Micromechanical Processes in PET/PC Multilayered Tapes: High Voltage Electron Microscopy Investigations

Abstract

Summary: A totally new kind of multilayered tape consisting of two macroscopically ductile polymers (PET and PC) was studied using high voltage electron microscopy (HVEM). Both components were co‐extruded as uniform laminates with thousands of alternating layers. The multilayered PET/PC samples were annealed at high temperature. Investigation of the multilayered PET/PC tapes with various compositions clearly demonstrated a transition of the microdeformation mechanism which was dependent on the thickness of the individual layers. The annealing of the tapes led to a significant change in the deformation behavior. However, no lamellae formation was revealed in the PET phase after annealing, leading to the assumption of constrained crystallization in very thin PET layers. magnified image

Study of the multilayered nanostructure and thermal stability of PMMA/PS amorphous films

“…It was estimated that the images from the central portion of the specimen were representative of a majority of the cross-section of the specimen. Similar images were obtained previously using standard transmission electron microscopy techniques [31]. Long spacings consisting of a pair of PS and PMMA layers were measured from AFM phase images.…”

Unified model of necking and shear banding in amorphous and semicrystalline polymers

“…Polypropylene exhibits similar macroscopic behavior, as reported, for example, by Drozdov and Christiansen 23 and Sweeney et al 24 The main distinguishing feature between polymers that neck and those that band appears to be that necking polymers undergo larger strains before the start of the instability. Recent work on multilayered poly(ethylene terephthalate)/polycarbonate tapes by Ivan'kova et al 25 has suggested that an increased network density can transform the deformation mechanism into a shear band.…”

Ultra‐Small‐Angle X‐Ray Scattering Study of PET/PC Nanolayers and Comparison to AFM Results

“…Coextruded PET/PC films constitute a new kind of multilayered tape consisting of two macroscopically ductile polymers which shows an interesting transition of the microdeformation mechanism which is dependent on the thickness of the individual layers. [15] One of the benefits of incorporating PET to the system is its ability to crystallize during annealing. This fact offers the opportunity of investigating the variation of the mechanical behavior of the material as PET crystallization develops.…”