Formation of a fibrillar morphology of crosslinked epoxy in a polystyrene continuous phase by reactive extrusion.: An article from: Polymer Engineering and Science
Book Details
PublisherSociety of Plastics Engineers, Inc.
ISBN / ASINB00082PBOA
ISBN-13978B00082PBO6
AvailabilityAvailable for download now
MarketplaceUnited States 🇺🇸
Description
This digital document is an article from Polymer Engineering and Science, published by Society of Plastics Engineers, Inc. on April 1, 2004. The length of the article is 6437 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
From the author: An immiscible polymer blend where the dispersed phase is fibrillar was prepared by in situ crosslinking of the minor phase. A model polystyrene/epoxy-amine blend was selected on the basis of rheological (achievement of the fibrillar structure) and reactivity (fast crosslinking) criteria. The system was a polystyrene/diglycidyl ether of bisphenol A (DGEBA)-aminoethyl piperazine (AEP) blend. At the temperature of extrusion. 180[degrees]C, the DGEBA is immiscible in PS and heterogeneous material is obtained. The elongational flow imposed by drawing the extrudate at the die exit permitted controlled generation of a fibrillar morphology of the dispersed epoxy phase, with a fiber diameter of 1 [micro]m and an aspect ratio greater than 100. It was shown that when the amine comonomer was injected into the extruder, its reactivity with DGEBA at high temperature was high enough to ensure partial crosslinking of the epoxy. The fibrils were formed even though the gel point of the epoxy phase was exceeded. However, above a certain critical insoluble fraction that we estimated to be between 45% and 70%, a coarsening of the structure appeared, caused by the decreasing deformability of the domains and their coalescence. Finally, for our system, the crosslinking of the dispersed phase up to 90% of insoluble fraction did not totally stabilize the morphology after the second processing step (injection molding). Polym. Eng. Sci. 44:625-637. 2004.
Citation Details
Title: Formation of a fibrillar morphology of crosslinked epoxy in a polystyrene continuous phase by reactive extrusion.
Author: Francoise Fenouillot
Publication:Polymer Engineering and Science (Refereed)
Date: April 1, 2004
Publisher: Society of Plastics Engineers, Inc.
Volume: 44 Issue: 4 Page: 625(13)
Distributed by Thomson Gale
From the author: An immiscible polymer blend where the dispersed phase is fibrillar was prepared by in situ crosslinking of the minor phase. A model polystyrene/epoxy-amine blend was selected on the basis of rheological (achievement of the fibrillar structure) and reactivity (fast crosslinking) criteria. The system was a polystyrene/diglycidyl ether of bisphenol A (DGEBA)-aminoethyl piperazine (AEP) blend. At the temperature of extrusion. 180[degrees]C, the DGEBA is immiscible in PS and heterogeneous material is obtained. The elongational flow imposed by drawing the extrudate at the die exit permitted controlled generation of a fibrillar morphology of the dispersed epoxy phase, with a fiber diameter of 1 [micro]m and an aspect ratio greater than 100. It was shown that when the amine comonomer was injected into the extruder, its reactivity with DGEBA at high temperature was high enough to ensure partial crosslinking of the epoxy. The fibrils were formed even though the gel point of the epoxy phase was exceeded. However, above a certain critical insoluble fraction that we estimated to be between 45% and 70%, a coarsening of the structure appeared, caused by the decreasing deformability of the domains and their coalescence. Finally, for our system, the crosslinking of the dispersed phase up to 90% of insoluble fraction did not totally stabilize the morphology after the second processing step (injection molding). Polym. Eng. Sci. 44:625-637. 2004.
Citation Details
Title: Formation of a fibrillar morphology of crosslinked epoxy in a polystyrene continuous phase by reactive extrusion.
Author: Francoise Fenouillot
Publication:Polymer Engineering and Science (Refereed)
Date: April 1, 2004
Publisher: Society of Plastics Engineers, Inc.
Volume: 44 Issue: 4 Page: 625(13)
Distributed by Thomson Gale
