A quantum mechanical study on polymer flexibility: Extended model from monomer to tetramer of 2- and 4-bromostyrenes

Navarro, Amparo; Fernández‐Liencres, M. Paz; Peña-Ruiz, Tomás; Granadino‐Roldán, José M.; Fernández-Gómez, Manuel; Dominguez-Espinosa, Gustavo; Sanchı́s, M. J.

doi:10.1016/j.polymer.2008.10.041

Cited by 9 publications

(4 citation statements)

References 43 publications

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“…The lower T g of the alternating copolymers having smaller substituents might be related to the energy barrier of backbone rotation. , Hence, we conducted DFT calculations to investigate the energy transition by the C–C bond rotation of model dimer compounds for the MMA-St copolymer: St-MMA, St-St meso, St-St racemo, MMA-St, and MMA-MMA (Figure B; see the Supporting Information). Assuming that the energies of the optimized structures were zero, the relative energies to them were scanned by changing the dihedral angles defined by the four carbons forming the red-colored bonds in Figure B.…”

Section: Resultsmentioning

confidence: 99%

One-Pot Preparation of Methacrylate/Styrene Alternating Copolymers via Radical Copolymerization and Alcoholysis Modification: Sequence Impacts on Glass Transition Temperature

Kametani

Ouchi

2021

ACS Polym. Au

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A series of methacrylate/styrene alternating copolymers were efficiently and systematically synthesized via alternating copolymerization of saccharin methacrylamide (1) with styrene and subsequent one-pot alcoholysis transformation with alcohols. The saccharin amide bond in 1 was stable enough that 1 was used as a bench-stable monomer, but the bond became reactive toward alcohols after the copolymerization. Thanks to the specific feature, the postpolymerization modification could be performed under mild conditions despite easy handling of the monomer. The quantitative transformation as well as the alternating sequence were certainly supported by 1H NMR and MALDI-TOF-MS analyses. The alternating copolymers carrying relatively short alkyl pendants expressed lower glass transition temperatures than those of the statistical counterparts. Moreover, the alternating copolymerization was controlled via a RAFT polymerization system, affording a unique block copolymer composed of alternating copolymer segments.

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Section: Resultsmentioning

confidence: 99%

One-Pot Preparation of Methacrylate/Styrene Alternating Copolymers via Radical Copolymerization and Alcoholysis Modification: Sequence Impacts on Glass Transition Temperature

Kametani

Ouchi

2021

ACS Polym. Au

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“…Since the two ester groups are vicinally substituted on the rings of these polyesters, there should be significant coupling between the θ and φ rotational degrees of freedom. Hence, instead of obtaining one-dimensional (1D) scans 42 – 44 of the potential energy surfaces (PES) corresponding to independent dihedral rotations around θ and φ , we performed full two-dimensional (2D) scans of the rotational PES for each polyester model compound (see Methods section). This approach is analogous to the Ramachandran plots used to study the rotational flexibility of the peptide backbone in proteins 45 , 46 and allows us to investigate the collective nature of these dihedral rotations.…”

Section: Resultsmentioning

confidence: 99%

Unraveling substituent effects on the glass transition temperatures of biorenewable polyesters

Jia

et al. 2018

Nat Commun

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Converting biomass-based feedstocks into polymers not only reduces our reliance on fossil fuels, but also furnishes multiple opportunities to design biorenewable polymers with targeted properties and functionalities. Here we report a series of high glass transition temperature (Tg up to 184 °C) polyesters derived from sugar-based furan derivatives as well as a joint experimental and theoretical study of substituent effects on their thermal properties. Surprisingly, we find that polymers with moderate steric hindrance exhibit the highest Tg values. Through a detailed Ramachandran-type analysis of the rotational flexibility of the polymer backbone, we find that additional steric hindrance does not necessarily increase chain stiffness in these polyesters. We attribute this interesting structure-property relationship to a complex interplay between methyl-induced steric strain and the concerted rotations along the polymer backbone. We believe that our findings provide key insight into the relationship between structure and thermal properties across a range of synthetic polymers.

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“…Thus, statistical methods such as multiple linear regression (MLR) and ANN could be used to develop correlations between the polymer properties and the descriptors obtained from the monomers. In fact, many researches have determined that the properties of polymers are correlated with their monomer structures 17, 18…”

Section: Methodsmentioning

confidence: 99%

A simple three‐descriptor model for the prediction of the glass‐transition temperatures of vinyl polymers

Wang

2009

J of Applied Polymer Sci

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An artificial neural network (ANN) implementing a back-propagation algorithm was applied for the prediction of the glass-transition temperature (T g ) values of 84 polyacrylates and 21 polyvinyls. The experimental T g data of the polymers were divided into a training set (50 polyacrylates) and a testing set (34 polyacrylates and 21 polyvinyls). Three molecule descriptors (mean atomic van der Waals volume, bond information content, and three-dimensional molecule representation of structures based on electron diffraction descriptor for signal 13/weighted by atomic masses, Mor13m) were used as input parameters of the neural network. Simu-lated with the optimum back-propagation ANN 3-[3-2]-1, the root mean square (rms) error for the testing set was 17.7 K, and the correlation coefficient was 0.942, which were accurate in comparison with existing models. The ANN model could be used not only to reveal the quantitative relation between T g and the molecular structure but also to predict the T g values of the polyacrylates and polyvinyls.

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A quantum mechanical study on polymer flexibility: Extended model from monomer to tetramer of 2- and 4-bromostyrenes

Cited by 9 publications

References 43 publications

One-Pot Preparation of Methacrylate/Styrene Alternating Copolymers via Radical Copolymerization and Alcoholysis Modification: Sequence Impacts on Glass Transition Temperature

One-Pot Preparation of Methacrylate/Styrene Alternating Copolymers via Radical Copolymerization and Alcoholysis Modification: Sequence Impacts on Glass Transition Temperature

Unraveling substituent effects on the glass transition temperatures of biorenewable polyesters

A simple three‐descriptor model for the prediction of the glass‐transition temperatures of vinyl polymers

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