Thermodynamics Of Rubber Elasticity

In the next section the choice of stress τ length l and temperature t as state variables is justified and a simple equation of state is presented.

Thermodynamics of rubber elasticity. Here we need to also consider the extension. Rubber is a member of a larger class of materials called elastomers and it is difficult to overestimate their economic and. The molecular processes responsible for rubber elasticity are most readily interpreted in terms of the constant volume coefficients u l v t and s l v t. Deformation is a constant volume process ν.

Thermodynamics of a rubber band. Thermoelastic measurements at constant volume are reported for a series of natural rubber samples. The cross linking property of polymers is vital to the band s elasticity. This paper describes only the thermodynamic properties of vulcanized rubber.

Theory of rubber elasticity thermodynamics statistical mechanics and chain statistics kelvin kuhn guth mark james treloar and flory second law of thermodynamics. Without this property the rubber band would have no reason to tend towards a tangled state since the entropy would be about the same in both states. If you released a rubber band with properties like that it would. Rubber elasticity is in fact the number of chains bounded by two cross link junctions a quantity called the number of active chains denoted.

Taken as a whole the results from thermodynamic studies on lightly cross linked rubbery polymers support the view that the retractive force is primarily intramolecular in origin. The elastic recovery of rubber is due to its tendency to maximize the entropy. Thermodynamics of rubber elasticity at constant volume. This can be repeated many times with no apparent degradation to the rubber.

Metallic materials possess energy elasticity while ideal. The molecular processes responsible for rubber elasticity are most readily interpreted in terms of the constant. Elastic properties of vulcanized rubber depend on the degree of linkage. The energy component of the stress supported by the network is more or less independent of.

Rubberlike elasticity is described. The process of vulcanization which links the polymer molecules into a three dimensional network enables reversible thermodynamic measurements to be made on elastomeric materials from which the entropy and energy contributions to the free energy of deformation can be determined. It can be stretched by up to a factor of 10 from its original length and when released returns very nearly to its original length. Thermodynamics of rubber elasticity article in journal of chemical education 78 2 february 2001 with 1 612 reads how we measure reads.

2 thermodynamics of elasticity when we write down the di erential of uin courses in chemical thermodynamics we nor mally only consider pressure volume work.