Plastics � Thermomechanical analysis (TMA)

2015 ◽  
Keyword(s):  
Thermomechanical Analysis

THERMOMECHANICAL ANALYSIS OF THE RESISTANCE SPOT-WELDING PROCESS

2018 ◽  
Vol 10 (5) ◽  
pp. 449-455 ◽  
Author(s):  
Habib Lebbal ◽  
Lahouari Boukhris ◽  
Habib Berrekia ◽  
Abdelkader Ziadi
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Thermomechanical Analysis ◽  
Resistance Spot

A Novel Approach for Thermomechanical Analysis of Stationary Rolling Tires within an ALE–Kinematic Framework

2013 ◽  
Vol 41 (3) ◽  
pp. 174-195 ◽  
Author(s):  
Anuwat Suwannachit ◽  
Udo Nackenhorst
Keyword(s):  
Constitutive Model ◽  
Numerical Solutions ◽  
Numerical Technique ◽  
Thermomechanical Analysis ◽  
Rolling Contact ◽  
Computational Technique ◽  
Heat Equations ◽  
Arbitrary Lagrangian Eulerian ◽  
Material Particle ◽  
Operator Split

ABSTRACT A new computational technique for the thermomechanical analysis of tires in stationary rolling contact is suggested. Different from the existing approaches, the proposed method uses the constitutive description of tire rubber components, such as large deformations, viscous hysteresis, dynamic stiffening, internal heating, and temperature dependency. A thermoviscoelastic constitutive model, which incorporates all the mentioned effects and their numerical aspects, is presented. An isentropic operator-split algorithm, which ensures numerical stability, was chosen for solving the coupled mechanical and energy balance equations. For the stationary rolling-contact analysis, the constitutive model presented and the operator-split algorithm are embedded into the Arbitrary Lagrangian Eulerian (ALE)–relative kinematic framework. The flow of material particles and their inelastic history within the spatially fixed mesh is described by using the recently developed numerical technique based on the Time Discontinuous Galerkin (TDG) method. For the efficient numerical solutions, a three-phase, staggered scheme is introduced. First, the nonlinear, mechanical subproblem is solved using inelastic constitutive equations. Next, deformations are transferred to the subsequent thermal phase for the solution of the heat equations concerning the internal dissipation as a source term. In the third step, the history of each material particle, i.e., each internal variable, is transported through the fixed mesh corresponding to the convective velocities. Finally, some numerical tests with an inelastic rubber wheel and a car tire model are presented.

Modifiers for Rigid Polyvinylchloride Compositions of Building Purpose

2020 ◽  
Vol 787 (12) ◽  
pp. 34-39
Author(s):  
L.A. Abdrakhmanova ◽  
◽  
K.R. Khuziakhmetova ◽  
R.K. Nizamov ◽  
V.G. Khozin ◽  
...  
Keyword(s):  
Phase Interface ◽  
Thermomechanical Analysis ◽  
Favorable Effect ◽  
Heterogeneous Structure ◽  
Electron Microscopic ◽  
Wear And Tear ◽  
Thermomechanical Testing ◽  
Building Purpose ◽  
Microscopy Data ◽  
Butadiene Styrene

A comparison of small doses (up to 0.7 mass part) of impact strength modifiers of foreign and domestic production in polyvinylchloride-based compositions is given. Domestic acrylicnitrile- butadiene styrene modifiers (ABS) were used. The developed shock-resistant polyvinylchloride compositions in the presence of ABS elastifier have high melt fluidity, which has a beneficial effect on the recyclability. Changes in supramolecular structure were estimated from thermomechanical testing and electron microscopy data for both unfilled and filled PVC samples. Thermomechanical analysis showed that the presence of ABS modifier had a favorable effect on the technological properties of PVC-based samples. Electron-microscopic images indicate that in unfilled PVC samples, the heterogeneous PVC structure is expressed in the presence of ABS copolymer in comparison with foreign acrylic modifiers. When the compositions are filled with micro-heterogeneous structure in dispersion medium, the filler-polymer is formed by chalk particles, while ABS elasticifier is at the phase interface. Due to the peculiarities of the structure ABS has a higher degree of “fixation” on the surface of the chalk particles in comparison with the basic compositions containing acrylic modifiers, which with increasing chalk concentration leads to lower wear and tear on the top of the forming equipment.

scholarly journals The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 890
Author(s):  
Mateusz Barczewski ◽  
Olga Mysiukiewicz ◽  
Aleksander Hejna ◽  
Radosław Biskup ◽  
Joanna Szulc ◽  
...  
Keyword(s):  
Impact Strength ◽  
Mechanical Stability ◽  
Thermomechanical Analysis ◽  
Thermomechanical Properties ◽  
Phenyl Isocyanate ◽  
Sem Analysis ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Expanded Vermiculite ◽  
Chain Extenders

In this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency of mechanochemical modification was evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The composites of PLA with three vermiculite types were prepared by melt mixing and subjected to mechanical, thermomechanical, thermal, and structural evaluation. The structure of composites containing a constant amount of the filler (20 wt%) was assessed using FTIR spectroscopy and SEM analysis supplemented by evaluating the final injection-molded samples’ physicochemical properties. Mechanical behavior of the composites was assessed by static tensile test and impact strength hardness measurements. Heat deflection temperature (HDT) test and dynamic thermomechanical analysis (DMTA) were applied to evaluate the influence of the filler addition and its functionalization on thermomechanical properties of PLA-based composites. Thermal properties were assessed by differential scanning calorimetry (DSC), pyrolysis combustion flow calorimetry (PCFC), and thermogravimetric analysis (TGA). The use of filler-reactive chain extenders (CE) made it possible to change the vermiculite structure and obtain an improvement in interfacial adhesion and more favorable filler dispersions in the matrix. This translated into an improvement in impact strength and an increase in thermo-mechanical stability and heat release capacity of composites containing modified vermiculites.

Effect of new metal–organic framework (zeolitic imidazolate framework [ZIF-12]) in mixed matrix membranes on structure, morphology, and gas separation properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mehtap Safak Boroglu ◽  
Ismail Boz ◽  
Busra Kaya
Keyword(s):  
Gas Separation ◽  
Gas Permeability ◽  
Metal Organic Framework ◽  
Thermomechanical Analysis ◽  
Variable Pressure ◽  
Mixed Matrix Membranes ◽  
Mixed Matrix ◽  
Sem Images ◽  
Zeolitic Imidazolate Framework ◽  
Matrix Membranes

Abstract In our study, the synthesis of zeolitic imidazolate framework (ZIF-12) crystals and the preparation of mixed matrix membranes (MMMs) with various ZIF-12 loadings were targeted. The characterization of ZIF-12 and MMMs were carried out by Fourier transform infrared spectroscopy analysis, thermogravimetric analysis, scanning electron microscopy (SEM), and thermomechanical analysis. The performance of MMMs was measured by the ability of binary gas separation. Commercial polyetherimide (PEI-Ultem® 1000) polymer was used as the polymer matrix. The solution casting method was utilized to obtain dense MMMs. In the SEM images of ZIF-12 particles, the particles with a rhombic dodecahedron structure were identified. From SEM images, it was observed that the distribution of ZIF-12 particles in the MMMs was homogeneous and no agglomeration was present. Gas permeability experiments of MMMs were measured for H2, CO2, and CH4 gases at steady state, at 4 bar and 35 °C by constant volume-variable pressure method. PEI/ZIF-12-30 wt% MMM exhibited high permeability and ideal selectivity values for H2/CH4 and CO2/CH4 were P H 2 / CH 4 = 331.41 ${P}_{{\text{H}}_{2}/{\text{CH}}_{4}}=331.41$ and P CO 2 / CH 4 = 53.75 ${P}_{{\text{CO}}_{2}/{\text{CH}}_{4}}=53.75$ gas pair.

scholarly journals Reconstruction of the Grenfell Tower Fire—Thermomechanical Analysis of Window Failure During the Grenfell Tower Disaster

2020 ◽  
Author(s):  
Maxime Koohkan ◽  
Virginie Dréan ◽  
Bertrand Girardin ◽  
Eric Guillaume ◽  
Talal Fateh ◽  
...  
Keyword(s):  
Thermomechanical Analysis

scholarly journals Study of the Ultraviolet Effect and Thermal Analysis on Polypropylene Nonwoven Geotextile

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  
Keyword(s):  
Uv Light ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Material Stiffness ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Physical Tests ◽  
Nonwoven Geotextile

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.

scholarly journals Films Based on a Blend of PVC with Copolymer of 3-Hydroxybutyrate with 3-Hydroxyhexanoate

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 270
Author(s):  
Evgeniy V. Belukhichev ◽  
Vera E. Sitnikova ◽  
Evgenia O. Samuylova ◽  
Mayya V. Uspenskaya ◽  
Daria M. Martynova
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Environmental Pollution ◽  
Polyvinyl Chloride ◽  
Polymer Films ◽  
Thermomechanical Analysis ◽  
Packaging Materials ◽  
Packaging Film ◽  
Scanning Calorimetry ◽  
Environmental Friendliness

Polymeric packaging materials are one of the factors of environmental pollution. Reducing the environmental burden is possible by increasing the environmental friendliness of packaging materials. In this work, we study polymer films based on polyvinyl chloride (PVC) with a copolymer of 3-hydroxybutyrate with 3-hydroxyhexanoate P (3-GB) (3-GG) with different component ratios. The process of processing blends in the process of obtaining a packaging film is considered. The optical characteristics of the obtained films are determined. Thermal analysis of the obtained films was carried out using the differential scanning calorimetry (DSC), TGA, and thermomechanical analysis (TMA) methods. The degree of gelling of the resulting mixture was determined. It is shown that PHB has miscibility with PVC.

Sign in / Sign up

Export Citation Format

Share Document