Pub Date : 2024-11-15DOI: 10.1021/acs.macromol.4c02074
Ikechukwu Martin Ogbu, Eli J. Fastow, Karen I. Winey, Marisa C. Kozlowski
To advance a strategy of polymer-to-polymer upcycling of waste polyolefin by dehydrogenation then functionalization, we report successful hydroesterification of polycyclooctene (PCOE), an analogue for partially unsaturated polyethylene. Here, we convert PCOE to a linear analog for poly(ethylene-co-ethyl acrylate) (EEA) across a range of ethyl acrylate incorporations (0 to 18 mol % of ethylene units). The ester incorporation was well controlled by reaction time, and the remaining C═C bonds were subsequently hydrogenated. The bulky ethyl acrylate groups did not incorporate into orthorhombic PE crystals, decreasing the crystallinity, crystallite size, and melting temperature with increasing functionalization. Additionally, hydroesterification tuned the dynamic mechanical properties, decreasing both the glass transition temperature and the storage modulus in the rubbery regime with greater functionalization. The linear EEA analogs reported here achieve remarkable extensibility (strain > 4000%) and high toughness, comparable to commercial random and branched EEA. Ultimately, we demonstrate successful conversion of an analogue to dehydrogenated PE to a linear EEA with favorable mechanical properties.
{"title":"Hydroesterification of Polycyclooctene to Access Linear Ethylene Ethyl Acrylate Copolymers as a Step Toward Polyolefin Functionalization","authors":"Ikechukwu Martin Ogbu, Eli J. Fastow, Karen I. Winey, Marisa C. Kozlowski","doi":"10.1021/acs.macromol.4c02074","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02074","url":null,"abstract":"To advance a strategy of polymer-to-polymer upcycling of waste polyolefin by dehydrogenation then functionalization, we report successful hydroesterification of polycyclooctene (PCOE), an analogue for partially unsaturated polyethylene. Here, we convert PCOE to a linear analog for poly(ethylene-<i>co</i>-ethyl acrylate) (EEA) across a range of ethyl acrylate incorporations (0 to 18 mol % of ethylene units). The ester incorporation was well controlled by reaction time, and the remaining C═C bonds were subsequently hydrogenated. The bulky ethyl acrylate groups did not incorporate into orthorhombic PE crystals, decreasing the crystallinity, crystallite size, and melting temperature with increasing functionalization. Additionally, hydroesterification tuned the dynamic mechanical properties, decreasing both the glass transition temperature and the storage modulus in the rubbery regime with greater functionalization. The linear EEA analogs reported here achieve remarkable extensibility (strain > 4000%) and high toughness, comparable to commercial random and branched EEA. Ultimately, we demonstrate successful conversion of an analogue to dehydrogenated PE to a linear EEA with favorable mechanical properties.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"75 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1021/acs.macromol.4c02046
Ellen J. Quane, Niels Elders, Anna S. Newman, Sophia van Mourik, Neal S. J. Williams, Keimpe J. van den Berg, Anthony J. Ryan, Oleksandr O. Mykhaylyk
A range of charge-stabilized aqueous polyurethane (PU) dispersions comprising hard segments formed from hydrogenated methylene diphenyl diisocyanate (H12MDI) with dimethylolpropionic acid (DMPA) and ethylenediamine, and soft segments of poly(tetramethylene oxide) of different molecular weights are synthesized. Characterization of the dispersions by mass spectrometry, gel permeation chromatography, small-angle X-ray scattering, atomic force microscopy, and infrared spectroscopy shows that they are composed of PUs self-assembled into spherical particles (primary population) and supramolecular structures formed by hydrogen-bonded H12MDI and DMPA acid-rich fragments (secondary population). Analysis of the scattering patterns of the dispersions, using a structural model based on conservation of mass, reveals that the proportion of supramolecular structures increases with DMPA content. It is also found that the PU particle radius follows the predictions of the particle surface charge density model, originally developed for acrylic statistical copolymers, and is controlled by hydrophile (DMPA) content in the PU molecules, where an increase in PU acidity results in a decrease in particle size. Moreover, there is a critical fractional coverage of hydrophiles stabilizing the particle surface for a given polyether soft-segment molecular weight, which increases with the polyether molecular weight, confirming that more acid groups are required to stabilize a more hydrophobic composition.
我们合成了一系列电荷稳定的水性聚氨酯（PU）分散体，这些分散体由氢化亚甲基二苯基二异氰酸酯（H12MDI）与二羟甲基丙酸（DMPA）和乙二胺形成的硬段以及不同分子量的聚四亚甲基氧化物软段组成。利用质谱法、凝胶渗透色谱法、小角 X 射线散射法、原子力显微镜和红外光谱法对分散体进行的表征表明，分散体由自组装成球形颗粒的 PU（原生群）和由氢键连接的 H12MDI 和 DMPA 富酸片段形成的超分子结构（次生群）组成。利用基于质量守恒的结构模型对分散体的散射模式进行分析后发现，超分子结构的比例随着 DMPA 含量的增加而增加。研究还发现，聚氨酯颗粒半径与最初针对丙烯酸统计共聚物开发的颗粒表面电荷密度模型的预测结果一致，并受聚氨酯分子中亲水基（DMPA）含量的控制，聚氨酯酸度的增加会导致颗粒尺寸的减小。此外，在给定的聚醚软段分子量条件下，有一个临界的亲水基团覆盖率可以稳定颗粒表面，该覆盖率随聚醚分子量的增加而增加，这证明需要更多的酸性基团才能稳定更疏水的成分。
{"title":"Synthesis, Morphology, and Particle Size Control of Acidic Aqueous Polyurethane Dispersions","authors":"Ellen J. Quane, Niels Elders, Anna S. Newman, Sophia van Mourik, Neal S. J. Williams, Keimpe J. van den Berg, Anthony J. Ryan, Oleksandr O. Mykhaylyk","doi":"10.1021/acs.macromol.4c02046","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02046","url":null,"abstract":"A range of charge-stabilized aqueous polyurethane (PU) dispersions comprising hard segments formed from hydrogenated methylene diphenyl diisocyanate (H<sub>12</sub>MDI) with dimethylolpropionic acid (DMPA) and ethylenediamine, and soft segments of poly(tetramethylene oxide) of different molecular weights are synthesized. Characterization of the dispersions by mass spectrometry, gel permeation chromatography, small-angle X-ray scattering, atomic force microscopy, and infrared spectroscopy shows that they are composed of PUs self-assembled into spherical particles (primary population) and supramolecular structures formed by hydrogen-bonded H<sub>12</sub>MDI and DMPA acid-rich fragments (secondary population). Analysis of the scattering patterns of the dispersions, using a structural model based on conservation of mass, reveals that the proportion of supramolecular structures increases with DMPA content. It is also found that the PU particle radius follows the predictions of the particle surface charge density model, originally developed for acrylic statistical copolymers, and is controlled by hydrophile (DMPA) content in the PU molecules, where an increase in PU acidity results in a decrease in particle size. Moreover, there is a critical fractional coverage of hydrophiles stabilizing the particle surface for a given polyether soft-segment molecular weight, which increases with the polyether molecular weight, confirming that more acid groups are required to stabilize a more hydrophobic composition.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"83 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1021/acs.chemrev.4c0055210.1021/acs.chemrev.4c00552
Christopher J. Chang*,
{"title":"Introduction: Fluorescent Probes in Biology","authors":"Christopher J. Chang*, ","doi":"10.1021/acs.chemrev.4c0055210.1021/acs.chemrev.4c00552","DOIUrl":"https://doi.org/10.1021/acs.chemrev.4c00552https://doi.org/10.1021/acs.chemrev.4c00552","url":null,"abstract":"","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"124 21","pages":"11639–11640 11639–11640"},"PeriodicalIF":51.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1021/acs.macromol.4c01714
Jaeyong Lee, Emily E. Abdo, Cody Pratt, Yong Hyun Kwon, Jaeeon Lim, Vivaan Patel, Lilin He, Nitash P. Balsara
We studied blend electrolytes comprising poly(ethylene oxide) (PEO), poly(pentyl malonate) (PPM), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Ion transport in the blend electrolytes resembles transport in PEO/LiTFSI and PPM/LiTFSI systems. The thermodynamic properties of the PEO/PPM/LiTFSI blend electrolytes were studied by small-angle neutron scattering (SANS). The effect of added salt on polymer blend thermodynamics is quantified by an effective Flory–Huggins interaction parameter, χeff. The blend electrolytes exhibit one-phase, and χeff is negative at all salt concentrations. This is noteworthy because the addition of salt generally leads to macrophase-separation in polymer blends.
{"title":"Completely Miscible Polymer Blend Electrolyte Studied by Small-Angle Neutron Scattering","authors":"Jaeyong Lee, Emily E. Abdo, Cody Pratt, Yong Hyun Kwon, Jaeeon Lim, Vivaan Patel, Lilin He, Nitash P. Balsara","doi":"10.1021/acs.macromol.4c01714","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c01714","url":null,"abstract":"We studied blend electrolytes comprising poly(ethylene oxide) (PEO), poly(pentyl malonate) (PPM), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Ion transport in the blend electrolytes resembles transport in PEO/LiTFSI and PPM/LiTFSI systems. The thermodynamic properties of the PEO/PPM/LiTFSI blend electrolytes were studied by small-angle neutron scattering (SANS). The effect of added salt on polymer blend thermodynamics is quantified by an effective Flory–Huggins interaction parameter, χ<sub>eff</sub>. The blend electrolytes exhibit one-phase, and χ<sub>eff</sub> is negative at all salt concentrations. This is noteworthy because the addition of salt generally leads to macrophase-separation in polymer blends.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"69 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142609836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1021/acs.macromol.4c01773
Hongdeok Kim, Joonmyung Choi
In this study, we investigated the mechanism by which the microphase structure of polyurethane (PU), manipulated by the chemical composition, determines its macroscopic mechanical properties. Increasing the hard segment content induced a microphase transition from globular to elongated to bicontinuous. This transition significantly altered the mechanical behavior of PU from hyperelastic to elasto-plastic. This enhancement in the mechanical properties was related to the load-transfer capacity of the hard domains in each microphase. In the globular phase, most of the strain energy was absorbed by the soft matrix, limiting the contribution of the hard phase to the mechanical properties. Conversely, elongated discontinuous structures facilitated a homogeneous strain distribution during tension, promoting an immediate load transfer to the hard domain. To quantitatively evaluate the load-transfer efficiency, a mechanical model in which one soft hyperelastic spring was coupled to two rigid elasto-plastic springs was considered. The effects of the microphase morphology and hard domain dissociation on the load-transfer capability were identified. This study contributes to a molecular-level understanding of the deformation behavior and mechanical response of microphase-separated PU.
{"title":"Molecular-Scale Investigation of the Microphase-Dependent Load Transfer Capability of Polyurethane","authors":"Hongdeok Kim, Joonmyung Choi","doi":"10.1021/acs.macromol.4c01773","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c01773","url":null,"abstract":"In this study, we investigated the mechanism by which the microphase structure of polyurethane (PU), manipulated by the chemical composition, determines its macroscopic mechanical properties. Increasing the hard segment content induced a microphase transition from globular to elongated to bicontinuous. This transition significantly altered the mechanical behavior of PU from hyperelastic to elasto-plastic. This enhancement in the mechanical properties was related to the load-transfer capacity of the hard domains in each microphase. In the globular phase, most of the strain energy was absorbed by the soft matrix, limiting the contribution of the hard phase to the mechanical properties. Conversely, elongated discontinuous structures facilitated a homogeneous strain distribution during tension, promoting an immediate load transfer to the hard domain. To quantitatively evaluate the load-transfer efficiency, a mechanical model in which one soft hyperelastic spring was coupled to two rigid elasto-plastic springs was considered. The effects of the microphase morphology and hard domain dissociation on the load-transfer capability were identified. This study contributes to a molecular-level understanding of the deformation behavior and mechanical response of microphase-separated PU.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"6 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1021/acs.macromol.4c02386
Mustafa H. Ahmed, Jinhyo Hwang, Bufan Xiao, Matthew R. Schiavone, Jagrity Chaudhary, Min Chen, Jianguo Mei
n-Doped poly(benzodifurandione) (n-PBDF) is an n-type conducting polymer with characteristics such as high electrical conductivity, solution processability, and weathering stability. Here, we systematically investigate the structure property relationship on the impact of structural modifications through aromatic substitution on the photophysical, electrical, and structural properties of n-PBDF and its oligomeric derivatives. We demonstrated that an electron donation group (methyl) raised the highest occupied molecular orbital energy level (+0.15 eV), while electron-withdrawing halogens (Br and Cl) decreased the lowest unoccupied molecular orbital energy level (−0.12 and −0.13 eV, respectively) in the polymers. Additionally, in both the undoped and doped oligomeric systems, these substitutions introduce large torsion angles (θ > 17°), causing the material to twist significantly. Moreover, the methyl-substituted polymer, n-PBDF-Me, was evaluated for its potential as a transparent organic conductor, due to its high optical transmittance (T550 > 93%). However, n-PBDF-Me films have significantly lower conductivity than n-PBDF (0.40 vs 1330 S/cm) at similar thickness.
n 掺杂聚（苯并二呋喃二酮）（n-PBDF）是一种 n 型导电聚合物，具有高导电性、溶液加工性和耐候稳定性等特点。在此，我们系统地研究了通过芳香族取代进行结构修饰对 n-PBDF 及其低聚衍生物的光物理、电学和结构特性的影响。我们发现，电子捐献基团（甲基）提高了聚合物的最高占有分子轨道能级（+0.15 eV），而电子抽离卤素（溴和氯）则降低了聚合物的最低未占有分子轨道能级（分别为-0.12 和-0.13 eV）。此外，在未掺杂和掺杂的低聚物体系中，这些取代物引入了较大的扭转角（θ >17°），导致材料明显扭曲。此外，由于甲基取代聚合物 n-PBDF-Me 具有很高的透光率（T550 >93%），因此对其作为透明有机导体的潜力进行了评估。然而，在厚度相似的情况下，n-PBDF-Me 薄膜的导电率明显低于 n-PBDF（0.40 vs 1330 S/cm）。
{"title":"Synthesis and Characterization of n-Doped Poly(benzodifurandione) (n-PBDF) Derivatives via Aromatic Substitution","authors":"Mustafa H. Ahmed, Jinhyo Hwang, Bufan Xiao, Matthew R. Schiavone, Jagrity Chaudhary, Min Chen, Jianguo Mei","doi":"10.1021/acs.macromol.4c02386","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02386","url":null,"abstract":"n-Doped poly(benzodifurandione) (<b>n-PBDF</b>) is an n-type conducting polymer with characteristics such as high electrical conductivity, solution processability, and weathering stability. Here, we systematically investigate the structure property relationship on the impact of structural modifications through aromatic substitution on the photophysical, electrical, and structural properties of <b>n-PBDF</b> and its oligomeric derivatives. We demonstrated that an electron donation group (methyl) raised the highest occupied molecular orbital energy level (+0.15 eV), while electron-withdrawing halogens (Br and Cl) decreased the lowest unoccupied molecular orbital energy level (−0.12 and −0.13 eV, respectively) in the polymers. Additionally, in both the undoped and doped oligomeric systems, these substitutions introduce large torsion angles (θ > 17°), causing the material to twist significantly. Moreover, the methyl-substituted polymer, <b>n-PBDF-Me</b>, was evaluated for its potential as a transparent organic conductor, due to its high optical transmittance (<i>T</i><sub>550</sub> > 93%). However, <b>n-PBDF-Me</b> films have significantly lower conductivity than <b>n-PBDF</b> (0.40 vs 1330 S/cm) at similar thickness.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"16 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1021/acs.macromol.4c01464
Yiming Chen, Jie Jiang, Yue Zhao
Combining a liquid crystal elastomer (LCE) and a hydrogel opens a new avenue for the development of materials for soft actuators. Herein, we report a novel liquid crystalline hydrogel (LCH) consisting of a cross-linked main-chain LC polyester as the LCE and cross-linked poly(vinyl alcohol) (PVA) as the hydrogel, whose actuator, in contrast to existing main-chain LCE actuators, features perpendicular alignment of LC mesogens with respect to the stretching direction and exhibits positive thermal expansion in the stretching direction over the LC–isotropic phase transition. This peculiar actuating behavior arises from a reorientation process of mesogens, switching from parallel alignment right after stretching to perpendicular alignment after thermal equilibrium of the LCH in hot water followed by cooling, which appears to occur due to a rearrangement of the LCE domains during the thermal relaxation as well as the anisotropic swelling of the surrounding hydrogel domains and thus is unique to the LCH actuator. Unlike the hydrogel actuator, whose deformation is mostly based on a water-diffusion-induced volume change and thus is generally slow, the LCH actuator is driven by the order–disorder phase transition of mesogens and is much faster, with an actuation rate in seconds. Moreover, the LCH actuator not only brings together the reversible actuation of the LCE and the water-controlled shape memory effect of the PVA hydrogel but also is capable of optical welding, which facilitates the actuator design and fabrication.
{"title":"Liquid Crystalline Hydrogel Actuator with Positive Thermal Expansion over Order–Disorder Phase Transition","authors":"Yiming Chen, Jie Jiang, Yue Zhao","doi":"10.1021/acs.macromol.4c01464","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c01464","url":null,"abstract":"Combining a liquid crystal elastomer (LCE) and a hydrogel opens a new avenue for the development of materials for soft actuators. Herein, we report a novel liquid crystalline hydrogel (LCH) consisting of a cross-linked main-chain LC polyester as the LCE and cross-linked poly(vinyl alcohol) (PVA) as the hydrogel, whose actuator, in contrast to existing main-chain LCE actuators, features perpendicular alignment of LC mesogens with respect to the stretching direction and exhibits positive thermal expansion in the stretching direction over the LC–isotropic phase transition. This peculiar actuating behavior arises from a reorientation process of mesogens, switching from parallel alignment right after stretching to perpendicular alignment after thermal equilibrium of the LCH in hot water followed by cooling, which appears to occur due to a rearrangement of the LCE domains during the thermal relaxation as well as the anisotropic swelling of the surrounding hydrogel domains and thus is unique to the LCH actuator. Unlike the hydrogel actuator, whose deformation is mostly based on a water-diffusion-induced volume change and thus is generally slow, the LCH actuator is driven by the order–disorder phase transition of mesogens and is much faster, with an actuation rate in seconds. Moreover, the LCH actuator not only brings together the reversible actuation of the LCE and the water-controlled shape memory effect of the PVA hydrogel but also is capable of optical welding, which facilitates the actuator design and fabrication.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"95 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1021/acs.macromol.4c01358
Vaishaly Duhan, Bimlesh Lochab
Natural abundant resources and safe chemicals are attractive feedstocks for achieving circular sustainability. A wide variety of biophenols and greener amines offered interesting avenues in the evolution of the upcoming class of phenolic thermosets, polybenzoxazines (PBZ). High dependence on formalin as a starting material for monomer synthesis has prompted exploration of alternative safe chemicals. In this study, we designed a family of glyoxal-based benzoxazine (BZ) monomers to synthesize formaldehyde-free biothermosets, leveraging a proximity and promiscuity oxazine–oxazine dependent polymerization. The bi-oxazine functionality at the reactive C2 center in the monomers demanded significantly low temperature for ring-opening polymerization with high polymerization enthalpy favoring an ease in polymer growth, overcoming challenges posed by earlier generation BZ monomers. Current work demonstrates the proof-of-concept for a highly efficient methodology for formaldehyde replacement in benzoxazine chemistry and holds promise for the exploration of a new platform chemical, glyoxal, toward the next generation of benzoxazine with unique reactivities.
{"title":"Glyoxal-Based Bi-Oxazine Benzoxazines: Formaldehyde-Free Biothermosets","authors":"Vaishaly Duhan, Bimlesh Lochab","doi":"10.1021/acs.macromol.4c01358","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c01358","url":null,"abstract":"Natural abundant resources and safe chemicals are attractive feedstocks for achieving circular sustainability. A wide variety of biophenols and greener amines offered interesting avenues in the evolution of the upcoming class of phenolic thermosets, polybenzoxazines (PBZ). High dependence on formalin as a starting material for monomer synthesis has prompted exploration of alternative safe chemicals. In this study, we designed a family of glyoxal-based benzoxazine (BZ) monomers to synthesize formaldehyde-free biothermosets, leveraging a proximity and promiscuity oxazine–oxazine dependent polymerization. The bi-oxazine functionality at the reactive C<sub>2</sub> center in the monomers demanded significantly low temperature for ring-opening polymerization with high polymerization enthalpy favoring an ease in polymer growth, overcoming challenges posed by earlier generation BZ monomers. Current work demonstrates the proof-of-concept for a highly efficient methodology for formaldehyde replacement in benzoxazine chemistry and holds promise for the exploration of a new platform chemical, glyoxal, toward the next generation of benzoxazine with unique reactivities.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"2 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1021/acs.macromol.4c02034
Joshua Lequieu
Particle and field-theoretic simulations are both commonly used methods to study the equilibrium properties of polymeric materials. Yet despite the formal equivalence of the two methods, no comprehensive comparisons of particle and field-theoretic simulations exist in the literature. In this work, we seek to fill this gap by performing a systematic and quantitative comparison of particle and field-theoretic simulations. In our comparison, we consider four representative polymeric systems: a homopolymer melt/solution, a diblock copolymer melt, a polyampholyte solution, and a polyelectrolyte gel. For each of these systems, we first demonstrate that particle and field-theoretic simulations are equivalent and yield exactly the same results for the pressure and the chemical potential. We next quantify the performance of each method across a range of different conditions including variations in chain length, system density, interaction strength, system size, and polymer volume fraction. The outcome of these calculations is a comprehensive look into the performance of each method and the systems and conditions when either particle or field-theoretic simulations are preferred. We find that field-theoretic simulations are equal to or faster than particle simulations for nearly all of the systems and conditions examined. In many situations, field-theoretic simulations are several orders of magnitude faster than particle simulations, especially if the polymer chains are long, the system density is high, and long-range Coulombic interactions are present. We also demonstrate that field-theoretic simulations are considerably faster at calculating the chemical potential and bypass the challenges associated with particle-based Widom insertion techniques. Taken together, our results provide quantitative evidence that field-theoretic simulations can reach and sample equilibrium considerably faster than particle simulations while simultaneously producing equivalent results.
{"title":"Quantitative Equivalence and Performance Comparison of Particle and Field-Theoretic Simulations","authors":"Joshua Lequieu","doi":"10.1021/acs.macromol.4c02034","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02034","url":null,"abstract":"Particle and field-theoretic simulations are both commonly used methods to study the equilibrium properties of polymeric materials. Yet despite the formal equivalence of the two methods, no comprehensive comparisons of particle and field-theoretic simulations exist in the literature. In this work, we seek to fill this gap by performing a systematic and quantitative comparison of particle and field-theoretic simulations. In our comparison, we consider four representative polymeric systems: a homopolymer melt/solution, a diblock copolymer melt, a polyampholyte solution, and a polyelectrolyte gel. For each of these systems, we first demonstrate that particle and field-theoretic simulations are equivalent and yield exactly the same results for the pressure and the chemical potential. We next quantify the performance of each method across a range of different conditions including variations in chain length, system density, interaction strength, system size, and polymer volume fraction. The outcome of these calculations is a comprehensive look into the performance of each method and the systems and conditions when either particle or field-theoretic simulations are preferred. We find that field-theoretic simulations are equal to or faster than particle simulations for nearly all of the systems and conditions examined. In many situations, field-theoretic simulations are several orders of magnitude faster than particle simulations, especially if the polymer chains are long, the system density is high, and long-range Coulombic interactions are present. We also demonstrate that field-theoretic simulations are considerably faster at calculating the chemical potential and bypass the challenges associated with particle-based Widom insertion techniques. Taken together, our results provide quantitative evidence that field-theoretic simulations can reach and sample equilibrium considerably faster than particle simulations while simultaneously producing equivalent results.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"23 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1021/acs.macromol.4c01000
Reima A. Terho, Tuomo P. Kainulainen, Mikko Aleksi Salonen, Juho Antti Sirviö, Juha P. Heiskanen
The increasing interest in reducing the dependence on fossil-based resources by searching and replacing them with renewable biobased sources has intensified in both industrial and academic sectors. Especially, lignocellulose-based biomass can be utilized in the production of many aromatic platform chemicals suitable as substitutes for known fossil-based chemicals. For example, cellulose-derived 5-(hydroxymethyl)furfural has been utilized successfully for the aforementioned purposes. On the other hand, hemicellulose-derived furfural has received rather minor attention, even though recent studies show various excellent results in applications especially utilizing furfural. In this work, two novel furfural-derived epoxy resins were synthesized. Comparative studies were conducted with commercially available and widely used fossil-based epoxy resin, diglycidyl ether of bisphenol A. Resins were cured with methylhexahydrophthalic anhydride with optimized amounts of the 2-ethyl-4-methylimidazole initiator. Curing behaviors were studied with differential scanning calorimetry while thermomechanical properties were evaluated using dynamic mechanical analysis and thermal stabilities with thermogravimetric analysis. Adhesion strengths were tested with single-lap joint steel plate samples using a tensile tester. Tensile testing was also carried out for dog-bone-shaped resin specimens. Lastly, the water absorptions were evaluated through immersion in water. Results showed that the synthesized bioresins have great potential to replace diglycidyl ether of bisphenol A in various applications.
工业界和学术界对通过寻找和使用可再生生物资源来减少对化石资源的依赖越来越感兴趣。特别是，以木质纤维素为基础的生物质可用于生产许多芳香族平台化学品，适合作为已知化石基化学品的替代品。例如，纤维素衍生的 5-（羟甲基）糠醛已成功用于上述目的。另一方面，半纤维素衍生的糠醛却很少受到关注，尽管最近的研究表明，特别是在利用糠醛的应用方面取得了各种优异的成果。本研究合成了两种新型糠醛衍生环氧树脂。树脂用甲基六氢邻苯二甲酸酐和优化量的 2-乙基-4-甲基咪唑引发剂固化。使用差示扫描量热法研究了固化行为，使用动态机械分析评估了热机械性能，使用热重分析评估了热稳定性。使用拉伸试验机测试了单搭接钢板样品的粘合强度。还对狗骨形树脂试样进行了拉伸测试。最后，通过浸泡在水中对吸水性进行了评估。结果表明，合成的生物树脂具有在各种应用中替代双酚 A 二缩水甘油醚的巨大潜力。
{"title":"Renewable Furfural-Based Sulfur-Bridged Epoxy Resins with Excellent Adhesive Properties","authors":"Reima A. Terho, Tuomo P. Kainulainen, Mikko Aleksi Salonen, Juho Antti Sirviö, Juha P. Heiskanen","doi":"10.1021/acs.macromol.4c01000","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c01000","url":null,"abstract":"The increasing interest in reducing the dependence on fossil-based resources by searching and replacing them with renewable biobased sources has intensified in both industrial and academic sectors. Especially, lignocellulose-based biomass can be utilized in the production of many aromatic platform chemicals suitable as substitutes for known fossil-based chemicals. For example, cellulose-derived 5-(hydroxymethyl)furfural has been utilized successfully for the aforementioned purposes. On the other hand, hemicellulose-derived furfural has received rather minor attention, even though recent studies show various excellent results in applications especially utilizing furfural. In this work, two novel furfural-derived epoxy resins were synthesized. Comparative studies were conducted with commercially available and widely used fossil-based epoxy resin, diglycidyl ether of bisphenol A. Resins were cured with methylhexahydrophthalic anhydride with optimized amounts of the 2-ethyl-4-methylimidazole initiator. Curing behaviors were studied with differential scanning calorimetry while thermomechanical properties were evaluated using dynamic mechanical analysis and thermal stabilities with thermogravimetric analysis. Adhesion strengths were tested with single-lap joint steel plate samples using a tensile tester. Tensile testing was also carried out for dog-bone-shaped resin specimens. Lastly, the water absorptions were evaluated through immersion in water. Results showed that the synthesized bioresins have great potential to replace diglycidyl ether of bisphenol A in various applications.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"29 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：