Influence of thermal aging on tensile and creep behavior of thermoplastic polyurethane

Abstract

Changes in mechanical and physical properties of polyurethane thermoplastic during aging at 70 • C and 90 • C were investigated. The loss weight response was analyzed by gravimetric measurements under these temperatures. Changes in appearance and morphology of TPU after thermal aging were revealed by optical microscopy. The prolongation of the thermal exposure time, up to 270 days, leads to a progressive increase in tensile strength. In fact, elastic modulus and stress at 200% of strain were increased with thermal exposure time. These results can be explained by the increase of thermal stability due to the increase of material rigidity and the decrease in chain mobility. The evolution of the mechanical properties from tensile tests seems to be well correlated to the creep behavior. Finally, Scanning Electron Microscopy (SEM) revealed the modification of TPU morphology fracture surface after thermal aging.

Determination of Exact Steady State Creep Behavior in Short Fiber Composites by Mapping Transformation Function (MTF) in MMC’s

“…The increasing application of short fiber composites in high loadings and temperatures environments requires a thorough knowledge of their creep characteristics and deformation mechanisms. Recently, extensive investigations have been performed to obtain the creep behaviour of short fiber composites in steady state creep [1][2][3][4][5][6]. Also, in the present new work, an analytical and mathematical solution for prediction of the steady state creep behaviour of short fiber composites based on mapping transformation polynomial function is determined without using of some theories.…”

“…Here, an axisymmetric unit cell representing a fiber with its surrounding matrix as two coaxial cylinders is assumed. For verification of the solution method, the SiC/6061Al composite is selected as a case study and the results will be compared with the previous experimental available results in [5] [2]. Creep of fibrous composite materials has been studied by Lilholt [3].…”

Analysis of Steady State Creep in Short Fiber Composites (SFC) by Polynomial Function (PF) and Boundary Condition Method (BCM)

“…Determination of shear stress values in interface (fiber and matrix) are used for analysis of failure, fracture and fatigue in short fiber composites in steady state creep. In recent times, comprehensive studies have been performed to determine the creep behaviour of short fiber composites in second stage creep [1][2][3][4][5][6]. Also, in the present new research, analytical and mathematical approaches for prediction of the steady state creep behaviour of short fiber composites based on polynomial function (PF) and boundary condition method (BCM) are proposed without using of some theories.…”

“…Boubakri et al investigated influence of thermal aging on tensile and creep behavior of thermoplastic polyurethane [2]. Creep of fibrous composite materials has been studied by Lilholt [3].…”

Neural Network Based Simulation of Micro Creeping Fibrous Composites SiC/Al6061 for Plastic Behaviour

“…Also, analysis of the creep deformation in non-reinforced regions of creeping short fiber composites has been performed under tensile stress using the virtual fiber method [16]. As a different work, changes in mechanical and physical properties of polyurethane thermoplastic during aging at 70 • C and 90 • C have been analyzed [17]. In addition, recently as a different research work, creep tests have been fulfilled at 923 and 973 K on two heats with different solution annealing conditions [18].…”