In Silico Tracking of Individual Species Accelerating Progress in Macromolecular Engineering and Design

Abstract

The beneficial use of computer simulations to track the microstructural evolution of individual species is highlighted in view of macromolecular engineering and design, considering two case studies on catalytic polymerization, and both "low" (<100) and "high" (>100) chain lengths, that is, i) atom transfer radical copolymerization of n-butyl acrylate and styrene aiming at the synthesis of functional macrospecies of "identical' chain length; and ii) chain shuttling polymerization of ethylene and 1-octene toward the production of segmented block copolymers with "soft" and "hard" segments. Model parameters are validated and/or tuned based on literature data. The modeling strategy supports the future identification of chemical structure-polymer property relationships and is based on the combination of principles from polymer reaction engineering, chemistry, and physics.

From time dependent incorporation of molecular building blocks to application properties for inorganic and organic three-dimensional network polymers

“…10 4 -10 5 ) linear or slightly branched chains. 14,25,26 Also in the physics research field, simplifications have been made with force-field-based molecular dynamic (MD) simulations mostly predicting ideal defect-free 3D network structures at high monomer conversion often neglecting molecular kinetic constraints. A key MD assumption is the free movement of atoms or atom groups until the thermodynamically equilibrated configuration is reached, typically recognizing a limited number of chemical bond types and thus ignoring many side (e.g.…”

Intelligent Machine Learning: Tailor-Making Macromolecules

“…The KMC simulator developed previously [19,20,21,22,23,24] acted as a virtual reactor to synthesize chains and look at microstructural aspects of OBCs. The microstructural variables of OBCs can be classified into two categories: (i) those that directly correspond to topological and architectural characteristics of chains, such as LP , DP n SOFT , DP n HARD , ESL SOFT , and ESL HARD ; and (ii) those that indirectly determine the ultimate properties of OBCs, such as LES SOFT , LES HARD , C8% SOFT , C8% HARD , and HB% .…”

“…Application of the IMT and IOT makes it possible to produce new grades of OBCs, with preset characteristics, without numerous trials but only via computer simulations ‘reverse-engineering’ the correct recipe to produce the desired OBC. This kind of approach-finding way to connect 10 microstructural features with highly complex inter-relations of seven synthesis factors, or to determine the possible synthesis variables to obtain a desired set of microstructural features, was tested for the OBC synthesis in references [19,20,21,22,23,24]. The basic scheme developed here can be used in numerous additional ways, spanning from biology to chemistry to physics, provided that some understanding of a possible mechanism exists that can link the input and output variables.…”

“…While this model was successful in obtaining a rough idea of the structure of the OBC, more powerful tools are required for gaining an in-depth understanding of the microstructure. This has been achieved by recent Kinetic Monte Carlo (KMC) simulations of chain-shuttling polymerizations [19,20,21,22,23,24].…”

“…The KMC simulation was designed to track every monomer, CSA, and catalyst molecule as well as every single chain in the virtual reactor in order to obtain the microstructural features of the OBC. These features are represented by average number of linkage points per chain ( LP ), ethylene sequence length ( ESL ) of hard and soft blocks, average degree of polymerization ( DP n ) of hard and soft blocks, longest ethylene sequence length ( LES ) of hard and soft blocks, comonomer content ( C8% ) of hard and soft blocks, and hard block percent ( HB% ) [19,20,21,22,23,24].…”