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), and dynamic mechanical analysis (DMA), are performed to study the variations of microstructures as well as the toughening mechanism of the beta-nucleated iPP after being annealed.

Effect of gamma-radiation on the thermal and mechanical properties of a commercial poly(butylene adipate-co-terephthalate)

BACKGROUND: Poly(butylene adipate-co-terephthalate) (PBAT) has attracted wide interest as a biodegradable polymer. However, its use is restricted in certain applications due to its low melting point.RESULTS: PBAT was treated using gamma-radiation. The radiation features were analyzed using Soxhlet extraction, and the ratio of chain scission and crosslinking and gelation dose were determined using the classical Charlesby-Pinner equation. The results showed that PBAT is a radiation-crosslinkable polymer. The degree of crosslinking increased with increasing radiation dose; the relation between sol fraction and dose followed the Charlesby-Pinner equation. Differential scanning calorimetry analyses showed that the melting temperature (T-m) and the heat of fusion (Delta H-m) of PBAT exhibited almost no change in the first scan. The second scan, however, showed a decrease in T-m and Delta H-m. The glass transition temperature of irradiated PBAT increased with increasing radiation dose.

Effects of SEBS-g-BTAI on the morphology, structure and mechanical properties of PA6/SEBS blends

Styrene-b-(ethylene-co-1-butene)-b-styrene (SEBS) triblock copolymer functionalized with epsilon-caprolactam blocked allyl (3-isocyanate-4-tolyl) carbamate (SEBS-g-BTAI) was used to toughen polyamide 6 (PA6) via reactive blending. Compared to the PA6/SEBS blends, mechanical properties such as tensile strength, Young's modulus, especially Izod notched strength of PA6/SEBS-g-BTAI blends were improved distinctly. Both theological and FTIR results indicated a new copolymer formed by the reaction of end groups of PA6 and isocyanate group regenerated in the backbone of SEBS-g-BTAI. Smaller dispersed particle sizes with narrower distribution were found in PA6/SEBS-g-BTAI blends, via field emitted scanning electron microscopy (FESEM). The core-shell structures with PS core and PEB shell were also observed in the PA6/SEBS-g-BTAI blends via transmission electron microscopy (TEM), which might improve the toughening ability of the rubber particles.

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

The rheological, morphological and mechanical properties of LLDPE/PS blends with a combined catalyst, Me3SiCl and InCl3 center dot 4H(2)O, 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.

Microstructure, thermal stability and mechanical properties of the novel (W1-xAlx)C-Co (x=0.2, 0.33, 0.4, 0.5) cemented carbide

Bulk novel cemented carbides (W1-xAlx)C-10.1 vol% Co (x = 0.2, 0.33, 0.4, 0.5) are prepared by mechanical alloying and hot-pressing sintering. Hot-pressing (HP) is used to fabricate the bulk bodies of the hard alloys. The novel cemented carbides have good mechanical properties compared with WC-Co. The density and operating cost of the novel material is much lower than a WC-Co system. The material is easy to process and the processing leads to nano-scaled, rounded, particles in the bulk material. The hardness of (W1-xAlx)C-10.1 vol% Co (x = 0.2, 0.33, 0.4, 0.5) hard material is 20.37, 21.16, 21.59 and 22.16 GPa, and the bending strength is 1257, 1238, 1211 and 1293 MPa, with the aluminum content varying from 20% to 50%. The relationship between the microstructure and the mechanical properties of the novel hard alloy is also discussed.