Macromolecular Chemistry and Physics最新文献_第8页

Poly(butylene terephthalate) Copolyesters with Dilinoleic Derivatives: Solution Properties and Influence of Short-Chain Branching 含二油酸衍生物的聚对苯二甲酸丁二醇酯共聚物：溶液特性和短链支化的影响

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-25 DOI: 10.1002/macp.202400148

C. Mielke, M. Geisler, H. Komber, J. Kuhnigk, B. Voit, A. Lederer, D. Pospiech

{"title":"Poly(butylene terephthalate) Copolyesters with Dilinoleic Derivatives: Solution Properties and Influence of Short-Chain Branching","authors":"C. Mielke, M. Geisler, H. Komber, J. Kuhnigk, B. Voit, A. Lederer, D. Pospiech","doi":"10.1002/macp.202400148","DOIUrl":"10.1002/macp.202400148","url":null,"abstract":"The solution behavior of poly(butylene terephthalate) (PBT) copolyesters with dilinoleic monomer units (dilinoleic diol (LD) / dilinoleic diacid (LA)) is studied to understand the processing behavior from melt. NMR investigations show that the short-chain branches are characterized by a distribution of different alkyl chain lengths, where n-butyl (C4) and longer chains have the largest content (>55 mol%). High-temperature size exclusion chromatography with threefold detection (multi-angle light-scattering, refractive index, and viscosity detector) in 1,2,4-trichlorobenzene is performed to determine molar masses, hydrodynamic radii, viscosity radii, and Kuhn–Mark–Houwink–Sakurada (KMHS) exponents α in dependence of the molar amount of short-chain branched comonomers. Low concentrations of dilinoleic comonomers in PBT copolyesters improve the solubility of the copolyesters significantly. Higher amounts cause contraction of the polymer coils as illustrated by smaller hydrodynamic radii as well as lower KMHS exponents. The α values decrease with increasing amount of short-chain branched comonomer except for very low concentrations. The solution behavior of LA and LD copolyesters with a higher aliphatic content shows different trends of the influence of short-chain branches on the melt behavior, which reflects the influence of intramolecular versus intermolecular entanglements in solution and in melt.","PeriodicalId":18054,"journal":{"name":"Macromolecular Chemistry and Physics","volume":"225 18","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/macp.202400148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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Reversibility of Semicrystalline Polymers in Creep Testing by Coarse-Grained Molecular Dynamics Simulations 通过粗粒度分子动力学模拟研究半结晶聚合物在蠕变测试中的可逆性

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-22 DOI: 10.1002/macp.202400076

Yuji Higuchi, Go Matsuba

{"title":"Reversibility of Semicrystalline Polymers in Creep Testing by Coarse-Grained Molecular Dynamics Simulations","authors":"Yuji Higuchi, Go Matsuba","doi":"10.1002/macp.202400076","DOIUrl":"10.1002/macp.202400076","url":null,"abstract":"Unraveling the deformation processes of semicrystalline polymers is essential for improving their durability. Owing to their hierarchical structures composed of lamellae and spherulites, many aspects of these deformation processes remain unclear at the molecular scale, such as the differences in molecular structure changes in the elastic and plastic regions and the molecular-scale structural changes during reversible and irreversible processes. Herein, simulated creep tests of the lamellar structure of polyethylene under a constant load are performed using the coarse-grained molecular dynamics method. Typical creep curves are observed under various constant loads. During the recovery process after stretching, the reversible and irreversible processes are distinguished by a strain of approximately 0.4 at the boundary of the elastic and plastic regions. Interestingly, during recovery, the interfaces between the amorphous and crystalline layers are highly oriented, which may inhibit strain relaxation. In terms of the molecular structure changes in the plastic region, the number of tie chains remains constant, whereas the numbers of chain ends and loops in the amorphous layers decrease. These simulation results advance current understanding of the molecular-scale deformation processes of semicrystalline polymers, which contribute to the improvement of long-term durability and reliability.","PeriodicalId":18054,"journal":{"name":"Macromolecular Chemistry and Physics","volume":"225 18","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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Masthead: Macromol. Chem. Phys. 12/2024 刊头：Macromol.Chem.12/2024

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-21 DOI: 10.1002/macp.202470025

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Benzoylation of Iota Carrageenan: Development of a Stable, Conductive, and Hydrophobic Drug Carrier with Reduced Toxicity and Improved Gel-Forming Ability Iota 卡拉胶的苯甲酰化：开发稳定、导电、疏水性药物载体，降低毒性并提高凝胶成型能力

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-21 DOI: 10.1002/macp.202470024

Akanksha Bhatt, Shashank Kailkhura, Priyank Purohit

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Influence of the Crosslinker Hydrophobicity on the Swelling Kinetics of Poly(Acrylic Acid) Microgels 交联剂疏水性对聚丙烯酸微凝胶溶胀动力学的影响

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-20 DOI: 10.1002/macp.202400138

Torsten Gereon Linder, Alima Heinzelmann, Juliane Kamphus, Sebastian Seiffert

{"title":"Influence of the Crosslinker Hydrophobicity on the Swelling Kinetics of Poly(Acrylic Acid) Microgels","authors":"Torsten Gereon Linder, Alima Heinzelmann, Juliane Kamphus, Sebastian Seiffert","doi":"10.1002/macp.202400138","DOIUrl":"10.1002/macp.202400138","url":null,"abstract":"Superabsorbent polymer gels are widely used in commercial areas, such as in hygiene products. A key aspect in these and other applications is the gel swelling kinetics, and a key factor of influence on that is the hydrophobicity of the gel. This paper reports on the synthesis of superabsorbent polymer microgel particles with four differently hydrophobic crosslinkers: N,N’-methylenebisacrylamide (MBAA), N,N’-ethylenebisacrylamide (EBAA), N,N’-propylenebisacrylamide (PBAA), and N,N’-butylenebisacrylamide (BBAA). This work uses droplet-based microfluidics to produce uniform and well-defined microgel specimen and study the influence of the crosslinker hydrophobicity on the swelling kinetics. In particular, this work determines swelling constants and their dependencies on the temperature of the swelling medium as well as the activation energies of swelling in relation to the crosslinker hydrophobicity. This work finds two competing effects, leading to a narrow window in which the activation energy of the swelling of the microgels decreases with increasing crosslinker hydrophobicity.","PeriodicalId":18054,"journal":{"name":"Macromolecular Chemistry and Physics","volume":"225 18","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/macp.202400138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141512939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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Thermal and Mechanical Properties of Bio-Based Polyamide 56/6 Filled with Talc 填充滑石粉的生物基聚酰胺 56/6 的热性能和机械性能

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-15 DOI: 10.1002/macp.202400098

Xiaoqi Zhang, Haoyu Yang, Yiming Liu, Jilin Liu, Jie Zhou, Wentao Liu

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Adaptable Polyurethane Networks Containing Tertiary Amines as Intrinsic Bond Exchange Catalyst 含有叔胺作为固有键交换催化剂的可适应性聚氨酯网络

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-12 DOI: 10.1002/macp.202400072

Lars Schwarzer, Seema Agarwal

{"title":"Adaptable Polyurethane Networks Containing Tertiary Amines as Intrinsic Bond Exchange Catalyst","authors":"Lars Schwarzer, Seema Agarwal","doi":"10.1002/macp.202400072","DOIUrl":"10.1002/macp.202400072","url":null,"abstract":"Vitrimers exhibit unique properties, such as thermal recyclability akin to thermoplastics, while structurally mirroring thermosets in terms of strength, durability, and chemical resistance. However, a significant limitation of these materials is their dependence on an external catalyst. Consequently, this research aims to develop vitrimer materials that incorporate an intrinsic catalyst, thus maintaining excellent thermomechanical properties and recyclability. Polyaddition polymerization is employed to synthesize the desired polymer, incorporating a self-synthesized tertiary amine unit, (bis(2-hydroxyethyl)-3,3′-((2-(dimethylamino)ethyl)azanediyl)dipropanoate) (N-diol), as an internal catalyst for transcarbamoylation and potential transesterification reactions. The resulting polymer, with a gel content of 97% and a glass transition temperature of 29 °C, is fabricated into test samples for comprehensive thermal and mechanical evaluations. The material demonstrates an initial Young's modulus of 555 MPa, retaining 81% of this value after two recycling processes. Additionally, using stress relaxation analysis (SRA), a topology freezing temperature of 82 °C, indicative of the characteristic Arrhenius-like relaxation behavior, is identified with a bond exchange activation energy of 163 kJ mol−1.","PeriodicalId":18054,"journal":{"name":"Macromolecular Chemistry and Physics","volume":"225 16","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/macp.202400072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141351445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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Masthead: Macromol. Chem. Phys. 11/2024 刊头：Macromol.Chem.11/2024

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-07 DOI: 10.1002/macp.202470023

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Fabrication of Superhydrophobic Polycaprolactone Foam via Phase Separation and Silica Modification for Oil–Water Separation 通过相分离和二氧化硅改性制造超疏水聚己内酯泡沫，实现油水分离

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-07 DOI: 10.1002/macp.202470022

Xiaolong Wang, Qianwei Liu, Yamin Pan, Yongqiang Tu, Xianhu Liu

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Functionalized Unsaturated Polyester as Electrical Insulation Varnish 用作电气绝缘漆的官能化不饱和聚酯

IF 2.5 4区化学

Macromolecular Chemistry and Physics Pub Date : 2024-06-06 DOI: 10.1002/macp.202400127

Selinay Gümüş, Kaan Aksoy, Ayse Aytac

{"title":"Functionalized Unsaturated Polyester as Electrical Insulation Varnish","authors":"Selinay Gümüş, Kaan Aksoy, Ayse Aytac","doi":"10.1002/macp.202400127","DOIUrl":"10.1002/macp.202400127","url":null,"abstract":"Silsesquioxanes (SQs) are mostly used to provide high-temperature electrical insulation of resins. Here, SQ is used to functionalize unsaturated polyester (UPE) varnish and investigate the effect of functionalization on the thermal and electrical properties of UPE varnishes. The solvent-free varnish incorporates a reactive diluent to decrease viscosity and a catalyst to expedite hardening, eliminating the need for solvents. Vinyl toluene (VT) and 1,4-butanediol dimethacrylate (BDDMA) serve as hardening agents, consistent with prior research. Various characterization tests, including Fourier transform infrared, thermogravimetric analyzer, assessment of thermal conductivity coefficient, and determination of electrical volume–surface resistance, are conducted to determine the physical, thermal, chemical, and electrical properties of the synthesized SQ-functionalized UPE (UPES) varnishes. Results indicate that the UPES–BDDMA varnish demonstrates the highest thermal decomposition temperature at 438.0 °C, while the UPES–VT varnish exhibits the highest electrical volume resistance of 2.85 × 1015 Ω cm. Volatile organic compound levels in UPE coatings range between 4.9% and 5.10% reflecting the growing demand for eco-friendly products. It is shown in this study that the use of BDDMA and VT reactive monomers in the synthesis of SQ-functionalized UPE resin and the properties of the resulting varnishes, especially electrical insulation and thermal stability, are improved.","PeriodicalId":18054,"journal":{"name":"Macromolecular Chemistry and Physics","volume":"225 13","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141378158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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