Mechanically Strong Polyurethane Composites Reinforced with Montmorillonite-Modified Sage Filler (Salvia officinalis L.)

Rigid polyurethane (PUR) foams reinforced with 1, 2, and 5 wt.% of salvia filler (SO filler) and montmorillonite-modified salvia filler (MMT-modified SO filler) were produced in the following study. The impact of 1, 2, and 5 wt.% of SO filler and MMT-modified SO filler on the morphological, chemical, and mechanical properties of PUR composites were examined. In both cases, the addition of 1 and 2 wt.% of SO fillers resulted in the synthesis of PUR composites with improved physicomechanical properties, while the addition of 5 wt.% of SO fillers resulted in the formation of PUR composites with a less uniform structure and, therefore, some deterioration in their physicomechanical performances. Moreover, the results showed that the modification of SO filler with MMT improved the interphase compatibility between filler surface and PUR matrix. Therefore, such reinforced PUR composites were characterized by a well-developed closed-cell structure and improved mechanical, thermal, and flame-retardant performances. For example, when compared with reference foam, the addition of 2 wt.% of MMT-modified SO filler resulted in the formation of PUR composites with greater mechanical properties (compressive strength, flexural strength) and improved dynamic-mechanical properties (storage modulus). The PUR composites were characterized by better thermal stability as well as improved flame retardancy—e.g., decreased peak rate of heat release (pHRR), reduced total smoke release (TSR), and increased limiting oxygen index (LOI).

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Casein/Apricot Filler in the Production of Flame-Retardant Polyurethane Composites

Materials ◽

10.3390/ma14133620 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3620

Author(s):

Sylwia Członka ◽

Agnė Kairytė ◽

Karolina Miedzińska ◽

Anna Strąkowska

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Dynamic Mechanical Properties ◽

Uniform Structure ◽

Thermal And Mechanical Properties ◽

Mechanical Performances ◽

Polyurethane Composites ◽

Natural Combination ◽

The Impact ◽

And Storage

Polyurethane (PUR) composites reinforced with 1, 2, and 5 wt.% of apricot filler modified with casein were synthesized in the following study. The impact of 1, 2, and 5 wt.% of casein/apricot filler on the cellular structure and physico-mechanical performances of reinforced PUR composites were determined. It was found that the incorporation of 1 and 2 wt.% of casein/apricot filler resulted in the production of PUR composites with improved selected physical, thermal, and mechanical properties, while the addition of 5 wt.% of casein/apricot filler led to some deterioration of their physico-mechanical performance. The best results were obtained for PUR composites reinforced with 2 wt.% of casein/apricot filler. Those composites were characterized by a uniform structure and a high content of closed cells. Compared with the reference foam, the incorporation of 2 wt.% of casein/apricot filler resulted in improvement in compressive strength, flexural strength, impact strength, and dynamic mechanical properties—such as glass transition temperature and storage modulus. Most importantly, PUR composites showed better fire resistance and thermal stability due to the good thermal performance of casein. The main aim of this article is to determine the influence of the natural combination of the apricot filler and casein on the mechanical properties and flammability of the obtained composites.

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Coir Fibers Treated with Henna as a Potential Reinforcing Filler in the Synthesis of Polyurethane Composites

Materials ◽

10.3390/ma14051128 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1128

Author(s):

Sylwia Członka ◽

Anna Strąkowska ◽

Agnė Kairytė

Keyword(s):

Mechanical Properties ◽

High Energy ◽

Dynamic Mechanical Properties ◽

Milling Process ◽

Coir Fiber ◽

Lawsonia Inermis ◽

Coir Fibers ◽

Mechanical Performances ◽

The Impact ◽

Reinforcing Filler

In this study, coir fibers were successfully modified with henna (derived from the Lawsonia inermis plant) using a high-energy ball-milling process. In the next step, such developed filler was used as a reinforcing filler in the production of rigid polyurethane (PUR) foams. The impact of 1, 2, and 5 wt % of coir-fiber filler on structural and physico-mechanical properties was evaluated. Among all modified series of PUR composites, the greatest improvement in physico-mechanical performances was observed for PUR composites reinforced with 1 wt % of the coir-fiber filler. For example, on the addition of 1 wt % of coir-fiber filler, the compression strength was improved by 23%, while the flexural strength increased by 9%. Similar dependence was observed in the case of dynamic-mechanical properties—on the addition of 1 wt % of the filler, the value of glass transition temperature increased from 149 °C to 178 °C, while the value of storage modulus increased by ~80%. It was found that PUR composites reinforced with coir-fiber filler were characterized by better mechanical performances after the UV-aging.

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Poly(Lactic Acid)–Poly(Butylene Succinate)–Sugar Beet Pulp Composites; Part I: Mechanics of Composites with Fine and Coarse Sugar Beet Pulp Particles

Polymers ◽

10.3390/polym13152531 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2531

Author(s):

Rodion Kopitzky

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Sugar Beet ◽

Cell Structure ◽

Sugar Beet Pulp ◽

Poly Lactic Acid ◽

Butylene Succinate ◽

Fracture Patterns ◽

Beet Pulp ◽

The Impact

Sugar beet pulp (SBP) is a residue available in large quantities from the sugar industry, and can serve as a cost-effective bio-based and biodegradable filler for fully bio-based compounds based on bio-based polyesters. The heterogeneous cell structure of sugar beet suggests that the processing of SBP can affect the properties of the composite. An “Ultra-Rotor” type air turbulence mill was used to produce SBP particles of different sizes. These particles were processed in a twin-screw extruder with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) and fillers to granules for possible marketable formulations. Different screw designs, compatibilizers and the use of glycerol as a thermoplasticization agent for SBP were also tested. The spherical, cubic, or ellipsoidal-like shaped particles of SBP are not suitable for usage as a fiber-like reinforcement. In addition, the fineness of ground SBP affects the mechanical properties because (i) a high proportion of polar surfaces leads to poor compatibility, and (ii) due to the inner structure of the particulate matter, the strength of the composite is limited to the cohesive strength of compressed sugar-cell compartments of the SBP. The compatibilization of the polymer–matrix–particle interface can be achieved by using compatibilizers of different types. Scanning electron microscopy (SEM) fracture patterns show that the compatibilization can lead to both well-bonded particles and cohesive fracture patterns in the matrix. Nevertheless, the mechanical properties are limited by the impact and elongation behavior. Therefore, the applications of SBP-based composites must be well considered.

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Experimental-numerical studies of the effect of cell structure on the mechanical properties of polypropylene foams

e-Polymers ◽

10.1515/epoly-2020-0060 ◽

2020 ◽

Vol 20 (1) ◽

pp. 713-723

Author(s):

Wei Gong ◽

Tuan-Hui Jiang ◽

Xiang-Bu Zeng ◽

Li He ◽

Chun Zhang

Keyword(s):

Mechanical Properties ◽

Size Distribution ◽

Cell Size ◽

Cell Structure ◽

Structure Parameters ◽

Cell Size Distribution ◽

Numerical Studies ◽

Polypropylene Foam ◽

The Impact ◽

The Relationship

AbstractThe effects of the cell size and distribution on the mechanical properties of polypropylene foam were simulated and analyzed by finite element modeling with ANSYS and supporting experiments. The results show that the reduced cell size and narrow size distribution have beneficial influences on both the tensile and impact strengths. Decreasing the cell size or narrowing the cell size distribution was more effective for increasing the impact strength than the tensile strength in the same case. The relationship between the mechanical properties and cell structure parameters has a good correlation with the theoretical model.

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Novel soy oil based polyurethane composites: Fabrication and dynamic mechanical properties evaluation

Journal of Materials Science ◽

10.1023/b:jmsc.0000016211.93689.89 ◽

2004 ◽

Vol 39 (5) ◽

pp. 1887-1890 ◽

Cited By ~ 16

Author(s):

J.-P. Latere Dwan'isa ◽

A. K. Mohanty ◽

M. Misra ◽

L. T. Drzal ◽

M. Kazemizadeh

Keyword(s):

Mechanical Properties ◽

Dynamic Mechanical Properties ◽

Soy Oil ◽

Dynamic Mechanical ◽

Polyurethane Composites

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Manufacture of Ultra-Dense Knitted Superelastic Structures

Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies ◽

10.1115/smasis2018-8225 ◽

2018 ◽

Author(s):

Henry Koon ◽

Jack Laven ◽

Julianna Abel

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Cell Structure ◽

Axial Loading ◽

Consumer Products ◽

Niti Shape Memory Alloy ◽

Structural Element ◽

Loading Tests ◽

Structural Architecture ◽

The Impact

Knitted Textiles made from Nickel-Titanium (NiTi) shape memory alloy wires are a new structural element with enhanced properties for a variety of applications. Potential advantages of this structural form include enhanced bending flexibility, tailorable in-plane, and through-thickness mechanical performance, and energy absorption and damping. Inspection of the knit pattern reveals a repeating cell structure of interlocking loops. Because of this repeating structure, knits can be evaluated as cellular structures that leverage their loop-based architecture for mechanical robustness and flexibility. The flexibility and robustness of the structure can be further enhanced by manufacturing with superelastic NiTi. The stiffness of superelastic NiTi, however, makes traditional knit manufacturing techniques inadequate, so knit manufacturing in this research is aided by shape setting the superelastic wire to a predefined pattern mimicking the natural curve of a strand within a knit fabric. This predefined shape-set geometry determines the outcome of the knit’s mechanical performance and tunes the mechanical properties. In this research, the impact of the shape setting process on the material itself is explored through axial loading tests to quantify the effect that heat treatment has on a knit sample. A means of continuously shape setting and feeding the wire into traditional knitting machines is described. These processes lend themselves to mass production and build upon previous textile manufacturing technologies. This research also proposes an empirical exploration of superelastic NiTi knit mechanical performance and several new techniques for manufacturing such knits with adjustable knit parameters. Displacement-controlled axial loading tests in the vertical (wale) direction determined the recoverability of each knit sample in the research and were iteratively increased until failure resulted. Knit samples showed recoverable axial strains of 65–140%, which could be moderately altered based on knit pattern and loop parameters. Furthermore, this research demonstrates that improving the density of the knit increases the stiffness of the knit without any loss in recoverable strains. These results highlight the potential of this unique structural architecture that could be used to design fabrics with adjustable mechanical properties, expanding the design space for aerospace structures, medical devices, and consumer products.

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Dynamic Mechanical Compression Impulse of Lithium-Ion Pouch Cells

Energies ◽

10.3390/en13082105 ◽

2020 ◽

Vol 13 (8) ◽

pp. 2105 ◽

Cited By ~ 2

Author(s):

Alon Ratner ◽

Richard Beaumont ◽

Iain Masters

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Strain Rate Sensitivity ◽

Lithium Ion ◽

Rate Sensitivity ◽

Dynamic Mechanical Properties ◽

Impact Testing ◽

Significant Feature ◽

Dynamic Mechanical ◽

The Impact

Strain rate sensitivity has been widely recognized as a significant feature of the dynamic mechanical properties of lithium-ion cells, which are important for their accurate representation in automotive crash simulations. This research sought to improve the precision with which dynamic mechanical properties can be determined from drop tower impact testing through the use of a diaphragm to minimize transient shock loads and to constrain off-axis motion of the indenter, specialized impact absorbers to reduce noise, and observation of displacement with a high speed camera. Inert pouch cells showed strain rate sensitivity in an increased stiffness during impact tests that was consistent with the poromechanical interaction of the porous structure of the jellyroll with the liquid electrolyte. The impact behaviour of the inert pouch cells was similar to that of an Expanded Polypropylene foam (EPP), with the exception that the inert pouch cells did not show hysteretic recovery under the weight of the indenter. This suggests that the dynamic mechanical behaviour of the inert pouch cells is analogous to a highly damped foam.

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Dynamic Fracture Experiment of Fractured Rock under Dynamic Loading

Shock and Vibration ◽

10.1155/2020/9761650 ◽

2020 ◽

Vol 2020 ◽

pp. 1-22

Author(s):

Yanbing Wang ◽

Xingyuan Zhou ◽

Ji Kong ◽

Bingbing Yu

Keyword(s):

Mechanical Properties ◽

Energy Loss ◽

Dynamic Loading ◽

Split Hopkinson Pressure Bar ◽

Fractured Rock ◽

Dynamic Mechanical Properties ◽

Dynamic Crack ◽

Loading Test ◽

Dynamic Mechanical ◽

The Impact

In order to examine the dynamic mechanical properties, dynamic crack proposition process, and energy loss of fractured rock under dynamic loading, the specimens with different fracture dig angles were processed with Φ50 mm × 50 mm cylindrical sandstone, the impact loading test was conducted on 50 mm stem diameter split Hopkinson pressure bar (SHPB) experiment platform, and the whole process of crack propagation and dynamic failure was recorded using a high-speed camera. As a result, the dynamic mechanical properties such as stress wave fluctuation characteristics, peak strength and stress-strain relationship, crack initiation angle, stress and other dependencies with prefabricated fracture angle of the prefabricated fracture specimens under high strain rate were obtained, and the incident energy, absorbed energy, and energy absorption rates were compared to investigate the energy loss law in the dynamic loading; on the contrary, the effects of different loading rates on the dynamic mechanical properties of the sandstone specimens were identified, and finally a set of findings were presented.

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Preparation and Characteristic of PC/PLA/TPU Blends by Reactive Extrusion

Advances in Materials Science and Engineering ◽

10.1155/2015/393582 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

Yueyun Zhou ◽

Lifa Luo ◽

Wenyong Liu ◽

Guangsheng Zeng ◽

Yi Chen

Keyword(s):

Mechanical Properties ◽

Fracture Behavior ◽

Reactive Extrusion ◽

Uniform Structure ◽

Intrinsic Properties ◽

Elongation At Break ◽

The Poor ◽

Properties Of Materials ◽

The Impact ◽

Thermal Stability Of

To overcome the poor toughness of PC/PLA blends due to the intrinsic properties of materials and poor compatibility, thermoplastic urethane (TPU) was added to PC/PLA blends as a toughener; meantime, catalyst di-n-butyltin oxide (DBTO) was also added for catalyzing transesterification of components in order to modify the compatibility of blends. The mechanical, thermal, and rheological properties of blends were investigated systematically. The results showed that the addition of TPU improves the toughness of PC/PLA blends significantly, with the increase of TPU, the elongation at break increases considerably, and the impact strength increases firstly and then falls, while the tensile strength decreases significantly and the blends exhibit a typical plastic fracture behavior. Meantime, TPU is conducive to the crystallinity of PLA in blends which is inhibited seriously by PC and damages the thermal stability of blends slightly. Moreover, the increased TPU makes the apparent viscosity of blends melt decrease due to the well melt fluidity of TPU; the melt is closer to the pseudoplasticity melt. Remarkably, the transesterification between the components improves the compatibility of blends significantly, and more uniform structure results in a higher crystallinity and better mechanical properties.

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Influence of Cyclic Impact Loading and Axial Stress on Dynamic Mechanical Properties of Burst-Prone Coal

Shock and Vibration ◽

10.1155/2021/6649308 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Shuang Gong ◽

Zhen Wang ◽

Lei Zhou ◽

Wen Wang

Keyword(s):

Mechanical Properties ◽

Impact Loading ◽

Coal Sample ◽

Impact Load ◽

Axial Stress ◽

Dynamic Mechanical Properties ◽

Dynamic Mechanical ◽

Cyclic Impact Loading ◽

Cyclic Impact ◽

The Impact

High in-situ stress and frequent dynamic disturbances caused by the mining process in deep coal mines can easily induce dynamic disasters such as coal burst. We conducted laboratory experiments to assess the effects of the axial stress loading and dynamic cyclic impact loading on the dynamic mechanical properties of burst-prone coals by using a modified split Hopkinson pressure bar (SHPB). Comparisons were made using two types of burst-prone and burst-resistant coal samples. The mineral components, organic macerals, and dynamic mechanical features of both burst-prone and burst-resistant coal samples were comparatively analyzed based on the obtained X-ray diffraction (XRD), optical microscope observations, and dynamic compressive stress-strain curves, respectively. The results of the microstructure analysis indicated a larger difference between the minimum and maximum reflectances of vitrinite for burst-prone coal. Compared to the burst-resistant coal samples, the burst-prone coals contained less corpocollinite and fusinite. While applying a high axial static load combined with cyclic impact load, the coal samples showed the characteristics of fatigue damage. The results also demonstrated that preaxial stress affected the burst resistance of coal samples. The greater the preaxial stress was, the less the coal samples could withstand the dynamic cyclic impact load. In comparison to the burst-resistant coal sample, the burst-prone coal sample showed a larger dynamic compressive strength and a lower deformation. They were also more positively capable of the propagation and activation of the coal burst. We believe that the results of the study are conducive to further understanding of the distribution of microcomponents of burst-prone coals. The results are also beneficial for realizing the dynamic mechanical characteristics of burst-prone coals under the impact of cyclic dynamic load.

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