The effect of chain length dispersity on self-assembly behaviors of block copolymers was quantitatively investigated. Two sets of binary blends with precisely controlled compositions were prepared by mixing A-homopolymers into AB2 linear-branched block copolymers, where the two B branches were of either equal or unequal lengths. The added A-homopolymers swell the corona A domain, resulting in a generic phase transition sequence as the volume fraction varies. The distribution of the A-homopolymers depends critically on their length relative to that of the A-block of the copolymers. Longer homopolymers tend to localize at the vertices of the Voronoi cells, while shorter ones distribute more evenly in the corona domain. While blends consisting of A-homopolymers and symmetric linear-branched block copolymers exhibit exclusively the cylindrical phase, the addition of A-homopolymers to asymmetric counterparts leads to a richer array of ordered structures, including the Frank–Kasper phases, quasicrystalline phases, and the hexagonally close-packed phase. The combination of architectural asymmetry in the core (intrachain dispersity) and the presence of A-homopolymers in the corona (interchain dispersity) synergistically stabilizes these exotic structures, which could not be achieved when these two effects were present individually.
{"title":"Synergistic Impact of Intra- and Interchain Dispersity on Block Copolymer Self-Assembly","authors":"Jinbin Li, Jiayu Xie, Zhanhui Gan, Zhuang Ma, An-Chang Shi, Xue-Hui Dong","doi":"10.1021/acs.macromol.5c00433","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00433","url":null,"abstract":"The effect of chain length dispersity on self-assembly behaviors of block copolymers was quantitatively investigated. Two sets of binary blends with precisely controlled compositions were prepared by mixing A-homopolymers into AB<sub>2</sub> linear-branched block copolymers, where the two B branches were of either equal or unequal lengths. The added A-homopolymers swell the corona A domain, resulting in a generic phase transition sequence as the volume fraction varies. The distribution of the A-homopolymers depends critically on their length relative to that of the A-block of the copolymers. Longer homopolymers tend to localize at the vertices of the Voronoi cells, while shorter ones distribute more evenly in the corona domain. While blends consisting of A-homopolymers and symmetric linear-branched block copolymers exhibit exclusively the cylindrical phase, the addition of A-homopolymers to asymmetric counterparts leads to a richer array of ordered structures, including the Frank–Kasper phases, quasicrystalline phases, and the hexagonally close-packed phase. The combination of architectural asymmetry in the core (intrachain dispersity) and the presence of A-homopolymers in the corona (interchain dispersity) synergistically stabilizes these exotic structures, which could not be achieved when these two effects were present individually.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"3 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782932","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}
Bacterial biofilm contamination poses a substantial threat to public health and safety while also leading to considerable economic losses. In this study, a series of both offensive and defensive poly(quaternary phosphonium salt-borneol) copolymers (P(QPx-BOy)), utilizing stereochemically structured borneol as the membrane breaking arrow and quaternary phosphonium salt cations as the electrostatic driving force, were successfully synthesized. Notably, this work exemplifies a novel integration of natural borneol with quaternary phosphonium cations. Subsequently, the molecular structure, molecular weight distribution, microstructure, and corresponding physicochemical properties of the P(QPx-BOy) were characterized using NMR, FT-IR, GPC, SEM, EDS, CA, and DLS. Leveraging the electrostatic interaction between the phosphonium cation and the stereochemical antibacterial mechanism of borneol, P(QPx-BOy) exhibited remarkable antibacterial efficacy against both E. coli and S. aureus, achieving a 100% antibacterial rate with MIC value as low as 30 μg/mL. Furthermore, crystal violet staining assays revealed that borneol’s unique antibiofilm mechanism exerts a significant inhibitory effect on bacterial biofilm formation. Finally, the biocompatibility and antibacterial potential of P(QPx-BOy) were evaluated through cytotoxicity assays and fabric antibacterial tests. Specifically, the integration of borneol essential oil with hydrophilic quaternary phosphonium salt cations effectively addresses the hydrophobic nature of borneol essential oil while mitigating the cytotoxic effects associated with quaternary phosphonium salts. This synergistic combination leverages the strengths of both components, thereby enhancing their suitability for applications in healthcare and public health sectors.
{"title":"Phosphonium Cationic Borneol Stereochemical Membrane Breaking Arrow: High Antibacterial and Antibiofilm Activity","authors":"Xiangbin Sun, Yuanyuan Xie, Xiaobing Ma, Yufeng He, Pengfei Song, Rongmin Wang","doi":"10.1021/acs.macromol.5c00203","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00203","url":null,"abstract":"Bacterial biofilm contamination poses a substantial threat to public health and safety while also leading to considerable economic losses. In this study, a series of both offensive and defensive poly(quaternary phosphonium salt-borneol) copolymers (P(QP<sub><i>x</i></sub>-BO<sub><i>y</i></sub>)), utilizing stereochemically structured borneol as the membrane breaking arrow and quaternary phosphonium salt cations as the electrostatic driving force, were successfully synthesized. Notably, this work exemplifies a novel integration of natural borneol with quaternary phosphonium cations. Subsequently, the molecular structure, molecular weight distribution, microstructure, and corresponding physicochemical properties of the P(QP<sub><i>x</i></sub>-BO<sub><i>y</i></sub>) were characterized using NMR, FT-IR, GPC, SEM, EDS, CA, and DLS. Leveraging the electrostatic interaction between the phosphonium cation and the stereochemical antibacterial mechanism of borneol, P(QP<sub><i>x</i></sub>-BO<sub><i>y</i></sub>) exhibited remarkable antibacterial efficacy against both <i>E. coli</i> and <i>S. aureus</i>, achieving a 100% antibacterial rate with MIC value as low as 30 μg/mL. Furthermore, crystal violet staining assays revealed that borneol’s unique antibiofilm mechanism exerts a significant inhibitory effect on bacterial biofilm formation. Finally, the biocompatibility and antibacterial potential of P(QP<sub><i>x</i></sub>-BO<sub><i>y</i></sub>) were evaluated through cytotoxicity assays and fabric antibacterial tests. Specifically, the integration of borneol essential oil with hydrophilic quaternary phosphonium salt cations effectively addresses the hydrophobic nature of borneol essential oil while mitigating the cytotoxic effects associated with quaternary phosphonium salts. This synergistic combination leverages the strengths of both components, thereby enhancing their suitability for applications in healthcare and public health sectors.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"37 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782878","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 : 2025-04-04DOI: 10.1021/acs.macromol.4c02601
Björn Grabbet, Abdullah Taiem, Răzvan C. Cioc, Pieter C. A. Bruijnincx, Arnaud Thevenon
Bioderived monomers, readily available from biomass via atom- and redox-efficient processes, will need to play a major role in the development of sustainable polymeric materials. Here, we show that a family of tricyclic monomers, efficiently made from biobased furans via Diels–Alder chemistry, allows the production of polyenes with diverse thermo/physical properties through ring opening metathesis polymerization (ROMP). Via small structural variations, we offer insight into the intricacies of monomer design and its implications for polymerization. Notably, the thermostable polyenes all show very similar head-to-tail regioregularities, trans-linkage isomerism distributions, and narrow dispersities. Additionally, the monomers exhibit rare reactivity with ethyl vinyl ether, which can be used as a chain transfer agent, enabling the synthesis of monotelechelic polyenes. The monomers do differ substantially in polymerization rate, spanning two orders of magnitude, in the extent of molecular weight control and in the properties of the resulting amorphous polymers. With glass transition temperatures ranging from 116 to 217 °C and degradation temperatures exceeding 350 °C, these materials are among the highest performing biobased homopolymers reported. We elucidate these variations, demonstrating that the ROMP is profoundly influenced by subtle structural changes in the monomers.
{"title":"Highly Strained Tricyclic Oxanorbornenes with Uncommon Reactivity Enable Rapid ROMP for Thermally High-Performing Polyenes","authors":"Björn Grabbet, Abdullah Taiem, Răzvan C. Cioc, Pieter C. A. Bruijnincx, Arnaud Thevenon","doi":"10.1021/acs.macromol.4c02601","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02601","url":null,"abstract":"Bioderived monomers, readily available from biomass via atom- and redox-efficient processes, will need to play a major role in the development of sustainable polymeric materials. Here, we show that a family of tricyclic monomers, efficiently made from biobased furans via Diels–Alder chemistry, allows the production of polyenes with diverse thermo/physical properties through ring opening metathesis polymerization (ROMP). Via small structural variations, we offer insight into the intricacies of monomer design and its implications for polymerization. Notably, the thermostable polyenes all show very similar head-to-tail regioregularities, <i>trans</i>-linkage isomerism distributions, and narrow dispersities. Additionally, the monomers exhibit rare reactivity with ethyl vinyl ether, which can be used as a chain transfer agent, enabling the synthesis of monotelechelic polyenes. The monomers do differ substantially in polymerization rate, spanning two orders of magnitude, in the extent of molecular weight control and in the properties of the resulting amorphous polymers. With glass transition temperatures ranging from 116 to 217 °C and degradation temperatures exceeding 350 °C, these materials are among the highest performing biobased homopolymers reported. We elucidate these variations, demonstrating that the ROMP is profoundly influenced by subtle structural changes in the monomers.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"23 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776136","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 : 2025-04-04DOI: 10.1021/acs.macromol.4c03161
Daniel C. Barzycki, Dana Ezzeddine, Sachin Shanbhag, Ralm G. Ricarte
Vitrimers are polymer networks connected by associative cross-links─covalent linkages that maintain network connectivity but exchange through reversible chemical reactions. Associative cross-links significantly change the dynamics of the molten polymer. This study focuses on the linear viscoelasticity of polystyrene vitrimers (PS-v) bearing imine cross-links. PS-v samples were prepared by condensation between precursor copolymers with pendant aldehydes and 1,6-hexanediamine cross-linker. The number-average molecular weights of the precursors were 6 and 8 kDa, and the amine-to-aldehyde molar ratio (r) ranged between 0.8 and 2.4. The glass transition temperature exhibited a nonmonotonic relationship with r. The linear viscoelasticity of PS-v was evaluated using a combination of small amplitude oscillatory shear (SAOS), stress relaxation, and creep and recovery. Time–temperature superposition analyses indicated two distinct relaxation regimes: (I) fast high frequency dynamics with a Williams–Landel–Ferry temperature dependence and (II) slow low frequency dynamics with Arrhenius behavior. The fast regime represented the segmental relaxations of the vitrimer backbone. The slow regime was described as a slow Arrhenius process (SAP), in which the long time dynamics have a temperature-independent rheological activation energy. For all PS-v samples in this study, the observed SAP had a much weaker temperature dependence than expected from sticky Rouse model predictions. Increasing r altered the plateau modulus and SAOS crossover frequency but did not affect the temperature dependences of the segmental motions or SAP. To describe the origin of the SAP, three hypotheses are proposed: cross-linker diffusion, polymer matrix effects, and local elasticity fluctuations.
维特瑞姆是一种通过缔合交联（共价键）连接的聚合物网络，这种交联可保持网络的连通性，但可通过可逆的化学反应进行交换。缔合交联大大改变了熔融聚合物的动态。本研究的重点是含有亚胺交联的聚苯乙烯玻璃聚合物（PS-v）的线性粘弹性。PS-v 样品是通过前体共聚物与挂醛和 1,6-己二胺交联剂的缩合制备的。前体的平均分子量分别为 6 和 8 kDa，胺与醛的摩尔比 (r) 介于 0.8 和 2.4 之间。采用小振幅振荡剪切（SAOS）、应力松弛以及蠕变和恢复相结合的方法对 PS-v 的线性粘弹性进行了评估。时间-温度叠加分析表明了两种截然不同的松弛状态：(I) 具有威廉姆斯-兰德尔-费里温度依赖性的快速高频动态；(II) 具有阿伦尼乌斯行为的慢速低频动态。快速机制代表了玻璃聚合物骨架的分段松弛。慢速体系被描述为慢速阿伦尼乌斯过程（SAP），其中的长时间动力学具有与温度无关的流变活化能。对于本研究中的所有 PS-v 样品，观察到的 SAP 与温度的相关性比根据粘性劳斯模型预测的要弱得多。增加 r 会改变高原模量和 SAOS 交叉频率，但不会影响分段运动或 SAP 的温度依赖性。为了描述 SAP 的起源，提出了三种假设：交联剂扩散、聚合物基质效应和局部弹性波动。
{"title":"Linear Viscoelasticity of Polystyrene Vitrimers: Segmental Motions and the Slow Arrhenius Process","authors":"Daniel C. Barzycki, Dana Ezzeddine, Sachin Shanbhag, Ralm G. Ricarte","doi":"10.1021/acs.macromol.4c03161","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03161","url":null,"abstract":"Vitrimers are polymer networks connected by associative cross-links─covalent linkages that maintain network connectivity but exchange through reversible chemical reactions. Associative cross-links significantly change the dynamics of the molten polymer. This study focuses on the linear viscoelasticity of polystyrene vitrimers (PS-<i>v</i>) bearing imine cross-links. PS-<i>v</i> samples were prepared by condensation between precursor copolymers with pendant aldehydes and 1,6-hexanediamine cross-linker. The number-average molecular weights of the precursors were 6 and 8 kDa, and the amine-to-aldehyde molar ratio (<i>r</i>) ranged between 0.8 and 2.4. The glass transition temperature exhibited a nonmonotonic relationship with <i>r</i>. The linear viscoelasticity of PS-<i>v</i> was evaluated using a combination of small amplitude oscillatory shear (SAOS), stress relaxation, and creep and recovery. Time–temperature superposition analyses indicated two distinct relaxation regimes: (I) fast high frequency dynamics with a Williams–Landel–Ferry temperature dependence and (II) slow low frequency dynamics with Arrhenius behavior. The fast regime represented the segmental relaxations of the vitrimer backbone. The slow regime was described as a slow Arrhenius process (SAP), in which the long time dynamics have a temperature-independent rheological activation energy. For all PS-<i>v</i> samples in this study, the observed SAP had a much weaker temperature dependence than expected from sticky Rouse model predictions. Increasing <i>r</i> altered the plateau modulus and SAOS crossover frequency but did not affect the temperature dependences of the segmental motions or SAP. To describe the origin of the SAP, three hypotheses are proposed: cross-linker diffusion, polymer matrix effects, and local elasticity fluctuations.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"81 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782877","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 : 2025-04-04DOI: 10.1021/acs.macromol.4c03101
Md Wali Ullah, Jiahui Liu, Marek W. Urban
This study elucidates the origin of inter- and intrachain interactions in a new family of poly(ionic liquids) (PILs) containing alternating hydrophobic and hydrophilic groups terminated with variable-length aliphatic tails. The repeating units are sequentially synthesized and are composed of quadrupole (styrene), polar sulphonyl (−SO2), dipolar aliphatic spacer, cation–anion pair, and variable-length aliphatic (methyl to n-butyl) tails. They participate in quadrupole (Q), dipolar (D), induced dipole (ID), ionic (C–A), and a combination of thereof interactions. When perturbed by polar H2O molecules or electric fields (EFs), molecular events revealed by spectroscopic analysis supported by molecular dynamic (MD) simulations enabled encoding of the origin of intra- and interchain interactions and their impact on electrical responses. This study shows that conductivity increases for longer aliphatic tails, particularly when perturbed by H2O, attributed to enhanced ID ⇔ H2O interactions. At the same time, quadrupole interactions remain unchanged but enhance the mechanical integrity. Encoding the dynamics and strength of the Q ⇔ Q, D ⇔ D, ID ⇔ ID, and C–A interactions without generating protic environments may provide an opportunity for designing new generations of solid-state electrolytes exclusively relying on nonfaradic electrochemical processes that may lead to electrode decomposition or generation of undesirable side reactions.
{"title":"Encoding Dipolar and Ionic Interactions in Comb-Like Poly(ionic Liquids)","authors":"Md Wali Ullah, Jiahui Liu, Marek W. Urban","doi":"10.1021/acs.macromol.4c03101","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03101","url":null,"abstract":"This study elucidates the origin of inter- and intrachain interactions in a new family of poly(ionic liquids) (PILs) containing alternating hydrophobic and hydrophilic groups terminated with variable-length aliphatic tails. The repeating units are sequentially synthesized and are composed of quadrupole (styrene), polar sulphonyl (−SO<sub>2</sub>), dipolar aliphatic spacer, cation–anion pair, and variable-length aliphatic (methyl to <i>n</i>-butyl) tails. They participate in quadrupole (Q), dipolar (D), induced dipole (ID), ionic (C–A), and a combination of thereof interactions. When perturbed by polar H<sub>2</sub>O molecules or electric fields (EFs), molecular events revealed by spectroscopic analysis supported by molecular dynamic (MD) simulations enabled encoding of the origin of intra- and interchain interactions and their impact on electrical responses. This study shows that conductivity increases for longer aliphatic tails, particularly when perturbed by H<sub>2</sub>O, attributed to enhanced ID ⇔ H<sub>2</sub>O interactions. At the same time, quadrupole interactions remain unchanged but enhance the mechanical integrity. Encoding the dynamics and strength of the Q ⇔ Q, D ⇔ D, ID ⇔ ID, and C–A interactions without generating protic environments may provide an opportunity for designing new generations of solid-state electrolytes exclusively relying on nonfaradic electrochemical processes that may lead to electrode decomposition or generation of undesirable side reactions.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"60 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782875","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}
Ionic specificity is of fundamental importance in understanding both the equilibrium and dynamic properties of electrolyte systems. Herein, we report a systematic simulation study of the ionic specificity of trivalent salt ions in a planar polyelectrolyte (PE) brush system. By exploring a wide parameter space of salt ionic size and salt concentration, we find that ionic specificity significantly affects and regulates the surface structures and dynamics of the PE brush. Specifically, solely varying trivalent salt cationic size, which represents ionic specificity, induces a sequence of structural transitions, from a homogeneously collapsed brush layer, to a laterally heterogeneous pinned micelle, to a homogeneously reswelling layer, which is confirmed through analyzing the nonmonotonic brush height variation, and both the real-space morphologies and the reciprocal-space structure factor. Salt concentration, as another key controlling parameter for ionic solutions, also regulates brush morphologies quite differently depending on the salt cationic size. Beyond these equilibrium properties, the dynamics of the system are also studied by analyzing diffusion coefficients and the probability density function of components to clarify the ionic specificity effect. These findings are explained through a careful analysis of the combined and competing effects of the electrostatic screening of small ions, the multivalent ion-induced electrostatic bridging, and the excluded volume interaction of bulky ions. Our results provide both an important reference for a fundamental understanding of ionic specificity and a practical guide for designing smart stimuli-responsive materials based on the PE brush.
{"title":"A Systematic Study on Trivalent Salt Cationic Specificity through Polyelectrolyte Brushes","authors":"Qing-Hai Hao, Han-Yang Qian, Ming-Lu Chao, Hong-Yan Zhang, Hong-Ge Tan, Bing Miao","doi":"10.1021/acs.macromol.4c02664","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02664","url":null,"abstract":"Ionic specificity is of fundamental importance in understanding both the equilibrium and dynamic properties of electrolyte systems. Herein, we report a systematic simulation study of the ionic specificity of trivalent salt ions in a planar polyelectrolyte (PE) brush system. By exploring a wide parameter space of salt ionic size and salt concentration, we find that ionic specificity significantly affects and regulates the surface structures and dynamics of the PE brush. Specifically, solely varying trivalent salt cationic size, which represents ionic specificity, induces a sequence of structural transitions, from a homogeneously collapsed brush layer, to a laterally heterogeneous pinned micelle, to a homogeneously reswelling layer, which is confirmed through analyzing the nonmonotonic brush height variation, and both the real-space morphologies and the reciprocal-space structure factor. Salt concentration, as another key controlling parameter for ionic solutions, also regulates brush morphologies quite differently depending on the salt cationic size. Beyond these equilibrium properties, the dynamics of the system are also studied by analyzing diffusion coefficients and the probability density function of components to clarify the ionic specificity effect. These findings are explained through a careful analysis of the combined and competing effects of the electrostatic screening of small ions, the multivalent ion-induced electrostatic bridging, and the excluded volume interaction of bulky ions. Our results provide both an important reference for a fundamental understanding of ionic specificity and a practical guide for designing smart stimuli-responsive materials based on the PE brush.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"21 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776137","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 : 2025-04-03DOI: 10.1021/acs.macromol.5c00158
Orrasa Prasitnok, Khongvit Prasitnok
We employed molecular dynamics simulations to investigate the efficiency of polylactic acid (PLA)-, poly(caprolactone) (PCL)-, and poly(ethylene glycol) (PEG)-based biodegradable copolymers as compatibilizers in PLA/PCL blends. Di- and triblock copolymers with various block sequences were systematically designed and studied. The findings reveal that the block type and architecture of the copolymers play a crucial role in determining their compatibilization efficiency. Specifically, our unentangled copolymers with PLA blocks at the chain ends, particularly triblock structures, exhibit good localization within both PLA and PCL homopolymer phases. This localization enhances interphase interactions and improves the melt tensile performance of the blends. In contrast, copolymers with PCL blocks at the chain ends, especially triblock architectures, tend to localize preferentially within the PCL phase, leading to less effective compatibilization. These insights could pave the way for the development of tailored compatibilizers to optimize the properties of immiscible polymer blends.
{"title":"Architectural Effects of Biodegradable Block Copolymers on Enhancing PLA/PCL Blend Compatibility: Molecular Dynamics Simulations","authors":"Orrasa Prasitnok, Khongvit Prasitnok","doi":"10.1021/acs.macromol.5c00158","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00158","url":null,"abstract":"We employed molecular dynamics simulations to investigate the efficiency of polylactic acid (PLA)-, poly(caprolactone) (PCL)-, and poly(ethylene glycol) (PEG)-based biodegradable copolymers as compatibilizers in PLA/PCL blends. Di- and triblock copolymers with various block sequences were systematically designed and studied. The findings reveal that the block type and architecture of the copolymers play a crucial role in determining their compatibilization efficiency. Specifically, our unentangled copolymers with PLA blocks at the chain ends, particularly triblock structures, exhibit good localization within both PLA and PCL homopolymer phases. This localization enhances interphase interactions and improves the melt tensile performance of the blends. In contrast, copolymers with PCL blocks at the chain ends, especially triblock architectures, tend to localize preferentially within the PCL phase, leading to less effective compatibilization. These insights could pave the way for the development of tailored compatibilizers to optimize the properties of immiscible polymer blends.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"183 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776138","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 : 2025-04-03DOI: 10.1021/acs.macromol.4c02895
Louise Kuehster, Michael Bingham, Jingyi Dai, Young Kuk Jhon, Yan Wang, Bin Qin, William C. Smith, Xiaoming Xu, Feng Zhang, Nathaniel A. Lynd
Established methods of characterizing repeat unit sequence by measuring changes in comonomer concentration during copolymerization and inferring the resulting copolymer sequence are inapplicable to poly(lactide-co-glycolide) due to reverse and transesterification reactions. In this case, measurement of repeat unit sequences must be based on direct measurement on the copolymer. Here, the assignment of the 13C NMR spectrum of the glycolyl methylene of poly(lactide-co-glycolide) to specific compositional ester tetrads is reported using insights provided by a stochastic model regression analysis of experimental reversible transesterification copolymerization data. The relative integrals of the deconvoluted compositional tetrad signals can be interpreted within the context of a model for repeat unit clustering that describes the cumulative population of homosequences with at least nG adjacent glycolyl esters, including the resonant glycolyl ester. The decay of the relative population of homosequence length nG is described by an exponential decay f(n) = e(1–n)/σb with the parameter σb describing the degree of clustering of glycolyl ester units. An empirical model describes the time-evolution of σb as a function of reaction time, which evolves due to comonomer reversibility and copolymer transesterification.
{"title":"Characterization of the Repeat Unit Sequence of Poly(lactide-co-glycolide)","authors":"Louise Kuehster, Michael Bingham, Jingyi Dai, Young Kuk Jhon, Yan Wang, Bin Qin, William C. Smith, Xiaoming Xu, Feng Zhang, Nathaniel A. Lynd","doi":"10.1021/acs.macromol.4c02895","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02895","url":null,"abstract":"Established methods of characterizing repeat unit sequence by measuring changes in comonomer concentration during copolymerization and inferring the resulting copolymer sequence are inapplicable to poly(lactide-<i>co</i>-glycolide) due to reverse and transesterification reactions. In this case, measurement of repeat unit sequences must be based on direct measurement on the copolymer. Here, the assignment of the <sup>13</sup>C NMR spectrum of the glycolyl methylene of poly(lactide-<i>co</i>-glycolide) to specific compositional ester tetrads is reported using insights provided by a stochastic model regression analysis of experimental reversible transesterification copolymerization data. The relative integrals of the deconvoluted compositional tetrad signals can be interpreted within the context of a model for repeat unit clustering that describes the cumulative population of homosequences with at least <i>n</i><sub>G</sub> adjacent glycolyl esters, including the resonant glycolyl ester. The decay of the relative population of homosequence length <i>n</i><sub>G</sub> is described by an exponential decay <i>f</i>(<i>n</i>) = <i>e</i><sup>(1–<i>n</i>)/σ<sub><i>b</i></sub></sup> with the parameter σ<sub>b</sub> describing the degree of clustering of glycolyl ester units. An empirical model describes the time-evolution of σ<sub>b</sub> as a function of reaction time, which evolves due to comonomer reversibility and copolymer transesterification.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"133 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766857","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 : 2025-04-03DOI: 10.1021/acs.macromol.5c00409
Kairu Qu, Linhan Du, Shuqi Zhou, Lujie Huo, Anqi Gu, Diannan Lu, Chunlai Chen, Jia Di, Zhenzhong Yang
Polymer rings are unique over their linear counterparts in fundamental and engineering aspects. Although ring closure of polymers is a proven general method toward rings, the large-scale synthesis in concentrated solutions remains challenging due to the concurrent intermolecular reactions. Herein, we propose the electrostatic-mediated ring closure of polymers in the dynamic single-chain nanoparticle (SCNP) globular state, enabling large-scale synthesis of highly pure polymer rings at an unprecedentedly high concentration of 150 mg/mL. The dynamic SCNPs are also achieved by the electrostatic-mediated intramolecular cross-linking of polymers in concentrated solutions. Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA)-based telechelic polymers are selected to demonstrate the concept. The charged dynamic SCNPs are constructed by simple amine-acid-specific interactions, and thiol–ene and Diels–Alder click reactions are employed for the ring closure to demonstrate the generality. The microstructure and composition of the rings can be tuned from the corresponding polymers with varied segmental sequences and compositions. The topology and function can be further tuned by the favorable growth of functional materials at the desired sites of the polymer rings.
{"title":"Large-Scale Synthesis of Polymer Rings by Electrostatic-Mediated Closure of Single-Chain Nanoparticles","authors":"Kairu Qu, Linhan Du, Shuqi Zhou, Lujie Huo, Anqi Gu, Diannan Lu, Chunlai Chen, Jia Di, Zhenzhong Yang","doi":"10.1021/acs.macromol.5c00409","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00409","url":null,"abstract":"Polymer rings are unique over their linear counterparts in fundamental and engineering aspects. Although ring closure of polymers is a proven general method toward rings, the large-scale synthesis in concentrated solutions remains challenging due to the concurrent intermolecular reactions. Herein, we propose the electrostatic-mediated ring closure of polymers in the dynamic single-chain nanoparticle (SCNP) globular state, enabling large-scale synthesis of highly pure polymer rings at an unprecedentedly high concentration of 150 mg/mL. The dynamic SCNPs are also achieved by the electrostatic-mediated intramolecular cross-linking of polymers in concentrated solutions. Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA)-based telechelic polymers are selected to demonstrate the concept. The charged dynamic SCNPs are constructed by simple amine-acid-specific interactions, and thiol–ene and Diels–Alder click reactions are employed for the ring closure to demonstrate the generality. The microstructure and composition of the rings can be tuned from the corresponding polymers with varied segmental sequences and compositions. The topology and function can be further tuned by the favorable growth of functional materials at the desired sites of the polymer rings.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"73 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766858","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}
This work presents the synthesis of bottlebrush copolymers with anionically polymerized hyperbranched polyglycerol (HPG) side chains via ring-opening metathesis polymerization (ROMP). The efficacy and mechanism of the bottlebrush copolymer and its macromonomer as carriers for the insoluble drug paclitaxel (PTX) were evaluated. Starting with O-(2-aminoethyl)polyethylene glycol (H2N-PEG–OH), the terminal −NH2 group was first protected by the triphenylmethyl (Trt) group, and then anionic ring-opening polymerization of PG was initiated from the −OH group by CsOH. Subsequently, ROMP was performed to obtain bottlebrush HPG with a degree of polymerization reaching 200. The abundant −OH groups of HPG were reacted with succinic anhydride and then PTX. The resulting covalent-bonded bottlebrush-PTX conjugate (denoted as BB-5-PTX) is amphiphilic and displayed two stages of self-assembly in the aqueous phase at a concentration above the critical micelle concentration (CMC). The antitumor activity of BB-5-PTX was examined at concentrations below the CMC and showed a notable enhancement compared to its macromonomer-PTX counterpart (MM-4-PTX7). Cellular uptake studies and flow cytometry unveiled the mechanism of this increased efficacy. Despite endocytosing fewer molecules, the bottlebrush copolymer effectively delivers more drug units across the cell membrane due to its amphiphilicity and higher number of binding sites per molecule than its corresponding macromonomer.
{"title":"Drug-Carrying Bottlebrush Copolymers via ROMP of Anionically Polymerized Hyperbranched Polyglycerol","authors":"Linxin Ge, Li Xu, Yueming Xu, Shumu Li, Xingchao Huang, Xiaojun Jiang, Yongjia Yang, Yu-ang Cui, Fang Wang, Li Deng, Zhiying Yang, Bingyin Jiang","doi":"10.1021/acs.macromol.5c00126","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00126","url":null,"abstract":"This work presents the synthesis of bottlebrush copolymers with anionically polymerized hyperbranched polyglycerol (HPG) side chains via ring-opening metathesis polymerization (ROMP). The efficacy and mechanism of the bottlebrush copolymer and its macromonomer as carriers for the insoluble drug paclitaxel (PTX) were evaluated. Starting with <i>O</i>-(2-aminoethyl)polyethylene glycol (H<sub>2</sub>N-PEG–OH), the terminal −NH<sub>2</sub> group was first protected by the triphenylmethyl (Trt) group, and then anionic ring-opening polymerization of PG was initiated from the −OH group by CsOH. Subsequently, ROMP was performed to obtain bottlebrush HPG with a degree of polymerization reaching 200. The abundant −OH groups of HPG were reacted with succinic anhydride and then PTX. The resulting covalent-bonded bottlebrush-PTX conjugate (denoted as BB-5-PTX) is amphiphilic and displayed two stages of self-assembly in the aqueous phase at a concentration above the critical micelle concentration (CMC). The antitumor activity of BB-5-PTX was examined at concentrations below the CMC and showed a notable enhancement compared to its macromonomer-PTX counterpart (MM-4-PTX<sub>7</sub>). Cellular uptake studies and flow cytometry unveiled the mechanism of this increased efficacy. Despite endocytosing fewer molecules, the bottlebrush copolymer effectively delivers more drug units across the cell membrane due to its amphiphilicity and higher number of binding sites per molecule than its corresponding macromonomer.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"16 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758221","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}
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