In-situ Structure Characterization of Elastomers during Deformation and Fracture

This thesis offers novel insights into the time-dependent structural evolution of polymers under deformation. In-situ tensile experiments at high-brilliance synchrotron sources allowed to characterize the material with unrivaled resolution in time and space. The strain-induced crystallization in natural rubber was studied by wide-angle X-ray diffraction. Special emphasis was put on the establishment of new structure-property relationships to give a more in-depth understanding of the mechanical performance of rubber parts, e.g. in tear fatigue loading. To this end, the kinetics of strain-induced crystallization were investigated, subjecting the material to high strain rates. The local structure around a crack tip was observed by scanning wide-angle X-ray diffraction. Ultra-small angle X-ray scattering served to study filled elastomers under deformation, from specially prepared model filler systems to industrially relevant carbon black filled rubbers. Other methods include electron microscopy coupled with in-situ tensile testing and optical dilatometry to examine cavitation in rubbers. The underlying theory as well as a literature review are covered by an extensive introductory chapter, followed by a description of the experimental techniques. The results are presented in more detail than in the original journal publications.

Nominated by the Technical University Dresden (Germany) and by the Leibniz Institute of Polymer Materials Dresden as an outstanding PhD thesis Provides new insight into the structural behavior of natural rubber under mechanical loads Employs a multitude of experimental investigation techniques (incl. WAXD, SAXS, SEM) and combines them with newly developed methodology for the sample preparation Includes a comprehensive introduction to and concise review of the field, introducing the reader carefully to the topic and methodology Includes supplementary material: sn.pub/extras

Inhalt
Introduction.- Motivation and Objectives.- Experimental.- Results.- Conclusion and Outlook.- Appendix.