Article
Polymer Science
Jacob Mahon, Nicholas Pagliocca, Virginia Harnack, Behrad Koohbor, Lei Yu, Xiao Hu, Robert Krchnavek, Wei Xue
Summary: This study develops a silicon dioxide reinforced polyamide nanocomposite with exceptional thermal stability as a solid dielectric coating solution to address the material challenges in high-temperature superconducting power transmission. Characterization of the fabricated nanocomposite reveals improved thermomechanical performance at cryogenic conditions and demonstrates the multifunctionality of low temperature processing.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Polymer Science
Gorkem Yildiz, Meral Akkoyun
Summary: The study found that adding different concentrations of BN and AlN fillers can significantly improve the thermal conductivity of PA6, slightly improve the electrical conductivity, and also improve the thermal stability, but the tensile strength slightly decreases.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Physical
Xuemei Zhang, Inge Hoff
Summary: The study compared the effects of thermal-oxidative aging and salt solution aging on bitumen performance, finding similar trends in oxygen content, physical, low-temperature, and high-temperature properties but different changes in morphology between the two aging methods. The aging degrees caused by the different aging methods were ranked as follows: PAV > 10% NaCl > TFOT > 10% CaCl2. The conclusions could provide a theoretical basis for establishing a standard for the solution aging of bitumen.
Article
Polymer Science
Qiang-Qiang Li, Zhao-Dong Xu, Quek-Ser Tong, Yao-Rong Dong, Ye-Shou Xu, Yong Lu
Summary: This paper comprehensively studies the influence of thermal-oxidative aging on the mechanical properties of viscoelastic materials (VEMs). By conducting thermal-oxidative aging tests and mechanical property tests, the authors analyze the effects of different chemical reactions during aging on the molecular chain structure and macroscopic mechanical behaviors of VEMs. A mathematical model is formulated to characterize the mechanical behavior of aging VEMs and is compared and verified using experimental data. The results demonstrate that thermal-oxidative aging can degrade the deformation capability and harden the modulus of VEMs, affecting the performance of VE damping devices.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Polymer Science
Mahsa Kamali, Fatemeh Gharibi, Alireza Sharif
Summary: By adjusting synthesis parameters, it is possible to maximize the permeance and selectivity of thin film composite polyamide membranes for CO2/N-2 separation. Key parameters include top layer fabrication methods, organic phase solvents, acid acceptors, and surfactant concentrations.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Chrysoula Pandelidi, Ryan Blakis, Kok Peng Marcian Lee, Stuart Bateman, Milan Brandt, Mladenko Kajtaz
Summary: The properties of both the polyamide-11 powder and the compression-moulded specimens derived from it were significantly affected within the first 24 hours of exposure to 180° Celsius, but consecutive exposure did not have a significant effect.
Article
Engineering, Chemical
Shunxin Qi, Xiangning Wen, Shaofan Li, Xungang Li, Chenxi Mao, Xia Dong, Ying Zhao, Yunlan Su, Kezhi Wang, Dujin Wang
Summary: The effects of aging temperature and time on crystallization behaviors of PA6 and stabilized PA6 were investigated, revealing that high temperature aging accelerates crystal formation and molecular chain degradation. Stabilized PA6 shows higher yellowness index and maximum decomposition temperature, with increased viscosity at the initial stage. The glass transition temperature of stabilized PA6 decreases during aging, suggesting hindered degradation by stabilizers.
POLYMER ENGINEERING AND SCIENCE
(2021)
Article
Polymer Science
Shuzhan Wang, Hui He, Xiaodong Peng, Handong Chen
Summary: This study successfully prepared a graphite-filled polypropylene/polyamide 6 composite using FDM technology, studied the effects of graphite on the composite properties, and explored the influence of different printing arrangements. Through microscopic morphology characterization and force analysis, the performance regulation mechanisms were deeply investigated.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Engineering, Manufacturing
Binbin Guo, Zhiyao Xu, Xue Luo, Jiaming Bai
Summary: PA12/glass beads composites manufactured via the MJF technique exhibit improved performance, including enhanced dimensional accuracy, lower surface roughness, higher surface hardness, increased decomposition temperature, and char yield compared to neat PA12. However, the flame retardance of the composite remains unchanged. The incorporation of glass beads effectively regulates the dimensional accuracy and improves the overall performance of the composite material.
VIRTUAL AND PHYSICAL PROTOTYPING
(2021)
Article
Polymer Science
Adrien Simon, Julie Pepin, Daphne Berthier, Stephane Meo
Summary: A thermal weak point of peroxide-cured fluoroelastomer (FKM) in the presence of triallylisocyanurate (TAIC) was identified using TGA measurements. Thermal stability and thermo-oxidative degradation were characterized, revealing TAIC as the weak point in the FKM system. Aging at 250 degrees C led to a decrease in crosslinking density before stabilization, allowing the material to retain mechanical properties. For longer exposures, chain scission caused a loss of mechanical properties. TGA-FTIR results suggested a dehydrofluorination mechanism followed by chain scission.
POLYMER DEGRADATION AND STABILITY
(2023)
Article
Polymer Science
Siyuan Jiang, Yufei Liu, Xiaoyu Zou, Min He, Kai Zhang, Guomin Xu, Shuhao Qin
Summary: Through various analysis methods, it was found that these two types of macromolecular antioxidants can protect the molecular chain, maintain the crystallization and stability of PA6, improve the thermal stability and activation energy of PA6, enhance the strength and elasticity of PA6, and maintain the mechanical properties of PA6 to a certain extent during aging.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Materials Science, Composites
Alp Eren Sahin, Eser Yarar, Hasan Kara, Emine Bas Cep, Mustafa Ozgur Bora, Taner Yilmaz
Summary: This study aims to reduce the harm caused by vehicles to the environment through design improvements, technological advancements, and the use of materials that can reduce weight and provide desired mechanical properties. Glass fiber-polyamide composites were used to produce automotive components using compression molding and Tailor Fiber Placement (TFP) technology. The effects of environmental exposure and aging on the wear behavior of the composites were evaluated. The experimental results showed that increasing holding time improved wear resistance, while aging had a negative impact.
POLYMER COMPOSITES
(2023)
Article
Materials Science, Ceramics
Jian Guo, Jianguo Chen, Jinrong Cheng, Qi Tan
Summary: Mn doping has a significant impact on the phase structure, aging behavior, and thermal stability of 0.75BF-0.25BT ceramics, leading to reduced aging rates and enhanced thermal stability. This is due to the decreased defect concentrations and improved poling state resulting from Mn modification.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Composites
Marina Lobanova, Vladislav Aleshkevich, Alexander Babkin, Alexey Kepman, Viktor Avdeev, Oleg Morozov, Boris Bulgakov
Summary: This work focuses on the thermal-oxidative aging behavior of phthalonitrile thermosets and composites at high temperatures, and reveals the negative effect of high-temperature post-curing on the properties of the materials.
POLYMER COMPOSITES
(2023)
Article
Construction & Building Technology
Yingcheng Luan, Weiguang Zhang, Shihui Shen, Shenghua Wu, Tao Ma, Xingye Zhou, Louay N. Mohammad, Yuan Fu
Summary: This paper aims to validate the relationship between thermal-related parameters and field-measured thermal cracking. Field thermal cracking data from four projects with twelve pavement sections are collected. Material properties including creep compliance m-value, tensile strength of mixture, and asphalt low-temperature performance grade (PG) are considered. A lower m-value and tensile strength result in higher thermal cracking, while a lower low-temperature PG shows a contrary trend. One or several material properties cannot fully characterize field thermal cracking for all projects. Three-dimensional finite element models (FEM) consider the changes in material properties, pavement structures, and climatic conditions. The aging effect of material properties contributes to an increase in thermal stress. The placement of chip seal can greatly reduce the aging rate, and thicker pavement leads to less thermal stress. Both material property and thickness are important design factors for thermal cracking resistance.
ROAD MATERIALS AND PAVEMENT DESIGN
(2023)