Article
Polymer Science
Assia Zennaki, Latifa Zair, Khadidja Arabeche, Lina Benkraled, Ulrich Maschke, Abdelkader Berrayah
Summary: This study investigated the effects of annealing temperature and time on the crystalline phase transition in PLA using DSC and DMA. A small exothermal peak was observed at 130 degrees C, indicating the disorder-to-order phase transition, when the sample was annealed at 80 degrees C for 10-30 hours. The sample annealed at 90-110 degrees C showed a double melting behavior, suggesting the alpha'-alpha phase transition. DMA results showed a significant increase in the glass modulus at 80 degrees C for 3 hours, followed by an improvement at 120 degrees C for all samples. These findings suggest that the improvement in E-g is correlated with the increase in crystallinity and the alpha'-alpha phase transition.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Materials Science, Composites
Arulmurugan Seetharaman, Venkateshwaran Narayanan
Summary: This research investigates the effect of adding aluminosilicate (bentonite) nanoclay powder on the mechanical and dynamic mechanical behavior of polyester composites. The results show that the addition of nanoclay can enhance the mechanical properties of the composites, and 5 wt% bentonite clay addition provides the best strength and storage modulus.
POLYMER COMPOSITES
(2022)
Article
Polymer Science
Yu-Ting Guo, Changxia Shi, Tian-Yi Du, Xiang-Yue Cheng, Fu-Sheng Du, Zi-Chen Li
Summary: The design and synthesis of closed-loop recyclable polymers using ring-opening polymerization (ROP) is a promising solution to address plastic pollution and economic loss. The resulting poly(ester-amide)s (PEAs) exhibit tunable mechanical properties, good thermal stability, and excellent recyclability.
Article
Materials Science, Multidisciplinary
Mirsadegh Seyedzavvar, Cem Boga, Samet Akar, Farzad Pashmforoush
Summary: Thermo-mechanical properties of PBT polymer reinforced with CaCO3 nanoparticles were investigated using molecular dynamics simulations. Experimental verification was conducted to confirm the accuracy of the MD simulation results. The results showed significant enhancement in mechanical properties and consistent increase in thermal conductivity and glass transition temperature with increasing ratio of nanoparticles.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Polymer Science
Roberta Motta Neves, Ademir Jose Zattera, Sandro Campos Amico
Summary: In this study, microcrystalline cellulose (MCC) was chemically modified with 3-(aminopropyl)triethoxysilane and incorporated into epoxy to enhance the chemical, thermal, and dynamic-mechanical properties of the composites. The amino-functionalized MCC showed improved dispersion and better dynamic-mechanical performance compared to untreated MCC. Surface modification of MCC with amino groups improved the adhesion with the epoxy matrix, leading to enhanced chemical interaction between the components.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Roberta Capuano, Roberto Avolio, Rachele Castaldo, Mariacristina Cocca, Giovanni Dal Poggetto, Gennaro Gentile, Maria Emanuela Errico
Summary: Plasticized nanocomposites based on poly(lactic acid) were prepared using a two-step approach, adding two different oligomeric esters of lactic acid (OLAs) as plasticizers and fumed silica nanoparticles. The nanocomposites maintained remarkable elongation at break in the presence of the nanoparticles, with minimal effects on modulus and strength. However, thermo-mechanical properties deteriorated over time due to phase separation, and the nature of the plasticizer played a crucial role. Materials with hydroxyl-terminated OLAs showed higher stability upon aging, while acid-terminated plasticizer combined with silica nanoparticles accelerated the hydrolytic degradation of PLA, leading to brittleness and a significant decrease in molecular weight after 16 weeks of aging.
Article
Construction & Building Technology
Ruikang Zhao, Fan Jing, Rui Wang, Jun Cai, Junsheng Zhang, Qingjun Wang, Hongfeng Xie
Summary: The research investigated the impact of oligomer content on the viscosity, dynamic mechanical properties, and mechanical behaviors of hot-mix epoxy asphalt binders. The results showed that the viscosity decreased and the construction time increased with higher oligomer content. The storage modulus decreased at the glassy stage but increased at the rubbery stage. The epoxy asphalt binders exhibited two glass transition temperatures and increased in the epoxy oligomer content. The damping properties and tensile strength increased with higher oligomer content, while the elongation at break and toughness showed an opposite trend.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Tianbo Zhou, Guoming Liu, Ming Wang, Yi Liu, Liuchun Zheng
Summary: PDMS-modified poly(butylene succinate) (PBS) was successfully synthesized, resulting in high-performance and functional PBS-b-PDMS copolymers. The copolymers exhibited excellent combined properties, thermal properties, and impact strength, as well as good antismudge, self-cleaning, and solvent resistance.
Article
Polymer Science
Walter W. Young, Hiromu Tabuchi, Ryo Iguchi, Takashi Konishi, Koji Fukao, Reika Katsumata
Summary: In broadband dielectric spectroscopy experiments, introducing an air gap reduces DC conductivity, enabling the study of low-frequency relaxations. A slower process than the alpha-relaxation process is observed in P2VP, and its mechanism is examined in two heterogeneous systems.
Article
Polymer Science
Ngoc Minh Ho, Thuy Chinh Nguyen, Thi Thanh Van Tran, Tien Dung Nguyen, Hoang Thai
Summary: The study focused on epoxy/silica nanocomposites containing various levels of m-nanosilica, showing the enhancement of flame retardancy and abrasion resistance, as well as the reduction of recovery energy. The results confirmed that the presence of m-nanosilica in the nanocomposites contributed to improving the thermal and mechanical properties, as well as the flame retardant capability.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Tian Li, Ying Shen, Guangping Zheng
Summary: A new exponent beta has been proposed to characterize the glass forming ability of metallic nano-glasses (NGs) and metallic glasses (MGs), showing that higher beta values indicate enhanced GFAs in NGs with a higher volume fraction of glass-glass interfaces (GGIs), which can potentially overcome the size limitation issue in MGs.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Composites
Juan Li, Bo Li, Shaowen Huang, Shanshan Luo, Shengbao He, Chengtao Gao, Shan Liu
Summary: The surface-grafting modification of nano clay, specifically using epoxy chain extender ADR-4468 to modify pyrophyllite, has yielded ADR-4468-modified pyrophyllite (A-Prl) which has shown to improve the properties of PET and PET/PETG composites. The A-Prl successfully synthesized in this study did not alter the crystal structure of pyrophyllite. Its addition improved the dispersion and crystallization properties of the composites, ultimately enhancing the mechanical performance. The impact toughness of the A-Prl/PET/PETG composite increased by 120% compared to pure PET. This functional additive has the potential to be utilized in the production of high-performance and recyclable PET composites.
POLYMER COMPOSITES
(2022)
Article
Polymer Science
Bin Du, Daodao Xue, Rubai Luo, Kenan Yang, Huailin Li, Shisheng Zhou
Summary: This paper mainly focuses on improving the properties of epoxy resin by utilizing carbon nanotubes (CNTs) for better dispersion and reinforcement in composites. The results show that the modified CNTs have better performance in the composites.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Polymer Science
Jie Cheng, Junjie Su, Yuan Tian, Xue Hu, Gutian Zhao, Zhonghua Ni
Summary: In this study, the factors influencing the mechanical properties of poly (L-lactic acid) (PLLA) vascular stents were investigated by accelerating the degradation process. The results showed that the radial strength of the stents initially increased and then decreased, while the radial stiffness showed an upward trend. The mass loss of the stents was negligible, indicating a bulk degradation behavior.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Polymer Science
Daria Guseva, Alexei A. Lazutin, Valentina V. Vasilevskaya
Summary: This study developed an atomistic model of poly(lactic acid) (PLA) and investigated the impact of the relative content of monomer units L and D on the structural and thermophysical properties of amorphous PLA melts using molecular dynamics method. The results showed that decreasing regioregularity of chains led to a reduction in radius of gyration and characteristic ratio. The study confirmed the efficiency of using the General Amber Force Field with charges calculated for helical poly(L-lactic acid) chain for accurate simulation of PLA.
