Structural Properties of Atactic Polystyrene of Different Thermal History Obtained from a Multiscale Simulation

被引：36

作者：

Mulder, Tim ^{[1
,2
]}

Harmandaris, V. A. ^{[3
]}

Lyuin, Alexey V. ^{[1
,2
]}

van der Vegt, N. F. A. ^{[3
]}

Kremer, K. ^{[3
]}

Michels, M. A. J. ^{[1
,2
]}

机构：

[1] Tech Univ Eindhoven, Eindhoven Polymer Labs, Grp Polymer Phys, NL-5600 MB Eindhoven, Netherlands

[2] Dutch Polymer Inst, NL-5600 AX Eindhoven, Netherlands

[3] Max Planck Inst Polymer Res, D-55128 Mainz, Germany

来源：

MACROMOLECULES | 2009年 / 42卷 / 01期

关键词：

MOLECULAR-DYNAMICS SIMULATION; AMORPHOUS POLYSTYRENE; ATOMISTIC SIMULATION; POLYMER MELTS; CONFORMATIONAL CHARACTERISTICS; GLASSY POLYSTYRENES; MONTE-CARLO; CHAIN; NMR; EQUILIBRATION;

D O I：

10.1021/ma800873z

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

A method is presented to obtain well-equilibrated atactic polystyrene (aPS) samples for Molecular simulations. The method starts with equilibrating the polymer in the melt at length scales beyond the Kuhn length l(K), using end-bridging Monte Carlo techniques; at this level a (2:1)-coarse-grained description of aPS is being employed. Subsequently atomistic detail is reintroduced, and the sample is equilibrated at the smallest length scales as well. At length scales beyond Is the simulated polymer chain conformations fulfill the random-coil hypothesis of Flory, and C-infinity = 8.7 +/- 0.1 at 463 K. Eventually various glassy samples are created by subjecting the melt sample to different cooling rates. Pair correlations are in agreement with existing X-ray data, and the amount of dihedral angles in the trans (1) state agrees with NMR data. On the level of dyads, the conformations of racemic dyads agree well with existing NMR results. At the same time, meso dyads conformations do not agree: 65% of meso dyads is in the gt/tg state (NMR: 80%) 25% is in it state (NMR: < 10%). An attempt has been made to relate the observation in simulations, namely that an increase in cooling time causes an increase in yield stress, to effects of the cooling rate on the polymer structure.

引用

页码：384 / 391

页数：8

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