Executive Summary : | Recycling incompatible mixed plastics waste is a significant challenge in addressing the plastics problem. A synergistic coupling of universal static crosslinking of polymers and adaptable time-dependent covalent bonds between polymers, known as universal dynamic crosslinkers (UDCs), is being developed for efficient recycling of mixed plastic waste. The goal is to understand the interplay between static and dynamic crosslinks in a polymer blend and design UDCs that can reactivate immiscible mixed plastic "dead" chains into compatibilized "living" grafted multiblock copolymers (gMBCPs). This work aims to improve reprocessability, enhance tensile strength and creep resistance, and maximize recovery of the endowed energy and materials value of individual plastics. The formation of gMBCPs will aid in compatibilizing immiscible blends, while their reconfigurability will facilitate their use through multiple cycles. Dynamically crosslinked networks, especially those with longer lifetimes, may slow down blend compatibilization kinetics but will help temporal stability under lower temperature conditions. Microphase-separated systems are most relevant from an end-use perspective as they retain the unique characteristics of individual components. The proposed work will focus on establishing these hypotheses using coarse-grained and all atom molecular simulations. The project will study the transformation from immiscibility to miscibility of the blend, establishing the correlation between miscibility extent, crosslink number, lifetime, and interaction between the two polymers. The study will also calculate the mechanical and elastic properties of the blend with gMBCPs via non-equilibrium molecular dynamic simulations. |