Water Addition and Suspension in molten Polymers – WASP
Water Addition and Suspension in molten Polymers
The addition of polar liquids with low viscosity in polymer melts is widely used in the manufacturing processes of polymers. they are as reactive or vector. Their nature is diverse, the common point being the presence of strong hydrogen bonding. Understanding the mechanisms dictating the dispersion of these liquids in condition of very different viscosity and very different physico-chemistry has an interest from both fundamental and technological. point of views
Large difference of viscosity and physico-chemistry
The first issue concerns the understanding of physical and chemical interactions between polar molecules linked by strong hydrogen bonds and less polar polymers in the vicinity of the boiling point of the liquid. The second issue relates to the huge difference in viscosity and rheological behavior between the water (very low viscosity Newtonian liquid) and polymer melts (high viscosity, viscoelasticity).
On one hand, this project focuses on the effects of temperature on the interactions between water and molten polymers and the influence on the
morphology. On the other hand the effect of the viscosity ratio of the morphology will be studied in given temperature conditions for
several types of polymer. Water and similar liquids with low viscosity hydrogen bonds are studied because they offer a wide range of viscosity between 1mPas and 1Pa. Mixers with shear or elongational effects will be studied
Model systems polymer / liquid were chose according to the compatibility of melting and boiling points. Two apolar and polar copolymers were selected. The liquids used are PEGwith various molar mass. Physical and rheological properties were measured.
Mixtures at low volume fraction of liquid will be carried out in an internal mixer where shear dominates. Morphology will be studied by SEM. In a second stage, an elongational mixer will be used. Capillary number versus viscosity ratio curves will be established.
Publications
The present proposal aims to get a better understanding of the interactions of water and other low viscosity hydrogen bonded liquids and molten polymers in the range of processing temperature below the boiling point of the low viscosity liquids.
This addresses two major issues regarding:
- the physical and chemical interactions between polar molecules linked by strong hydrogen bonds and less polar molten polymers in the vicinity of the boiling point of the low viscosity liquids,
- the huge difference in terms of viscosity and rheological behavior between water (very low viscosity, newtonian fluid) and molten polymer (high viscosity, viscoelastic fluid).
Therefore, this project will focus on:
-the effects of temperature on the interactions between water and polymer melts and the influence on the morphology.
-the effect of the viscosity ratio on the morphology at defined temperature conditions, for various polymer species.
Extensions to other low viscosity hydrogen bonded liquids is also of interest (alcohols, polyethyleneglycol) since this offers a large range of viscosities from 1mPas to 1Pas.
Project coordination
Christian Carrot (UNIVERSITE DE SAINT ETIENNE) – carrot@univ-st-etienne.fr
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Partner
IMP@UJM UNIVERSITE DE SAINT ETIENNE
IMP@INSA INSTITUT NATIONAL DES SCIENCES APPLIQUEES DE LYON - INSA
Help of the ANR 239,824 euros
Beginning and duration of the scientific project:
- 36 Months
