A morphological study of melt-spun polypropylene filaments by atomic force microscopy

Abstract

Surface morphology of melt-spun polypropylene (PP) filaments, spun from an additive-free PP powder and from a commercial-grade PP with different draw ratios, were examined with atomic force microscopy (AFM). The surface morphology of as-spun filaments was spherulitic. The gradual transformation of the surface structure from a spherulitic morphology to a fibrillar morphology during stretching was studied. In the filaments spun from the commercial-grade PP, the transformation was initiated by deformation of spherulites with a draw ratio of 1.2 and continued with association of lamellar stacks into fibrillar chains with a draw ratio between 1.2 and 2.0. A hierarchical morphological microstructure of fibrils, microfibrils, and nanofibrils was developed with a draw ratio of 4.0. In the filaments spun from the additive-free PP, the association of lamellar stacks into fibrillar morphology occurred considerably later, between draw ratios of 2.0 and 4.0. An oriented lamellar structure was found in these filaments, still with a draw ratio of 4.0.

Surface Properties of Structural Modified PA 6 Fibers

“…The effect of stretching of melt-spun PP filaments was studied by Hautojärvi and Leijala. [26] The surface morphology of as-spun filaments was spherulitic. Wool fibers and their nano-mechanical properties were studied using AFM by Parbhu et al [27] We did not, however, find any references concerning the AFM study of PA 6 fibers.…”

Photodegradation of partially oriented and drawn polypropylene filaments

“…As a result, it was determined that the mesophase remains almost constant during continuous drawing. The surface morphology of melt‐spun PP filaments was examined with atomic force microscopy . In the filaments spun from commercial grade PP, the transformation of a spherulitic morphology to fibrillar morphology during the drawing process and the microstructure of fibrils, microfibrils, and nanofibrils, were pictured …”

“…A model can be assumed based on the previous studies and others not discussed for the sake of brevity. The model for the structure of PP fibers (partially oriented and drawn) is a three‐phase model consisting of fibrils, oriented molecules (mesophase), and an amorphous region .…”

“…27 In the filaments spun from commercial grade PP, the transformation of a spherulitic morphology to fibrillar morphology during the drawing process and the microstructure of fibrils, microfibrils, and nanofibrils, were pictured. 27 A model can be assumed based on the previous studies 1,2,[15][16][17][18][19][20][21][22][23][24][25][26][27] and others not discussed for the sake of brevity. The model for the structure of PP fibers (partially oriented and drawn) is a three-phase model consisting of fibrils, oriented molecules (mesophase), and an amorphous region.…”

Short melamine fiber filled nitrile rubber composites

“…Scanning electron microscopic (SEM) and atomic force microscopic (AFM) studies have been carried out to study the morphological changes on the matrix and the fiber surfaces and at the fiber‐matrix interphase with the incorporation of a dry bonding system to the melamine fiber filled nitrile rubber compound. Though AFM is widely used in the field of polymers,11–18 there are only a few reports available on the use of AFM in the studies of short fiber filled rubber composites 9, 10, 19. Since the dry bonding system comprising resorcinol, hexamine, and silica is known to provide effective reinforcement to elastomeric matrices filled with short fibers,4, 5, 20–22 the same system has been chosen in the present study.…”