Investigation of Crystallization and Relaxation Effects in Coarse-Grained Polyethylene Systems after Uniaxial Stretching.

Polymers (Basel)

Institute of Technology, Resource and Energy-Efficient Engineering (TREE), Bonn-Rhein-Sieg University of Applied Sciences, Grantham-Allee 20, 53757 Sankt Augustin, Germany.

Published: December 2021

In this study, we investigate the thermo-mechanical relaxation and crystallization behavior of polyethylene using mesoscale molecular dynamics simulations. Our models specifically mimic constraints that occur in real-life polymer processing: After strong uniaxial stretching of the melt, we quench and release the polymer chains at different loading conditions. These conditions allow for free or hindered shrinkage, respectively. We present the shrinkage and swelling behavior as well as the crystallization kinetics over up to 600 ns simulation time. We are able to precisely evaluate how the interplay of chain length, temperature, local entanglements and orientation of chain segments influences crystallization and relaxation behavior. From our models, we determine the temperature dependent crystallization rate of polyethylene, including crystallization onset temperature.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8703326PMC
http://dx.doi.org/10.3390/polym13244466DOI Listing

Publication Analysis

Top Keywords

crystallization relaxation
8
uniaxial stretching
8
crystallization
5
investigation crystallization
4
relaxation effects
4
effects coarse-grained
4
coarse-grained polyethylene
4
polyethylene systems
4
systems uniaxial
4
stretching study
4

Similar Publications

Time evolution of a pumped molecular magnet-A time-resolved inelastic neutron scattering study.

Proc Natl Acad Sci U S A

January 2025

William H. Miller III Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218.

Introducing an experimental technique of time-resolved inelastic neutron scattering (TRINS), we explore the time-dependent effects of resonant pulsed microwaves on the molecular magnet CrFPiv. The octagonal rings of magnetic Cr atoms with antiferromagnetic interactions form a singlet ground state with a weakly split triplet of excitations at 0.8 meV.

View Article and Find Full Text PDF

Elucidation of the Off-Center Displaced Mo in Octahedral Coordination in BaMoO.

Inorg Chem

January 2025

Radiation Science & Technology Department, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, Delft 2629JB, The Netherlands.

The detailed crystal structure as well as the heat capacity at low temperature and standard entropy of BaMoO are reported for the first time. High-resolution X-ray and neutron diffraction were employed to reveal the structural features of this compound. BaMoO has a six-coordinated Mo and a strongly negative excess volume with respect to the binary oxides.

View Article and Find Full Text PDF

Spectroscopic Signatures of Phonon Character in Molecular Electron Spin Relaxation.

ACS Cent Sci

December 2024

Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States.

Spin-lattice relaxation constitutes a key challenge for the development of quantum technologies, as it destroys superpositions in molecular quantum bits (qubits) and magnetic memory in single molecule magnets (SMMs). Gaining mechanistic insight into the spin relaxation process has proven challenging owing to a lack of spectroscopic observables and contradictions among theoretical models. Here, we use pulse electron paramagnetic resonance (EPR) to profile changes in spin relaxation rates ( ) as a function of both temperature and magnetic field orientation, forming a two-dimensional data matrix.

View Article and Find Full Text PDF

Research on perovskite light-emitting diodes (PeLEDs) has primarily focused on modulating crystal growth to achieve smaller grain sizes and defect passivation using organic additives. However, challenges remain in controlling the intermolecular interactions between these organic additives and perovskite precursor ions for precise modulation of crystal growth. In this study, we synthesize two triphenylphosphine oxide (TPPO)-based multidentate additives: bidentate hexane-1,6-diyl-bis(oxy-4-triphenylphosphine oxide) (2-TPPO) and tetradentate pentaerythrityl-tetrakis(oxy-4-triphenylphosphine oxide) (4-TPPO).

View Article and Find Full Text PDF

Synthesis, Trans-Cis Photoisomerization, Fluorescence Decay Studies of Methoxy Ester Functionalized Alkoxy Side Chain Azobenzene Compounds and Their Photoluminescence Dynamics.

J Fluoresc

December 2024

Centre for Nano and Material Sciences, Jain (Deemed-to-be) University, Jain Global Campus, Ramanagaram, Bangalore, 562112, Kanakpuram, Karnataka, India.

In this study, a series of new methoxy ester functionalized core fluorinated, chloro-fluorinated azobenzene derivatives were synthesized. The molecular structures of the azobenzene derivatives (3a-3c and 4a-4c) were confirmed through various analytical methods, with variations in the alkoxy chain length on one end of the aromatic ring. Optical absorption studies of 3a, 3b revealed π-π* transitions around 368-392 nm.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!