A nanoscopic view of structure and deformation of hard elastic polypropylene wit

2019-10-10 11:07:00

force surface crystalline elongation rows

责任者: Hild, S.;Gutmannsbauer, W.;Luthi, R.;Fuhrmann, J.;Guntherodt, H.-J. 单位: Inst. of Exp. Phys., Ulm Univ., Germany 来源出处: Journal of Polymer Science, Part B (Polymer Physics)(J. Polym. Sci. B, Polym. Phys. (USA)),15 Sept. 1996,34(12):1953-9 摘要: Scanning force microscopy (SFM) was used to visualize the surface of hard elastic polypropylene (HEPP) film. The surface morphology of unstrained HEPP shows crystalline and noncrystalline rows oriented parallel to the extrusion direction. The crystalline rows are composed of lamellar blocks. The dimensions of crystalline and noncrystalline regions are determined. The structural surface changes induced by stepwise elongation of the film with a home-built stretching device are documented by SFM. Stretching of HEPP perpendicular to the extrusion direction causes cracks advancing through several crystalline rows. During elongation parallel to the extrusion direction the separation of adjacent lamellae by their translatory displacement occurs. Deformation-induced structural changes of HEPP on the nanometer scale are compared with proposed deformation models. Nanostructural changes are correlated with characteristic variations in the force-elongation curve 关键词: atomic force microscopy;brittle fracture;cracks;elongation;extrusion;plastic deformation;polymer films;polymer structure;surface structure;structure;force-elongation curve;hard elastic polypropylene;scanning force microscopy;surface morphology;noncrystalline rows;crystalline rows;parallel;extrusion direction;lamellar blocks;crystalline regions;noncrystalline regions;structural surface;stepwise elongation;film;home-built stretching device;perpendicular;cracks;adjacent lamellae;translatory displacement;deformation-induced structural changes;nanometer scale