Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editors: Stefan Spiegel, Kirsten Severing
Online ISSN: 1521-3919
Associated Title(s): Macromolecular Chemistry and Physics, Macromolecular Materials and Engineering, Macromolecular Rapid Communications, Macromolecular Reaction Engineering
Changwoon Jang, Timothy W. Sirk, Jan W. Andzelm and Cameron F. Abrams
Article first published online: 29 JAN 2015 | DOI: 10.1002/mats.201400094
MD simulations with ad-hoc cross-linking algorithms have been used to generate molecular models of fully cross-linked epoxy materials. Two such algorithms are compared, and it is shown that glassy-state thermal and mechanical properties were not significantly influenced by the algorithm choice. This result notwithstanding, it is shown that the two algorithms result in very different network isomers, pointing toward a possible experimental method of structure validation in future work.
L. Tom Hillegers and Johan J. M. Slot
Article first published online: 29 JAN 2015 | DOI: 10.1002/mats.201400091
From the recipe straight to the MSD. For step-growth polymerized systems of general type “AfiBgi”, a computer algebra method is presented that leads via a few transformation steps from the recipe to the MSD.
Sebastian Primpke and Philipp Vana
Article first published online: 23 JAN 2015 | DOI: 10.1002/mats.201400087
A kinetic scheme describing Catalytic Chain Growth (CCG) polymerization was developed and implemented into the computer program PREDICI, by which experimental concentration versus time traces of the participating individual species obtained from online NMR spectroscopy as well as full molecular weight distributions could successfully be modeled. The method was demonstrated on the CCG of styrene-d8 in toluene-d8 using Cp*2ZrCl2 as the catalyst precursor and dibenzyl magnesium as the transfer agent.
Gülru Kayık and Nurcan Ş. Tüzün
Article first published online: 13 JAN 2015 | DOI: 10.1002/mats.201400096
Propagation kinetics in free radical polymerization of N,N-dimethylacrylamide and N-methylacrylamide is modeled with quantum chemical calculations at dimeric model stage. The propagation rate constant ratio of these monomers is calculated with various density functionals. Calculations shed light on the electronic and steric effects and hydrogen bonding interactions within the reactive species that co-play a role in determining the favorable modes of additions.
Ana West and James T. Kindt
Article first published online: 8 JAN 2015 | DOI: 10.1002/mats.201400093
A simple equation relating the microscopic lifetime of associating chains in a transient network to the shear stress relaxation time, in terms of the concentration dependence of the plateau modulus, is proposed and tested against published experimental data on associating polymers near the gelation transition and against simulated networks well above the gelation transition.
Janusz Walasek and Radosław Jedynak
Article first published online: 8 JAN 2015 | DOI: 10.1002/mats.201400095
Numerical exact calculations show that for long chains the chain end-to-end probability can be Gaussian or non-Gaussian. It depends on the intensity of the orienting interactions inside the system of chains. That result verifies often accepted assumption that long chains are always Gaussian.
Yousef Mohammadi, Hossein Ali Khonakdar, Seyed Hassan Jafari, Mohammad Reza Saeb, Mahdi Golriz, Udo Wagenknecht, Gert Heinrich, Stanislaw Sosnowski and Ryszard Szymanski
Article first published online: 7 JAN 2015 | DOI: 10.1002/mats.201400086
A detailed information on microstructural evolutions during reactive blending of PET and PEN based on fitting of results of numerical integration of differential equations and Kinetic Monte Carlo simulations to experimental data is reported. A broad understanding of transesterification kinetics which enables precise control of architecture of PET-PEN copolymer chains during reactive blending is provided.
Erlita Mastan, Li Xi and Shiping Zhu
Article first published online: 7 JAN 2015 | DOI: 10.1002/mats.201400085
This paper discusses a fundamental question: how thick can a polymer layer grow to in surface-initiated ATRP (SI-ATRP)? or equivalently, what limits the growing of chains from surface? Two models developed from existing theories are compared to experiment trends from literature. It is shown that the current understanding of the mechanism behind SI-ATRP is still incomplete and requires further investigations.
Pascal Hebbeker, Felix A. Plamper and Stefanie Schneider
Article first published online: 2 JAN 2015 | DOI: 10.1002/mats.201400077
Polymeric systems consisting of two different weakly attractive components are investigated using Monte Carlo simulations, comparing various architectures. When arranged in a miktoarm star polymer, complexation is promoted compared to a linear block copolymer and a strictly alternating copolymer.
Jiří Škvor and Zbyšek Posel
Article first published online: 30 DEC 2014 | DOI: 10.1002/mats.201400079
Commensuration of lamellar morphology and simulation box is studied by means of dissipative particle dynamics. The lamellar spacing is found to be influenced by incommensurability effect even for large cubic simulation boxes. The adjusted box dimensions and components of pressure tensor are used for estimating the natural lamellar spacing for generally oriented lamellar planes.
A. M. Schmalzer and A. J. Giacomin
Article first published online: 29 DEC 2014 | DOI: 10.1002/mats.201400058
We examine the simplest relevant molecular model for large-amplitude oscillatory shear flow of a polymeric liquid: the dilute suspension of rigid dumbbells in a Newtonian solvent. We find explicit analytical expressions for the orientation distribution, and use these expressions to examine the detailed shape of the orientation distribution with detailed visualizations all the way around one full alternant cycle.
Article first published online: 15 DEC 2014 | DOI: 10.1002/mats.201400071
A Markovian model is proposed for the self-condensing vinyl polymerization (SCVP), to investigate the full distributions of chain lengths, degrees of branching, and molecular dimensions. When the polymer molecules are fractionated by the chain length, the universal curves for the degree of branching, and the molecular dimension, which are invariant during the course of polymerization were discovered.
Florian Fürstenberg, Andrey A. Gurtovenko, Maxim Dolgushev and Alexander Blumen
Article first published online: 19 NOV 2014 | DOI: 10.1002/mats.201400063
Highly symmetrical, deterministic structures are important representatives for hyperbranched macromolecules; in particular, fractal structures cover a broad class of model polymeric systems. Here, polyamidoamine Vicsek fractals are studied by employing extensive molecular dynamics simulations along with the coarse-grained MARTINI force-field to unravel their structural and dynamic characteristics in dilute solution.
Yang Zhou, Hong-Gang Xia, Xin-Ping Long, Xiang-Gui Xue and Wen Qian
Article first published online: 17 NOV 2014 | DOI: 10.1002/mats.201400072
Rich multicompartment micelles, such as raspberry-onion, helix-on-sphere, cage, ring, worm, bowl, can be formed by the self-assembly of the simplest linear ABC terpolymers in solutions, which is beyond the traditional understanding.
Article first published online: 24 SEP 2014 | DOI: 10.1002/mats.201400047
Numerically calculated values of hydrodynamic branching index in dependence of the radius-of-gyration branching index, g, obey the h3 rule (data of Kurata and Fukatsu (1-4) and ours (straight line)) whereas the points of Zimm and Kilb deviate heavily (5). The value of the branching exponent equal to one appears therefore a plausible approximation.