Self-Assembly and Mechanical Properties of Thermally Reversible Triblock Copolymer Gels

Self-Assembly and Mechanical Properties of Thermally Reversible Triblock Copolymer Gels

Mahla Zabet, ¹ Satish Mishra, ¹ Katie Weigandt, ² and Santanu Kundu^1*

1. Dave C. Swalm School of Chemical Engineering, Mississippi State University, MS State, MS, 39762
2. NIST Center for Neutron Research Gaithersburg, MD 20899-6100, US

Self-assembly of block copolymers in selective solvents resulted in ordered structures such as micelles, vesicles, and physically cross-linked gels. The polymeric gels are of particular interest because of their applications in many areas such as in drug delivery, tissue engineering, and food materials. This study presents the self-assembly and mechanical properties of a thermoreversible gel prepared by dissolving poly (methyl methacrylate)-poly (n-butyl acrylate)-poly (methyl methacrylate) [PMMA-PnBA-PMMA] in 1-butanol, a selective solvent for the PnBA block. At low temperature the PMMA end blocks form aggregates, which are connected by PnBA midblock. Utilizing the RheoSANS set-up at NIST, the evolution of microstructure in these gels having polymer concentration of 7%, 10% was captured at three different temperatures: in viscous liquid state, in gel state, and near the gelation point. The structural change of these gels as a function of applied strain and temperature, captured from SANS experiments, will be reported in this presentation.