Faculty Sponsor: Faculty Name Goes Here
Live Poster Session: Zoom Link
Abstract: Poor miscibility in polymer blends is a major obstacle for the recycling of mixed-waste plastics. The recycling process requires intensive plastic-waste sorting because phase separation in inhomogeneous polymer blends weakens the tensile strength of recycled materials.(1) Adding crosslinks is one path toward compatibilization. As opposed to the static crosslinks often suggested in literature, dynamic crosslinks are advantageous because they can break and reform over time, which facilitates large-scale rearrangement in the material.(2) This project conducts molecular simulations to study the effect of dynamic crosslinks on polymer miscibility. Our goal is to use dynamic crosslinks to reduce the surface tension between the interface of the two polymers. The resulting material will be the most robust over multiple recycling processes if polymers can repeatedly mix and de- mix. Therefore, it is desirable to increase physical miscibility without significantly reducing the temperature of phase separation. We find that dynamic bonds reduce the critical temperature, Tc, and the 0.1 magnitude of this effect depends on the chemical potential, 𝜇. We measure the miscibility of the system using two methods for evaluating surface tension, Irving-Kirkwood (1949) and Gloor (2005). Surface tension exhibits dependence on both temperature and dynamic bonds, where higher chemical potentials decrease the temperature for which the system has zero surface tension. This project focuses exclusively on inter-type crosslinks between the two different polymers. We hope to find a method to reduce surface tension to zero at temperatures below Tc with future work on intra-type crosslinks.
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