Experimental study of elastomer swelling kinetics

The obtained solutions can be applied to experimental study of the diffusive and thermodynamic properties of elastomers. In particular, with the relation 

Experimental estimates of the parameter r can be obtained from the strain curve l(t) using Eqs. [6.1.31] and [6.1.40]. Then by making use of the formula 

The value of diffusion coefficient in an equilibrium swelling state can be determined from die final section of kinetic swelling curve using Eq. [6.1.44], which is expressed in terms of dimensional variables as 

Note that all these relations are valid only for sufficiently high values of elastomer swelling ratio. 

The obtained theoretical predictions have been verified in experiments on real elastomers. The elastomers tested in our experiments were amorphous polybutadiene urethanes (PBU) wifli polymer network of different density 0.3 kmol/m (PBU-1), 0.05 kmol/m (PBU-2), 0.2 kmol/m (PBU-3), 0.1 kmol/m (PBU-4). Oligooxypropylene triol - Laprol 373 was used as a crosslinking agent at the curing of prepolymer of oligobutadiene diol. The elastomer specimens were manufactured in the form of disks, 35 mm in diameter and 2 mm thick. The kinetics of specimen swelling was determined in low-molecular liquids toluene, dibutyl sebacate (DBS), dioctyl sebacate (DOS). 

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