Rotational Isomeric State Research Articles

Monte Carlo simulation of the crystallization of polyethylene nanocomposites with different shape nanofillers

Monte Carlo simulation of coarse-grained models of polyethylene (PE) nanocomposites was developed to study the effect of nanofiller shapes (nanosphere, nanoplate and nanostick) on the early stage of polymer crystallization under stepwise cooling from the melts. The “polymer forcefield” to describe intra- and intermolecular interaction is composed of the rotational isomeric state (RIS) model of PE and the Lennard-Jones (LJ) potential energetics of ethylene units, respectively. Carbon-based nanofillers were used such that polymer-nanofiller interaction was treated using the same LJ parameters as polymer–polymer interaction. The content of trans conformation and the chain/bond order parameter were determined to quantify the degree of polymer crystallization. Simulation suggests that PE nanocomposites filled with nanostick and nanoplate tend to induce earlier crystalline formation and have more ordered structures, especially nanocomposites with nanoplate filler. In contrast, PE nanocomposites filled with nanosphere exhibit slower crystallization with a lower amount of trans fraction and, as a result, form less ordered structures.

Molecular simulation for the effect of chain stiffness on polymer crystallization from the melts

The chain stiffness that arises from structural constraints and hindrances to internal rotation is intimately related to the macroscopic properties of polymeric materials. The main goal of this study is to examine the role chain stiffness plays in controlling polymer crystallization. Molecular simulations of the coarse-grained (CG) polymer model were used to determine the effect of chain stiffness on the structural formation upon stepwise cooling from the melts. The polyethylene (PE)-like model with different chain stiffness parameter (k) was proposed to modify the statistical weights in the rotational isomeric state (RIS) chains. The PE-like models with 0.5 < k < 1.0 and 1.0 < k < 1.5, can be regarded as more flexible to stiffer chains than normal PE (k = 1.0). Simulation results indicate that the rate of structural formation and the degree of crystallinity are increased better for normal PE chains (k = 1.0). Highly flexible chains (the case of k = 0.5) adopt larger amount of gauche conformation and have much difficulty to form the ordered structure. On the other hand, much stiffer chains (the case of k = 1.5), can still have some gauche conformation which cannot be converted to the trans state upon cooling from the melts. Our study implies that only polymers with the appropriate chain stiffness can exhibit clear evidence for crystallization.

Molecular Simulation of the Crystallization of Polyethylene Nanocomposites: The Effect of Surface Affinity of Nanofillers

AbstractMonte Carlo simulation of coarse‐grained models is used to investigate the effect of polymer–nanofiller interaction on the structural formation of polyethylene nanocomposites with stepwise cooling from the melts. Polyethylene (PE) is represented by the rotational isomeric state (RIS) model and the Lennard–Jones potential function for intrachain energetics and non‐bonded interactions, respectively. Crystallization is monitored using the fraction of trans state and the orientation order parameter at bond and chain scale. The results show that PE nanocomposites with repulsive polymer–surface interaction can enhance faster structural formation and induce larger degree of the ordered structures. On the other hand, nanofiller with attractive polymer–surface interaction causes the chain with lower amount of trans conformation resulted in less ordered structures.

An Efficient Method to Generate Dense Amorphous Structures for Molecular Simulation of Vinyl Polymers

AbstractAn efficient technique to construct dense amorphous polymers at the bulk density is illustrated for two vinyl polymers, i.e., PVX, –[CH2–CH(X)]–. Bulk amorphous polypropylene (PP) and polystyrene (PS) structures are generated starting from coarse‐graining polymer chains and are mapped onto the second nearest neighbor diamond (2nnd) lattice. PVX are represented by the rotational isomeric state (RIS) model and non‐bonded interactions are treated by the Lennard–Jones (LJ) potential function. Lattice Monte Carlo (MC) simulation is utilized to equilibrate coarse‐grained (C) PVX and the fully atomistic models can be recovered by the reverse‐mapping procedure to restore the missing atoms. After geometry optimization, chain and material properties of bulk PVX structure are computed to validate the atomistic models including conformational characteristics, Hildebrand solubility parameter, pair correlation function, and scattering structure factor.

Molecular Simulation of Conformational and Structural Properties of Random Copolymer Nanoparticles

AbstractRandom copolymer nanoparticles are studied by Monte Carlo simulation of coarse‐grained models on the second nearest neighbor diamond (2nnd) lattice. Molecular and surface properties of free‐standing nanoparticle are characterized as a function of co‐monomer fraction. “Polyethylene‐like copolymer” chains are treated by the Rotational Isomeric State (RIS) model of polyethylene (PE). To mimic the characteristics of copolymer chain, non‐bonded interactions with stronger attraction of comonomer units are described by different Lennard‐Jones (LJ) potential parameters. For higher co‐monomer fraction, the bulk densities of nanoparticles are increased and the interfacial profile is sharper. Molecular dimension and shape are changed as a function of co‐monomer composition and mostly in the region close to the surface.

Simulating Stress-Strain Behavior by Using Individual Chains: Uniaxial Deformation of Amorphous Cis- and Trans-1,4-Polybutadiene.

This work develops a probability-based numerical method for quantifying mechanical properties of non-Gaussian chains subject to uniaxial deformation, with the intention of being able to incorporate polymer-polymer and polymer-filler interactions. The numerical method arises from a probabilistic approach for evaluating the elastic free energy change of chain end-to-end vectors under deformation. The elastic free energy change, force, and stress computed by applying the numerical method to uniaxial deformation of an ensemble of Gaussian chains were in excellent agreement with analytical solutions that were obtained with a Gaussian chain model. Next, the method was applied to configurations of cis- and trans-1,4-polybutadiene chains of various molecular weights that were generated under unperturbed conditions over a range of temperatures with a Rotational Isomeric State (RIS) approach in previous work (Polymer2015, 62, 129-138). Forces and stresses increased with deformation, and further dependences on chain molecular weight and temperature were confirmed. Compression forces normal to the imposed deformation were much larger than tension forces on chains. Smaller molecular weight chains represent the equivalent of a much more tightly cross-linked network, resulting in greater moduli than larger chains. Young's moduli computed from the coarse-grained numerical model were in good agreement with experimental results.

Conformational characteristics of poly(3-hydroxyvalerate) (P3HV) and structure-property relationships of P3HV and poly(3-hydroxybutyrate).

Conformational analysis of biosynthetic and biodegradable poly(3-hydroxyvalerate) (P3HV), an analog of poly(3-hydroxybutyrate) (P3HB), was performed. The only structural difference between the two polymers consists in the side chain, which is either methyl (P3HB) or ethyl (P3HV). Molecular orbital calculations and NMR experiments were conducted on a monomeric model compound to determine the bond conformations of the main and side chains of P3HV. The refined rotational isomeric state (RIS) scheme was applied to derive configurational properties of P3HV. The characteristic ratio of P3HV (2.1-3.0) is smaller than that of P3HB (5.4-5.6), indicating greater conformational flexibility of the P3HV chain. The increased flexibility due to the internal rotation of the ethyl side group of P3HV results in a lower equilibrium melting point (130 °C) compared with P3HB (203 °C). The RIS calculations on P3HV also suggested its potential for rubber-like properties. Periodic density functional theory calculations were used to optimize the crystal structures of P3HB and P3HV and obtain their elastic moduli. Three-dimensional Young's modulus distributions of both crystals are closer to isotropic than anisotropic. In conclusion, the material design and usage of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) are discussed.

How asymmetric chirality and chain density affect chain stiffness of polymer melts

Chain stiffness plays a critical role in influencing the thermodynamic and dynamic properties of polymers. Here, all-atom molecular dynamics simulations are employed to study the effects of chain tacticity and temperature on polymer stiffness. Our results show that local stiffness is enhanced by introducing an asymmetric stereochemical unit with opposite chirality joined by all-trans series on polymer chains. The free energy landscape of adjacent dihedral pairs can explain the various chain stiffness of polymer chain with different tacticities. In literature, the temperature dependence of chain stiffness measured by small-angle neutron scattering (SANS)-based experiments contradicts with rotational isomeric state (RIS) predictions and recent single chain simulation results. Our results show that chain stiffness of isotactic PP and PB-1 melt is almost temperature independent, which is consistent with SANS-based measurements. By considering the chain density of polymer melt which is ignored by original RIS theory and single-chain simulations, we point that RIS theory and SANS-based experiments can be harmonic, but the chain density must be explicitly considered for polymer melt.

Monte Carlo simulation of molecular and structural properties of random copolymer thin films.

Molecular and structural properties of random copolymer thin films were studied by Monte Carlo simulation of coarse-grained copolymer model on the high coordination lattice. Random copolymer thin films with 50% comonomer fraction with varied interaction strength between comonomer units were studied. Intramolecular interaction was represented by Flory's rotational isomeric state (RIS) model of polyethylene (PE). The non-bonded interactions were treated by Lennard-Jones potential with different parameter sets for comonomer units. When the interaction strength of comonomer is increased, the density of thin films is higher in the inner region and significantly dropped near the free surface along the normal direction of the film. Higher bulk densities and narrower interfacial thicknesses are observed for random copolymer with stronger bead interaction. End beads were segregated at the free surface region and tend to orient perpendicularly to the surface. Copolymer size and shape were significantly changed as a function of bead interaction. For orientation of the whole chain, the largest molecular axis tends to orient along the film surface, but changed toward random orientation for weaker bead interaction. The intra-chain energies were decreased at the surface region while the non-bonded energies were increased. The stronger the comonomer bead attraction, the more change in energetics across the thin film.

Efficient generation of self-avoiding, semiflexible rotational isomeric chain ensembles in bulk, in confined geometries, and on surfaces

We provide an efficient ready-to-run code gensaw that generates single or large ensembles of self-avoiding, flexible, semiflexible, rotationally isometric or helical chains in the bulk or subject to arbitrary confinement and tethering conditions, where we allow for arbitrary intramolecular bending and dihedral energy functions. The resulting configuration files are provided in various common formats and can be immediately used to do molecular simulations or statistical analysis. We work out analytic expressions for the mean squared end-to-end distance and gyration radius of the semiflexible, helical and rotational isomeric state models with a finite number of bonds and arbitrary interaction potentials for direct comparison and testing of the code in the limiting case of unconfined phantom chains. In addition to the graphics-free linux standalone batch version gensaw that creates configuration and other files for high throughput applications from the command line, we provide an interactive online version gensaw-visualization that serves as platform-independent graphical user interface, and animates the resulting conformations using a remote gensaw server. Program summaryProgram title:gensawCPC Library link to program files:https://doi.org/10.17632/8xfgf88f3w.1Licensing provisions: MITProgramming languages: fortran 90, perl (standalone batch version) or java (interactive online version)Required software:ifort 16+ or gfortran 4+, perl 5+ (standalone batch version), jre 1.8.0+ (interactive online version)Nature of problem: Efficient creation of self-avoiding, semiflexible multibead walks/chains of variable contour length, subject to arbitrary confinement and tethering conditions, characterized by a conformational energy that is composed of arbitrary bending and torsion contributions. The code must produce an ensemble of such chains, using a flexible output format. For the limiting case of chains with zero thickness, the code should reproduce analytic results for the ideal chains.Solution method: We use an adapted enrichment procedure that optimizes its parameters on the fly and derive all analytic results for semiflexible chains with arbitrary bending and torsion potentials for comparison with the created ensembles. While gensaw creates configuration and optionally other files from the command line, gensaw-visualization serves as a platform-independent graphical user interface and allows to visualize and animate the conformations.

Molecular simulation of molecular and surface properties of random copolymer nanoparticle

Random copolymer nanoparticles were studied by Monte Carlo simulation of coarse-grained models on the high coordination lattice. Molecular and surface properties of free-standing nanoparticle were characterized at fixed 50% co-monomer content as a function of the interaction strength between co-monomer units. Intramolecular interaction for all copolymer chains were treated by the Rotational Isomeric State (RIS) model of polyethylene (PE). To simulate the copolymer model, the non-bonded interactions for comonomer units were described by different parameter sets of the Lennard-Jones energy. When the co-monomer interaction was stronger, the bulk densities of nanoparticles were increased and the interfacial widths were narrower. Near the surface, end beads of copolymer chains were segregated and the bond orientation was preferably perpendicular to the surface. Molecular shape and molecular size of copolymer chains were slightly changed as a function of co-monomer interaction strength and most of which occurs close to the surface. For chain orientation, the largest principal axis tended to orient parallelly to the surface, and then changed toward randomly isotropic orientation for weaker co-monomer interaction. The intrachain energies were decreased at the surface region implying more trans conformation while the non-bonded energies were increased due to better monomer packing at the surface region. The change of system energetics was more apparent as a function of the co-monomer interaction.

A Dual-Phase Approach to Reveal the Presence and Impact of the TLL Transition in Polymer Melts. Part II. The Theoretical and Practical Relevance of the TLL Existence and Characteristics on the Understanding of the Melt Thermal Analysis and Rheological Properties of Polymers: Duality and Cross-Duality of the Interactions

In Part I of these 2 parts article, we derived mathematically the existence of a unique state for polymeric melts, occurring at a specific temperature above Tg, which we recognized to be the liquid–liquid transition, TLL, observed and described by Boyer and others. TLL is the temperature at which the melt is in an iso-free-volume and iso-enthalpic state independent of the molecular weight. It is a fundamental property of the material. The purpose of part II is to examine and explain the following: 1) the elusive character of TLL (at the origin of the controversy about the existence of TLL in the past), 2) the increase of free volume at TLL, and 3) the endothermal change of heat capacity on heating across TLL. Finally, our objective is to provide an explanation of TLL and emphasize its importance as an example of a self-dissipative dynamic process that converts, at TLL, into a classical thermally activated process. In this article, the experimental evidence found in the literature for TLL is critically examined to point out the often biased reviews offered by the antagonistic authors of a controversy, here the pros and cons TLL. We propose a Dual-Phase origin of the interactions in polymers to explain the weak and elusive manifestations of TLL and show, by DSC, that the TLL manifestations are made much more visible and prominent when the samples’ state has been brought out of equilibrium. We analyze, in detail, the thermally activated depolarization of samples which have been submitted to a polarization stage by a voltage field. The experimental technique of thermal stimulated depolarization (TSD), and its sister derivative the thermal windowing deconvolution (TWD), are unique and powerful analytical tools that can experimentally characterize “interactive coupling”, the factor that we have assumed is quantitatively responsible for the behavior of polymers and in particular of TLL. The existence and the characteristics of TLL were understood and predicted in Part I from rheological results by the use of the Thermo–Vogel–Fulcher equation whose thermo-kinetic terms, ΔH, ΔS, and T∞, could be interpreted by the interactive coupling of the local free volume and the rotational isomeric conformational state of dual-conformers belonging to the macromolecules, themselves embedded in a collective dissipative system of interactions. The statistics controlling the interactive coupling parameters was described by the Dual-Phase and Cross-Dual-Phase models. In Part II, the same models are used to explain the interactive coupling manifestations specific to the TSD and TWD results. We show that certain characteristics of the TSD and TWD results are directly related to specific parameters of the Dual-Phase model. It is the case for the transitions visible by TSD, such as Tg,ρ related to space charges and local free volume (F-conformers), and TLL marking the end of the specific impact of the Dual-Phase statistics on the properties. It is also the case when interactive coupling is analyzed by TWD: the compensation of the enthalpy and entropy of activation of the relaxations taking place at various polarization temperatures only occurs below TLL, permitting its specific determination. We conclude pointing out the perhaps crucial importance of TLL in establishing the distinct role of thermal energy in structuring or modulating the dynamics of the interactions. The Dual-Phase view of the interactions in polymers suggests that the local density difference between the b-grains and the F-conformers is “time-averaged” by the constant wiping (above Tg) of an “elastic dissipative wave” having a frequency, ωo, i.e., a function of temperature and molecular weight, and thus is different from the Brownian dissipation, i.e., the thermal fluctuation characteristic of the Boltzmann’s mean field (the classical kT/h term). The elastic dissipative wave kinetically loses its collective modulation role and becomes the thermal wave at TLL.

A multiscale simulation of amorphous polystyrene

A multiscale simulation method to investigate amorphous polymeric materials for vinyl polymer was applied for glassy polystyrene (PS) with different tacticity. PS chains were coarse-grained and then mapped onto the second nearest neighbor diamond (2nnd) lattice incorporating short- and long-range interactions from the modified rotational isomeric state (RIS) model and the discretized Lennard-Jones (LJ) potential function, respectively. Bulk PS structures composed of 14 chains with 42 monomer units was generated and equilibrated on lattice Monte Carlo (MC) simulation. The on-lattice properties including molecular size, conformational statistics and chain dynamics were compared. The chain mobility of neat PS melts with different stereochemistry are qualitatively ordered as: iPS < aPS << sPS. There is no clear correlation for these relative diffusions with molecular size and chain stiffness but can possibly be related to the intermolecular contribution i.e. chain packing among neighboring chains. Next, fully atomistic amorphous PS models at the bulk density were obtained by the reverse-mapping procedure to convert the coarse-grained chains to recover the missing atoms. After energy minimization, molecular and material properties including torsional angle distribution, solubility parameter, radial distribution function and neutron scattering intensity are determined and compared for amorphous PS structures.

Molecular Design of Aromatic Polythionoesters

As an example of molecular design of new polymers, structures and properties of poly(ethylene thionoterephthalate) (PET[S2]) and the related polymers have been predicted from calculations of ab initio molecular orbital (MO) theory, rotational isomeric state (RIS) scheme, and periodic density functional theory (DFT). The MO calculations were confirmed by NMR experiments and introduced to the RIS scheme for PET[S2] to yield its configurational properties, which are compared herein with those of analogous polyester, polythioester, and polydithioester. Configurational properties of randomly thiono-substituted poly(ethylene terephthalate) (PET), PET[SzO1–z], were also evaluated as a function of sulfidity (z). On the assumption that the crystal of PET[S2] can be expressed as an isomorphic replacement of the PET crystal, the crystal structure was optimized by a periodic DFT simulation and its Young’s moduli in the a-, b-, and c-axis directions were, respectively, evaluated to be Ea = 0.94(7.20) GPa, Eb = 19.58(22.26) GPa, and Ec = 142.1(182.4) GPa, where the parenthetic values are those of the PET crystal. There is a possibility that properties of PET[SzO1–z] will be controlled between those of PET and PET[S2] by adjusting the sulfidity. The potential practical applications of the polythionoesters are also discussed herein. By purely theoretical computations, the structures and properties of the not-yet synthesized polymers were predicted quantitatively; that is, the theoretical molecular design of new polymers has been achieved.

Effect of Charge Regulation and Conformational Equilibria in the Stretching Properties of Weak Polyelectrolytes

Weak polyelectrolytes can modulate their charge in response to external perturbations, such as changes in the pH, ionic strength (I), or electrostatic interactions with other charged species, a phenomenon known as charge regulation (CR). On the other hand, it is well established that CR is highly coupled with the conformational degrees of freedom. In this paper, the influence of CR in the stretching properties of weak polyelectrolytes is analyzed, and the possibility of CR induced by mechanical stretching is explored. With this aim, we make use of a minimal model, which captures the fundamental aspects present in the stretching of a flexible weak linear polyelectrolyte: internal angle rotation, bond stretching, bond bending, and proton binding, which is the paradigmatic mechanism of CR. The angle rotation is described by using the rotational isomeric state approximation, while for protonation, the site binding model is assumed. Mechanical stretching is studied by performing semi-grand canonical Monte Carl...

Structure–Property Relationships of Poly(glycolic acid) and Poly(2-hydroxybutyrate)

Conformational analysis of poly(glycolic acid) (PGA) and poly(2-hydroxybutyrate) (P2HB) has been carried out via molecular orbital (MO) calculations and NMR experiments on model compounds. The MO energies validated through comparison with the NMR data were introduced into the rotational isomeric state (RIS) scheme to yield the configurational properties of the two polymers. The spatial configuration of the P2HB chain with chiral centers was calculated by the RIS scheme combined with stochastic processes and expressed as a function of (S)/(R) or meso/ racemo ratio. The above results are compared with those obtained previously for poly(lactic acid) and discussed. The density functional theory calculations with a dispersion force correction were performed for PGA crystal under periodic boundary conditions and revealed the origin of its superior thermostability and mechanical strengths.

Molecular simulation of structural and dynamic properties of polymer nanoparticles composed of linear and cyclic polyethylene

Polymer nanoparticles were investigated using Monte Carlo simulation of coarse-grained linear and cyclic polyethylene (PE). The method employs the Flory’s rotational isomeric state (RIS) model and Lennard-Jones potential; respectively, for intra- and inter-molecular interaction. The density of nanoparticle with cyclic chains is slightly higher than that of linear polymers, and the interfacial region is slightly narrower. Structural and orientational properties of linear and ring chains are quite similar. Increased mobility toward the free surface on the scale of beads, bonds and chain is due to the decrease in density. Cyclic polymers move slower than the linear chains. The region of an increased mobility is deeper than the bond length and is attributed to the low density in the surface region rather than to the segregation of chain ends. Rotational and translational motion are faster for linear chains before the molecules encounter the confinement effect of nanoparticles, then there is the cross-over point and chains move slower.

Structural characterization and conformational properties of a polysaccharide isolated from Dendrobium nobile Lindl.

A water-soluble polysaccharide (JCP-40) from Dendrobium nobile Lindl. was extracted and purified. It was demonstrated as a single symmetrical peak based on HPSEC analysis and had an average molecular weight of 67.5 kDa. Combined with monosaccharide composition analysis, methylation analysis, 1D/2D NMR spectroscopy, the structural features of JCP-40 was proposed as follows: the major sugar residues of JCP-40 consisted of →4)-β-ᴅ-Manp-(1→ and →4)-β-ᴅ-Glcp-(1 → . Acetyl groups were found attached to the O-2 or O-3 positions on mannosyl residues based on NMR spectrum results. Rotational isomeric state (RIS)-Metropolis Monte Carlo method indicated that repeating unit increased from 30 to 120, the influence of Mw in this range affected chain flexibility. The conformational parameters (derived from Rg vs Mw and [η] vs Mw) from HPSEC suggested a random coil conformation for JCP-40.

Coupling of Charge Regulation and Conformational Equilibria in Linear Weak Polyelectrolytes: Treatment of Long-Range Interactions via Effective Short-Ranged and pH-Dependent Interaction Parameters.

The classical Rotational Isomeric State (RIS) model, originally proposed by Flory, has been used to rationalize a wide range of physicochemical properties of neutral polymers. However, many weak polyelectrolytes of interest are able to regulate their charge depending on the conformational state of the bonds. Recently, it has been shown that the RIS model can be coupled with the Site Binding (SB) model, for which the ionizable sites can adopt two states: protonated or deprotonated. The resulting combined scheme, the SBRIS model, allows for analyzing ionization and conformational equilibria on the same foot. In the present work, this approach is extended to include pH-dependent electrostatic Long-Range (LR) interactions, ubiquitous in weak polyelectrolytes at moderate and low ionic strengths. With this aim, the original LR interactions are taken into account by defining effective Short-Range (SR) and pH-dependent parameters, such as effective microscopic protonation constants and rotational bond energies. The new parameters are systematically calculated using variational methods. The machinery of statistical mechanics for SR interactions, including the powerful and fast transfer matrix methods, can then be applied. The resulting technique, which we will refer to as the Local Effective Interaction Parameters (LEIP) method, is illustrated with a minimal model of a flexible linear polyelectrolyte containing only one type of rotating bond. LEIP reproduces very well the pH dependence of the degree of protonation and bond probabilities obtained by semi-grand canonical Monte Carlo simulations, where LR interactions are explicitly taken into account. The reduction in the computational time in several orders of magnitude suggests that the LEIP technique could be useful in a range of areas involving linear weak polyelectrolytes, allowing direct fitting of the relevant physical parameters to the experimental quantities.

Infrared emissivity property study and conformational analysis of helical polysilane

ABSTRACTLeft and right single‐handed helical polysilane (L‐HPS and D‐HPS) and racemic helical polysilane (R‐HPS) were synthesized by the Wurtz‐type coupling reaction. The chiral dichloro(methoxycarbonyl ethyl propyl ether)methylsilane monomers applied in copolymerization were derived from methyl d/l‐lactate. The obtained polymers were characterized by 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, circular dichroism spectroscopy, gel permeation chromatography and X‐ray diffraction. Infrared emissivity (IRE) values were also investigated. Compared to R‐HPS, L‐HPS, and D‐HPS, a pair of mirror image, showed higher crystallinity, better thermal stability, and lower IRE (8–14 mm) at the values of 0.592 and 0.576, respectively. The higher regular secondary structure of HPSs was attributed to the formation of intermolecular hydrogen bonds. To further study the configurations of L‐HPS, D‐HPS, and R‐HPS, rotational isomeric state scheme with molecular dynamics simulation have been utilized. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46335.