Ghislaine Barouti, Cédric Gaillard, Sophie M Guillaume, Christophe Chassenieux
Polyester-based amphiphilic block copolymers are the most widely investigated ones for biomedical applications, and in particular as drug delivery systems. Self-assemblies derived from such biocompatible and biodegradable copolymers are most often centered on poly(lactic acid), poly(glycolic acid), poly(lactic acid-co-glycolic acid), or poly(-caprolactone), and commonly involve the use of a surfactant during their elaboration. Herein, we report the use of nanoprecipitation rather than surfactant-assisted self-assembling based on biocompatible and biodegradable polyhydroxyalkanoates (PHAs), namely poly(3-hydroxybutyrate) (PHB) the ubiquitous PHA, and poly(-malic acid) (PMLA). Analogous diblock PMLA-b-PHB and triblock PMLA-b-PHB-b-PMLA copolymers were comparatively explored. Tuning both the hydrophilic weight fraction f (i.e., the PMLA content) and the polymer topology enabled to design a range of PHA-type nano-objects, as investigated and rationalized through light scattering measurements. While large aggregates (Rh ca. 300 nm) were obtained in aqueous solutions from PMLA-b-PHB copolymers exhibiting a low hydrophilic weight fraction (f ca. 10%), well-defined spherically shaped core-shell micelles (Rh ca. 1030 nm) were prepared from diblock copolymers with higher f values (ca. 5076%). Triblock copolymers within such a similar f range (ca. 1582%) formed smaller aggregates (Rh ca. 20to26 nm) distinct from the better-defined core-shell micelles recovered from the diblock copolymers. Furthermore, blending two f-distinct diblock copolymers resulted in self-assembled systems displaying characteristics (Rh ca. 53 to 67 nm) intermediate to those of the pristine copolymers, thus supporting the co-assembly of the two diblock copolymers within the same particles. Finally, the structure of the copolymers is shown to enable tailoring the stability and resilience of their self-assemblies upon ageing in physiological-like conditions.
{"title":"Stable self-assemblies of polyhydroxybutyrate-based diblock and triblock copolymers nanoprecipitated in water: influence of their hydrophilic weight fraction","authors":"Ghislaine Barouti, Cédric Gaillard, Sophie M Guillaume, Christophe Chassenieux","doi":"10.1039/d5py00378d","DOIUrl":"https://doi.org/10.1039/d5py00378d","url":null,"abstract":"Polyester-based amphiphilic block copolymers are the most widely investigated ones for biomedical applications, and in particular as drug delivery systems. Self-assemblies derived from such biocompatible and biodegradable copolymers are most often centered on poly(lactic acid), poly(glycolic acid), poly(lactic acid-co-glycolic acid), or poly(-caprolactone), and commonly involve the use of a surfactant during their elaboration. Herein, we report the use of nanoprecipitation rather than surfactant-assisted self-assembling based on biocompatible and biodegradable polyhydroxyalkanoates (PHAs), namely poly(3-hydroxybutyrate) (PHB) the ubiquitous PHA, and poly(-malic acid) (PMLA). Analogous diblock PMLA-b-PHB and triblock PMLA-b-PHB-b-PMLA copolymers were comparatively explored. Tuning both the hydrophilic weight fraction f (i.e., the PMLA content) and the polymer topology enabled to design a range of PHA-type nano-objects, as investigated and rationalized through light scattering measurements. While large aggregates (Rh ca. 300 nm) were obtained in aqueous solutions from PMLA-b-PHB copolymers exhibiting a low hydrophilic weight fraction (f ca. 10%), well-defined spherically shaped core-shell micelles (Rh ca. 1030 nm) were prepared from diblock copolymers with higher f values (ca. 5076%). Triblock copolymers within such a similar f range (ca. 1582%) formed smaller aggregates (Rh ca. 20to26 nm) distinct from the better-defined core-shell micelles recovered from the diblock copolymers. Furthermore, blending two f-distinct diblock copolymers resulted in self-assembled systems displaying characteristics (Rh ca. 53 to 67 nm) intermediate to those of the pristine copolymers, thus supporting the co-assembly of the two diblock copolymers within the same particles. Finally, the structure of the copolymers is shown to enable tailoring the stability and resilience of their self-assemblies upon ageing in physiological-like conditions.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"96 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
π-Conjugated materials incorporating tricoordinate boron are known to possess relatively deep LUMO energy levels owing to the interaction between the empty p orbital of boron and the π* orbital. However, polymers with simple triarylborane structures do not have deep LUMO energy levels for applications in electron-accepting optoelectronic materials, such as n-type semiconductors. In this study, we synthesized new p−π* conjugated polymers by copolymerizing thiaborin units containing boron and sulfur atoms and diketopyrrolopyrrole (DPP), a well-known acceptor unit. The resulting polymers exhibited extended conjugation through the boron p orbital and strong absorption in the visible to near-infrared region. Although these polymers did not show n-type semiconductor behavior, they possessed deep LUMO energy levels lower than –3.6 eV. Furthermore, titration experiments using an amine base revealed that the polymer containing a sulfone unit has strong Lewis acidity, as evidenced by changes in the UV-vis absorption spectrum upon coordination of the base.
{"title":"Synthesis of electron-deficient polymers based on sulfur-bridged dithienylboranes as a building block","authors":"Yohei Adachi, Ryuji Matsuura, Mitsuru Sakabe, Hiroki Tobita, Hideki Murakami, Joji Ohshita","doi":"10.1039/d5py00203f","DOIUrl":"https://doi.org/10.1039/d5py00203f","url":null,"abstract":"π-Conjugated materials incorporating tricoordinate boron are known to possess relatively deep LUMO energy levels owing to the interaction between the empty p orbital of boron and the π* orbital. However, polymers with simple triarylborane structures do not have deep LUMO energy levels for applications in electron-accepting optoelectronic materials, such as n-type semiconductors. In this study, we synthesized new p−π* conjugated polymers by copolymerizing thiaborin units containing boron and sulfur atoms and diketopyrrolopyrrole (DPP), a well-known acceptor unit. The resulting polymers exhibited extended conjugation through the boron p orbital and strong absorption in the visible to near-infrared region. Although these polymers did not show n-type semiconductor behavior, they possessed deep LUMO energy levels lower than –3.6 eV. Furthermore, titration experiments using an amine base revealed that the polymer containing a sulfone unit has strong Lewis acidity, as evidenced by changes in the UV-vis absorption spectrum upon coordination of the base.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"40 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Panfeng Gao, Han Shen, Xiaoman Gui, Jianling Ni, Shisong Sun, Meixiu Wan, Lijun Huo
The low tolerance of thickness variations in all-polymer solar cells (all-PSCs) is currently becoming a new challenge to achieving efficient power conversion efficiencies (PCEs) and large-scale production. Compared with small molecular acceptors (SMA) systems, polymer acceptors in all-PSCs usually possess lower crystalline properties and imbalanced charge transportation characteristics, which limit their active layer thicknesses and PCEs. In this work, ester-substituted side chains were incorporated onto a thiophene–vinylene–thiophene (TVT) backbone to construct a non-fullerene Y-series polymer acceptor. It exhibited strengthened π–π stacking and higher charge mobility than its alkyl-substituted counterpart. When the ester-substituted polymer acceptor was blended with the donor PM6, it delivered a champion PCE of 16.48% with a high Voc and FF. Impressively, the device efficiencies are insensitive to variation in the photoactive layer thickness and can maintain over 80% of the optimized efficiency as the film thickness increases to 400 nm, which is the best result for an all-PSC so far. This work not only achieved synergism between high efficiency and thickness-insensitivity in an all-PSC device, but also demonstrated that the TVT-containing backbone can be further optimized by incorporating reasonable functional groups to construct highly crystalline Y series polymer acceptors.
{"title":"Efficient thick film all-polymer solar cells enabled by incorporating an ester-substituted non-fullerene-based polymer acceptor","authors":"Panfeng Gao, Han Shen, Xiaoman Gui, Jianling Ni, Shisong Sun, Meixiu Wan, Lijun Huo","doi":"10.1039/d5py00302d","DOIUrl":"https://doi.org/10.1039/d5py00302d","url":null,"abstract":"The low tolerance of thickness variations in all-polymer solar cells (all-PSCs) is currently becoming a new challenge to achieving efficient power conversion efficiencies (PCEs) and large-scale production. Compared with small molecular acceptors (SMA) systems, polymer acceptors in all-PSCs usually possess lower crystalline properties and imbalanced charge transportation characteristics, which limit their active layer thicknesses and PCEs. In this work, ester-substituted side chains were incorporated onto a thiophene–vinylene–thiophene (TVT) backbone to construct a non-fullerene Y-series polymer acceptor. It exhibited strengthened π–π stacking and higher charge mobility than its alkyl-substituted counterpart. When the ester-substituted polymer acceptor was blended with the donor PM6, it delivered a champion PCE of 16.48% with a high <em>V</em><small><sub>oc</sub></small> and FF. Impressively, the device efficiencies are insensitive to variation in the photoactive layer thickness and can maintain over 80% of the optimized efficiency as the film thickness increases to 400 nm, which is the best result for an all-PSC so far. This work not only achieved synergism between high efficiency and thickness-insensitivity in an all-PSC device, but also demonstrated that the TVT-containing backbone can be further optimized by incorporating reasonable functional groups to construct highly crystalline Y series polymer acceptors.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"133 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anisha Patel, Georgia Lucy L Maitland, Evelina Liarou, Paul D. Topham, Matthew J Derry
We report the first reversible addition-fragmentation chain transfer polymerisation-induced self assembly (RAFT-PISA) in ionic liquid (IL) that proceeds under emulsion conditions. Moreover, this formulation exploits refractive index contrast matching to generate highly transparent nanoparticle dispersions. Specifically, 1-ethyl-3-methyl-imidazolium ethylsulfate, [EMIM][EtOSO3], was used as the solvent for the chain extension of poly(2-hydroxyethyl methacrylate) (PHEMA) macromolecular chain transfer agents (macro-CTAs) using n-butyl methacrylate (BuMA) via RAFT emulsion polymerisation. Two series of PHEMAx-b-PBuMAy diblock copolymers with target PBuMA degrees of polymerisation (DPs) varying from 50 to 1000 were synthesised using either a PHEMA21 or PHEMA77 macro-CTA. All resulting nanoparticle dispersions yielded highly transparent dispersions, even when nanoparticle diameters exceeded 100 nm, due to the closely matched refractive index values of the [EMIM][EtOSO3] solvent and PBuMA nanoparticle core. Detailed analysis using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) confirmed the presence of spherical nanoparticles. Furthermore, the synthesis of PHEMA-b-PBuMA via this new PISA formulation was directly compared to equivalent block copolymer syntheses conducted in N,N-dimethylformamide (DMF) or ethanol/water mixtures. It was found that syntheses conducted in [EMIM][EtOSO3] resulted in the highest monomer conversions (up to >99%) and lowest dispersity (ĐM) values (as low as 1.16) in the shortest reaction times (2 hours) compared to the other solvent systems. This work demonstrates the use of ILs as a more sustainable and effective solvent for RAFT PISA via the development of the first emulsion PISA formulation in IL.
{"title":"Transparent diblock copolymer nanoparticle dispersions via efficient RAFT emulsion polymerisation in ionic liquid","authors":"Anisha Patel, Georgia Lucy L Maitland, Evelina Liarou, Paul D. Topham, Matthew J Derry","doi":"10.1039/d5py00076a","DOIUrl":"https://doi.org/10.1039/d5py00076a","url":null,"abstract":"We report the first reversible addition-fragmentation chain transfer polymerisation-induced self assembly (RAFT-PISA) in ionic liquid (IL) that proceeds under emulsion conditions. Moreover, this formulation exploits refractive index contrast matching to generate highly transparent nanoparticle dispersions. Specifically, 1-ethyl-3-methyl-imidazolium ethylsulfate, [EMIM][EtOSO3<small><sub></sub></small>], was used as the solvent for the chain extension of poly(2-hydroxyethyl methacrylate) (PHEMA) macromolecular chain transfer agents (macro-CTAs) using <em>n</em>-butyl methacrylate (BuMA) via RAFT emulsion polymerisation. Two series of PHEMA<small><sub>x</sub></small>-<em>b</em>-PBuMA<small><sub>y</sub></small> diblock copolymers with target PBuMA degrees of polymerisation (DPs) varying from 50 to 1000 were synthesised using either a PHEMA<small><sub>21</sub></small> or PHEMA<small><sub>77</sub></small> macro-CTA. All resulting nanoparticle dispersions yielded highly transparent dispersions, even when nanoparticle diameters exceeded 100 nm, due to the closely matched refractive index values of the [EMIM][EtOSO<small><sub>3</sub></small>] solvent and PBuMA nanoparticle core. Detailed analysis using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) confirmed the presence of spherical nanoparticles. Furthermore, the synthesis of PHEMA-<em>b</em>-PBuMA via this new PISA formulation was directly compared to equivalent block copolymer syntheses conducted in <em>N</em>,<em>N</em>-dimethylformamide (DMF) or ethanol/water mixtures. It was found that syntheses conducted in [EMIM][EtOSO<small><sub>3</sub></small>] resulted in the highest monomer conversions (up to >99%) and lowest dispersity (<em>Đ</em><small><sub>M</sub></small>) values (as low as 1.16) in the shortest reaction times (2 hours) compared to the other solvent systems. This work demonstrates the use of ILs as a more sustainable and effective solvent for RAFT PISA via the development of the first emulsion PISA formulation in IL.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"75 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143945886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Krishna Vippala, Nicole Edelstein-Pardo, Shahar Tevet, Parul Rathee, Gil Koren, Roy Beck, Roey J. Amir
The ability to program cascades of enzymatically induced transitions of polymeric assemblies across various mesophases holds promise for developing new dynamic materials with complex response mechanisms, mimicking the intricate behavior of proteins and other biological systems. In this study, we demonstrate the feasibility of controlling the rates of such sequential transitions by molecular engineering of the polymeric building blocks. To this end, we utilized a hydrogel forming PEG-based tri-block amphiphile (TBA) and micelles forming di-block amphiphiles (DBAs), composed of dendrons with enzymatically cleavable ester end-groups as their hydrophobic blocks, to create co-assembled nano-micellar formulations. We investigated their multi-step mesophase transitions, first from micelles into macroscopic hydrogels and subsequently into water-soluble polymers, in the presence of the activating enzyme porcine liver esterase (PLE). To demonstrate the ability to control the time frame of the micelle-to-hydrogel mesophase transition, we designed and synthesized three DBAs with varying dendritic architectures and degrees of hydrophobicity. These DBAs are composed of hydrophobic dendrons with two, three, and four lipophilic end-groups, designated as DBA-C6x2, DBA-C6x3, and DBA-C6x4, respectively. Our results indicated that the co-assembled micelles containing the least hydrophobic DBA-C6x2 rapidly transformed into a hydrogel within less than two hours upon exposure to PLE. In contrast, the micellar formulation with the most hydrophobic DBA-C6x4 took over two days to transition into the hydrogel mesophase. These findings underscore the potential of using molecular engineering to tailor the behavior of programable polymeric assemblies.
{"title":"Programming Cascade Mesophase Transitions of Enzyme-Responsive Formulations Via Molecular Engineering of Dendritic Amphiphiles","authors":"Krishna Vippala, Nicole Edelstein-Pardo, Shahar Tevet, Parul Rathee, Gil Koren, Roy Beck, Roey J. Amir","doi":"10.1039/d4py01378f","DOIUrl":"https://doi.org/10.1039/d4py01378f","url":null,"abstract":"The ability to program cascades of enzymatically induced transitions of polymeric assemblies across various mesophases holds promise for developing new dynamic materials with complex response mechanisms, mimicking the intricate behavior of proteins and other biological systems. In this study, we demonstrate the feasibility of controlling the rates of such sequential transitions by molecular engineering of the polymeric building blocks. To this end, we utilized a hydrogel forming PEG-based tri-block amphiphile (TBA) and micelles forming di-block amphiphiles (DBAs), composed of dendrons with enzymatically cleavable ester end-groups as their hydrophobic blocks, to create co-assembled nano-micellar formulations. We investigated their multi-step mesophase transitions, first from micelles into macroscopic hydrogels and subsequently into water-soluble polymers, in the presence of the activating enzyme porcine liver esterase (PLE). To demonstrate the ability to control the time frame of the micelle-to-hydrogel mesophase transition, we designed and synthesized three DBAs with varying dendritic architectures and degrees of hydrophobicity. These DBAs are composed of hydrophobic dendrons with two, three, and four lipophilic end-groups, designated as DBA-C6x2, DBA-C6x3, and DBA-C6x4, respectively. Our results indicated that the co-assembled micelles containing the least hydrophobic DBA-C6x2 rapidly transformed into a hydrogel within less than two hours upon exposure to PLE. In contrast, the micellar formulation with the most hydrophobic DBA-C6x4 took over two days to transition into the hydrogel mesophase. These findings underscore the potential of using molecular engineering to tailor the behavior of programable polymeric assemblies.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"3 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we report a new method of preparing bottlebrush polymers (BBPs) with a poly vinyl ether (PVE) backbone using a combination of cationic polymerization and atom transfer radical polymerization (ATRP). A Br-functionalized vinyl ether monomer, 2-vinyloxyethyl-2-bromoisobutyrate (VEBB), was synthesized for the “grafting-from” synthesis of BBPs, which can readily undergo cationic polymerization in the presence of organic Brønsted acid and allow for subsequent ATRP of different monomers to introduce side chains. Accordingly, a series of bottle brush polymers with well-defined backbone and different side chains can be prepared via this combination of cationic polymerization and ATRP technology. The thermal transition of PVE-based bottle brush polymers was studied by differential scanning calorimetry (DSC). The surface morphologies and aggregation behaviours of these nanoscopic single molecules were studied by tapping-mode atomic force microscopy (AFM) measurements on mica.
{"title":"“Grafting-from” synthesis of polyvinyl ether bottlebrush polymers via a combination of cationic polymerization and ATRP","authors":"Junqi Huang, Wenpei Xiao, Zan Yang, Xi Yan, Liuyin Jiang, Saihu Liao","doi":"10.1039/d5py00338e","DOIUrl":"https://doi.org/10.1039/d5py00338e","url":null,"abstract":"In this paper, we report a new method of preparing bottlebrush polymers (BBPs) with a poly vinyl ether (PVE) backbone using a combination of cationic polymerization and atom transfer radical polymerization (ATRP). A Br-functionalized vinyl ether monomer, 2-vinyloxyethyl-2-bromoisobutyrate (VEBB), was synthesized for the “grafting-from” synthesis of BBPs, which can readily undergo cationic polymerization in the presence of organic Brønsted acid and allow for subsequent ATRP of different monomers to introduce side chains. Accordingly, a series of bottle brush polymers with well-defined backbone and different side chains can be prepared via this combination of cationic polymerization and ATRP technology. The thermal transition of PVE-based bottle brush polymers was studied by differential scanning calorimetry (DSC). The surface morphologies and aggregation behaviours of these nanoscopic single molecules were studied by tapping-mode atomic force microscopy (AFM) measurements on mica.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"39 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143946037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the goal to produce high quality polyethylene wax, five distinct bis(cyclohexyl)-fused bis(imino)pyridine-cobalt complexes, Co1–Co5, bearing a remote para-phenyl group have been synthesized and employed as precatalysts in ethylene polymerization. All complexes, under activation with methylaluminoxane (MAO) or modified MAO (MMAO), exhibited extremely high catalytic activity reaching up to 25.36 × 106 g (PE) mol–1 (Co) h–1 for Co1/MAO, levels that surpass that found for most related cobalt analogues. In terms of the polymer, ultra-low molecular weight (Mw < 1.00 kg mol–1) linear polyethylene of narrow polydispersity was obtained with the Mw remaining almost constant (range: 0.500–0.600 kg mol–1) on varying the temperature, Al/Co molar ratios and reaction time, reflecting the excellent control displayed by this cobalt catalyst. Moreover, high selectivity for vinyl chain-ends was a common feature of the polymers (range: 73–97%) that could be exploited in the form of post-functionalization via epoxidation. Furthermore, a comparison of the number-average molecular weight (Mn) determined through NMR spectroscopy and GPC analysis has been studied, highlighting the merit of using NMR spectroscopy over GPC for measuring polymer molecular weight of less than 1.00 kg mol–1.
为了生产高质量的聚乙烯蜡，合成了五种不同的含远端对苯基的双（环己基）-熔融双（亚氨基）吡啶-钴配合物Co1-Co5，并将其用作乙烯聚合的预催化剂。所有配合物在甲基铝氧烷（MAO）或改性MAO （MMAO）的活化下，对Co1/MAO的催化活性都达到了25.36 × 106 g (PE) mol-1 (Co) h-1，超过了大多数相关钴类似物的催化活性。在聚合物方面，超低分子量(Mw <；在温度、Al/Co摩尔比和反应时间变化的情况下，在分子量为0.500 ~ 0.600 kg mol-1的条件下，得到了窄分散性的线性聚乙烯，表明该钴催化剂具有良好的控制性能。此外，乙烯基链末端的高选择性是聚合物的一个共同特征（范围：73-97%），可以通过环氧化以后功能化的形式进行开发。此外，还比较了核磁共振光谱法和GPC法测定的数平均分子量（Mn），突出了核磁共振光谱法比GPC法测定小于1.00 kg mol-1的聚合物分子量的优点。
{"title":"Ultra-low-molecular-weight PE wax using a cyclohexyl-fused bis(imino)pyridine-cobalt catalyst functionalized with a remote para-phenyl group","authors":"Yizhou Wang, Zheng Wang, Qiuyue Zhang, Quanchao Wang, Gregory Solan, Xuelei Duan, Yanping Ma, Jiahao Gao, Zhe Zhou, Wen Hua Sun","doi":"10.1039/d5py00358j","DOIUrl":"https://doi.org/10.1039/d5py00358j","url":null,"abstract":"With the goal to produce high quality polyethylene wax, five distinct bis(cyclohexyl)-fused bis(imino)pyridine-cobalt complexes, Co1–Co5, bearing a remote para-phenyl group have been synthesized and employed as precatalysts in ethylene polymerization. All complexes, under activation with methylaluminoxane (MAO) or modified MAO (MMAO), exhibited extremely high catalytic activity reaching up to 25.36 × 106 g (PE) mol–1 (Co) h–1 for Co1/MAO, levels that surpass that found for most related cobalt analogues. In terms of the polymer, ultra-low molecular weight (Mw < 1.00 kg mol–1) linear polyethylene of narrow polydispersity was obtained with the Mw remaining almost constant (range: 0.500–0.600 kg mol–1) on varying the temperature, Al/Co molar ratios and reaction time, reflecting the excellent control displayed by this cobalt catalyst. Moreover, high selectivity for vinyl chain-ends was a common feature of the polymers (range: 73–97%) that could be exploited in the form of post-functionalization via epoxidation. Furthermore, a comparison of the number-average molecular weight (Mn) determined through NMR spectroscopy and GPC analysis has been studied, highlighting the merit of using NMR spectroscopy over GPC for measuring polymer molecular weight of less than 1.00 kg mol–1.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"51 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143940514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nikunjkumar R. Visaveliya, Seda Kelestemur, Firdaus Khatoon, Jin Xu, Kelvin Leo, Karisma McCoy, Lauren St. Peter, Christopher Chan, Tatiana Mikhailova, Visar Bexheti, Geri Shentolli, Anushan Alagaratnam, Saad Ahmed, Piyali Maity, Dorthe M. Eisele
Surface-capping agents—for example, amphiphilic surfactant molecules, water-soluble polymers, or polyelectrolytes—play a critical role during polymerization reactions for both the formation and stability of colloidal polymer particles. Here, we investigated the effect of the molecular weight and concentration of polymeric surface-capping agents on the assembling of polyvinyl methacrylate (PVMA) colloidal nanoparticles (NPs) via microfluidic-supported emulsion polymerization. Specifically, the impacts of the molecular weight and concentration of polyvinylpyrrolidone (PVP, molecular weights of 10 000, 40 000, 360 000, and 1 300 000 MW, concentrations of 0.05, 0.5, 1, 2.5, 5, and 10 mM, repeating unit concentration) and poly(sodium styrene sulfonate) (PSSS, molecular weights of 70 000 and 200 000 MW, concentrations of 0.1, 1, 2.5, 5, 10, and 20 mM, repeating unit concentration) on the formation of PVMA NPs were investigated. Depending on the molecular weight and concentration of surface-capping agents, we obtained finely textured assembled, spherical, flower-shaped, fluffy, and elongated spherical PVMA NPs with sizes ranging from 70 to 500 nm. With our microfluidic-supported synthesis of PVMA NPs, we contributed to a basic understanding of how the molecular weight and concentration of surface-capping agents impact the formation of polymer NPs.
{"title":"Microfluidic-supported emulsion polymerization: molecular weight and concentration of surface-capping agents impact the formation of anisotropic polyvinylmethacrylate particles","authors":"Nikunjkumar R. Visaveliya, Seda Kelestemur, Firdaus Khatoon, Jin Xu, Kelvin Leo, Karisma McCoy, Lauren St. Peter, Christopher Chan, Tatiana Mikhailova, Visar Bexheti, Geri Shentolli, Anushan Alagaratnam, Saad Ahmed, Piyali Maity, Dorthe M. Eisele","doi":"10.1039/d5py00334b","DOIUrl":"https://doi.org/10.1039/d5py00334b","url":null,"abstract":"Surface-capping agents—for example, amphiphilic surfactant molecules, water-soluble polymers, or polyelectrolytes—play a critical role during polymerization reactions for both the formation and stability of colloidal polymer particles. Here, we investigated the effect of the molecular weight and concentration of polymeric surface-capping agents on the assembling of polyvinyl methacrylate (PVMA) colloidal nanoparticles (NPs) <em>via</em> microfluidic-supported emulsion polymerization. Specifically, the impacts of the molecular weight and concentration of polyvinylpyrrolidone (PVP, molecular weights of 10 000, 40 000, 360 000, and 1 300 000 MW, concentrations of 0.05, 0.5, 1, 2.5, 5, and 10 mM, repeating unit concentration) and poly(sodium styrene sulfonate) (PSSS, molecular weights of 70 000 and 200 000 MW, concentrations of 0.1, 1, 2.5, 5, 10, and 20 mM, repeating unit concentration) on the formation of PVMA NPs were investigated. Depending on the molecular weight and concentration of surface-capping agents, we obtained finely textured assembled, spherical, flower-shaped, fluffy, and elongated spherical PVMA NPs with sizes ranging from 70 to 500 nm. With our microfluidic-supported synthesis of PVMA NPs, we contributed to a basic understanding of how the molecular weight and concentration of surface-capping agents impact the formation of polymer NPs.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"51 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lea-Sophie Hornberger, Julian Fischer, Alexandra Friedly, Ingo Hartenbach, Thomas Sottmann, Friederike Adams
Poly(dihydrocarvide) (PDHC) is synthesized through ring-opening polymerization (ROP) of terpene-based 7-membered lactone dihydrocarvide (DHC) using an amino-alkoxy-bis(phenolate) yttrium amido catalyst and isopropanol (iPrOH) as a chain transfer agent while retaining the pendant-group double bond in the monomer unit. Polymerization under conditions found to be favorable (60 °C, 1 eq. iPrOH) yielding PDHC with tunable molecular weights and low to moderate polydispersities (Ð = 1.2-1.5). Crystalline fractions are introduced into amorphous PDHC by producing block copolymers with 16-membered ω-pentadecalactone (PDL) or 4-membered racemic β-butyrolactone (BBL) via sequential addition following the coordination strength hierarchy (PDL ˂ DHC ˂ BBL). This resulted in semi-crystalline renewable block copolymers P(PDL-b-DHC) and P(DHC-b-PHB) that were further analyzed by PXRD and SAXS measurements. Additionally, PDHC is functionalized via thiol-ene reaction with 2-mercaptoethanol, introducing hydroxyl functionality and opening up a multitude of functionalization possibilities. As one example, atom transfer radical polymerization (ATRP) initiators are attached, and SARA and ARGET ATRP techniques are employed to graft poly(ethyl acrylate) (PEA) as model compound, forming PDHC-g-PEA brush polymers. The TPMANMe2-based ARGET ATRP system demonstrates superior control over molecular weight and polydispersity compared to SARA ATRP, though both methods yield well-defined polymer brushes with molecular weight growth correlating with the initial amount of ethyl acrylate. This approach demonstrates the potential of PDHC for constructing diverse polymer architectures from different types of lactones or vinyl monomers by combining ROP and ATRP.
{"title":"Yttrium-mediated ring-opening polymerization of functionalizable dihydrocarvide: tunable terpene-based polyesters using grafting from and block copolymerization strategies","authors":"Lea-Sophie Hornberger, Julian Fischer, Alexandra Friedly, Ingo Hartenbach, Thomas Sottmann, Friederike Adams","doi":"10.1039/d5py00322a","DOIUrl":"https://doi.org/10.1039/d5py00322a","url":null,"abstract":"Poly(dihydrocarvide) (PDHC) is synthesized through ring-opening polymerization (ROP) of terpene-based 7-membered lactone dihydrocarvide (DHC) using an amino-alkoxy-bis(phenolate) yttrium amido catalyst and isopropanol (iPrOH) as a chain transfer agent while retaining the pendant-group double bond in the monomer unit. Polymerization under conditions found to be favorable (60 °C, 1 eq. iPrOH) yielding PDHC with tunable molecular weights and low to moderate polydispersities (Ð = 1.2-1.5). Crystalline fractions are introduced into amorphous PDHC by producing block copolymers with 16-membered ω-pentadecalactone (PDL) or 4-membered racemic β-butyrolactone (BBL) via sequential addition following the coordination strength hierarchy (PDL ˂ DHC ˂ BBL). This resulted in semi-crystalline renewable block copolymers P(PDL-b-DHC) and P(DHC-b-PHB) that were further analyzed by PXRD and SAXS measurements. Additionally, PDHC is functionalized via thiol-ene reaction with 2-mercaptoethanol, introducing hydroxyl functionality and opening up a multitude of functionalization possibilities. As one example, atom transfer radical polymerization (ATRP) initiators are attached, and SARA and ARGET ATRP techniques are employed to graft poly(ethyl acrylate) (PEA) as model compound, forming PDHC-g-PEA brush polymers. The TPMA<small><sup>NMe2</sup></small>-based ARGET ATRP system demonstrates superior control over molecular weight and polydispersity compared to SARA ATRP, though both methods yield well-defined polymer brushes with molecular weight growth correlating with the initial amount of ethyl acrylate. This approach demonstrates the potential of PDHC for constructing diverse polymer architectures from different types of lactones or vinyl monomers by combining ROP and ATRP.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"118 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sustainably producing thermoplastics with well-defined structures across various material chemistries remains challenging. Herein, we report a new synthetic methodology for thermoplastic polyesters with side-chain imide groups via one-pot melt polycondensation enabled by thermodynamic imide ring and ester formation, using either a two-component system of amino diol/dicarboxylic acid or a three-component system of amino diol/diol/dicarboxylic acid. Unlike traditional trifunctional systems, the amino groups of amino diols are fully converted into imide without cross-linking. This methodology was inspired by the model reaction of amino alcohol and dicarboxylic acid to form di(ester imide) via melt condensation, where the esterification, imidization and molecular chain propagation mechanisms can be extended to polymerization. The resulting series of imide-containing polyesters exhibited controllable weight-average molecular weights up to 110.8 kDa, a wide range of glass transition temperatures (−24.6 to 115.4 °C), and tunable mechanical properties with ultimate tensile strengths ranging from 8.0 to 34.5 MPa and elongations at break up to 472%. The programmable one-pot synthesis technology has extensive potential for sustainable and functional materials.
{"title":"Sustainable one-pot synthesis of imide-containing polyesters with programmable structures and tunable performance","authors":"Tianhua Ren, Feng Yu, Jialong Li, Jinlin Li, Kechun Zhang","doi":"10.1039/d5py00190k","DOIUrl":"https://doi.org/10.1039/d5py00190k","url":null,"abstract":"Sustainably producing thermoplastics with well-defined structures across various material chemistries remains challenging. Herein, we report a new synthetic methodology for thermoplastic polyesters with side-chain imide groups <em>via</em> one-pot melt polycondensation enabled by thermodynamic imide ring and ester formation, using either a two-component system of amino diol/dicarboxylic acid or a three-component system of amino diol/diol/dicarboxylic acid. Unlike traditional trifunctional systems, the amino groups of amino diols are fully converted into imide without cross-linking. This methodology was inspired by the model reaction of amino alcohol and dicarboxylic acid to form di(ester imide) <em>via</em> melt condensation, where the esterification, imidization and molecular chain propagation mechanisms can be extended to polymerization. The resulting series of imide-containing polyesters exhibited controllable weight-average molecular weights up to 110.8 kDa, a wide range of glass transition temperatures (−24.6 to 115.4 °C), and tunable mechanical properties with ultimate tensile strengths ranging from 8.0 to 34.5 MPa and elongations at break up to 472%. The programmable one-pot synthesis technology has extensive potential for sustainable and functional materials.","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"3 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143920447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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