Morphology development from rod-like to nanofibrillar structures of dispersed poly (lactic acid) phase in a binary blend with poly (vinyl alcohol) matrix along the spinline

作者：Nguyen Hoai An Tran^*; Bruenig Harald; Boldt Regine; Heinrich Gert

来源：Polymer, 2014, 55(24): 6354-6363.

DOI：10.1016/j.polymer.2014.10.002

• Nanofibrils
• Dispersed phase
• Melt spinning

The morphological evolution of thermoplastic poly (vinyl alcohol) (PVA) and poly (lactic acid) (PLA) blend filaments along the spinline is investigated for the first time. Emphasis of the study is given on considering the axial velocity gradient and tensile stress that influence the final state of deformation of the dispersed PLA phase. In this study, pieces of the PVA/PLA blend filaments at different locations along the spinline are collected by using a special self-constructed fiber-capturing device. This fiber-capturing device allows closer off-line study of the morphological properties of PVA/PLA blend filaments. The axial velocity gradient at different zones along the spinline is calculated from velocity data using Laser Doppler Velocimetry (LDV) technique. The tensile stress is determined from the momentum balance equation. It is observed that the fibrillation process takes place up to a certain distance from the die exit, where the polymeric PVA/PLA blend filament reaches its glass transition temperature. In this region, the axial velocity and tensile stress undergoes major changes. A phase inversion of dispersed PLA phase from rodlike structures to continuous long thin fibrils has been found at the point in which the axial velocity gradient reaches a maximum value.

• 出版日期2014-11-18