Macromolecular Theory and Simulations最新文献_第10页

Predicting Multi-Component Phase Equilibria of Polymers using Approximations to Flory–Huggins Theory 用Flory-Huggins理论的近似值预测聚合物的多组分相平衡

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-02-24 DOI: 10.1002/mats.202300001

Stijn H. M. van Leuken, Rolf A. T. M. van Benthem, Remco Tuinier, Mark Vis

{"title":"Predicting Multi-Component Phase Equilibria of Polymers using Approximations to Flory–Huggins Theory","authors":"Stijn H. M. van Leuken, Rolf A. T. M. van Benthem, Remco Tuinier, Mark Vis","doi":"10.1002/mats.202300001","DOIUrl":"10.1002/mats.202300001","url":null,"abstract":"The rational development of sustainable polymeric materials demands tunable properties using mixtures of polymers with chemical variations. At the same time, the sheer number of potential variations and combinations makes experimentally or numerically studying every new mixture impractical. A direct predictive tool quantifying how material properties change when molecular features change provides a less time- and resource-consuming route to optimization. Numerically solving Flory–Huggins theory provides such a tool for mono-disperse mixtures with a limited number of components, but for multi-component systems the large number of equations makes numerical computations challenging. Approximate solutions to Flory–Huggins theory relating miscibility and solubility to molecular features are presented. The set of approximate relations show a wider range of accuracy compared to existing approximations. The combination of the analytical, lower-order, and more accurate higher-order approximations together contribute to a broader applicability and extensibility of Flory–Huggins theory.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 4","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202300001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45001968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Secondary Structure Formation in Hybrid Synthetic/Peptide Polymers: Insights from Molecular Dynamics Simulations 合成/肽杂化聚合物二级结构形成的分子动力学模拟研究

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-02-23 DOI: 10.1002/mats.202200070

Thomas Kunze, Christian Dreßler, Daniel Sebastiani

引用次数: 0

Emergence and Stability of Hierarchical Structures under Cylindrical Confinement 圆柱约束下层次结构的产生与稳定性

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-02-22 DOI: 10.1002/mats.202200076

Tiancheng Chen, Yuci Xu

{"title":"Emergence and Stability of Hierarchical Structures under Cylindrical Confinement","authors":"Tiancheng Chen, Yuci Xu","doi":"10.1002/mats.202200076","DOIUrl":"10.1002/mats.202200076","url":null,"abstract":"Focusing on the formation of hierarchical structure under cylindrical confinement, the self-assembly of A(BC)2B multiblock copolymer of chain length N in a nanopore with size R is studied using the self-consistent field theory. The hierarchical concentric ring (HCk), hierarchical perforated cylinder (HPk), hierarchical helix (HHk), and even hierarchical disk (HDk) is obtained with different number of mid-thin layers k via a proposed design principle. The results show that large pore size and χAB favor the hierarchical structure with more k, while χBC prefers hierarchical structure with less k, consistent with the results of hierarchical structure in bulk. By investigating the effect of the volume fraction of the tail A block (fA), the phase transition sequence, HCk → HPk → HHk → HDk is explored, which shares the same transition of multiblock copolymer in bulk with Lk → Gk → Ck → Sk. Finally, the phase diagram with respect to the fA and R is explored, where the stability regime of these hierarchical structures is well understood. The results provide a compelling panacea for the fabrication of hierarchical 3D nanostructures under confinement.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 3","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42836221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Masthead: Macromol. Theory Simul. 1/2023 刊头：Macromol。理论模拟。2023年1月

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-01-19 DOI: 10.1002/mats.202370002

引用次数: 0

Numerical Characterization of Mixing in a Kneading Element Channel of Dual-Speed Corotating Non-Twin Screws Using Lagrangian Statistics Method 用拉格朗日统计方法对双速旋转非双螺杆捏合元件通道内混合的数值表征

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-01-19 DOI: 10.1002/mats.202370001

Baiping Xu, Ruifeng Liang, Shuping Xiao, Lingcao Tan, Jian Song, Huiwen Yu

引用次数: 0

Combining 13C-NMR Triad Sequence Data with Joint Molecular Weight and Composition Data to Estimate Parameters in a Gas-Phase Polyethylene Reactor Model 结合13c‐NMR三重序列数据与联合分子量和组成数据来估计气相聚乙烯反应器模型的参数

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-01-12 DOI: 10.1002/mats.202200073

Jakob I. Straznicky, Jennifer P. Aiello, Lauren A. Gibson, Yan Jiang, Timothy Boller, Hsu Chiang, Kimberley B. McAuley

{"title":"Combining 13C-NMR Triad Sequence Data with Joint Molecular Weight and Composition Data to Estimate Parameters in a Gas-Phase Polyethylene Reactor Model","authors":"Jakob I. Straznicky, Jennifer P. Aiello, Lauren A. Gibson, Yan Jiang, Timothy Boller, Hsu Chiang, Kimberley B. McAuley","doi":"10.1002/mats.202200073","DOIUrl":"10.1002/mats.202200073","url":null,"abstract":"A three-site metallocene catalyst is used in a gas-phase semi-batch reactor to produce ethylene/hexene copolymers. At the end of each batch, polyethylene (PE) is collected and analyzed to determine the carbon-13 nuclear magnetic resonance (13C-NMR) triad sequence distribution. Joint molecular weight (MW) and composition distribution data are obtained using gel permeation chromatography with an infrared detector (GPC-IR). Data from ten experimental runs are used for kinetic parameter estimation. Using a mean-squared error (MSE) selection methodology, 23 of the 36 model parameters are selected for estimation using the available polymerization rate and PE characterization data. The remaining parameters are held at initial guesses to avoid overfitting. Addition of the triad data to the parameter estimation problem allows for one additional parameter to be estimated and results in improved parameter estimates. Standard deviations of all but one of the estimated parameters decreased due to inclusion of triad data. The updated parameter estimates result in good fits for the triad data and for joint MW and composition data. The model accurately predicts four validation data sets not used for parameter estimation. The new model and its updated parameter estimates will be valuable for scaling up new polymer grades from laboratory-scale to commercial-scale.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 3","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42656307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molecular Simulation and Experimental Study on the Damping and Aging Properties of 4010NA/Hydrogenated Nitrile Butadiene/Nitrile Butadiene Rubber Composites 4010NA/氢化丁腈橡胶/丁腈橡胶复合材料阻尼与老化性能的分子模拟与实验研究

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-01-06 DOI: 10.1002/mats.202200072

Meng Song, Meng Wang, Chaole Wang, Jihong Song, Yunan Li, Fengyi Cao, Guomin Yu, Qi Qin

{"title":"Molecular Simulation and Experimental Study on the Damping and Aging Properties of 4010NA/Hydrogenated Nitrile Butadiene/Nitrile Butadiene Rubber Composites","authors":"Meng Song, Meng Wang, Chaole Wang, Jihong Song, Yunan Li, Fengyi Cao, Guomin Yu, Qi Qin","doi":"10.1002/mats.202200072","DOIUrl":"10.1002/mats.202200072","url":null,"abstract":"The effects of N-isopropyl-N′-phenyl-phenylenediamine (4010NA) content on the damping and aging properties of hydrogenated nitrile butadiene rubber (HNBR)/nitrile butadiene rubber (NBR) (abbreviated as H-NBR) matrix are studied via molecular simulation and experiments. The effects of 4010NA addition on the damping and aging properties of H-NBR are analyzed by molecular simulation using solubility parameters (δ), hydrogen bonds, free volume fraction (FFV), binding energy (Ebinding), hydrogen bond dissociation energy (ΔG), and mean square displacement (MSD). The damping, mechanical, and thermo-oxygen aging properties of the 4010NA/H-NBR composites are studied experimentally using infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results indicate that 4010NA has good compatibility with HNBR and NBR, and the addition of 4010NA can effectively improve the damping properties of H-NBR. When 4010NA is added at 32 phr, the composite has better damping properties, mechanical properties, and aging resistance, which provides a new insight for the construction of high performance elastomer composites.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 2","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41316722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effect of Topology on the Collapse Transition and the Instantaneous Shape of a Model Heteropolymer 拓扑结构对模型异聚物塌缩跃迁和瞬时形状的影响

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-01-04 DOI: 10.1002/mats.202200074

Thoudam Vilip Singh, Lenin S. Shagolsem

引用次数: 0

Random Branching and Cross-linking of Polymer Chains, Analytical Functions for the Bivariate Molecular Weight Distributions 聚合物链的随机分支和交联，二元分子量分布的分析函数

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2022-12-23 DOI: 10.1002/mats.202200062

Rolf Bachmann, Marcel Klinger, Jan Meyer

{"title":"Random Branching and Cross-linking of Polymer Chains, Analytical Functions for the Bivariate Molecular Weight Distributions","authors":"Rolf Bachmann, Marcel Klinger, Jan Meyer","doi":"10.1002/mats.202200062","DOIUrl":"10.1002/mats.202200062","url":null,"abstract":"Cross-linking and branching of primary polymer molecules are investigated using the Galton–Watson (GW) process. Starting with the probability generating function (pgf) of the primary molecular weight distribution (MWD), analytical expressions are derived for the bivariate pgfs g(nbr, s) of branched polymers which depend also on the number of branch points nbr. The bivariate MWDs n(nbr, i) (i: number of molecular units) are then derived as Taylor expansions in s. All three cases of random branching: X-shaped (cross-linking), T-shaped (only one end takes part in the branching process), and H-shaped (both ends can take part in the branching process) are treated. An extension of the formalism does not require the construction of the pgf and allows the direct use of the MWD of the primary chains. However, using pgfs allows to go past the gel point and to determine the MWD and content of the sol. Explicit expressions are given for special distributions: the mono modal, the most probable, the Schulz-Zimm, the Poisson, and the Catalan distribution for the cases of X-shaped and T-shaped branching.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 3","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44506970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Polyimide/Silica Nanocomposites with Enhanced Tensile Strength: Size Effects and Covalently Bonded Interface 增强拉伸强度的聚酰亚胺/二氧化硅纳米复合材料：尺寸效应和共价键合界面

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2022-12-07 DOI: 10.1002/mats.202200066

Yu Wang, Wenlong Yang, Jiaqi Lin, Xinmei Liu, Yuhang Zuo, Hongguo Sun, Ying Yang

{"title":"Polyimide/Silica Nanocomposites with Enhanced Tensile Strength: Size Effects and Covalently Bonded Interface","authors":"Yu Wang, Wenlong Yang, Jiaqi Lin, Xinmei Liu, Yuhang Zuo, Hongguo Sun, Ying Yang","doi":"10.1002/mats.202200066","DOIUrl":"10.1002/mats.202200066","url":null,"abstract":"In this work, the tensile strength of polyimide/silica composites with the covalently bonded interface (bonded PI/SiO2) is investigated by molecular dynamic simulation. It is found that the nanofiller with smaller size can bring out a larger number of hydrogen bonds and interfacial non-bond energy in the composites, resulting in higher tensile strength. As the immobilization of the PI chains in the vicinity of SiO2, the covalently bonded interface is found to offer a greater reinforcing effect than the unbonded interface that is confirmed by the self-diffusion coefficient. The tensile strength of 9 wt.% bonded PI/SiO2 composites is 11.34% higher than that of the unbounded composites. The tensile strength of PI/SiO2 composites is enhanced with the increase of SiO2 concentration up to critical mass percent (Xc), beyond which it will be decreased. To quantitatively predict Xc of PI/SiO2 composites, an empirical equation based on the non-bond energy of the composites is proposed. The empirical equation showed that the Xc of PI/SiO2 composites ranged from 8.03 to 10.36 wt.%, which is consistent with experimental values. These results provided the understanding of size-dependent covalently bonded interface structure, which would be beneficial to the design of nanocomposites with excellent mechanical performances.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 2","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45908224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1