(713g) Initiator-Dependent Kinetics of Lyotropic Liquid Crystal-Templated Thermal Polymerization | AIChE

(713g) Initiator-Dependent Kinetics of Lyotropic Liquid Crystal-Templated Thermal Polymerization

Authors 

Saadat, Y. - Presenter, New Mexico State University
Kim, K., University of Minnesota
Foudazi, R., University of Oklahoma
In this study, we evaluate the initiator-dependent kinetics of thermal polymerization in lamellar and hexagonal lyotropic liquid crystal (LLC) structures directed by Pluronic L64. Ammonium persulfate is used to initiate the polymerization from the water phase, whereas azobisisobutyronitrile and benzoyl peroxide are employed to commence the reaction through the monomer phase. We show while that the mesophase structure remains intact for all the initiation systems, the kinetics of polymerization and conversion vary significantly. The obtained differential scanning calorimetry (DSC) results reveal that, under same conditions, initiation from water (IFW) system results in enhanced reaction rates as well as higher monomer conversions compared to initiation from oil (IFO) one. Higher termination rate in LLC nanoconfinements induces lower reaction rates in IFO system. Moreover, our work on different LLC structures show that the effect of nanoconfinement on polymerization rate can be minimized through IFW. Chemorheology not only confirms the results obtained from DSC, but also shows that, in similar monomer conversions, the polymers obtained from IFW system exhibit improved mechanical properties over the samples produced though IFO process.