Viscoelastic scaling in polymer gels

✍ Scribed by T. S. Chow

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 379 KB
• Volume: 7
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/(sici)1521-3919(19980301)7:2<257::aid-mats257>3.0.co;2-7

✦ Synopsis

New scaling laws for chain networks are derived to describe the fundamental relationships between the viscosity exponent ( K ) , viscoelastic exponent (m), stretched exponent @), spatial dimension (d), fractal dimension (df), and a universal constant (y). The scaling of the total number of monomers and the radius of gyration is defined by df. We have discovered y = mlb to be a universal constant which relates the shear modulus of a polymer gel melt to the shear modulus near the glass transition. Analyzing the size-dependent shear viscosity, we have determined y = 3dfcd/(7d-5dfc) = 2.647 ford = 3 where dfc is the fractal dimension of critical clusters at the gel point. By using y, the present theory extends previous work pertaining to systems near the sol-gel transition, and shows how properties far from the critical point can be explained. The theoretical prediction is in good agreement with viscoelastic measurements.