Premium
Swelling and Tensile Properties of Tetra‐Polyethylene glycol via Coarse‐Grained Molecular Models
Author(s) -
Wang Endian,
Escobedo Fernando
Publication year - 2017
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.201600098
Subject(s) - swelling , polyethylene glycol , materials science , peg ratio , tetra , modulus , solvent , molecular dynamics , composite material , ultimate tensile strength , polymer chemistry , chemistry , computational chemistry , organic chemistry , finance , medicinal chemistry , economics
Coarse‐grained (CG) implicit‐solvent potentials are developed for tetra‐polyethylene glycol (PEG) at different water concentrations using the iterative Boltzmann inversion (IBI) technique. The resulting potentials are used to study the swelling and tensile properties of tetra‐PEG gels at various swelling degrees φ m . Two types of network topologies are considered, one “ideal” with a defect‐free diamond connectivity and the other “realistic” as simulated from an experimentally based cross‐linking process. Equilibrium swelling results for the realistic Tetra‐PEG networks are consistent with available experimental data, while those for the ideal tetra‐PEG networks exhibit much larger swelling. The realistic networks have higher Young's modulus E m at the same φ m than ideal networks due to the presence of trapped entanglements. Uniaxial deformation results of realistic networks show that E m increases with degree of swelling, in accord with experimental results. The Young's moduli of gels at different φ m confirm that the CG potentials developed by IBI are most suited to predict swelling states commensurate with the φ m values at which the potentials were calibrated. A more generic, coarser potential, based on matching the persistence length of atomistic PEG chains in water, is able to produce a similar swelling behavior of an ideal diamond network.