In Situ Observation of Tensile Deformation Processes of Soft Colloidal Crystalline Latex Fibers

Abstract

The deformation mechanism of styrene/n-butyl acrylate copolymer latex films with fiber symmetric crystalline structure subjected to uniaxial stretching was studied using synchrotron small-angle X-ray scattering technique. The fibers were drawn at angles of 0, 35, and 55°with respect to the fiber axis. In all cases, the microscopic deformation within the crystallites was found to deviate from affine deformation behavior with respect to the macroscopic deformation ratio. Moreover, the extent of this deviation is different in the three cases. This peculiar behavior can be attributed to the relative orientation of the (111) plane of the crystals, the plane of densest packing, with respect to the stretching direction in each case. When the stretching direction coincides with the crystallographic (111) plane, which is the case for stretching directions of 0 and 55°with respect to the fiber axis, the microscopic deformation deviates less from affine behavior than when the stretching direction is arbitrarily oriented with respect to the crystallographic (111) plan. The dependence of tilting angle and d-spacing of selected (111) or (220) planes from the microscopic crystalline draw ratio are fully in accordance with theoretical considerations.

Large‐Deformation Behavior of Honeycomb‐Structured Polymer Sheets as a Function of Polar Angle

“…Upon stretching HSPS along the different polar angles from 0 to 30°, the stress concentration and distribution of HSPS with 19 holes are also monitored and their photographs at the 80% elongation are represented in Figure Figure 6a–g, respectively. The deformed square meshes, exhibiting the local deformations and stress concentrations, are surprisingly well matched with the computer‐simulated results for the deformed hexagonal structure of diblock copolymers in the nanometer length scale 42–44. This result means that, even though this research looking for the correlation between the mechanical property and the deformed morphology of the patterned polymer structure cannot provide quantitative values in the different length scale, this research can provide the intuitive experimental pictures for the construction of the structure/property relationships of the patterned polymer architecture depending on the symmetry.…”

Crystallographic deformation in mechanically soft colloidal crystals derived from polymeric latex dispersions

“…22,23 The aim of this short article is not to present the functional properties of those materials but it will focus on the underlying mechanism of structural evolution of colloidal crystals constituted by purely mechanically soft polymeric particles during their tensile deformation using synchrotron SAXD techniques. [24][25][26][27] X-ray diffraction has its advantages over optical investigations because the often met problem of multiple scattering during measurements using visible light is not observed in X-ray scattering experiments. In addition, synchrotron sources provide much brighter and better collimated X-ray beams than that from conventional sources making in situ characterization of different systems under non-equilibrium conditions possible, such as in polymers, 28,29 lipidic systems 30,31 and inorganic nano-particle formation 32,33 to name only a few.…”

Nanoparticle rearrangement under stress in networks of cellulose nanofibrils using in situ SAXS during tensile testing

“…[16][17][18] The structural evolution of nanoparticles has previously been analyzed with SAXS, for example, tensile testing of latex films caused the spherical latex nanoparticles to become more ellipsoidal. 19 However, despite analysis of composites of inorganic nanoparticles in cellulose networks and polymer matrices, the use of CNFs as the composite matrix and their interactions with tailored PISA-latexes, especially during the straining-process, has, to the best of our knowledge, not been studied. 16,20 The structural evolution of PISA-latex NPs in the CNF network, and the subsequent toughening, was monitored with SAXS during in situ tensile testing by analyzing the anisotropy in scattering, as well as the direct change in the form and structure factors of the NPs.…”