Article
Polymer Science
Ziwei Lai, Nan Zheng, Ziying Liang, Yuanjie Wang, Hui Niu, Ming-Sheng Ji, Bo Ni, Xiang Huang, Xing Ouyang, Xiaoguang Li, Bernard Lotz, Yan Cao
Summary: The research demonstrates the presence of three-dimensional helical chain assembly in isotactic polypropylene under 2D confinement, with integrated assembly observed in both alpha- and gamma-phase crystals. Additionally, two unit-cell orientations of the gamma-phase crystal are shown under cylindrical confinement. The formation mechanism for the radial gamma-phase crystals is explained by the kinetic favorability of alignment with the rod long axis.
Article
Polymer Science
Dong Lyu, Ran Chen, Ying Lu, Yongfeng Men
Summary: Beta alpha recrystallization refers to the melting of beta crystallites followed by recrystallization into alpha phase in iPP. This phenomenon is typically observed after cooling down beta-nucleated iPP from the crystallization temperature to below 100 degrees C before heating. The study investigated this recrystallization process in beta-iPP with different molecular weights during heating starting at the crystallization temperature. It was found that beta-iPP12K, with a molar mass of about 12 kg/mol, exhibited beta alpha recrystallization during slow heating, which gradually reduced with an increase in the Tc of beta-iPP12K. As for beta-iPP with high molar mass, the temperature at which amorphous self-nuclei were induced was already beyond the appropriate temperature for alpha growth.
Article
Engineering, Chemical
Kuo Gai, Xiangfeng Ren, Junyu Chen, Xiling Zhou, Qianbing Wan, Qi Wang, Yijun Li
Summary: In this study, a syndiotactic polypropylene (sPP)/ isotactic polypropylene (iPP) composite tube with reinforced hoop strength and considerable biocompatibility was demonstrated. An iPP network was constructed in situ by rotation extrusion technology, which increased the orientation degree in the hoop direction. The modulus of the iPP fiber-reinforced tubes reached 4.28 MPa/rad, about three times higher than that of the sPP tube. The biocompatibility of the as-prepared tube was evaluated and confirmed to have no impact on cell shape or proliferation, overcoming the current lack of composite materials for medical interventional tubes and expanding the application of sPP matrix.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Polymer Science
Przemyslaw Sowinski, Sivanjineyulu Veluri, Ewa Piorkowska
Summary: This study prepared nanocomposites of isotactic polypropylene with fibrillated PTFE and investigated their crystallization behavior and resulting structure under high pressure. It was found that the addition of fibrillated PTFE increased the crystallization peak temperature of polypropylene and formed a fine-grain structure. This suggests that fibrillated PTFE can promote the crystallization of polypropylene under high pressure.
Article
Polymer Science
Shu-Gui Yang, Liang-Qing Zhang, Changlong Chen, Jiaming Cui, Xiang-bing Zeng, Liying Liu, Feng Liu, Goran Ungar
Summary: Polymorphism of semicrystalline polymers has a significant impact on their physical properties, but determining the shape, spatial distribution, and volume fraction of different coexisting crystal polymorphs remains a challenge. In this study, 3D imaging using two-photon fluorescence confocal microscopy and synchrotron X-ray beam scanning was employed to visualize and quantify the different crystal forms and their specific morphologies. The ability to distinguish crystal forms and their distributions is demonstrated, providing valuable insights into the processing and properties of semicrystalline polymers.
Article
Polymer Science
Miriam Scoti, Fabio De Stefano, Filomena Piscitelli, Giovanni Talarico, Angelo Giordano, Claudio De Rosa
Summary: This study synthesized random isotactic propene-butene copolymers (iPPC4) with different stereoregularity using three different homogeneous single center metallocene catalysts with different stereoselectivity. The findings showed that at high cooling rates, the crystallization of the alpha form was preferred, while at low cooling rates, the crystallization of the gamma form was more common. In the presence of defect concentrations, the gamma form was thermodynamically stable, while the alpha form was kinetically favored.
Article
Polymer Science
Zhixin Guo, Chenyuhe Yuan, Chunfeng Song, Rui Xin, Chunyue Hou, Jian Hu, Huihui Li, Xiaoli Sun, Zhongjie Ren, Shouke Yan
Summary: The epitaxial crystallization of isotactic polystyrene (iPS) on oriented isotactic polypropylene (iPP) substrate and the reverse process of epitaxial growth of iPP crystals on iPS film have been investigated, showing a temperature-dependent relationship between the two processes.
Article
Chemistry, Multidisciplinary
Lucas Stieglitz, Tim M. Lenz, Andreas Saurwein, Bernhard Rieger
Summary: For over 40 years, the synthesis of symmetric non-racemic metallocenes for propylene polymerization required tedious separation. However, under specific conditions, isomerization of non-racemic metallocenes resulted in highly isotactic polypropylene, leading to increased yield.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Thermodynamics
Enrique Blazquez-Blazquez, Tamara M. Diez-Rodriguez, Ernesto Perez, Maria L. Cerrada
Summary: Recycling of plastics, especially commodity polymers such as isotactic polypropylene (iPP) from fossil resources, is crucial in a circular economy. Evaluating the factors that affect the performance of recycled materials is necessary for obtaining new products with optimal properties. Protecting the plastics materials from external degradation and radicals generated during their previous service life is important.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Polymer Science
Jiugeng Cheng, Zhenxing Zhong, Yuan Lin, Zhaohui Su, Chunyu Zhang, Xuequan Zhang
Summary: This work investigates the miscibility behavior of high molecular weight isotactic poly(1-butene) and isotactic polypropylene blends using AFM-IR technique. It is found that the two polymers partially miscible under certain conditions, and the content of polypropylene in each phase can be determined using a quantitative analysis method. The phase separation kinetics and phase diagram of the blends were studied, suggesting a lower critical solution temperature-type phase behavior of PB/PP blends.
Article
Materials Science, Composites
Jingru Liu, Po Yu
Summary: This study investigates the incorporation of liquid-phase exfoliated graphene (G) nanosheets into isotactic polypropylene (iPP) matrix and the subsequent annealing treatment. The results show that the presence of G improves the crystalline structure of iPP and enhances the mobility of chain segments. The addition of well-dispersed G also has a positive effect on stabilizing the beta-crystal during the injection molding process.
POLYMER COMPOSITES
(2022)
Article
Polymer Science
Liyuan Liu, Ying Zhao, Chunbo Zhang, Zhiyuan Dong, Kezhi Wang, Dujin Wang
Summary: The research investigated the impact of the morphological characteristics of N,N'-dicyclohexylterephthalamide (DCHT) on the polymorphic composition of isotactic polypropylene (iPP), showing that small-sized DCHT crystals have a greater influence on the formation of beta-crystals.
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)
Article
Polymer Science
Peiru Liu, Li Peng, Jiajie Chen, Bo Yang, Yanan Chen, Zhongfu Luo, Charles C. Han, Xianbo Huang, Yongfeng Men
Summary: The tensile creep properties of isotactic polypropylene were investigated under different loads and temperatures. The analysis of the true strain-time creep curves revealed a constant increment of strain during the secondary creep, independent of stretching temperature and stress level. The end of the secondary creep and the creep failure time were reached when the deformation of the crystalline skeleton reached its limit. The relationship between creep failure time and temperature followed an Arrhenius behavior, which could be used for predicting creep failure time at lower temperatures.
Article
Polymer Science
Jolanta Kowalonek, Halina Kaczmarek, Boguslaw Krolikowski, Ewa Klimiec, Marta Chylinska
Summary: A new approach was presented for obtaining piezoelectric polymeric films based on isotactic-polypropylene through corona discharge. The study found that surface quality played a crucial role in the possibility of charging the polymeric composites and inducing the piezoelectric effect. High surface smoothness of the polymer films contributed to improved piezoelectric properties without the need for additional polymer modifications.
Article
Polymer Science
Carolus H. R. M. Wilsens, Laurence G. D. Hawke, Gijs W. de Kort, Sarah Saidi, Manta Roy, Nils Leone, Daniel Hermida-Merino, Gerrit W. M. Peters, Sanjay Rastogi
Article
Polymer Science
F. Paolucci, M. J. H. van Mook, L. E. Govaert, G. W. M. Peters
Article
Polymer Science
Fabio Paolucci, Leon Govaert, Gerrit Peters
Article
Polymer Science
Fabio Paolucci, Gerrit W. M. Peters, Leon E. Govaert
JOURNAL OF APPLIED POLYMER SCIENCE
(2020)
Article
Polymer Science
Rosaria Anastasio, Ruth Cardinaels, Gerrit W. M. Peters, Lambert C. A. van Breemen
JOURNAL OF APPLIED POLYMER SCIENCE
(2020)
Article
Polymer Science
Giovanna Grosso, Enrico M. Troisi, Nick O. Jaensson, Gerrit W. M. Peters, Patrick D. Anderson
Article
Polymer Science
Leire Sangroniz, Martin van Drongelen, Ruth Cardinaels, Antxon Santamaria, Gerrit W. M. Peters, Alejandro J. Mueller
Article
Instruments & Instrumentation
Jessica Pepe, Lucien C. Cleven, Eduard J. M. C. Suijkerbuijk, Erwin C. A. Dekkers, Daniel Hermida-Merino, Ruth Cardinaels, Gerrit W. M. Peters, Patrick D. Anderson
REVIEW OF SCIENTIFIC INSTRUMENTS
(2020)
Article
Polymer Science
Nazila Yaghini, Gerrit W. M. Peters
Summary: This paper presents a model of the crystallization kinetics of polyamide 6, including different stages of crystallization and the evolution of the amorphous phase. Parameterized with experimental data, the model shows that the thickness of the rigid amorphous layer plays a crucial role in determining mechanical properties.
Article
Mechanics
F. P. A. van Berlo, R. Cardinaels, G. W. M. Peters, P. D. Anderson
Summary: Filament stretching rheometry is an experimental method for determining rheological properties in extensional flow. This study presents a finite element model to describe flow and stresses, incorporating non-linear viscoelasticity. A modified shear correction factor is proposed for the non-linear viscoelastic flow regime, showing good agreement with simulations for a range of polymers.
Article
Chemistry, Multidisciplinary
Vaidyanath Ramakrishnan, Johannes G. P. Goossens, Theodorus L. Hoeks, Gerrit W. M. Peters
Summary: This paper investigates the terminal viscosity behavior of a polymer melt containing grafted nanosilica particles, revealing that the viscosity of nanocomposites is influenced by the interaction between the polymer matrix and the nanoparticle surface. The study explores the trends in viscosity at different concentrations and suggests that the thickness of the graft layer plays a role in viscosity reduction.
Article
Polymer Science
M. M. A. Spanjaards, G. W. M. Peters, M. A. Hulsen, P. D. Anderson
Summary: This paper presents an experimental strategy for characterizing the rheological behavior of filled, uncured rubber compounds, using oscillatory shear experiments and a phenomenological thixotropy model. The authors compare kinetic equations for a structure parameter to determine the dynamic thixotropic behavior of the material. They aim to keep the models simple and straightforward for maximum applicability.
Article
Polymer Science
Michelle Spanjaards, Gerrit Peters, Martien Hulsen, Patrick Anderson
Summary: The study focuses on the effect of thixotropy on the extrusion swell behavior of highly filled elastomers, finding that thixotropy generally decreases the swell ratio. Changes in the damage and recovery parameters of the fluid, as well as variations in viscosity within the die, significantly impact the extrudate swell ratio.
Article
Polymer Science
Harm J. M. Caelers, Anke de Cock, Stan F. S. P. Looijmans, Ralf Kleppinger, Enrico M. Troisi, Martin van Drongelen, Gerrit W. M. Peters
Summary: This article examines the crystallization behavior of propylene-ethylene random copolymers (PPR) and develops an extended model framework to predict crystallization kinetics and final crystallinity. The accuracy of the model is validated through experiments, providing a new tool for PPR systems.
Article
Crystallography
Frank P. A. van Berlo, Ruth Cardinaels, Gerrit W. M. Peters, Patrick D. Anderson
Summary: A finite element model is developed to describe flow, stress, and crystallization in a filament stretching extensional rheometer (FiSER). The study shows that crystallization affects rheological behavior and the onset of crystallization during filament stretching is influenced by temperature, strain rate, and sample aspect ratio. Nucleation and structure formation are strongly dependent on these factors.
POLYMER CRYSTALLIZATION
(2021)
