scholarly journals UV Aging Behavior of Functionalized Mullite Nanofiber-Reinforced Polypropylene

ACS Omega ◽  
2020 ◽  
Vol 5 (42) ◽  
pp. 27083-27093
Author(s):  
Anish M. Varghese ◽  
Vengatesan M. Rangaraj ◽  
Gisha Luckachan ◽  
Vikas Mittal
Keyword(s):  
Aging Behavior ◽  
Uv Aging

New preparation method of bitumen samples for UV aging behavior investigation

2020 ◽  
Vol 233 ◽  
pp. 117278 ◽  
Author(s):  
Xiaolong Sun ◽  
Xiao Qin ◽  
Zhisheng Liu ◽  
Yingmei Yin ◽  
Chao Zou ◽  
...  
Keyword(s):  
Preparation Method ◽  
Aging Behavior ◽  
Uv Aging

Aging behavior of nano-CaCO3-modified polypropylene nonwoven fabric composites

2020 ◽  
pp. 096739112090354
Author(s):  
Zongqian Wang ◽  
Yu Li ◽  
Yinchun Fang ◽  
Ganyu Feng ◽  
Jingjing Xu
Keyword(s):  
Corrosion Resistance ◽  
Acid Corrosion ◽  
Filter Material ◽  
Strong Acid ◽  
Nonwoven Fabric ◽  
Weak Acid ◽  
Aging Behavior ◽  
Acid Condition ◽  
Uv Aging ◽  
Fabric Composite

Nano-CaCO3-modified polypropylene (PP) nonwoven fabric composite is widely used as the filter material which could overcome the poor lightfastness and low weight of the pure one, while its aging performances would be influenced. In this article, the aging behavior of the nano-CaCO3-modified PP nonwoven fabric composite was investigated. At first, the difference between untreated and CaCO3-modified PP nonwoven fabric was analyzed by scanning electron microscopy, thermogravimetric/differential thermal analysis, and X-ray diffraction. Then the aging behaviors of these two PP nonwoven fabrics were studied in detail. The results showed that the PP nonwoven fabric exhibited good acid corrosion resistance. On the contrary, acid corrosion resistance of the modified PP nonwoven fabric was poor; although its weight and strength didn’t change under weak acid condition, its weight and strength loss both increased obviously under medium and strong acid condition with the prolongation of corrosion time. Due to the ultraviolet (UV) energy dissipation of nano-CaCO3 particles, the UV aging resistance of the modified PP nonwoven fabric was improved, and the compound UV aging under weak acid condition was also superior to that of the untreated PP fabric. This article will provide experimental and theoretical base for the structural regulation of CaCO3-modified PP fibers.

Lifetime Prediction of Tires with Regard to Oxidative Aging5

2008 ◽  
Vol 36 (1) ◽  
pp. 63-79 ◽  
Author(s):  
L. Nasdala ◽  
Y. Wei ◽  
H. Rothert ◽  
M. Kaliske
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Distribution ◽  
Superposition Principle ◽  
Accelerated Aging ◽  
Material Model ◽  
Aging Behavior ◽  
Element Analysis ◽  
Material Parameters ◽  
Reaction Processes

Abstract It is a challenging task in the design of automobile tires to predict lifetime and performance on the basis of numerical simulations. Several factors have to be taken into account to correctly estimate the aging behavior. This paper focuses on oxygen reaction processes which, apart from mechanical and thermal aspects, effect the tire durability. The material parameters needed to describe the temperature-dependent oxygen diffusion and reaction processes are derived by means of the time–temperature–superposition principle from modulus profiling tests. These experiments are designed to examine the diffusion-limited oxidation (DLO) effect which occurs when accelerated aging tests are performed. For the cord-reinforced rubber composites, homogenization techniques are adopted to obtain effective material parameters (diffusivities and reaction constants). The selection and arrangement of rubber components influence the temperature distribution and the oxygen penetration depth which impact tire durability. The goal of this paper is to establish a finite element analysis based criterion to predict lifetime with respect to oxidative aging. The finite element analysis is carried out in three stages. First the heat generation rate distribution is calculated using a viscoelastic material model. Then the temperature distribution can be determined. In the third step we evaluate the oxygen distribution or rather the oxygen consumption rate, which is a measure for the tire lifetime. Thus, the aging behavior of different kinds of tires can be compared. Numerical examples show how diffusivities, reaction coefficients, and temperature influence the durability of different tire parts. It is found that due to the DLO effect, some interior parts may age slower even if the temperature is increased.

Evaluation of the Aging Behavior of High Density Polyethylene in Thermal Oxidative Environment by Principal Component Analysis

2017 ◽  
Vol 727 ◽  
pp. 447-449 ◽  
Author(s):  
Jun Dai ◽  
Hua Yan ◽  
Jian Jian Yang ◽  
Jun Jun Guo
Keyword(s):  
Principal Component Analysis ◽  
Impact Strength ◽  
High Density Polyethylene ◽  
Tensile Modulus ◽  
Principal Component ◽  
Component Analysis ◽  
High Density ◽  
Aging Behavior ◽  
Data Set ◽  
The Impact

To evaluate the aging behavior of high density polyethylene (HDPE) under an artificial accelerated environment, principal component analysis (PCA) was used to establish a non-dimensional expression Z from a data set of multiple degradation parameters of HDPE. In this study, HDPE samples were exposed to the accelerated thermal oxidative environment for different time intervals up to 64 days. The results showed that the combined evaluating parameter Z was characterized by three-stage changes. The combined evaluating parameter Z increased quickly in the first 16 days of exposure and then leveled off. After 40 days, it began to increase again. Among the 10 degradation parameters, branching degree, carbonyl index and hydroxyl index are strongly associated. The tensile modulus is highly correlated with the impact strength. The tensile strength, tensile modulus and impact strength are negatively correlated with the crystallinity.

Aging behavior and precipitate characterization of Zn-rich Al–Zn–Mg–Cu alloys with various Mg and Cu contents

2021 ◽  
Author(s):  
Hai-chao Li ◽  
Ming Li ◽  
Dong-ye Yang ◽  
Fu-yang Cao ◽  
Yan-dong Jia ◽  
...  
Keyword(s):  
Aging Behavior ◽  
Cu Alloys

scholarly journals Physical Aging Behavior of a Glassy Polyether

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 954
Author(s):  
Xavier Monnier ◽  
Sara Marina ◽  
Xabier Lopez de Pariza ◽  
Haritz Sardón ◽  
Jaime Martin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Physical Aging ◽  
Glassy State ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Narrow Temperature Range ◽  
Glass Forming ◽  
Fast Scanning Calorimetry

The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.

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