Poster Session 6, 4:15 PM - 5:00 PM: Campus Center Auditorium [A3]

Presenter: Stephen Demetri Bate

Faculty Sponsor: Jessica Schiffman

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

ABSTRACT

Polymer membrane and film processing has progressively moved away from the toxic non-solvent induced phase separation (NIPS) process and towards the more sustainable aqueous phase separation (APS) method. Recently, it has been shown that a combination of natural and synthetic polyelectrolytes can be used in APS to produce a greener final product by reducing the amount of synthetic polymer present. In order to better understand the effects of APS process parameters on these films, this study evaluates how varying the temperature at different processing steps impacts the final film morphology and properties. The methods used to describe these effects will include the tuning of various film fabrication parameters. Previously, our group has shown optimal casting thickness for coacervates composed of carboxymethyl cellulose (CMC) and poly(diallyldimethylammonium chloride) (PDADMAC) was 40 mil. Using this established casting procedure, this study evaluated temperature as a variable at different steps in the processing method. Shifting temperature in the coagulation, during the drying process, and as a post-process annealing step were all evaluated for their influence on film mechanics and structure. Initial results show that when the coagulation bath is above the glass-transition temperature (45°C), the mechanical behavior of the films drastically changes. Furthermore, when subject to increased temperatures during drying and annealing, films underwent additional shifts in mechanical behavior. This work identifies optimal thermal processing conditions for enhancing the strength and stability of hybrid CMC/PDADMAC films, highlighting the great impact of temperature on the structure and morphology of polymer films.