PASTA

English : Japanese

(Polymer rheology Analyzer with Slip-link model of enTAnglement)

PASTA is a stochastic simulation program which calculates the rheological properties of polymeric liquids from a knowledge of the molecular weight distribution and branching structure. The simulation method is based on the slip-link model, in which polymer molecules interact only through the creation and release of binary entanglements.
The three important relaxation mechanisms, i.e., reptation, contour-length fluctuation and constraint release, are taken into account. PASTA can handle polydisperse linear and star polymers, and can calculate various linear and nonlinear rheological properties.

Examples of applications

Linear viscoelasticity
- Linear relaxation modulus
- Storage and loss moduli
Nonlinear stress relaxation
Nonlinear viscosity (shear and elongation)
Dielectric relaxation
Self diffusion coefficient


GPC profile : Polystyrene(PS) (Mw=2.9x10^5, Mw/Mn=2.0) blended with 1.5wt% of high molecular weight PS (Mw=3.2x10^6)	Dynamic moduli : The dynamic moduli of the blend (simulations and experiments)	Elongational viscosity : Uniaxial elongational viscosity of the blend (simulations and experiments)	Slip-link model: Each slip-link constrains a pair of chains, and disappears when either one of the chain moves away from the slip-link.

PASTA Slide Show