Matrix Chain Deformation in Reinforced Networks:  a SANS Approach

Abstract

A small-angle neutron scattering (SANS) investigation of matrix chain deformation in an especially designed composite model system for a filled rubber-elastic network is presented. SANS experiments on the structure of polyisoprene homopolymer chains introduced into a well-microphaseseparated triblock polyisoprene-polystyrene-polyisoprene (PI-PS-PI) system of the ABA type are reported. Use is made of the phase-and composition-matching techniques. The data are described in terms of the scattering behavior of the corresponding pure polyisoprene network at larger microscopic than macroscopic strains. The results confirm the model for the strain enhancement in reinforced networks and give the first direct microscopic insights into the mechanisms of reinforcement. A complementary small-angle X-ray scattering (SAXS) study yields all relevant geometrical parameters of the model filler and its detailed behavior under strain.

A 2-dimensional small-angle X-ray scattering study of the microphase-separated morphology exhibited by thermoplastic polyurethanes and its response to deformation

“…Kinning and Thomas [51] used the model to fit SANS data from spherical domains in a microphase-separated block copolymer, while Krakovský et al [27] and Chen-Tsai et al [39] used it to describe SAXS data from PU formulations. The Percus-Yevick model provided the basis for Westermann et al [55] to interpret changes in SAXS from microphase-separated triblock poly(isoprene)-poly(styrene)-poly(isoprene) copolymer and its blends with polyisoprene during deformation.…”

Silica filled elastomers: polymer chain and filler characterization in the undeformed state by a SANS–SAXS approach

“…This condition is quite realistic in the case of a model system, whose composition is known and controllable. Then, by a suitable mixing of labeled and unlabeled chains the filler can be made invisible though its influence is inherently present [5,26]. As a more realistic system in Ref.…”

Polymer Networks in Research and Application

“…Colleagues from the German Federal Research Centre in Jü lich [10] were interested in a method that would allow them to measure the reinforcement by scattering techniques. The idea was, if an unfilled and a filled rubber are stretched to the same extent, the network chains in the filled matrix will be stretched more, Figure 2.…”