Justin Koh , Chloe A. Baker , Marianna N. Diamantakis , Nicholas J. Long , Charles Romain
Exploiting non-covalent interactions (NCIs) has become a powerful tool in catalyst design, including those for polymerisation reactions. Herein we report a simple strategy relying on the addition of silver salt to Ti-salen complexes, leading to Ti/Ag cooperativity via cation-π interactions. Three different Ti-salen complexes were investigated alongside several silver salts. In all cases, these Ti/Ag systems led to good or high activity at room temperature for rac-lactide ROP, a rare feature for Ti-based catalysts. Interestingly, the weakly coordinating anion (WCA) of the silver salt was found not only to affect activity but also stereocontrol in the polymerisation. Heterotactic PLA with Pr up to 0.7 was obtained.
{"title":"A pinch of silver salt to enable rac-lactide ring-opening polymerisation at room temperature using Ti-salen complexes†","authors":"Justin Koh , Chloe A. Baker , Marianna N. Diamantakis , Nicholas J. Long , Charles Romain","doi":"10.1039/d4py01319k","DOIUrl":"10.1039/d4py01319k","url":null,"abstract":"<div><div>Exploiting non-covalent interactions (NCIs) has become a powerful tool in catalyst design, including those for polymerisation reactions. Herein we report a simple strategy relying on the addition of silver salt to Ti-salen complexes, leading to Ti/Ag cooperativity <em>via</em> cation-π interactions. Three different Ti-salen complexes were investigated alongside several silver salts. In all cases, these Ti/Ag systems led to good or high activity at room temperature for <em>rac</em>-lactide ROP, a rare feature for Ti-based catalysts. Interestingly, the weakly coordinating anion (WCA) of the silver salt was found not only to affect activity but also stereocontrol in the polymerisation. Heterotactic PLA with <em>P</em><sub>r</sub> up to 0.7 was obtained.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 13","pages":"Pages 1503-1508"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/py/d4py01319k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143507206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengzhi Guo , Jinye He , Junhong Liang , Tiantian Wang , Mingruo Li , Jianhong Wei , Wentao Miao , Zezhou Liang , Yuan Zhou , Junfeng Tong , Xunchang Wang , Chenglong Wang , Yangjun Xia
Modification of conjugated polymer skeletons using side chain engineering is important for the development of efficient conjugated donor polymers. In this work, alkylthio-substituted BDD units (SBDD) were introduced into the high-efficiency donor PM6 to construct a series of conjugated polymers (PBDB-TF-S5, PBDB-TF-S10 and PBDB-TF-S20, with the molar ratios of SBDD of 5%, 10%, and 20%, respectively), and the effect of the third component SBDD on the photovoltaic performance of organic solar cells (OSCs) was systematically investigated. First, we demonstrated that the highest occupied molecular orbital energy level (EHOMO) of polymers gradually decreases when the content of SBDD increases, which facilitates the obtainment of progressively higher open-circuit voltages (VOC) for the corresponding devices. Second, the detailed experimental results proved that OSCs based on PBDB-TF-S5:Y6 revealed a lower energy loss (Eloss), suitable degree of crystallinity, good miscibility with Y6, more balanced carrier mobilities and weaker charge recombination. Eventually, the power conversion efficiency (PCE) of the device based on PM6:Y6 (15.47%) was increased to 16.46% with a JSC of 25.68 mA cm−2, VOC of 0.861 V and fill factor (FF) of 74.45% with the help of an alkylthio side chain. This work provides a sufficient reference for optimizing the efficient donor polymer PM6 and confirms that PBDB-TF-S5 is a promising and efficient donor polymer for OSCs.
{"title":"An alkylthio side chain tuned the PM6 structure and elevated photovoltaic performance of ternary donor polymers†","authors":"Pengzhi Guo , Jinye He , Junhong Liang , Tiantian Wang , Mingruo Li , Jianhong Wei , Wentao Miao , Zezhou Liang , Yuan Zhou , Junfeng Tong , Xunchang Wang , Chenglong Wang , Yangjun Xia","doi":"10.1039/d4py01152j","DOIUrl":"10.1039/d4py01152j","url":null,"abstract":"<div><div>Modification of conjugated polymer skeletons using side chain engineering is important for the development of efficient conjugated donor polymers. In this work, alkylthio-substituted BDD units (SBDD) were introduced into the high-efficiency donor PM6 to construct a series of conjugated polymers (PBDB-TF-S5, PBDB-TF-S10 and PBDB-TF-S20, with the molar ratios of SBDD of 5%, 10%, and 20%, respectively), and the effect of the third component SBDD on the photovoltaic performance of organic solar cells (OSCs) was systematically investigated. First, we demonstrated that the highest occupied molecular orbital energy level (<em>E</em><sub>HOMO</sub>) of polymers gradually decreases when the content of SBDD increases, which facilitates the obtainment of progressively higher open-circuit voltages (<em>V</em><sub>OC</sub>) for the corresponding devices. Second, the detailed experimental results proved that OSCs based on PBDB-TF-S5:Y6 revealed a lower energy loss (<em>E</em><sub>loss</sub>), suitable degree of crystallinity, good miscibility with Y6, more balanced carrier mobilities and weaker charge recombination. Eventually, the power conversion efficiency (PCE) of the device based on PM6:Y6 (15.47%) was increased to 16.46% with a <em>J</em><sub>SC</sub> of 25.68 mA cm<sup>−2</sup>, <em>V</em><sub>OC</sub> of 0.861 V and fill factor (FF) of 74.45% with the help of an alkylthio side chain. This work provides a sufficient reference for optimizing the efficient donor polymer PM6 and confirms that PBDB-TF-S5 is a promising and efficient donor polymer for OSCs.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 13","pages":"Pages 1493-1502"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143477435","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}
Corinna Smith , Oliver B. Penrhyn-Lowe , Samuel Mckeating , Stephen Wright , Andrew B. Dwyer , Steve P. Rannard
The use of Transfer-dominated Branching Radical Telomerisation (TBRT) in the homopolymerisation of neopentyl glycol dimethacrylate has shown the formation of highly cyclised structures even at relatively highly concentrated reaction conditions. This is contrary to previous reports of the TBRT of unconstrained multi-vinyl taxogens and is the first indication of geometry directed cyclisation within the formation of branched polyesters via TBRT methods. Surprisingly, there was limited impact of increased reaction temperature on recovered samples. Dilution led to an expected increase in cyclisation, however, the recovered polymer samples are unprecedented in the extent of cyclisation and the reduction in the use of telogen required to suppress gelation and form soluble branched polymers.
{"title":"Geometry-directed cyclisation within the transfer-dominated branching radical telomerisation of dimethacrylates†","authors":"Corinna Smith , Oliver B. Penrhyn-Lowe , Samuel Mckeating , Stephen Wright , Andrew B. Dwyer , Steve P. Rannard","doi":"10.1039/d4py01368a","DOIUrl":"10.1039/d4py01368a","url":null,"abstract":"<div><div>The use of Transfer-dominated Branching Radical Telomerisation (TBRT) in the homopolymerisation of neopentyl glycol dimethacrylate has shown the formation of highly cyclised structures even at relatively highly concentrated reaction conditions. This is contrary to previous reports of the TBRT of unconstrained multi-vinyl taxogens and is the first indication of geometry directed cyclisation within the formation of branched polyesters <em>via</em> TBRT methods. Surprisingly, there was limited impact of increased reaction temperature on recovered samples. Dilution led to an expected increase in cyclisation, however, the recovered polymer samples are unprecedented in the extent of cyclisation and the reduction in the use of telogen required to suppress gelation and form soluble branched polymers.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 13","pages":"Pages 1486-1492"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/py/d4py01368a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143486547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Here, the functionalization of bio-based polycarbonates by post-polymerization modification with boronic acids was demonstrated as an effective method for tuning the thermal and physical properties of original polymers without losing their original nature, i.e., the degradability into monomers and urea by ammonolysis. Poly(isosorbide carbonate)-based copolymers with hydroxy groups in the polymer main chain were modified using low-molecular-weight boronic acids and polymers containing boronic acids, respectively. The modifications significantly changed the glass transition temperature, solubility, and mechanical properties. In particular, the use of modifiers with two or more boronic acids noticeably varied the mobility of the polymer, resulting in cross-linked structures. All the modified polymers, including cross-linked polymers, were successfully degraded to monomers and urea by aqueous ammonia treatment. Thus, this study provides a design guideline to control the physical properties of PIC copolymers by balancing their stability as a polymer material and their degradability after use.
{"title":"Chemical modification of poly(isosorbide carbonate)-based copolymers with boronic acids and the ammonolysis of the modified copolymers†","authors":"Kazuaki Rikiyama , Akari Matsunami , Shunsuke Fujimata , Tatsuo Taniguchi , Daisuke Aoki","doi":"10.1039/d4py01365d","DOIUrl":"10.1039/d4py01365d","url":null,"abstract":"<div><div>Here, the functionalization of bio-based polycarbonates by post-polymerization modification with boronic acids was demonstrated as an effective method for tuning the thermal and physical properties of original polymers without losing their original nature, <em>i.e.</em>, the degradability into monomers and urea by ammonolysis. Poly(isosorbide carbonate)-based copolymers with hydroxy groups in the polymer main chain were modified using low-molecular-weight boronic acids and polymers containing boronic acids, respectively. The modifications significantly changed the glass transition temperature, solubility, and mechanical properties. In particular, the use of modifiers with two or more boronic acids noticeably varied the mobility of the polymer, resulting in cross-linked structures. All the modified polymers, including cross-linked polymers, were successfully degraded to monomers and urea by aqueous ammonia treatment. Thus, this study provides a design guideline to control the physical properties of PIC copolymers by balancing their stability as a polymer material and their degradability after use.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 13","pages":"Pages 1448-1457"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443979","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}
Xin Yi , Hao Zeng , Chunyu Chen , Ziwei Luo , Ningyu Li , Junyang Cen , Yuening Pan , Ze Li , Pinglu Zhang
The incorporation of heteroatoms in polymeric structures may promote some physical or chemical properties of polymers. Polythioethers are widely used as functional materials and are of great importance in both academia and industry. In conventional synthetic strategies, thiols with unpleasant odor are typically used as the starting materials. Here, we disclose a novel thiolation polymerization using dithiosulfonate as a surrogate thiolation reagent, which was applied with aliphatic dibromide in a nickel catalyzed reductive cross-coupling polymerization for the synthesis of polythioethers. An array of polythioethers were prepared with well-defined structures and decent thermal properties. Moreover, the refractive index of these polythioethers could reach up to 1.72, indicating a potential application as optical materials. This work establishes a novel thiolation polymerization toward polythioethers and starts an avenue for their applications.
{"title":"Nickel-catalyzed reductive cross-coupling polymerization of dithiosulfonates and dibromides for the synthesis of polythioethers†","authors":"Xin Yi , Hao Zeng , Chunyu Chen , Ziwei Luo , Ningyu Li , Junyang Cen , Yuening Pan , Ze Li , Pinglu Zhang","doi":"10.1039/d4py01374c","DOIUrl":"10.1039/d4py01374c","url":null,"abstract":"<div><div>The incorporation of heteroatoms in polymeric structures may promote some physical or chemical properties of polymers. Polythioethers are widely used as functional materials and are of great importance in both academia and industry. In conventional synthetic strategies, thiols with unpleasant odor are typically used as the starting materials. Here, we disclose a novel thiolation polymerization using dithiosulfonate as a surrogate thiolation reagent, which was applied with aliphatic dibromide in a nickel catalyzed reductive cross-coupling polymerization for the synthesis of polythioethers. An array of polythioethers were prepared with well-defined structures and decent thermal properties. Moreover, the refractive index of these polythioethers could reach up to 1.72, indicating a potential application as optical materials. This work establishes a novel thiolation polymerization toward polythioethers and starts an avenue for their applications.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 13","pages":"Pages 1441-1447"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546978","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}
Stephen T. Knox , Kai E. Wu , Nazrul Islam , Roisin O'Connell , Peter M. Pittaway , Kudakwashe E. Chingono , John Oyekan , George Panoutsos , Thomas W. Chamberlain , Richard A. Bourne , Nicholas J. Warren
The application of artificial intelligence and machine learning is revolutionising the chemical industry, with the ability to automate and self-optimise reactions facilitating a step change in capability. Unlike small-molecules, polymer nanoparticles require navigation of a more complex parameter space to access the desired performance. In addition to the chemical reaction, it is desirable to optimise the polymer molecular weight distribution, particle size and polydispersity index. To solve this many-objective optimisation problem, a self-driving laboratory is constructed which synthesises and characterises polymer nanoparticles (incorporating NMR spectroscopy, gel permeation chromatography and dynamic light scattering). This facilitates the autonomous exploration of parameter space with programmable screens or AI driven optimisation campaigns via a cloud-based framework. The RAFT polymerisation of diacetone acrylamide mediated by a poly(dimethylacrylamide) macro-CTA was optimised to maximise monomer conversion, minimise molar mass dispersity, and target 80 nm particles with minimised polydispersity index. A full-factorial screen between 6- and 30-minutes residence time, between 68 and 80 °C and between 100 and 600 for the [monomer] : [CTA] ratio enabled mapping of the reaction space. This facilitated in-silico simulations using a range of algorithms – Thompson sampling efficient multi-objective optimisation (TSEMO), radial basis function neural network/reference vector evolutionary algorithm (RBFNN/RVEA) and multi objective particle swarm optimisation, hybridised with an evolutionary algorithm (EA-MOPSO), which were then applied to in-lab optimisations. This approach accounts for an unprecedented number of objectives for closed-loop optimisation of a synthetic polymerisation; and enabled the use of algorithms operated from different geographical locations to the reactor platform.
{"title":"Self-driving laboratory platform for many-objective self-optimisation of polymer nanoparticle synthesis with cloud-integrated machine learning and orthogonal online analytics†","authors":"Stephen T. Knox , Kai E. Wu , Nazrul Islam , Roisin O'Connell , Peter M. Pittaway , Kudakwashe E. Chingono , John Oyekan , George Panoutsos , Thomas W. Chamberlain , Richard A. Bourne , Nicholas J. Warren","doi":"10.1039/d5py00123d","DOIUrl":"10.1039/d5py00123d","url":null,"abstract":"<div><div>The application of artificial intelligence and machine learning is revolutionising the chemical industry, with the ability to automate and self-optimise reactions facilitating a step change in capability. Unlike small-molecules, polymer nanoparticles require navigation of a more complex parameter space to access the desired performance. In addition to the chemical reaction, it is desirable to optimise the polymer molecular weight distribution, particle size and polydispersity index. To solve this <em>many-objective</em> optimisation problem, a self-driving laboratory is constructed which synthesises and characterises polymer nanoparticles (incorporating NMR spectroscopy, gel permeation chromatography and dynamic light scattering). This facilitates the autonomous exploration of parameter space with programmable screens or AI driven optimisation campaigns <em>via</em> a cloud-based framework. The RAFT polymerisation of diacetone acrylamide mediated by a poly(dimethylacrylamide) macro-CTA was optimised to maximise monomer conversion, minimise molar mass dispersity, and target 80 nm particles with minimised polydispersity index. A full-factorial screen between 6- and 30-minutes residence time, between 68 and 80 °C and between 100 and 600 for the [monomer] : [CTA] ratio enabled mapping of the reaction space. This facilitated <em>in-silico</em> simulations using a range of algorithms – Thompson sampling efficient multi-objective optimisation (TSEMO), radial basis function neural network/reference vector evolutionary algorithm (RBFNN/RVEA) and multi objective particle swarm optimisation, hybridised with an evolutionary algorithm (EA-MOPSO), which were then applied to in-lab optimisations. This approach accounts for an unprecedented number of objectives for closed-loop optimisation of a synthetic polymerisation; and enabled the use of algorithms operated from different geographical locations to the reactor platform.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 12","pages":"Pages 1355-1364"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/py/d5py00123d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents the synthesis of a novel methylene blue acrylamide monomer and its incorporation into a diblock copolymer, , which exhibits potent antimicrobial activity against Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria when photoirradiated under red light (λ = 630 nm). Mechanistic investigations revealed that singlet oxygen species, and not superoxides, are responsible for the antimicrobial activity, most likely by damaging cellular components such as proteins and DNA. The advantage of using red light as an external trigger because of its ability to penetrate skin and tissue is demonstrated here, where is still active against E. coli when irradiated through a cover of chicken skin. In terms of biocompatibility, is, significantly, 130 times more biocompatible than the original methylene blue dye. Overall, this study demonstrates the efficient modification of a red light-active photosensitiser into an antimicrobial macromolecule with improved biological properties for potential photodynamic applications in healthcare.
{"title":"Photoactive methylene blue-functionalized polymer for antimicrobial activation under red light†","authors":"Zeyu Shao , Huanli Sun , Edgar H. H. Wong","doi":"10.1039/d5py00068h","DOIUrl":"10.1039/d5py00068h","url":null,"abstract":"<div><div>This study presents the synthesis of a novel methylene blue acrylamide monomer and its incorporation into a diblock copolymer, , which exhibits potent antimicrobial activity against Gram-negative (<em>Escherichia coli</em>, <em>Pseudomonas aeruginosa</em>) and Gram-positive (<em>Staphylococcus aureus</em>) bacteria when photoirradiated under red light (<em>λ</em> = 630 nm). Mechanistic investigations revealed that singlet oxygen species, and not superoxides, are responsible for the antimicrobial activity, most likely by damaging cellular components such as proteins and DNA. The advantage of using red light as an external trigger because of its ability to penetrate skin and tissue is demonstrated here, where is still active against <em>E. coli</em> when irradiated through a cover of chicken skin. In terms of biocompatibility, is, significantly, 130 times more biocompatible than the original methylene blue dye. Overall, this study demonstrates the efficient modification of a red light-active photosensitiser into an antimicrobial macromolecule with improved biological properties for potential photodynamic applications in healthcare.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 12","pages":"Pages 1373-1382"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/py/d5py00068h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Linear polymers carrying electron-rich dialkoxy-carbazole (DACBZ) units linked by flexible oligooxyethylene segments were induced into a zigzag folded state by an external folding agent, which carries two subunits: an electron-deficient dinitro-naphthalene monoimide (NMI(NO2)2) acceptor and an ammonium perchlorate unit. The ammonium unit of the folding agent interacts with the backbone oxyethylene segment and, in turn, brings two adjacent CBZ moieties on either side of the electron-deficient NMI(NO2)2 unit of the folding agent to induce a charge-transfer (CT) interaction; this two-point interaction was shown to be crucial for the stability of the pleated chain structure. An interesting, and potentially useful, feature of this system is the possibility to incorporate a pendant unit at the carbazole nitrogen (N) site; a variety of segments, such as linear, branched, or chiral alkyl chains, were installed to examine if the folding of the chain is influenced by the nature of the pendant segment. The formation of the pleated structure was studied by 1H-NMR and UV-visible titration experiments; both these clearly revealed the presence of strong charge transfer (CT) interactions between the donor (D) and acceptor (A) units. The length of the spacer segment linking the NMI(NO2)2 acceptor unit and the ammonium group in the folding agent was varied, and it was seen that a 3-carbon spacer yielded the strongest cooperative interaction. To translate the folded conformation into the solid state, a solution of the donor polymer and the most efficient acceptor, taken in a 1 : 1 (D:A) ratio, was cast on a quartz plate. UV-visible studies of the film revealed the retention of the CT band; more importantly, immersing the film into an aqueous NaHCO3 solution neutralized the ammonium group to generate the free amine. This caused an unexpected deepening of the colour, along with a hypsochromic shift of the CT band, suggesting that the free amine acceptor readjusts within the film to improve the CT interaction, exploiting the newly garnered freedom after de-coordination with the oligooxyethylene segment.
{"title":"Chain folding of carbazole-donor containing polymers via a two-point interaction with naphthalene monoimide-based acceptors†","authors":"Arun Kumar Gayen , S. Ramakrishnan","doi":"10.1039/d4py01234h","DOIUrl":"10.1039/d4py01234h","url":null,"abstract":"<div><div>Linear polymers carrying electron-rich dialkoxy-carbazole (DACBZ) units linked by flexible oligooxyethylene segments were induced into a zigzag folded state by an external folding agent, which carries two subunits: an electron-deficient dinitro-naphthalene monoimide (NMI(NO<sub>2</sub>)<sub>2</sub>) acceptor and an ammonium perchlorate unit. The ammonium unit of the folding agent interacts with the backbone oxyethylene segment and, in turn, brings two adjacent CBZ moieties on either side of the electron-deficient NMI(NO<sub>2</sub>)<sub>2</sub> unit of the folding agent to induce a charge-transfer (CT) interaction; this two-point interaction was shown to be crucial for the stability of the pleated chain structure. An interesting, and potentially useful, feature of this system is the possibility to incorporate a pendant unit at the carbazole nitrogen (N) site; a variety of segments, such as linear, branched, or chiral alkyl chains, were installed to examine if the folding of the chain is influenced by the nature of the pendant segment. The formation of the pleated structure was studied by <sup>1</sup>H-NMR and UV-visible titration experiments; both these clearly revealed the presence of strong charge transfer (CT) interactions between the donor (D) and acceptor (A) units. The length of the spacer segment linking the NMI(NO<sub>2</sub>)<sub>2</sub> acceptor unit and the ammonium group in the folding agent was varied, and it was seen that a 3-carbon spacer yielded the strongest cooperative interaction. To translate the folded conformation into the solid state, a solution of the donor polymer and the most efficient acceptor, taken in a 1 : 1 (D:A) ratio, was cast on a quartz plate. UV-visible studies of the film revealed the retention of the CT band; more importantly, immersing the film into an aqueous NaHCO<sub>3</sub> solution neutralized the ammonium group to generate the free amine. This caused an unexpected deepening of the colour, along with a hypsochromic shift of the CT band, suggesting that the free amine acceptor readjusts within the film to improve the CT interaction, exploiting the newly garnered freedom after de-coordination with the oligooxyethylene segment.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 12","pages":"Pages 1345-1354"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385599","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}
We prepared phenyl-substituted corner-opened type polyhedral oligomeric silsesquioxanes (CO-POSSs) bearing tris(dimethoxysilyl)-groups with variable linker lengths at the opening vertex; that is, tris(dimethoxysilyl-ethyl-dimethylsiloxy)- and tris(dimethoxysilyl-propylthioethyl-dimethylsiloxy)-heptaphenyl-substituted CO-POSSs ( and ). Optically transparent free-standing films of phenyl-substituted open-cage silsesquioxane-pendant polysiloxanes () were prepared by optimizing the sol–gel reaction conditions for . Polycondensation of afforded an optically transparent and flexible phenyl-substituted CO-POSS-pendant polysiloxane film (). The polycondensations of and were fully completed even at 50 °C for 6 h under vacuum. 29Si cross-polarization magic angle spinning (CP-MAS) NMR analysis suggests that the films included cyclotrisiloxane (D3) and linear siloxane (Dlinear) structures. The effects of the polysiloxane structures on the thermal and mechanical properties were studied. The highest temperature at which the sample lost 5 wt% of the original mass (Td5) under N2 (381 °C) was obtained for , even though it contained a flexible linker unit. The predominant linear siloxane structures may provide increase higher thermal stability. The UV-vis spectra of the resulting transparent films were mostly unchanged even after six days of exposure to UV irradiation in air. The present study shows that phenyl-substituted CO-POSS-pendant polysiloxanes represent alternative UV-resistant, optically transparent materials with higher heat resistance.
{"title":"Preparation of phenyl-substituted open-cage silsesquioxane-pendant polysiloxanes and their thermal and optical properties†","authors":"Miku Kosaka , Kenji Kanaori , Hiroaki Imoto , Kensuke Naka","doi":"10.1039/d4py01460j","DOIUrl":"10.1039/d4py01460j","url":null,"abstract":"<div><div>We prepared phenyl-substituted corner-opened type polyhedral oligomeric silsesquioxanes (CO-POSSs) bearing tris(dimethoxysilyl)-groups with variable linker lengths at the opening vertex; that is, tris(dimethoxysilyl-ethyl-dimethylsiloxy)- and tris(dimethoxysilyl-propylthioethyl-dimethylsiloxy)-heptaphenyl-substituted CO-POSSs ( and ). Optically transparent free-standing films of phenyl-substituted open-cage silsesquioxane-pendant polysiloxanes () were prepared by optimizing the sol–gel reaction conditions for . Polycondensation of afforded an optically transparent and flexible phenyl-substituted CO-POSS-pendant polysiloxane film (). The polycondensations of and were fully completed even at 50 °C for 6 h under vacuum. <sup>29</sup>Si cross-polarization magic angle spinning (CP-MAS) NMR analysis suggests that the films included cyclotrisiloxane (D<sub>3</sub>) and linear siloxane (D<sub>linear</sub>) structures. The effects of the polysiloxane structures on the thermal and mechanical properties were studied. The highest temperature at which the sample lost 5 wt% of the original mass (<em>T</em><sub>d5</sub>) under N<sub>2</sub> (381 °C) was obtained for , even though it contained a flexible linker unit. The predominant linear siloxane structures may provide increase higher thermal stability. The UV-vis spectra of the resulting transparent films were mostly unchanged even after six days of exposure to UV irradiation in air. The present study shows that phenyl-substituted CO-POSS-pendant polysiloxanes represent alternative UV-resistant, optically transparent materials with higher heat resistance.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 12","pages":"Pages 1365-1372"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/py/d4py01460j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oliver J. Harris , Peter Tollington , Calum J. Greenhalgh , Ryan R. Larder , Helen Willcock , Fiona L. Hatton
Polymeric materials based on fatty acids (FAs) have a combination of characteristics (alkene groups, hydrophobicity, tuneable Tg) that give them great potential as renewable, high value materials. Here, we investigate the base catalysed transesterification of four different plant oils (high oleic sunflower, olive, hydrogenated coconut and hydrogenated rapeseed) with N-hydroxyethyl acrylamide. By conducting kinetics experiments, investigating potential side reactions and improving isolation of the target products, we were able to identify reactive impurities (radical inhibitors, unintended co-monomers) that were found to remain in the impure brine washed plant oil-based monomers (POBM). Kinetics experiments were then performed to investigate the RAFT polymerisation of these monomers. It was found that the more sustainable brine washing process was viable for the controlled radical polymerisation of the higher kp app (saturated) monomers, however column purification was necessary for good control of unsaturated monomers. Polymers with values of Mn between 3000 and 12 000 g mol−1 were synthesised and dependent on the FA source exhibited either amorphous or semi-crystalline behaviour (Tg values between −1 and 33 °C, Tm values between 48 and 66 °C). This work demonstrates the first example of RAFT polymerisation of acrylamide monomers derived from plant oils by a one step direct transesterification, opening the door for novel well-defined, functional bio-based polymers.
{"title":"Synthesis and RAFT polymerisation of hydrophobic acrylamide monomers derived from plant oils†","authors":"Oliver J. Harris , Peter Tollington , Calum J. Greenhalgh , Ryan R. Larder , Helen Willcock , Fiona L. Hatton","doi":"10.1039/d4py01100g","DOIUrl":"10.1039/d4py01100g","url":null,"abstract":"<div><div>Polymeric materials based on fatty acids (FAs) have a combination of characteristics (alkene groups, hydrophobicity, tuneable <em>T</em><sub>g</sub>) that give them great potential as renewable, high value materials. Here, we investigate the base catalysed transesterification of four different plant oils (high oleic sunflower, olive, hydrogenated coconut and hydrogenated rapeseed) with <em>N</em>-hydroxyethyl acrylamide. By conducting kinetics experiments, investigating potential side reactions and improving isolation of the target products, we were able to identify reactive impurities (radical inhibitors, unintended co-monomers) that were found to remain in the impure brine washed plant oil-based monomers (POBM). Kinetics experiments were then performed to investigate the RAFT polymerisation of these monomers. It was found that the more sustainable brine washing process was viable for the controlled radical polymerisation of the higher <em>k</em><sub>p app</sub> (saturated) monomers, however column purification was necessary for good control of unsaturated monomers. Polymers with values of <em>M</em><sub>n</sub> between 3000 and 12 000 g mol<sup>−1</sup> were synthesised and dependent on the FA source exhibited either amorphous or semi-crystalline behaviour (<em>T</em><sub>g</sub> values between −1 and 33 °C, <em>T</em><sub>m</sub> values between 48 and 66 °C). This work demonstrates the first example of RAFT polymerisation of acrylamide monomers derived from plant oils by a one step direct transesterification, opening the door for novel well-defined, functional bio-based polymers.</div></div>","PeriodicalId":100,"journal":{"name":"Polymer Chemistry","volume":"16 12","pages":"Pages 1321-1331"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/py/d4py01100g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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