Mechanical and Thermal Properties of Polyurethane Materials and Inflated Insulation Chambers

Evaluating mechanical and thermal characteristics of garment systems or their segments is important in an attempt to provide optimal or at least satisfying levels of comfort and safety, especially in the cold environment. The target groups of users may be athletes engaged in typical sports that are trained in the cold, as well as football players that play matches and train outdoors during the winter season. Previous studies indicated an option to substitute the inner layers of an intelligent garment with polyurethane inflated chambers (PIC) to increase and regulate thermal insulation. In this paper, the authors investigate the mechanical properties of polyurethane material with and without ultrasonic joints. Furthermore, they investigate the potential of designed PICs in terms of efficiency and interdependence of air pressure and heat resistance. The results indicated that an inflated PIC with four diagonal ultrasonic joints has the highest ability to maintain the optimal thermal properties of an intelligent clothing system. The influence of direction and number of ultrasonic joints on the mechanical properties of polyurethane material is confirmed, especially in terms of compression resilience and tensile energy.

Download Full-text

The Effect of Modification on the Properties of Polyetherimide and Its Carbon-Filled Composite

Polymers ◽

10.3390/polym12051056 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1056

Author(s):

Azamat Slonov ◽

Ismel Musov ◽

Azamat Zhansitov ◽

Elena Rzhevskaya ◽

Diana Khakulova ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Heat Resistance ◽

Mechanical And Thermal Properties ◽

Melt Viscosity ◽

Deposit Modeling ◽

High Level ◽

Filled Composite

The effect of oligophenylene sulfone (OPSU) and polycarbonate (PC) on the rheological, mechanical and thermal properties of polyetherimide (PEI) and a carbon-filled composite based on it was studied. It is shown that the introduction of OPSU and PC leads to a decrease in the melt viscosity of PEI and a carbon-filled composite based on it with the preservation of their mechanical properties and heat resistance at a sufficiently high level. It was found that composites with OPSU have higher mechanical and thermal properties compared with composites with PC. Samples from modified carbon-filled PEI were printed by the fused deposit modeling (FDM) method. Three-dimensionally printed samples from carbon-filled PEI modified by OPSU showed significantly higher mechanical properties than composites with PC.

Download Full-text

Development of PE/PCL Bilayer Films Modified with Casein and Aluminum Oxide

Molecules ◽

10.3390/molecules26113090 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3090

Author(s):

Anita Ptiček Siročić ◽

Ana Rešček ◽

Zvonimir Katančić ◽

Zlata Hrnjak-Murgić

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Water Vapor ◽

Aluminum Oxide ◽

Water Vapor Permeability ◽

Vapor Permeability ◽

Mechanical And Thermal Properties ◽

Oxide Compound ◽

Bilayer Films ◽

Oxide Particles

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.

Download Full-text

Exceptional Mechanical Properties and Heat Resistance of Photocurable Bismaleimide Ink for 3D Printing

Materials ◽

10.3390/ma14071708 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1708

Author(s):

Wenqiang Hua ◽

Qilang Lin ◽

Bo Qu ◽

Yanyu Zheng ◽

Xiaoying Liu ◽

...

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Heat Resistance ◽

Three Dimensional ◽

Mechanical And Thermal Properties ◽

Amino Group ◽

Building Models ◽

Fast Processing ◽

Forming Precision ◽

Complex Structural

Photosensitive resins used in three-dimensional (3D) printing are characterized by high forming precision and fast processing speed; however, they often possess poor mechanical properties and heat resistance. In this study, we report a photocurable bismaleimide ink with excellent comprehensive performance for stereolithography (SLA) 3D printing. First, the main chain of bismaleimide with an amino group (BDM) was synthesized, and then, the glycidyl methacrylate was grafted to the amino group to obtain the bismaleimide oligomer with an unsaturated double bond. The oligomers were combined with reaction diluents and photo-initiators to form photocurable inks that can be used for SLA 3D printing. The viscosity and curing behavior of the inks were studied, and the mechanical properties and heat resistance were tested. The tensile strength of 3D-printed samples based on BDM inks could reach 72.6 MPa (166% of that of commercial inks), glass transition temperature could reach 155 °C (205% of that of commercial inks), and energy storage modulus was 3625 MPa at 35 °C (327% of that of commercial inks). The maximum values of T-5%, T-50%, and Tmax of the 3D samples printed by BDM inks reached 351.5, 449.6, and 451.9 °C, respectively. These photocured BDM inks can be used to produce complex structural components and models with excellent mechanical and thermal properties, such as car parts, building models, and pipes.

Download Full-text

The influence of adding long basalt fiber on the mechanical and thermal properties of composites based on poly(oxymethylene)

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705718806549 ◽

2018 ◽

Vol 33 (4) ◽

pp. 435-450 ◽

Cited By ~ 4

Author(s):

Patrycja Bazan ◽

Stanisław Kuciel ◽

Mariola Sądej

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Average Length ◽

Flexural Modulus ◽

Basalt Fiber ◽

Charpy Impact ◽

Mechanical And Thermal Properties ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Atr Spectroscopy

The work has evaluated the possibility of the potential reinforcing of poly(oxymethylene) (POM) by basalt fibers (BFs) and influence of BFs addition on thermal properties. Two types of composites were produced by injection molding. There were 20 and 40 wt% long BFs content with an average length of 1 mm. The samples were made without using a compatibilizer. In the experimental part, the basic mechanical properties (tensile strength, modulus of elasticity, strain at break, flexural modulus, flexural strength, and deflection at 3.5% strain) of composites based on POM were determined. Tensile properties were also evaluated at three temperatures −20°C, 20°C, and 80°C. The density and Charpy impact of the produced composites were also examined. The influence of water absorption on mechanical properties was investigated. Thermal properties were conducted by the differential scanning calorimetry, thermal gravimetric analysis, and fourier transform infrared (FTIR)-attenuation total reflection (ATR) spectroscopy analysis. In order to make reference to the effects of reinforcement and determine the structure characteristics, scanning electron microscopy images were taken. The addition of 20 and 40 wt% by weight of fibers increases the strength and the stiffness of such composites by more than 30–70% in the range scale of temperature. Manufactured composites show higher thermal and dimensional stability in relation to neat POM.

Download Full-text

Influence of extrusion screw speed on the properties of halloysite nanotube impregnated polylactic acid nanocomposites

Journal of Polymer Engineering ◽

10.1515/polyeng-2020-0228 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Chaitra Venkatesh ◽

Yuanyuan Chen ◽

Zhi Cao ◽

Shane Brennan ◽

Ian Major ◽

...

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Thermal Properties ◽

Composite Films ◽

Polymer Melt ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Screw Speed ◽

Halloysite Nanotube ◽

The Past

Abstract Poly (lactic acid)/halloysite nanotube (PLA/HNT) nanocomposites have been studied extensively over the past few years owing to the interesting properties of the polymer, PLA, and the nanoclay, HNT, individually and as composites. In this paper, the influence of the screw speed during extrusion was investigated and was found to have a significant impact on the mechanical and thermal performance of the extruded PLA/HNT nanocomposites. To determine the effect of screw speed on PLA/HNT nanocomposites, 5 and 10 wt% of HNTs were blended into the PLA matrix through compounding at screw speeds of 40, 80, and 140 rpm. Virgin PLA was compounded for comparison. The resultant polymer melt was quench cooled onto a calendar system to produce composite films which were assessed for mechanical, thermal, chemical, and surface properties. Results illustrate that in comparison to 40 and 80 rpm, the virgin PLA when compounded at 140 rpm, indicated a significant increase in the mechanical properties. The PLA/HNT 5 wt% nanocomposite compounded at 140 rpm showed significant improvement in the dispersion of HNTs in the PLA matrix which in turn enhanced the mechanical and thermal properties. This can be attributed to the increased melt shear at higher screw speeds.

Download Full-text

Performance of lightweight mortar reinforced with doum palm fiber

Journal of Composite Materials ◽

10.1177/0021998320975196 ◽

2020 ◽

pp. 002199832097519

Author(s):

Fatma Naiiri ◽

Allègue Lamis ◽

Salem Mehdi ◽

Zitoune Redouane ◽

Zidi Mondher

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Natural Fiber ◽

Cement Mortar ◽

Low Cost ◽

Natural Fibers ◽

Construction Materials ◽

Mechanical And Thermal Properties ◽

Palm Fiber ◽

And Control

Natural fibers are increasingly used in composites because of their low cost and good mechanical properties. Cement reinforced with natural fibersis contemplates as a new generation of construction materials with superior mechanical and thermal performance. This study of three sizes’effect of Doum palm fiber explores the mortar’s behavior reinforced with different fiber ratio. The aim is to determine the optimal addition to improve mechanical and thermal properties of natural fiber reinforced cements. Physical, mechanical and thermal properties of composite are examined. Tensile properties of Doum fibers are verified to determine their potential as reinforced material. Findings prove that the use of alkali-treated Doum fiber as reinforcement in cement mortar composite leads to the upgrading of the mechanical properties including thermo-physical properties against composites reinforced with raw fibers and control cement mortars. While, the compression and flexural strength of the cement mortar reinforced with alkali-treated Doum fiber with diameter 0.3 mm (CT3) are metered to be 11.11 MPa, 5.22 MPa, respectively for fiber content 0.5%. Additionally, based on thermo-physical tests, it is assessed that the thermal conductivity and diffusivity decrease for cement mortar reinforced with Doum fiber with diameter 0.2 mm (CT2).

Download Full-text

Mechanical and thermal properties of PP/compatibilized PP/acid treated SWNTs nanocomposites: Effect of different acid treatment times

e-Polymers ◽

10.1515/epoly.2008.8.1.1766 ◽

2008 ◽

Vol 8 (1) ◽

Author(s):

Morteza Ghorbanzadeh Ahangari ◽

Abdolhosein Fereidoon ◽

Seyfolah Saedodin

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Acid Treatment ◽

Treatment Process ◽

Tensile Tests ◽

Acid Mixture ◽

Mechanical And Thermal Properties ◽

Thermal And Mechanical Properties ◽

Maleated Polypropylene ◽

Carboxylic Groups

AbstractIn the present work, the effect of different acid treatment times of singlewalled carbon nanotubes (SWNTs) on the mechanical and thermal properties of polypropylene (PP)/maleated polypropylene (PP-g-MA) nanocomposites was investigated. The acid treatment process was based on a mixture of concentrated sulphuric and nitric acids. The SWNTs were treated with the acid mixture for 1, 3, and 6 h. FTIR, Raman spectroscopy and TEM revealed the values of carboxylic groups, graphitization and morphology of acid treated SWNTs, respectively. The thermal and mechanical properties and the morphology of nanocomposites were investigated by tensile tests, DMTA, DSC, and SEM.

Download Full-text

Effect of Coal Structure on Mechanical and Thermal Properties of Coal Filled Soy Protein Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.288 ◽

2011 ◽

Vol 236-238 ◽

pp. 288-291

Author(s):

Guang Heng Wang ◽

An Ning Zhou

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Soy Protein ◽

Water Resistance ◽

Group Analysis ◽

Surface Functional Group ◽

Hydroxyl Groups ◽

Mechanical And Thermal Properties ◽

Coal Rank ◽

Coal Structure

Using different rank coals as filler, coal-soy protein isolate (SPI) composites were prepared by compression molding processing using glycerol as plasticizer. The structure of the coals used were characterized by Fourier transform infrared (FTIR), ultimate analysis, and surface functional group analysis. The effects of coal structure on the mechanical properties, water resistance, and thermal properties were investigated. The results showed that, in different rank coals, the atomic ratio of oxygen to carbon, carboxylic acid groups, phenolic hydroxyl groups, lactone bonds, and aliphatic chains decreased with coal rank. The strength, water resistance, and glass transition temperature of coal-SPI composites decreased with coal rank. Lower ran coal filler with more reactive functional groups caused the composites strong but brittle. While, higher rank coals provide poor mechanical properties for the composites.

Download Full-text

Effect of Selected Commercial Plasticizers on Mechanical, Thermal, and Morphological Properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer Biodegradable Blends for Three-Dimensional (3D) Print

Materials ◽

10.3390/ma11101893 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1893 ◽

Cited By ~ 14

Author(s):

Přemysl Menčík ◽

Radek Přikryl ◽

Ivana Stehnová ◽

Veronika Melčová ◽

Soňa Kontárová ◽

...

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Thermal Properties ◽

Three Dimensional ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Modulated Differential Scanning Calorimetry ◽

3D Print ◽

3D Printed ◽

Biodegradable Blends

This paper explores the influence of selected commercial plasticizers structure, which are based on esters of citric acid, on mechanical and thermal properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer biodegradable blends. These plasticizers were first tested with respect to their miscibility with Poly(3-hydroxybutyrate)/Poly(lactic acid) (PHB/PLA) blends using a kneading machine. PHB/PLA/plasticizer blends in the weight ratio (wt %) of 60/25/15 were then prepared by single screw and corotating meshing twin screw extruders in the form of filament for further three-dimensional (3D) printing. Mechanical, thermal properties, and shape stability (warping effect) of 3D printed products can be improved just by the addition of appropriate plasticizer to polymeric blend. The goal was to create new types of eco-friendly PHB/PLA/plasticizers blends and to highly improve the poor mechanical properties of neat PHB/PLA blends (with majority of PHB) by adding appropriate plasticizer. Mechanical properties of plasticized blends were then determined by the tensile test of 3D printed test samples (dogbones), as well as filaments. Measured elongation at break rapidly enhanced from 21% for neat non-plasticized PHB/PLA blends (reference) to 328% for best plasticized blends in the form of filament, and from 5% (reference) to 187% for plasticized blends in the form of printed dogbones. The plasticizing effect on blends was confirmed by Modulated Differential Scanning Calorimetry. The study of morphology was performed by the Scanning Electron Microscopy. Significant problem of plasticized blends used to be also plasticizer migration, therefore the diffusion of plasticizers from the blends after 15 days of exposition to 110 °C in the drying oven was investigated as their measured weight loss. Almost all of the used plasticizers showed meaningful positive softening effects, but the diffusion of plasticizers at 110 °C exposition was quite extensive. The determination of the degree of disintegration of selected plasticized blend when exposed to a laboratory-scale composting environment was executed to roughly check the “biodegradability”.

Download Full-text

Composites of Rigid Polyurethane Foams Reinforced with POSS

Polymers ◽

10.3390/polym11020336 ◽

2019 ◽

Vol 11 (2) ◽

pp. 336 ◽

Cited By ~ 17

Author(s):

Sylwia Członka ◽

Anna Strąkowska ◽

Krzysztof Strzelec ◽

Agnieszka Adamus-Włodarczyk ◽

Agnė Kairytė ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

Water Absorption ◽

Viscoelastic Behavior ◽

Physical And Mechanical Properties ◽

Polyurethane Foams ◽

Bending Test ◽

Mechanical And Thermal Properties ◽

Rigid Polyurethane Foams ◽

Cell Shapes

Rigid polyurethane foams (RPUFs) were successfully modified with different weight ratios (0.5 wt%, 1.5 wt% and 5 wt%) of APIB-POSS and AEAPIB-POSS. The resulting foams were evaluated by their processing parameters, morphology (Scanning Electron Microscopy analysis, SEM), mechanical properties (compressive test, three-point bending test and impact strength), viscoelastic behavior (Dynamic Mechanical Analysis, DMA), thermal properties (Thermogravimetric Analysis, TGA, and thermal conductivity) and application properties (contact angle, water absorption and dimensional analysis). The results showed that the morphology of modified foams is significantly affected by the type of the filler and filler content, which resulted in inhomogeneous, irregular, large cell shapes and further affected the physical and mechanical properties of resulting materials. RPUFs modified with APIB-POSS represent better mechanical and thermal properties compared to the RPUFs modified with AEAPIB-POSS. The results showed that the best results were obtained for RPUFs modified with 0.5 wt% of APIB-POSS. For example, in comparison with unfilled foam, compositions modified with 0.5 wt% of APIB-POSS provide greater compression strength, better flexural strength and lower water absorption.

Download Full-text