Wallace ML, Joós B, Plischke M. Rigidity transition in polymer melts with van der Waals interaction.
PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004;
70:041501. [PMID:
15600413 DOI:
10.1103/physreve.70.041501]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 07/16/2004] [Indexed: 05/24/2023]
Abstract
We study the onset of rigidity near the glass transition (GT) in a short-chain polymer melt modelled by a bead-spring model, where all beads interact with Lennard-Jones potentials. The properties of the system are examined above and below the GT. In order to minimize high-cooling-rate effects and computational times, equilibrium configurations are reached via isothermal compression. We monitor quantities such as the heat capacity CP, the short-time diffusion constants D, the viscosity eta , and the shear modulus; the time-dependent shear modulus Gt is compared with the shear modulus mu obtained from an externally applied instantaneous shear. We give a detailed analysis of the effects of such shearing on the system, both locally and globally. It is found that the polymeric glass displays long-time rigid behavior only below a temperature T1 , where T1 < TG. Furthermore, the linear and nonlinear relaxation regimes under applied shear are discussed.
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