The recent status of Japan's government-driven project to establish carbon fiber reinforced thermoplastic composites (CFRTP) technology for automotive applications conducted in the National Composites Center (NCC) Japan is introduced first. baseline discontinuous (C-LFT-D: – long thermoplastic-direct) using press compaction. All components target car chassis made aluminum alloy are replaced by C-LFT-D and a 10% weight reduction with same rigidity has been verified. basic physics length...

A new model for Brownian dynamics simulations of entangled polymeric liquids is proposed here. Chains are coarse grained at the level segments between consecutive entanglements; hence, system in fact a network primitive chains. The incorporates not only “individual” mechanisms reptation and tube length fluctuation, but also collective contributions arising from 3D structure system, such as constraint release. Chain coupling achieved by fulfilling force balance on entanglement nodes. Langevin...

Well-entangled monodisperse linear polystyrene melts exhibit monotonic thinning of the steady state elongational viscosity with increasing strain rate ε̇ even beyond Rouse relaxation frequency, τR-1. This behavior is quite different from followed by hardening at > τR-1 observed for entangled semidilute solutions. We attempt to elucidate molecular origin this difference focusing on concept stretch/orientation-dependent monomeric friction ζ recently proposed Ianniruberto and co-workers....

Oxidative metabolic pathways of propranolol consist naphthalene ring-hydroxylations (at the 4-, 5-, and 7-positions) side-chain N-desisopropylation in mammals. We characterized cytochrome P450 isozymes responsible for metabolism, especially 5-hydroxylation, human liver microsomes. 4-Hydroxy, 5-hydroxy-, N-desisopropylpropranolol were detected as primary metabolites, whereas 7-hydroxypropranolol was trace amounts. Good correlations obtained activities 4- 5-hydroxylases with immunochemically...

Brownian dynamics simulations of the linear viscoelastic response entangled polymers have been performed, and compared quantitatively with some existing solution data at a fixed concentration variable molecular weight. The model is three-dimensional network where nodes are sliplinks connecting chains in pair. make use Langevin equations both for node motion space, one-dimensional monomer sliding through sliplinks. Comparison very satisfactory, but weight between entanglements that emerges...

We revisit previously published dielectric and viscoelastic data of binary blends linear cis-polyisoprene [Watanabe, H.; Ishida, S.; Matsumiya, Y.; Inoue, T. Macromolecules2004, 37, 6619] in order to test the validity dynamic tube dilution (DTD) picture determine most appropriate value exponent α. conclude that DTD with α = 1 is more at short times, while longer time, a larger 4/3 gives better description experiments. Furthermore, between these two time regions, broad crossover zone found,...

We report a multi-chain approach for dissipative particle dynamics where the uncrossability constraints of polymer chains are mimicked by temporary cross-links, so-called slip-springs. The conformational statistics not affected introduction Dynamical properties such as mean square displacements, diffusion coefficient, and longest relaxation time in good agreement with results reptation theory. According to our analysis, present formalism is 500 times faster requires 7 fewer beads than...

We report on recent progress in our understanding of the rheological behavior polymer melts, resulting from work several investigators, mostly fast extensional flows. They contributed new data cleverly conceived experiments, results Brownian and molecular dynamics simulations, suitable theoretical models. The outcome such collective effort is plausible certainty that flow-induced coalignment Kuhn segments modifies friction coefficient, which may depart considerably equilibrium value. It also...

The effect of molecular structure polypropylene (PP) on the melt rheological properties were investigated for electron irradiated polymer and di-2-ethylhexyl peroxy dicarbonate (EHPC)-treated polymer. modifications examined in terms behaviors, weight distribution, degree branching. high strength PP was obtained by irradiating with 50 80 kGy adding EHPC. modified PPs showed strain hardening uniaxial elongational viscosity, though linear viscosity lower than that unmodified PP. Low angle laser...

It has been established that entangled polymer dynamics can be reasonably described by single chain models such as tube and slip-link models. Although the entanglement effect is a result of hard-core interaction between chains, linkage real multi-chain system not yet. In this study, we propose slip-spring model where bead-spring chains are dispersed in space connected slip-springs inspired [A. E. Likhtman, Macromolecules 38, 6128 (2005)]. replaced slip-springs, beads so located niche...

For entangled linear monodisperse polymers, uniaxial elongational flow behavior was examined with the primitive chain network (PCN) simulation, which originally formulated for a of Gaussian chains bound by sliplinks but modified in this study to properly take into account finite extensibility actual chains. On an increase rate ε̇ from terminal relaxation frequency 1/τd (at equilibrium) Rouse 1/τR, original and simulations gave indistinguishable steady state viscosity ηE that almost scaled as...

Nonlinear rheological behavior under uniaxial elongation was examined for unentangled melts of polystyrene (PS27; molecular weight M = 27k) and poly(p-tert-butylstyrene) (PtBS53; 53k) having nearly the same number Kuhn segments per chain (nK 30 35 PS27 PtBS53, respectively). For both materials, steady state elongational viscosity, ηE, exhibited strain-rate-hardening then strain-rate-softening on an increase Weissenberg Wi ≥ 0.3 (Wi ε̇τ1eq, with τ1eq ε̇ being longest relaxation time in linear...

Diphenylamine is a common structure of nonsteroidal anti-inflammatory drugs (NSAIDs) to uncouple mitochondrial oxidative phosphorylation and cause decrease in hepatocellular ATP content hepatocyte injury. The mechanism for acute cell injury induced by diphenylamine its structurally related NSAIDs was investigated with rat liver mitochondria freshly isolated hepatocytes, focusing on the relation uncoupling phosphorylation. Incubation as well mefenamic acid diclofenac caused pseudoenergetic...

Uniaxial extensional flow behavior was measured for the high-melt-strength polypropylene using a Meissner-type rheometer under transient with constant tensile strain rate. The equibiaxial of via lubricated squeezing method consists (PP) as main component and high-molecular-weight polyethylene (PE) long relaxation time (see part 1). This system is generally believed to be an immiscible system, at least quiescent state. Nevertheless, in 1, we have found that PP very PE shows distinctly...

Birefringence measurement demonstrates that the segment orientation of entangled polymers overshoots on start-up fast shear [Pearson et al. J. Rheol. 1989 33, 517-535]. The stress-optical rule holds for those polymers, so overshoot results in stress. On other hand, an opposite result was deduced from recent molecular dynamics simulation bead-spring chain [Lu ACS Macro Lett. 2014 3, 569-573]: evolution does not but stretch induces stress overshoot, even at rate γ̇ smaller than reciprocal...

Entanglement dynamics of polymers under fast elongation has not been fully understood. Namely, the steady-state uniaxial elongational viscosity entangled polystyrene (PS) solutions increases with an increase strain rate above reciprocal Rouse time, whereas PS melts monotonically decreases even at such high rates. This qualitative difference between solution and melt hypothesized to result from orientation/stretch-induced reduction friction (SORF). study examines universality mechanism SORF...

Although the tube models have attained remarkable success, development of a simulation method for entangled branch polymer dynamics is still challenge. In this study, multichain slip-spring model has been examined to polymers first time. model, bead–spring chains are dispersed in box, and entanglement mimicked by virtual spring, so-called slip-spring, which connects hops along chain. The slip-springs created destructed only at chain ends. Besides, relaxation entanglements formed between...

Effects of branch functionality on mechanical properties polymer networks are yet to be fully elucidated, although multi-functional approaches have been mainly attempted. For instance, Fujiyabu et al. [Sci. Adv. 2022, 8, abk0010] recently reported that made from tri-branch prepolymers exhibit superior tetra-branch analogues. Although they attribute the difference stretch-induced crystallization observed in poly (ethylene glycol) networks, mechanism still needs clarified. In this study, we...

Modeling of polymer oxidative aging has been actively studied since the 1990s. Insights from these studies suggest that transport oxygen and radicals significantly influences heterogeneity, alongside chemical reaction kinetics. A recent simulation study [Ishida et al., Macromolecules, 56(21), 8474-8483, 2023] demonstrated mesoscale heterogeneity arises when H-abstraction occurs faster than relaxation times chains. In this study, simulations were extended by modeling rate addition to (k_2)...

Reverse nonequilibrium molecular dynamics (RNEMD) simulations impose a flux by swapping the velocities of two particles. This method allows for calculation transport coefficients, such as thermal conductivity and viscosity. The relation between induced fluxes control parameters RNEMD (such time interval successive swap events) is not clear. Thus, trial-and-error required to realize desired in simulations. In this study, we develop theoretical framework using extreme value statistics estimate...

We investigate the concentration dependence of surfactant diffusion in wormlike micellar solutions using dissipative particle dynamics simulations. The simulations show that self-diffusion coefficient surfactants exhibits a nonmonotonic on concentration, as observed previous experiments. quantitatively reveal this behavior results from competition between center-of-mass and within micelles by decomposing mean-square displacement into corresponding contributions. Furthermore, our detailed...