Synthesis and properties of poly(norbornene)s with lateral aramid groups

Kong, Phally; Drechsler, Susanne; Balog, Sandor; Schrettl, Stephen; Weder, Christoph; Kilbinger, Andreas F. M.

doi:10.1039/c9py00187e

Cited by 9 publications

(3 citation statements)

References 23 publications

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“…Although exo -5-norbornenecarboxylic acid is one of the most commonly employed functional monomer precursors for ROMP, 5-norbornene- endo -2,3-dicarboxylic anhydride represents an attractive low-cost alternative (e.g., <$15/kg) , that can be easily transformed into a diverse array of functional diester or imide monomers in a single step. However, literature examples conventionally use exo -norbornene monomers − for ROMP owing to their reduced steric encumbrance and concomitantly increased reactivity and polymerization control relative to their endo-counterparts. − Although reports on ROMP of endo -norbornene monomers exist, − the utility of stable chelated initiators in combination with these less reactive, yet more accessible endo -derivatives has not been systematically examined. The reduced accessibility of exo -norbornene imide monomers arises in part from the requisite endo -to- exo isomerization for norbornene-anhydride that is both energy (∼180 to 250 °C) and time/material intensive (up to 16 h reaction time and as many as six recrystallizations from benzene with <20% overall yield). ,− From an applied perspective, endo -norbornene imide polymers have been observed to possess higher glass transition temperatures relative to their exo -analogues, a likely consequence of increased segmental packing and energetic barriers to backbone rotation while retaining comparable thermal stability and mechanical performance. , Thus, a rapid and controlled polymerization strategy for endo -norbornene monomers using a tunable and stable metathesis initiator would be of significant utility to the polymer science community.…”

Section: Introductionmentioning

confidence: 99%

User Guide to Ring-Opening Metathesis Polymerization of endo-Norbornene Monomers with Chelated Initiators

et al. 2022

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The development of facile synthetic strategies to access well-defined polymers promises to provide advanced soft materials with functionality that rivals that observed from nature. To this end, ring-opening metathesis polymerization (ROMP) presents a compositionally simple and rapid strategy for controlled polymerization, yet it has received far less attention relative to radical counterparts. This limited attention arises in part from scattered reports on optimization strategies and a narrow monomer scope. Contemporary ROMP methods favor the use of exo-norbornene derivatives and highly reactive nonchelated Ru-alkylidenes, such as Grubbs Catalysts. In contrast, endo-norbornene derivatives, from which analogous exo-forms are often generated, present a more accessible alternative, yet examples of their utility in ROMP remain scarce. Herein, a systematic examination of ROMP with endo-norbornene monomers using stable chelated Ru-alkylidene initiators is presented. Through initiator screening and polymerization optimization, the ROMP process is shown to be versatile and robust, providing rapid access to polymers with excellent molecular weight control, low dispersities (Đ < 1.1), good functional group tolerance, and high chain-end fidelity that enabled the preparation of block copolymers via sequential monomer addition. Furthermore, the process is oxygen-tolerant, allowing for ROMP to be performed under ambient conditions on the bench, which was showcased in synthesizing mechanically robust endonorbornene imide thermoplastics with high glass transition and decomposition temperatures. This report provides a comprehensive overview of the scope and limitations of endo-norbornene ROMP with chelated initiators, serving as a user guide for the polymer chemistry community to develop well-defined next-generation functional plastics.

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Section: Introductionmentioning

confidence: 99%

User Guide to Ring-Opening Metathesis Polymerization of endo-Norbornene Monomers with Chelated Initiators

et al. 2022

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“…Norbornene polynomial scaffolds have recently gained interest in optical, electronic, and theragnostic applications due to an ability to retain low scattering loss while possessing high glass transition temperatures, adhesion, and low values of dielectric constants. , The glass transition temperature ( T g ) and dielectric constant (ε) are crucial parameters dictating a polymer’s physical and chemical properties in dielectric polymer applications. The dielectric constant determines the permittivity characteristics of a polymer and can be changed significantly upon the incorporation of various functional groups.…”

Section: Methodsmentioning

confidence: 99%

Dielectric Polymer Property Prediction Using Recurrent Neural Networks with Optimizations

Nazarova

Yang

Liu

et al. 2021

J. Chem. Inf. Model.

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Despite the growing success of machine learning for predicting structure−property relationships in molecules and materials, such as predicting the dielectric properties of polymers, it is still in its infancy. We report on the effectiveness of solving structure−property relationships for a computer-generated database of dielectric polymers using recurrent neural network (RNN) models. The implementation of a series of optimization strategies was crucial to achieving high learning speeds and sufficient accuracy: (1) binary and nonbinary representations of SMILES (Simplified Molecular Input Line System) fingerprints and (2) backpropagation with affine transformation of the input sequence (ATransformedBP) and resilient backpropagation with initial weight update parameter optimizations (iRPROP − optimized). For the investigated database of polymers, the binary SMILES representation was found to be superior to the decimal representation with respect to the training and prediction performance. All developed and optimized Elman-type RNN algorithms outperformed nonoptimized RNN models in the efficient prediction of nonlinear structure−activity relationships. The average relative standard deviation (RSD) remained well below 5%, and the maximum RSD did not exceed 30%. Moreover, we provide a C++ codebase as a testbed for a new generation of open programming languages that target increasingly diverse computer architectures.

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“…3,4 Functional group tolerance of Grubbs catalysts for ring-opening metathesis polymerization (ROMP) allows the direct polymerization of monomers having certain reactive functional groups like hydroxyl, carboxyl, amide, azo, and epoxy groups. [5][6][7][8][9][10][11][12][13] Cycloolefin polymers (COPs) are generally synthesized through the ROMP of cycloolefins with high ring strain followed by subsequent hydrogenation of the remaining double bonds in the polymer backbone (Scheme 1a). [14][15][16][17][18][19][20][21] Hydrogenation decreases the glass transition temperature of COPs due to the increased backbone flexibility but enhances the chemical and heat resistance.…”

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confidence: 99%

Epoxy functionalized cycloolefin polymers by ring-opening metathesis polymerization

Cho

Kim

2022

Polym. Chem.

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Synthesis and properties of poly(norbornene)s with lateral aramid groups

Abstract: This paper deals with the synthesis and investigation of comb-like poly(norbornene)s carrying lateral rod-like aramid groups.

Cited by 9 publications

References 23 publications

User Guide to Ring-Opening Metathesis Polymerization of endo-Norbornene Monomers with Chelated Initiators

User Guide to Ring-Opening Metathesis Polymerization of endo-Norbornene Monomers with Chelated Initiators

Dielectric Polymer Property Prediction Using Recurrent Neural Networks with Optimizations

Epoxy functionalized cycloolefin polymers by ring-opening metathesis polymerization

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