Hydroplasticization of polymers: model predictions and application to emulsion polymers
John G Tsavalas1, Donald C Sundberg
1Nanostructured Polymers Research Center, Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824, USA. john.tsavalas@unh.edu
Langmuir : the ACS Journal of Surfaces and Colloids
|January 21, 2010
Summary
Predicting polymer behavior with water as a solvent is crucial for eco-friendly materials. A simple calculation using the polymer
Area of Science:
- Polymer Science
- Materials Chemistry
- Physical Chemistry
Background:
- Plasticization by solvents significantly alters polymer thermal and mechanical properties.
- Water is increasingly used as the sole solvent in polymer synthesis and formulations, driving demand for zero volatile organic compound (VOC) materials.
- Understanding water's impact on the glass transition temperature (T(g)) is critical for predicting polymer performance in aqueous systems.
Purpose of the Study:
- To develop a facile method for predicting the hydroplasticized state of polymers, specifically their glass transition temperature.
- To validate a modified Flory-Fox equation for accurate prediction of water-induced plasticization.
- To extend the predictive model to account for the influence of ionization in pH-responsive polymers.
Main Methods:
- Utilizing the dry state glass transition temperature (T(g)) of the (co)polymer, the T(g) of water, and the saturated weight fraction of water.
- Employing water sorption data and the group additivity method to determine the saturated water content.
- Applying a modified Flory-Fox equation for predictive modeling.
- Incorporating pK(a) values to extend predictions for pH-responsive polymers.
Main Results:
- A modified Flory-Fox equation accurately predicts the hydroplasticized state of copolymers, showing exceptional agreement with experimental measurements.
- The saturated weight fraction of water can be readily calculated using water sorption data and the group additivity method.
- The predictive model was successfully extended to include the impact of ionization for pH-responsive components, validated by experimental data.
Conclusions:
- A simple and accurate method exists to predict the impact of water on polymer glass transition temperature.
- The developed model provides a valuable tool for designing and formulating waterborne polymer systems, particularly for zero VOC applications.
- The inclusion of ionization effects enhances the model's applicability to advanced functional polymers.
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