Article
Thermodynamics
Mine Begum Alanalp, Burcu Ozdemir, Mohammadreza Nofar, Ali Durmus
Summary: The effect of CNC content on the crystallization and melting behaviors of PLA nanocomposites was investigated. CNC acted as a nucleating agent for cold crystallization of PLA, but differently affected the crystal growth behavior. CNC addition increased the overall cold crystallization activation energy.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Polymer Science
Qun Yang, Run Zhang, Jing Tian, Hailong He, Ping Xue, Xiaonong Chen, Mingyin Jia
Summary: In this study, the effect of adding two types of nano-materials (multi-walled carbon nanotubes and graphene nanoplatelets) to ultra-high molecular weight polyethylene (UHMWPE) on its isothermal and non-isothermal crystallization processes was investigated. The results revealed that the nano-materials did not act as heterogeneous nucleating agents and their addition was unfavorable to the crystallization process. The samples modified by nano-materials had a lower crystallization rate than the neat UHMWPE at the initial crystallization stage, but a faster crystallization rate at the end crystallization stage. This phenomenon may be attributed to the reduction of physical entanglement points of UHMWPE molecular chains by the incorporated nano-materials, which weakened the restriction on molecular chain movement and increased the crystallization rate at the initial stage. However, the crystallization rate of the samples incorporated with nano-materials decreased rapidly with time.
JOURNAL OF POLYMER RESEARCH
(2023)
Article
Polymer Science
Xiaodong Li, Meishuai Zou, Lisha Lei, Longhao Xi
Summary: The study found that the non-isothermal crystallization behaviors of PEG and PEG-PCL vary under different cooling rates, with the cooling rate significantly affecting the crystallization of PEG-PCL.
Article
Polymer Science
Akihiko Toda, Rene Androsch, Christoph Schick
Summary: Quantitative analyses of the melting kinetics of superheated polymer crystals revealed unique characteristics and discussed possible mechanisms underlying the obtained results.
Article
Thermodynamics
Nithya Christopher, Kritika Anand, A. K. Srivastava, Nidhi Singh
Summary: The thermal and kinetic analysis of partially crystallized Hf1.5Zr0.5Co10FeB melt-spun ribbon was studied using differential scanning calorimetry, showing a three-step exothermic crystallization process. The kinetics of crystallization revealed that the alloy's crystallization is initially governed by three-dimensional growth, shifting to one-dimensional growth later.X-ray diffraction confirmed the crystalline phases in optimized annealed samples, while scanning electron microscopy investigated the microstructural dependence of grain growth during annealing. Magnetic hysteresis loop measurements demonstrated the evolution of hard magnetic properties upon annealing at 823 K.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Thermodynamics
S. P. Magalhaes da Silva, Monica A. Silva, Jose M. Oliveira
Summary: This study investigated the non-isothermal cold crystallization behaviors of cork-polymer composites based on polylactic acid matrix. The results showed that cork powder residues act as a nucleating agent, accelerating the crystallization rate and reducing the half-time crystallization values. Additionally, the addition of cork was found to decrease the cold crystallization temperature of the PLA matrix.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Polymer Science
Shouang Wu, Bocheng Wang, Xiaoling Xu, Chonggang Wu, Tao Hu, Xuan Zheng, Xinghou Gong
Summary: The addition of S-MA compatibilizer had a positive impact on the dispersion and crystallization behavior of SBS in PLA blends. The study found that SBS exhibited both plasticization and dilution effects under different conditions, with the effects being enhanced with increasing S-MA content.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Medicinal
Tamaki Miyazaki, Ryo Mizoguchi, Keisuke Ueda, Taeko Shinozaki, Mie Kamoto, Yoshihiro Takeda, Satoshi Sakuma, Naoya Ito, Michiko Momo, Kohsaku Kawakami
Summary: High inter-laboratory reproducibility is crucial for collaborative experiments among multiple laboratories. In this study, we aimed to establish a protocol for isothermal storage tests to ensure consistent data quality from all participating laboratories. Sharing a detailed protocol similar to the experimental section of general papers was not sufficient for achieving high inter-laboratory reproducibility. By investigating the causes of data variations among laboratories, we gradually refined the protocol to improve reproducibility. Specific instructions on sample temperature control during transfer contributed to reducing variability. Our findings also revealed differences in the physical stabilities of amorphous drugs when prepared in differently shaped aluminum pans designed for various differential scanning calorimeters.
JOURNAL OF PHARMACEUTICAL SCIENCES
(2023)
Article
Chemistry, Physical
Yasser Boucenna, Abdelheq Layachi, Abdelhakim Cherfia, Fouad Laoutid, Hamid Satha
Summary: This study investigates the effect of adding 0.4 wt.% carbon black (CB) to polyamide 66 (PA66) with 30 wt.% short glass fibers (GFs) on the thermal crystallization behavior of the composite. The results show that the nucleation effect of GFs enhances the crystallization of PA66, and the combination of GF and CB reduces the activation energy of crystallization, facilitating the process.
Article
Polymer Science
Janetty Jany Pereira Barros, Carlos Pereira Soares, Esperidiana Augusta Barretos de Moura, Renate Maria Ramos Wellen
Summary: This study investigates the effect of gamma radiation on the interaction between kraft lignin and PBAT/PLA blend. The results show that irradiation promotes the miscibility and compatibility of PBAT/PLA/lignin. The crystallization peak of PBAT/PLA/lignin shifts to lower temperatures and the crystallization rate decreases after irradiation.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Materials Science, Ceramics
Suman Pawaria, Jyoti Ahlawat, Preeti Sharma, Sajjan Dahiya, Anil Ohlan, R. Punia, A. S. Maan
Summary: The glass transition and crystallization kinetics of lithium-modified zinc borate glasses with different compositions were studied using differential scanning calorimetry. The glass composition of 20ZnO·10Li2O·70B2O3 showed the highest thermal stability and glass-forming tendency among all other compositions. The activation energies for crystallization and glass transition were determined and found to be in close agreement with each other. The formation of a pure monoclinic LiZnBO3 crystalline phase was observed in certain compositions, which has potential for electric double-layer capacitance fabrication.
CERAMICS INTERNATIONAL
(2023)
Article
Polymer Science
Saeed Dolatshah, Shervin Ahmadi, Amir Ershad-Langroudi, Hedieh Jashni
Summary: This study investigated the synergistic effect of different chain extenders and catalysts on the rheological behavior of PET, finding that a combination of PMDA and PENTA at 1.5% and 0.5% respectively resulted in the best rheological properties for modified PET. Additionally, DBTDL acted as an accelerator for chain extension reaction, improving the rheological properties of PET by increasing the chain extending rate. Thermal properties of modified PET were also studied using differential scanning calorimetry.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Dario Heidrich, Michael Gehde
Summary: According to the study, the structural composition of both PBT and PET is mainly characterized by a large fraction of the rigid amorphous phase. The rigid amorphous phase is mainly formed during the primary or secondary crystallization processes at different temperature ranges.
Article
Engineering, Environmental
Dongxing Dun, Yu'an Bai, Longzhen Wang, Bo Xu, Hongfu Zhou, Xiangdong Wang
Summary: Biodegradable poly (lactic acid) (PLA) is widely used as a substitute for petroleum-based plastics to reduce environmental pollution. However, its practical application is limited due to poor crystallization, mechanical and heat resistance properties. To address these issues, a heterogeneous nucleating agent (HNA) was incorporated into PLA matrix, which significantly improved its crystallization rates and mechanical properties. This study provides a feasible method for preparing PLA with excellent mechanical and heat resistance properties.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2023)
Article
Thermodynamics
Pixiang Wang, Yifen Wang, Xueqi Wang, Yucheng Peng, Shaoyang Liu
Summary: The crystallization kinetics of isotactic homopolymer polypropylene (HPP), impact copolymer polypropylene (ICPP), and their composites were investigated. The Avrami-Jeziorny and Mo models accurately described the crystallization process. The nucleation activity and crystallization rate were influenced by the content of ICPP, with the highest rate observed at 60% ICPP. The changes in chain mobility and crystal-crystal interactions accounted for the fluctuations in crystallization rate and activation energy.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)