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Can I read Molecular Orientation in Polycarbonate Induced by Cooling Stresses: On the Origin of the Surface Maximum on EtoBox?
Molecular Orientation in Polycarbonate Induced by Cooling Stresses: On the Origin of the Surface Maximum by R. Wimberger-Friedl is a Materials Science article available to read on EtoBox.
What is Molecular Orientation in Polycarbonate Induced by Cooling Stresses: On the Origin of the Surface Maximum about?
Molecular Orientation in Polycarbonate Induced by Cooling Stresses ## On the Origin of the Surface Maximum The origin of the maximum of the birefringence at the surface of injection-molded polymer products is discussed. By systematic variation of the molding conditions with polycarbonate, it is shown that the maximum at the surface not only depends on the filling, but even more so on the packing conditions. The birefringence at the surface is equal in the flow direction and transverse to it. The height scales with the cavity pressure during compression and packing. This cannot be explained by stresses due to the classical fountain flow at the flow front. Instead, the dominating contribution comes from transient deviatoric stresses induced by the compression of the vitrifying polymer in combination with wall adhesion. The pressure-induced stress history in the vitrifying polymer leads to molecular orientation and residual stresses giving a birefringence maximum at the surface.
Who reads Molecular Orientation in Polycarbonate Induced by Cooling Stresses: On the Origin of the Surface Maximum?
It is typically read by researchers, students, and practitioners in Materials Science.
- Author
- R. Wimberger-Friedl
- Publisher
- Walter de Gruyter GmbH
- Published
- 1996
- Language
- EN
- Field
- Materials Science (Physical Sciences)