Properties and functionalities of polymeric materials can be influenced by the incorporation during synthesis of different chemical species - chain transfer agents, crosslinkers, hydrophilic and hydrophobic monomers - to tailor properties such as chain length, architecture, or composition. Competitive effects of crosslinkers and chain transfer agents on the polymer characteristics and on their behavior under different environmental conditions are assessed by spectroscopic and thermal methods, used in a synergistic approach to highlight differences in polymer chain architecture.<br/>High molecular weight acrylamide-based copolymers with different crosslinker content, synthesized via inverse emulsion polymerization are chosen as case study. The incorporation of chain crosslinking segments onto the hydrophilic main chains confers them unique properties, particularly of interest in enhanced oil recovery.<br/>Molecular weight distribution and details on chain conformation and structure are investigated by size exclusion chromatography (SEC) while changes in behavior under different environmental conditions (ionic strength) are followed by non-separation characterization routes; the automated light scattering & viscosity-based methodologies are especially useful in applications concerning high molecular weight polymers and branched macromolecules since they offer a multi-faceted characterization and, in the same time, overcome SEC limitations.<br/>Influencing the polymer chain architecture allows also tuning their thermal and mechanical properties. The response of the glass transition temperature and other parameters to changes in the polymer chain length and degree of crosslinking are followed by differential scanning calorimetry and thermogravimetric analysis.<br/>The study highlights not only the variables more effective, under certain conditions, in influencing the endproduct properties, but also the polymer features most affected by these changes and thus, more relevant in comparing the products performance. In the same time, it engages the characterization techniques in a continuous dialogue for enhanced accuracy and relevance of the information for targeted applications.

Competitive effects of synthesis parameters on polymer chain architecture and behavior under changes in environmental conditions

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.