Macromolecules最新文献

{"title":"Alkyl Side-Chain-Induced Improvement of Dielectric Properties of Polymers. 1. Fluorene–Benzocyclobutene-Based Polymers","authors":"Manling Shi, Jing Sun, Qiang Fang","doi":"10.1021/acs.macromol.4c01056","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c01056","url":null,"abstract":"Alkyl side chains have been demonstrated to significantly affect the interchain packing of π-conjugated polymers, while their potential for modifying low-<i>k</i> materials remains unexplored. Herein, four low-<i>k</i> nonconjugated polymers based on the fluorenyl group with linear alkyl side chains of different lengths have been prepared. With the increase of the side chain length, their dielectric constants (<i>D</i>_k) gradually decrease. For example, when the side chains are butyl, hexyl, dodecyl, and octadecyl, the <i>D</i>_k values of the polymers are 2.62, 2.59, 2.50, and 2.45, respectively. Moreover, the polymers also display dielectric loss (<i>D</i>_f) values of below 5.0 × 10^–4 at 10 GHz. This discovery indicates that the alkyl side chains also have a big effect on the dielectric properties of the nonconjugated polymers via disrupting the close packing of the polymer chains, inducing the improvement of the dielectric properties of the polymers. This contribution provides a new strategy for the design of low-<i>k</i> materials used in the microelectronic industry.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462055","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}

{"title":"Insights into Conformation, Crystal Structure, and Material Properties of Plant-Derived Poly(alkylene 2,5-furandicarboxylate)s as Sustainable Alternatives to Petroleum-Derived Analogues","authors":"Mitsutoshi Hoshide, Hiromu Kawasaki, Shota Abe, Sayaka Iwabuchi, Shinnosuke Kogure, Yuji Sasanuma","doi":"10.1021/acs.macromol.4c00838","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00838","url":null,"abstract":"Conformational characteristics and conformation-dependent properties of poly(ethylene 2,5-furandicarboxylate) (PEF), poly(trimethylene 2,5-furandicarboxylate) (PTF), and poly(butylene 2,5-furandicarboxylate) (PBF) have been revealed via NMR experiments and molecular orbital calculations on their model compounds, along with refined rotational isomeric state calculations for the polymers. The O(CH₂)_<i>y</i>O (<i>y</i> = 2, 3, and 4) segments of the polyesters exhibit conformational preferences similar to those found in the corresponding poly(alkylene terephthalate)s. The most stable conformations identified for PEF, PTF, and PBF are tg ^± t, tg ^± g ^± t, and tg ^± tg^∓t, respectively. Their spatial configurations and conformational flexibilities significantly depend on conformations around the (furan)C–C(═O) bonds. Additionally, periodic density functional theory calculations were employed to optimize the α′ crystal structure of PEF, resulting in the equilibrium α form with a monoclinic lattice containing two all-trans chains. Young’s moduli along the <i>a</i>, <i>b</i>, and <i>c</i> axes of the optimized α crystal were calculated to be 26.8, 12.5, and 141 GPa, respectively. These values are comparable to those of poly(ethylene terephthalate).","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462093","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}

{"title":"Sugar-Derived Cyclic Acetals as Comonomers for Cationic Copolymerization with Vinyl Ethers","authors":"Aya Katto, Sadahito Aoshima, Arihiro Kanazawa","doi":"10.1021/acs.macromol.4c00847","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00847","url":null,"abstract":"Sugar-derived cyclic acetals were demonstrated to undergo cationic copolymerization with a vinyl ether (VE) via the vinyl-addition and ring-opening mechanisms. Cyclic acetals were synthesized by the condensation reactions of sugar alcohols (mannitol, xylose, erythritol, and sorbitol) with aldehydes or ketones. These cyclic acetals differ in the number of cyclic acetal moieties, the number of ring members, substituents, and stereo configuration. Such structural features greatly affected the copolymerization behavior. For example, erythritol-derived cyclic acetals consisting of two isolated five-membered cyclic acetal moieties undergo copolymerization with 2-chloroethyl VE, while mannitol-derived cyclic acetals consisting of three fused seven- and six-membered cyclic acetal moieties were not incorporated into polymer chains. Moreover, a xylose-derived cyclic acetal that has a <i>p</i>-methoxyphenyl substituent at the carbon atom adjacent to two oxygen atoms underwent copolymerization most effectively among the cyclic acetals examined in this study, which is likely due to the efficient generation of a carbocation via ring-opening. In addition, cationic initiators or Lewis acid catalysts affected the frequency of crossover reactions, resulting in a difference in incorporated ratios of sugar-derived cyclic acetals in polymer chains. The copolymers synthesized from VEs and sugar-derived cyclic acetals were degraded by acid via cleavage of the VE-to-cyclic acetal crossover reaction-derived acetal moieties in the main chain. A gluconic acid-derived cyclic acetal that has both cyclic acetal and cyclic hemiacetal ester moieties was ineffective for copolymerization with a VE, whereas an oxirane was successfully copolymerized with the gluconic acid-derived monomer via the ring-opening of the cyclic hemiacetal ester moiety.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462066","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}

{"title":"Direct and Reversible Transformations between Intermolecular Polymer Networks and Single-Chain Nanoparticles Based on Thermally Dissociable Bis(hindered amino)disulfide Linkages","authors":"Gota Tomono, Hirogi Yokochi, Akira Takahashi, Daisuke Aoki, Hideyuki Otsuka","doi":"10.1021/acs.macromol.4c00359","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00359","url":null,"abstract":"We report a direct topological reorganization between intermolecularly cross-linked polymers and single-chain nanoparticles (SCNPs) via thermal exchange reactions based on bis(2,2,6,6-tetramethylpiperidin-1-yl)disulfide (BiTEMPS) linkages. The network architecture of cross-linked poly(hexyl methacrylate) incorporating BiTEMPS at the cross-linking points can be directly transformed to SCNPs merely by heating in a dilute solution. Diffusion-ordered NMR spectroscopy and GPC analyses confirmed the smaller hydrodynamic radii of the SCNPs compared to those of the chain polymers obtained by de-cross-linking the original networks. The reverse transformation from the SCNPs to the polymer networks was achieved simply by heating under solvent-free conditions. Time-course monitoring of the storage moduli showed a clear increase as a function of heating time due to the restoration of the intermolecular cross-links via disulfide-exchange reactions. The restored cross-linked polymers exhibited comparable cross-linking densities and mechanical properties to those of the original cross-linked polymers, and the properties were again replicated well after an additional network–SCNP transformation cycle. Such an on-demand network-modulation feature enables a postsynthetic adjustment of the elastomer properties by, e.g., fusing SCNPs prepared from cross-linked polymers with different cross-linking densities.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462001","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}

{"title":"Spin-State Manipulation in a Luminescent Diradical Polymer","authors":"Shengjie Wang, Xing Wang, Junshuai Ding, Zihao Zhu, Jingmin Wang, Li Shen, Alim Abdurahman, Geyu Lu, Jianpu Wang, Qiming Peng","doi":"10.1021/acs.macromol.4c00895","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00895","url":null,"abstract":"Controlling the spin states to modulate their optical properties is crucial for spintronics and emerging quantum technologies. Open-shell luminescent diradicals are promising candidates for achieving this goal due to the independent spins. However, achieving spin-optical modulation in traditional diradicals still faces significant challenges owing to low luminescence efficiency and inevitable aggregate effects. In this study, we first achieved efficient luminescence of a diradical by suspending luminescent diradicals on a polymer main chain. The resulting diradical polymer exhibits a high photoluminescence efficiency of 44.0% in the condensed state along with excellent photostability. Most importantly, we have demonstrated successful spin-state manipulation through temperature control and application of a magnetic field. These findings open up new avenues for spin-optical modulation based on luminescent diradical materials, providing important guidance for the development spin-optoelectronics.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462121","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}

{"title":"In-Plane Movement of Isolated Poly(methacrylate) Chains on a Hydrophilic Solid Surface","authors":"Masayuki Kawano, Yuma Morimitsu, Yuwei Liu, Noboru Miyata, Tsukasa Miyazaki, Hiroyuki Aoki, Daisuke Kawaguchi, Satoru Yamamoto, Keiji Tanaka","doi":"10.1021/acs.macromol.4c00724","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00724","url":null,"abstract":"A better understanding of the dynamic behavior of polymer chains on solid surfaces is indispensable for the design and construction of high-performance polymer composites. We herein visualized the in-plane movement of isolated poly(methyl methacrylate) (PMMA) and poly(<i>tert</i>-butyl methacrylate) (P<i>t</i>BMA) single chains on hydrophilic silicon wafers under ambient conditions by atomic force microscopy. Isolated PMMA chains adsorbed to the substrate, whereas P<i>t</i>BMA chains diffused, the degree of which was dependent on the humidity. Neutron reflectivity revealed the formation of a layer of condensed water on the substrate. All-atomistic molecular dynamics simulations implied that the diffusivity difference of the two polymers was based on the submerged depth in which a part of a chain existed. That is, the interaction of a polymer with the surface of the hydrophilic substrate primarily governs its lateral movement, or adsorption behavior, facilitated by the presence of water.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462059","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}

{"title":"Peculiar Transition between Chiral and Achiral Networks in Self-Assembly of Chiral Block Copolymers","authors":"Sook-Hui Lien, Pin-Hua Lin, Sheng-Wei Shao, Po-Ting Chiu, Cheng-Yen Chang, Yu-Chuan Sung, Jing-Cherng Tsai, Rong-Ming Ho","doi":"10.1021/acs.macromol.4c00361","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00361","url":null,"abstract":"Herein, a peculiar phase transition between the mesochiral and achiral networks can be found in the self-assembly of chiral block copolymers. A chiral network phase, an alternating gyroid (G^A), with controlled helicity can be achieved by the self-assembly of chiral triblock terpolymers, polyisoprene-<i>block</i>-polystyrene-<i>block</i>-poly(<span>l</span>-lactide) (PI–PS-PLLA), and polyisoprene-<i>block</i>-polystyrene-<i>block</i>-poly(<span>d</span>-lactide) (PI–PS-PDLA). An interesting phase transition between chiral G^A with negative PLLA network and positive PI network within the PS matrix and core–shell double gyroid (DG) with a pair of PLLA networks but opposite handedness with PS shells in the PI matrix can be found, reflecting a phase transformation between the dispersed PI network and PI matrix with minor compositional variation. Similar results can also be found in the case of PDLA but with opposite handedness. Homochiral evolution at different length scales via self-assembly can be evidenced by vibrational circular dichroism (VCD) spectra of C═O stretching (conformational chirality due to intrachain chiral interaction) and the C–O–C parallel mode (hierarchical chirality due to interchain chiral interaction). Most interestingly, the molecular dispositions of the helical polymer chains in the self-assembled phase based on the VCD results of the C–O–C parallel mode are in line with the observed phase behaviors at which the VCD signals from G^A will be nullified after the formation of the core–shell DG. As a result, the transition mechanism can be clarified from the conformational level to the mesoscale with respect to the self-assembly process.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462110","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}

{"title":"A Compatibilizing Strategy for Upcycling Polyethylene and Polystyrene with Ethylene/(Phenyl Functionalized α-Olefin) Copolymers Containing Continuous Comonomer Segments","authors":"Hui Tian, Yifan Wang, Chunji Wu, Baoli Wang","doi":"10.1021/acs.macromol.4c00275","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00275","url":null,"abstract":"Polyethylene (PE) and polystyrene (PS) are commercial plastics with large amounts of output, and their wastes have brought serious burden to our living environment. These usually exist as PE/PS mixtures and are hard or expensive to sort in some cases. PE/PS blends have poor mechanical properties due to thermodynamic incompatibilization. In principle, ethylene/(phenyl functionalized α-olefin) copolymers (containing PE and continuous phenyl α-olefin segments on one polymeric chain) would be good compatibilizers for PE/PS, but the synthesis of corresponding copolymers is much more difficult. Herein, we report the synthesis of ethylene-styrene (<b>E</b>-<b>St</b>), ethylene-allylbenzene (<b>E</b>-<b>AP</b>), and ethylene-(4-phenyl-1-butene) (<b>E</b>-<b>BP</b>) copolymers containing continuous comonomer segments via the copolymerization of <b>E</b> with various phenyl functionalized α-olefin monomers (<b>St</b>, <b>AP</b>, and <b>BP)</b> catalyzed by thiophene-fused cyclopentadienyl scandium complexes and study the compatibilization of resultant copolymers for HDPE/PS blends by using tensile test experiment and SEM and TEM analyses. <b>E</b>-<b>BP</b> copolymers behaved like adhesive materials with high <b>BP</b> incorporation ranged from 13.5 to 24.1 mol % and showed better compatibilization effect for HDPE/PS blends compared with <b>E</b>-<b>St</b> and <b>E</b>-<b>AP</b>, probably because of the longer distance between the polymeric main chain and phenyl group on its molecular structure, which favors the intermolecular π–π interaction between <b>E</b>-<b>BP</b> and PS during melting mixing. HDPE/PS/<b>P4</b> (weight ratio: 80/20/2) blend (<b>P4</b>: <b>E</b>-<b>BP</b> copolymer with 24.1 mol % <b>BP</b> content) exhibited the greatest improvement in elongation at break (1397%), which showed a 26.3% increase, compared with the uncompatibilized HDPE/PS (80/20) blend and reached 91.5% of ultimate elongation of pure HDPE, and its tensile stress was also close to that of HDPE, indicating that <b>P4</b> could be used as an effective compatibilizer for HDPE/PS mixtures that are difficult or expensive to sort.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462002","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}

{"title":"Synthesis of Thermal-Resistant Polyester-Polycarbonate with Fully Rigid Structure from Biobased Isosorbide","authors":"Chao Zeng, JiaWei Ren, WuFeng Shen, ShengMing Zhang, Peng Ji, ChaoSheng Wang, HuaPing Wang","doi":"10.1021/acs.macromol.4c00647","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00647","url":null,"abstract":"Developing green and sustainable polymers is one of the effective ways to limit carbon emissions and reduce dependence on petroleum resources. Therefore, polyester-polycarbonates based on carbon dioxide (CO₂) have attracted extensive attention. However, polyester-polycarbonates with fully rigid structures are difficult to prepare by traditional transesterification methods, which result in low glass transition temperatures and insufficient mechanical properties. Here, a series of polyester-polycarbonates (PCCITs) with a fully rigid structure were prepared by end hydroxyl shielding using dimethyl carbonate derived from CO₂ and biologically sourced isosorbide (IS), and the IS content is 0–60 mol %. The ester bond structure of polyester-polycarbonate was analyzed by two-dimensional correlation spectroscopy (2DCOS). Due to the V-shaped fused ring structure of IS, the heat resistance of the copolyester is significantly improved. The glass transition temperature of PCCITs ranges from 64.2 to 131.1 °C, and its heat distortion temperature can reach up to 120.1 °C. Furthermore, all copolyesters are entirely amorphous and exhibit good transparency (&gt;88%) and low haze value (&lt;4%). Notably, the mechanical properties of PCCITs are comparable to those of commercial heat-resistant polyethylene terephthalate glycol (PETG), with the tensile strength of PCCT to PCCIT₆₀ increasing from 43.5 to 57.8 MPa, elongation at break ranging from 206.0 to 4.5%, and impact strength up to 820.3 J m^–1. Life cycle assessment evaluation showed that the GWP value of PCCIT was significantly reduced, up to 41.5%, compared with commercial PETG. This work constructs sustainable IS-based polyester-polycarbonate with fully rigid through the terminal hydroxyl shielding method.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462006","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}

{"title":"Preparation of Structural Heat-and-Radiation-Resistant Integrated Epoxy by Constructing a Carborane-Hybridized Cross-Linked Network","authors":"Ran Xu, Zhixi Zhao, Fei Chen, Chen Qiu, Chuxiang Zhou, Yang Chen, Mei Liang, Ying Wu, Xiaoqiang Pan, Jing Yang, Zhengguang Heng, Huawei Zou","doi":"10.1021/acs.macromol.4c00800","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c00800","url":null,"abstract":"The polymer materials in nuclear facilities are exposed to high temperatures, radiation, and high loads. Their excellent heat resistance, radiation resistance, and shielding properties are important for the safe operation of nuclear facilities. In this study, 1,2-bis(hydroxymethyl)carborane (CBOH) was first synthesized in large quantities through water extraction and then introduced into an epoxy resin cross-linked network. The incorporation of a carborane structure significantly improved the heat resistance of epoxy. Under air atmosphere, the <i>T</i>_5% (the temperature at 5 wt % degradation), <i>T</i>_10% (the temperature at 10 wt % degradation), and char yield at 800 °C of the materials were 315.67 °C (16.51 °C increased), 326.29 °C (12.96 °C increased), and 33.22% (33.22% increased), respectively. The maximum decomposition temperature of the material increased from 550 to 750 °C, and 7.05 wt % of the carbon constituent was protected after thermal degradation at 800 °C. The glass transition temperature (<i>T</i>_g) of the materials greatly increased up to over 300 °C after introducing the carborane structure into the networks. The radiation resistance of the material was enhanced due to the in situ capture of oxygen radicals by the carborane structure. Moreover, the incorporation of carborane structure also increased the content of H and B in materials, improving their neutron-shielding capability. This work confers multifunctionality to epoxy resin and enhances its various properties, ensuring the safety of epoxy resin in nuclear facilities.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462028","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}