Journal Papers Published by the Rubber Research Group
"The effect of low temperature crystallization on the mechanical behaviour of rubber"
Author(s): K.N.G. Fuller, J. Gough and A.G. Thomas
Journal: Journal of Polymer Science: Part B: Polymer Physics, Vol. 42, 2181-2190
In cold climates the correct performance of rubber components such as seismic isolators depends on them maintaining their elastic properties when exposed to prolonged periods at low temperatures. The high damping compounds developed for seismic isolation are normally especially prone to crystallization when exposed to subzero temperatures for periods of a few weeks. The effect of low-temperature crystallization on the mechanical stiffening of natural rubber is evaluated. The relationship between the shear modulus and amount of crystallization is measured using a technique in which the dimensional change and stiffness are monitored simultaneously. The relationship is found to be approximately independent of the crosslink density and the temperature of crystallization. It appears not to be realistically modelled by considering the crystals to behave as rigid filler particles but good qualitative agreement with experiment was obtained by modelling the crystals as a network of threads. Partially crystalline rubbers are found to yield under the application of a large stress like other partially crystalline polymers. Mechanisms for suppressing crystallization in rubber are discussed and the low-temperature stiffening of specially formulated rubber compounds for seismic isolation is presented. These results show that carefully formulated high damping natural rubber compounds can give adequate performance at low temperatures.
Related site: http://www.materials.qmul.ac.uk/rubber