Pub Date : 2026-04-09Epub Date: 2026-03-11DOI: 10.1016/j.polymer.2026.129845
Amir Jangizehi, Philipp Föckler, Otto Pazer, Mostafa Ahmadi, Sebastian Seiffert
Interpenetrating polymer networks (IPNs) consist of two interconnected networks that provide distinct physical and mechanical properties. When one of these networks is thermo-responsive, the volume phase transition temperature (VPTT) remains largely unaffected by the hydrophilicity of the second network. This makes IPNs an ideal candidate for modifying properties of hydrogels without altering VPTT. In this study, we explore the use of IPNs, based on poly(N-isopropyl acrylamide) (PNiPAAm) and sodium alginate (SAlg), as draw agents in forward osmosis (FO) desalination. The charged repeating units of SAlg increase the osmotic pressure, enabling water draw, and form crosslinks in the presence of calcium ions. Moreover, PNiPAAm is thermo-responsive and shrinks above VPTT, releasing the absorbed water. Additionally, incorporating graphene oxide (GO) as a light-absorbing agent further enhances the process efficiency by increasing temperature upon exposure to light. The results show that the swelling capacity, shrinkage behavior, and mechanical properties of the hydrogels are influenced by the content of SAlg and GO. However, the VPTT of the IPN hydrogels remains similar to that of the single PNiPAAm network. In FO desalination tests, the IPN hydrogel with 10 wt% SAlg and 0.2 wt% GO demonstrates the best balance between water flux and thermo-responsivity.
{"title":"Light- and heat-responsive interpenetrating polymer networks for solar-driven water desalination","authors":"Amir Jangizehi, Philipp Föckler, Otto Pazer, Mostafa Ahmadi, Sebastian Seiffert","doi":"10.1016/j.polymer.2026.129845","DOIUrl":"10.1016/j.polymer.2026.129845","url":null,"abstract":"<div><div>Interpenetrating polymer networks (IPNs) consist of two interconnected networks that provide distinct physical and mechanical properties. When one of these networks is thermo-responsive, the volume phase transition temperature (VPTT) remains largely unaffected by the hydrophilicity of the second network. This makes IPNs an ideal candidate for modifying properties of hydrogels without altering VPTT. In this study, we explore the use of IPNs, based on poly(N-isopropyl acrylamide) (PNiPAAm) and sodium alginate (SAlg), as draw agents in forward osmosis (FO) desalination. The charged repeating units of SAlg increase the osmotic pressure, enabling water draw, and form crosslinks in the presence of calcium ions. Moreover, PNiPAAm is thermo-responsive and shrinks above VPTT, releasing the absorbed water. Additionally, incorporating graphene oxide (GO) as a light-absorbing agent further enhances the process efficiency by increasing temperature upon exposure to light. The results show that the swelling capacity, shrinkage behavior, and mechanical properties of the hydrogels are influenced by the content of SAlg and GO. However, the VPTT of the IPN hydrogels remains similar to that of the single PNiPAAm network. In FO desalination tests, the IPN hydrogel with 10 wt% SAlg and 0.2 wt% GO demonstrates the best balance between water flux and thermo-responsivity.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129845"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388309","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}
Pub Date : 2026-04-09Epub Date: 2026-02-25DOI: 10.1016/j.polymer.2026.129789
Fei Wang , Ting Qu , Hao He , Ning Liu , Lin Yang , Jie Wang , Huiyu Yang , Ying Ou , Quanyuan Zhang , Fan Cheng , Fuqiang Hu , Guoliang Liu , Hai Liu , Zushun Xu , Chunli Gong
Preparing high-performance anion exchange membranes (AEMs) with dimensional stability and long-term durability is challenging. Here, a series of functional filler-modified bacterial cellulose (BC)-based AEMs was fabricated by infiltrating a cationic monomer (vinylbenzyl trimethylammonium chloride, VBTAC) into polydopamine-coated BC (PDA@BC), followed by ultraviolet (UV)-induced polymerization. The resulting membranes, denoted as BC/PDVD, exhibited superior alkali stability and hydroxide ion conductivity. The highest water uptake and area swelling of BC/PDVD were 1138.82% and 36.05%, respectively. The hydroxide conductivity of the BC/PDVD membranes ranged from 78.49 to 82.78 mS cm−1 at 80 °C. Moreover, the in situ polymerization of the ionic filling polymer and its effective cross-linking with BC nanofiber network significantly enhanced the compatibility and alkali resistance of the composite membranes. After immersion in a 1 M KOH solution at 60 °C for 1500 h, BC/PDVD10% maintained 91.86% of its initial conductivity. This UV radiation-induced in-situ graft polymerization and pore-filling strategy provides a reliable approach to reduce the “trade-off” between mechanical stability and electrochemical characteristic of AEMs.
制备具有尺寸稳定性和长期耐久性的高性能阴离子交换膜（AEMs）是一项具有挑战性的工作。本研究通过将阳离子单体（乙烯苄基三甲基氯化铵，VBTAC）渗透到聚多巴胺包被的BC （PDA@BC）中，然后进行紫外线（UV）诱导聚合，制备了一系列功能性填料改性细菌纤维素（BC）基AEMs。所得膜，记为BC/PDVD，表现出优异的碱稳定性和氢氧离子导电性。BC/PDVD的吸水率和面积膨胀率最高，分别为1138.82%和36.05%。BC/PDVD膜在80℃时的氢氧化物电导率为78.49 ~ 82.78 mS cm-1。此外，离子填充聚合物的原位聚合及其与BC纳米纤维网络的有效交联显著提高了复合膜的相容性和耐碱性。在60°C的1 M KOH溶液中浸泡1500 h后，BC/PDVD10%保持其初始电导率的91.86%。这种紫外辐射诱导的原位接枝聚合和孔隙填充策略为减少机械稳定性和电化学特性之间的“权衡”提供了一种可靠的方法。
{"title":"Construction of alkaline-stable bacterial-cellulose-based anion exchange membranes by radiation-induced in-situ graft polymerization","authors":"Fei Wang , Ting Qu , Hao He , Ning Liu , Lin Yang , Jie Wang , Huiyu Yang , Ying Ou , Quanyuan Zhang , Fan Cheng , Fuqiang Hu , Guoliang Liu , Hai Liu , Zushun Xu , Chunli Gong","doi":"10.1016/j.polymer.2026.129789","DOIUrl":"10.1016/j.polymer.2026.129789","url":null,"abstract":"<div><div>Preparing high-performance anion exchange membranes (AEMs) with dimensional stability and long-term durability is challenging. Here, a series of functional filler-modified bacterial cellulose (BC)-based AEMs was fabricated by infiltrating a cationic monomer (vinylbenzyl trimethylammonium chloride, VBTAC) into polydopamine-coated BC (PDA@BC), followed by ultraviolet (UV)-induced polymerization. The resulting membranes, denoted as BC/PDVD, exhibited superior alkali stability and hydroxide ion conductivity. The highest water uptake and area swelling of BC/PDVD were 1138.82% and 36.05%, respectively. The hydroxide conductivity of the BC/PDVD membranes ranged from 78.49 to 82.78 mS cm<sup>−1</sup> at 80 °C. Moreover, the in situ polymerization of the ionic filling polymer and its effective cross-linking with BC nanofiber network significantly enhanced the compatibility and alkali resistance of the composite membranes. After immersion in a 1 M KOH solution at 60 °C for 1500 h, BC/PDVD<sub>10%</sub> maintained 91.86% of its initial conductivity. This UV radiation-induced in-situ graft polymerization and pore-filling strategy provides a reliable approach to reduce the “trade-off” between mechanical stability and electrochemical characteristic of AEMs.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129789"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147279809","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}
Pub Date : 2026-04-09Epub Date: 2026-02-28DOI: 10.1016/j.polymer.2026.129802
Ping Zhu , Lihui Yuan , Feng Tian , Xia Dong
The microscopic crystalline structures of unfoamed bead (UFB), foamed bead (FB), foamed bead-welded part (FBWP), extrudate (EXT) and foamed extrudate (FEXT) of poly(ether-b-amide) were investigated by micro-wide-angle X-ray diffraction/small angle X-ray scattering (μWAXD/SAXS). The crystallinity of the polyamide hard segment was improved after super-critical foaming (SCF), and double-melting peaks were incurred. A gradient crystalline structure with a core-skin difference was found in the FB, EXT, and FEXT, where higher crystallinity and orientation were found in the skin parts, i.e., the crystallinity in the skin could be 1 % higher than that in the core. It is not beneficial for a good steam-welding. The failure mode during tear process of FBWP is majorly adhesive failure, secondly cohesive failure of the skin detachment from the core, confirmed by digital image correlation (DIC) of the tear propagation and scanning electron microscope (SEM) of the fractured surface The tensile strength of FEXT and FBWP was 1/4 and 1/16 of that of hot-pressed film (HPF) respectively. The evolution of the microscopic structures of HPF, FEXT and FBP during tensile elongation were probed by in situ WAXD/SAXS. The long periods were increased remarkably after SCF, due to the increased crystallinity and improved phase separation. The lattice orientation of FEXT increased rapidly upon stretching, during which the strain-induced crystallization occurred. However, that of FBWP was not so high, since the inadequate inter-bead adhesion led the FBWP to break prematurely.
{"title":"Unveiling the gradient crystalline structure in the poly(ether-b-amide) foams","authors":"Ping Zhu , Lihui Yuan , Feng Tian , Xia Dong","doi":"10.1016/j.polymer.2026.129802","DOIUrl":"10.1016/j.polymer.2026.129802","url":null,"abstract":"<div><div>The microscopic crystalline structures of unfoamed bead (UFB), foamed bead (FB), foamed bead-welded part (FBWP), extrudate (EXT) and foamed extrudate (FEXT) of poly(ether-<em>b</em>-amide) were investigated by micro-wide-angle X-ray diffraction/small angle X-ray scattering (<em>μ</em>WAXD/SAXS). The crystallinity of the polyamide hard segment was improved after super-critical foaming (SCF), and double-melting peaks were incurred. A gradient crystalline structure with a core-skin difference was found in the FB, EXT, and FEXT, where higher crystallinity and orientation were found in the skin parts, i.e., the crystallinity in the skin could be 1 % higher than that in the core. It is not beneficial for a good steam-welding. The failure mode during tear process of FBWP is majorly adhesive failure, secondly cohesive failure of the skin detachment from the core, confirmed by digital image correlation (DIC) of the tear propagation and scanning electron microscope (SEM) of the fractured surface The tensile strength of FEXT and FBWP was 1/4 and 1/16 of that of hot-pressed film (HPF) respectively. The evolution of the microscopic structures of HPF, FEXT and FBP during tensile elongation were probed by <em>in situ</em> WAXD/SAXS. The long periods were increased remarkably after SCF, due to the increased crystallinity and improved phase separation. The lattice orientation of FEXT increased rapidly upon stretching, during which the strain-induced crystallization occurred. However, that of FBWP was not so high, since the inadequate inter-bead adhesion led the FBWP to break prematurely.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129802"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330009","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}
Physical foaming of ethylene-vinyl acetate (EVA) elastomers for high expansion ratio remains challenging due to the narrow processing window and low matrix modulus. This work systematically investigates the topological influence of chemical crosslinking on the viscoelasticity and subsequent foaming behavior of EVA. Crosslinking transforms the EVA melt into a robust elastic network, significantly extending stress relaxation times and inhibiting viscous flow. An optimal sparse network containing 0.2 – 0.6 phr crosslinker effectively balances melt strength against chain mobility, facilitating stable cell growth. Notably, by leveraging the synergistic effect of a CO2/N2 mixture, an ultrahigh expansion ratio of 30–fold (density: 0.031 g/cm3) with uniform cell morphology was achieved in the lightly crosslinked sample. In contrast, excessive crosslinking induces brittle fracture due to the restricted chain extensibility under high expansion force. The foaming mechanism is governed by the competition between the gas expansion force and the confinement of the crosslinked network. This work provides a strategic framework for designing high-performance elastomeric foams through the precise modulation of network architecture and blowing agent composition.
{"title":"Regulating foamability of crosslinked EVA through network design and gas expansion force control during physical foaming","authors":"Junjie Jiang , Ziwei Qin , Fangwei Tian , Hanyi Huang , Yaozong Li , Wentao Zhai","doi":"10.1016/j.polymer.2026.129842","DOIUrl":"10.1016/j.polymer.2026.129842","url":null,"abstract":"<div><div>Physical foaming of ethylene-vinyl acetate (EVA) elastomers for high expansion ratio remains challenging due to the narrow processing window and low matrix modulus. This work systematically investigates the topological influence of chemical crosslinking on the viscoelasticity and subsequent foaming behavior of EVA. Crosslinking transforms the EVA melt into a robust elastic network, significantly extending stress relaxation times and inhibiting viscous flow. An optimal sparse network containing 0.2 – 0.6 phr crosslinker effectively balances melt strength against chain mobility, facilitating stable cell growth. Notably, by leveraging the synergistic effect of a CO<sub>2</sub>/N<sub>2</sub> mixture, an ultrahigh expansion ratio of 30–fold (density: 0.031 g/cm<sup>3</sup>) with uniform cell morphology was achieved in the lightly crosslinked sample. In contrast, excessive crosslinking induces brittle fracture due to the restricted chain extensibility under high expansion force. The foaming mechanism is governed by the competition between the gas expansion force and the confinement of the crosslinked network. This work provides a strategic framework for designing high-performance elastomeric foams through the precise modulation of network architecture and blowing agent composition.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129842"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388216","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}
Pub Date : 2026-04-09Epub Date: 2026-03-09DOI: 10.1016/j.polymer.2026.129838
Chenlong Su , Yuting Ren , Tianyi Ma , Ping Zhu , Yong Zhou , Dujin Wang , Xianbo Huang , Xia Dong
Intrinsic flame-retardant polyamide 66 (PA66) is highly desirable for solving processing challenges in high-fire-safety applications, but the poor thermal stability of phosphorus-based intrinsic flame retardant DDP ((6H-Dibenz [c,e] [1,2] oxaphosphorin-6-ylmethyl)-p-oxide-butanedioic acid) causes severe thermal degradation during PA66 copolymerization, limiting its application. Herein, a synergistic strategy of introducing caprolactam (CPL) as the third monomer and optimizing the polymerization process was proposed to address this issue. By reducing the temperature of each polymerization stage, DDP was more completely incorporated into the PA66 molecular chains and PA66-5PA6-nDDP copolymers (5 wt% PA6, n wt% DDP) were obtained confirming by 1H NMR, 31P NMR and FTIR. The incorporation of DDP improved the flame retardancy of PA66. PA66-5PA6-5DDP achieved a limiting oxygen index (LOI) of 29.0% and passed UL-94 V-0 rating, with a 22.4% reduction in peak heat release rate (pHRR) compared to PA66-5PA6. Notably, the copolymers showed potential spinnability fibers with smooth surface and uniform element distribution (diameter ≈ 30 μm) were obtained via rapid stretching simulation, and the tensile strength and modulus of PA66-5PA6-5DDP fibers increased by 25.9% and 57.1% respectively compared to PA66-5PA6 fibers, which is conducive to expanding the application of flame-retardant PA66 in textile and special fiber fields. Systematic investigations on flame-retardant mechanism via TG-FTIR, Py-GC/MS and SEM-EDS revealed a gas-condensed phase synergistic effect. A unique layered char structure was observed. Specifically, P and O elements were enriched in the outer layer, forming a P—O conjugated barrier, whereas C elements were concentrated in the inner layer and contributed to maintaining char integrity. This layered structure can efficiently block heat/mass transfer in the outer layer and maintain the integrity of the char layer via the inner layer, thereby enhancing the flame-retardant efficiency. This work provides an effective strategy for preparing intact flame-retardant PA66 copolymers with balanced flame retardancy, spinnability and mechanical properties, and deepens the understanding of phosphorus-based flame-retardant mechanisms in PA66.
{"title":"Suppress thermal degradation of DDP in copolymerized PA66 with better intrinsic flame retardancy by regulating prepolymerization","authors":"Chenlong Su , Yuting Ren , Tianyi Ma , Ping Zhu , Yong Zhou , Dujin Wang , Xianbo Huang , Xia Dong","doi":"10.1016/j.polymer.2026.129838","DOIUrl":"10.1016/j.polymer.2026.129838","url":null,"abstract":"<div><div>Intrinsic flame-retardant polyamide 66 (PA66) is highly desirable for solving processing challenges in high-fire-safety applications, but the poor thermal stability of phosphorus-based intrinsic flame retardant DDP ((6H-Dibenz [c,e] [1,2] oxaphosphorin-6-ylmethyl)-p-oxide-butanedioic acid) causes severe thermal degradation during PA66 copolymerization, limiting its application. Herein, a synergistic strategy of introducing caprolactam (CPL) as the third monomer and optimizing the polymerization process was proposed to address this issue. By reducing the temperature of each polymerization stage, DDP was more completely incorporated into the PA66 molecular chains and PA66-5PA6-nDDP copolymers (5 wt% PA6, n wt% DDP) were obtained confirming by <sup>1</sup>H NMR, <sup>31</sup>P NMR and FTIR. The incorporation of DDP improved the flame retardancy of PA66. PA66-5PA6-5DDP achieved a limiting oxygen index (LOI) of 29.0% and passed UL-94 V-0 rating, with a 22.4% reduction in peak heat release rate (pHRR) compared to PA66-5PA6. Notably, the copolymers showed potential spinnability fibers with smooth surface and uniform element distribution (diameter ≈ 30 μm) were obtained via rapid stretching simulation, and the tensile strength and modulus of PA66-5PA6-5DDP fibers increased by 25.9% and 57.1% respectively compared to PA66-5PA6 fibers, which is conducive to expanding the application of flame-retardant PA66 in textile and special fiber fields. Systematic investigations on flame-retardant mechanism via TG-FTIR, Py-GC/MS and SEM-EDS revealed a gas-condensed phase synergistic effect. A unique layered char structure was observed. Specifically, P and O elements were enriched in the outer layer, forming a P—O conjugated barrier, whereas C elements were concentrated in the inner layer and contributed to maintaining char integrity. This layered structure can efficiently block heat/mass transfer in the outer layer and maintain the integrity of the char layer via the inner layer, thereby enhancing the flame-retardant efficiency. This work provides an effective strategy for preparing intact flame-retardant PA66 copolymers with balanced flame retardancy, spinnability and mechanical properties, and deepens the understanding of phosphorus-based flame-retardant mechanisms in PA66.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129838"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388307","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}
Pub Date : 2026-04-09Epub Date: 2026-03-06DOI: 10.1016/j.polymer.2026.129808
N.V. Fathima Safeeda , Meera Balachandran , Minu Elizabeth Thomas , Jesús Esteban , Johan Stanley
Poly (ethylene furanoate) (PEF) is a promising bio-based polyester that serves as a biobased alternative to the petroleum derived poly (ethylene terephthalate) (PET) polymer. Conventionally, heavy metal-based catalysts dominate polyester synthesis. Considering the concerns over the environmental impact of the catalyst, a novel, greener and safer Ti-based hybrid catalyst using 2,5-furan dicarboxylic acid (FDCA) as an organic linker was developed. In this work, the Ti-FDCA MOF catalyst was synthesized by the hydrothermal method, and a detailed structural characterization of catalysts was done. A comparative analysis with Ti-based catalyst such as conventional titanium Ⅳ butoxide (TBT) and Ti-FDCA MOF in the melt polycondensation of FDCA and ethylene glycol was also studied. While exhibiting similar polymer yield of 85.7%, Ti-FDCA MOF catalyzed PEF resulted in an intrinsic viscosity value of 0.69 dL/g compared to 0.52 dL/g with the TBT catalyzed PEF. The presence of Lewis acid sites on the Ti-FDCA MOF catalyst shows that this is a good candidate for PEF polymerization. The proposed catalytic reaction mechanism was elucidated by DFT calculation, with the rate limiting step having an activation energy of 25.9 kcal mol−1. Moreover, investigation of thermal and rheological characteristics showed that the green Ti-FDCA MOF catalyst exhibited comparable behavior to that of TBT, indicating good compatibility for polymerization.
{"title":"Poly (ethylene furanoate) synthesis with renewable-linker MOF catalyst: Mechanistic insights and thermo-rheological characterization","authors":"N.V. Fathima Safeeda , Meera Balachandran , Minu Elizabeth Thomas , Jesús Esteban , Johan Stanley","doi":"10.1016/j.polymer.2026.129808","DOIUrl":"10.1016/j.polymer.2026.129808","url":null,"abstract":"<div><div>Poly (ethylene furanoate) (PEF) is a promising bio-based polyester that serves as a biobased alternative to the petroleum derived poly (ethylene terephthalate) (PET) polymer. Conventionally, heavy metal-based catalysts dominate polyester synthesis. Considering the concerns over the environmental impact of the catalyst, a novel, greener and safer Ti-based hybrid catalyst using 2,5-furan dicarboxylic acid (FDCA) as an organic linker was developed. In this work, the Ti-FDCA MOF catalyst was synthesized by the hydrothermal method, and a detailed structural characterization of catalysts was done. A comparative analysis with Ti-based catalyst such as conventional titanium Ⅳ butoxide (TBT) and Ti-FDCA MOF in the melt polycondensation of FDCA and ethylene glycol was also studied. While exhibiting similar polymer yield of 85.7%, Ti-FDCA MOF catalyzed PEF resulted in an intrinsic viscosity value of 0.69 dL/g compared to 0.52 dL/g with the TBT catalyzed PEF. The presence of Lewis acid sites on the Ti-FDCA MOF catalyst shows that this is a good candidate for PEF polymerization. The proposed catalytic reaction mechanism was elucidated by DFT calculation, with the rate limiting step having an activation energy of 25.9 kcal mol<sup>−1</sup>. Moreover, investigation of thermal and rheological characteristics showed that the green Ti-FDCA MOF catalyst exhibited comparable behavior to that of TBT, indicating good compatibility for polymerization.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129808"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388308","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}
Pub Date : 2026-04-09Epub Date: 2026-03-03DOI: 10.1016/j.polymer.2026.129812
Yanmin Ma , Xue Lv , Huiwen Jia , Wang Xu , Xiaoning Yang
Conductive hydrogels have been widely used in flexible electronics and biosensing applications. However, the difficulty in achieving uniform dispersion of conductive fillers often leads to inconsistent gel properties, thereby limiting the accuracy and reliability of sensors. To address this issue, we first disperse the conductive filler, graphene, using an ionic liquid with a short alkane chain, followed by the addition of an ionic liquid with a long alkane chain to further enhance its dispersion. Then we use 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and polyacrylic acid (AA) as the main body, with adenine and uracil introduced as base pairs. Notably, the sulfonic acid and carboxyl groups in AMPS and AA dynamically cross-link with the amino groups on the base pairs via hydrogen bonds, forming a robust network. Meanwhile, the IL-GN acts as a nano-tough and conductive filler. This synergistic effect endows the hydrogel with exceptional tensile strain, high toughness, and a rapid electrical response, high conductivity, and excellent strain sensing. These advantages allow our composite hydrogels to exhibit a high degree of stability under large deformations and repeatability under pressure and strain. In addition, it has high adhesion, making them a promising material for multifunctional sensors and flexible electrodes.
导电水凝胶已广泛应用于柔性电子和生物传感领域。然而，难以实现导电填料的均匀分散往往导致凝胶性质不一致，从而限制了传感器的准确性和可靠性。为了解决这个问题，我们首先使用短链的离子液体分散导电填料石墨烯，然后添加长链的离子液体来进一步增强其分散性。然后以2-丙烯酰胺-2-甲基丙磺酸（AMPS）和聚丙烯酸（AA）为主体，引入腺嘌呤和尿嘧啶作为碱基对。值得注意的是，AMPS和AA中的磺酸和羧基通过氢键与碱基对上的氨基动态交联，形成一个强大的网络。同时，IL-GN作为纳米韧性和导电填料。这种协同效应使水凝胶具有优异的拉伸应变（2500%）、高韧性（665 kJ/m3）、快速电响应（50 ms）、高电导率（8.83 ms /cm）和优异的应变传感（GF = 5.74，应变= 750%）。这些优点使我们的复合水凝胶在大变形下表现出高度的稳定性和在压力和应变下的可重复性。此外，它具有高附着力（附着强度为5.2 kPa），使其成为多功能传感器和柔性电极的有前途的材料。
{"title":"Nucleotide-graphene synergistically enhanced smart hydrogel: Construction of an adhesive and self-healing sensing platform","authors":"Yanmin Ma , Xue Lv , Huiwen Jia , Wang Xu , Xiaoning Yang","doi":"10.1016/j.polymer.2026.129812","DOIUrl":"10.1016/j.polymer.2026.129812","url":null,"abstract":"<div><div>Conductive hydrogels have been widely used in flexible electronics and biosensing applications. However, the difficulty in achieving uniform dispersion of conductive fillers often leads to inconsistent gel properties, thereby limiting the accuracy and reliability of sensors. To address this issue, we first disperse the conductive filler, graphene, using an ionic liquid with a short alkane chain, followed by the addition of an ionic liquid with a long alkane chain to further enhance its dispersion. Then we use 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and polyacrylic acid (AA) as the main body, with adenine and uracil introduced as base pairs. Notably, the sulfonic acid and carboxyl groups in AMPS and AA dynamically cross-link with the amino groups on the base pairs via hydrogen bonds, forming a robust network. Meanwhile, the IL-GN acts as a nano-tough and conductive filler. This synergistic effect endows the hydrogel with exceptional tensile strain, high toughness, and a rapid electrical response, high conductivity, and excellent strain sensing. These advantages allow our composite hydrogels to exhibit a high degree of stability under large deformations and repeatability under pressure and strain. In addition, it has high adhesion, making them a promising material for multifunctional sensors and flexible electrodes.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129812"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147359978","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}
Pub Date : 2026-04-09Epub Date: 2026-03-06DOI: 10.1016/j.polymer.2026.129824
Wenwei Liu, Min Gong, Fengxian Gao, Liang Zhang, Dongrui Wang, Xiang Lin
Compared with the intrinsic strength of raw material, the mechanical properties of 3D-printed polymers normally demonstrate significant deviation and reduction, revealing poor uniformity in batch-type printing process and low reliability in applications. Here, to reveal the mechanism behind such trade-off and explore a method for intelligent optimization, the mechanical dependence of a 3D-printed elastomer (e.g. thermoplastic polyurethane) on the formed porous morphology was investigated by varying layer height, feeding ratio and rastering angle. Then the internal pores within the middle tensile region were precisely mapped via μ-CT tomography, and the correlation between pore morphology and mechanical property were analyzed through machine learning. The measured ultimate tensile stress (UTS) and elongation at break (EB) were regarded as the output metrices for discussion. Interestingly, insignificant dependence of UTS or EB on any single one parameter was observed through Gaussian distribution analysis, implying the strong coupling effect among the three printing parameters. To pave the way for intelligent process-online optimization, Random Forest algorithm was further employed to evaluate the weightiness of each selected parameter, revealing an predictive correlation of 0.88 and errors less than 10%. Overall, this work provides a framework to analyze or even predict the mechanical properties of 3D-printed polymers, and thereby ensures reliability for industrial manufacturing.
{"title":"How internal voids affect the mechanical properties of 3D-printed thermoplastic polyurethane: A study based on porous morphology and machine learning analysis","authors":"Wenwei Liu, Min Gong, Fengxian Gao, Liang Zhang, Dongrui Wang, Xiang Lin","doi":"10.1016/j.polymer.2026.129824","DOIUrl":"10.1016/j.polymer.2026.129824","url":null,"abstract":"<div><div>Compared with the intrinsic strength of raw material, the mechanical properties of 3D-printed polymers normally demonstrate significant deviation and reduction, revealing poor uniformity in batch-type printing process and low reliability in applications. Here, to reveal the mechanism behind such trade-off and explore a method for intelligent optimization, the mechanical dependence of a 3D-printed elastomer (e.g. thermoplastic polyurethane) on the formed porous morphology was investigated by varying layer height, feeding ratio and rastering angle. Then the internal pores within the middle tensile region were precisely mapped via μ-CT tomography, and the correlation between pore morphology and mechanical property were analyzed through machine learning. The measured ultimate tensile stress (UTS) and elongation at break (EB) were regarded as the output metrices for discussion. Interestingly, insignificant dependence of UTS or EB on any single one parameter was observed through Gaussian distribution analysis, implying the strong coupling effect among the three printing parameters. To pave the way for intelligent process-online optimization, Random Forest algorithm was further employed to evaluate the weightiness of each selected parameter, revealing an predictive correlation of 0.88 and errors less than 10%. Overall, this work provides a framework to analyze or even predict the mechanical properties of 3D-printed polymers, and thereby ensures reliability for industrial manufacturing.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129824"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368062","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}
Pub Date : 2026-04-09Epub Date: 2026-03-10DOI: 10.1016/j.polymer.2026.129841
Jiaying Deng , Lei Wu , Xiaojie Chen , Lingxun Qi , Haotian Wu , Jie Chen , Sarah Palloks , Wei Chen
With the rapid advancement of flexible electronic technology, foldable displays have emerged as a leading application requiring highly reliable optical clear adhesives (OCAs). However, conventional OCAs lead to crease formation and interfacial failure on the screen under repeated folding. Here, a novel, flexible bilayer OCA with Janus feature in crosslinking density (v) is proposed, balancing high interfacial adhesion and high internal cohesion. The bilayer design enables a gradient v along the thickness direction, which is directly quantified by advanced unilateral NMR (UNMR). The optimized Janus OCA achieves comparable optical performance but superior mechanical properties compared to conventional OCA, effectively mitigating screen creases during dynamic folding test. Such enhanced performance originates from its asymmetric architecture, in which the low-v layer accommodates deformation on the compressive side, while the high-v layer maintains integrity on the tensile side. This design strategy offers a promising pathway toward next-generation flexible and foldable display technologies.
{"title":"Janus optical clear adhesive with tunable crosslinking density gradient for foldable display","authors":"Jiaying Deng , Lei Wu , Xiaojie Chen , Lingxun Qi , Haotian Wu , Jie Chen , Sarah Palloks , Wei Chen","doi":"10.1016/j.polymer.2026.129841","DOIUrl":"10.1016/j.polymer.2026.129841","url":null,"abstract":"<div><div>With the rapid advancement of flexible electronic technology, foldable displays have emerged as a leading application requiring highly reliable optical clear adhesives (OCAs). However, conventional OCAs lead to crease formation and interfacial failure on the screen under repeated folding. Here, a novel, flexible bilayer OCA with Janus feature in crosslinking density (<em>v</em>) is proposed, balancing high interfacial adhesion and high internal cohesion. The bilayer design enables a gradient <em>v</em> along the thickness direction, which is directly quantified by advanced unilateral NMR (UNMR). The optimized Janus OCA achieves comparable optical performance but superior mechanical properties compared to conventional OCA, effectively mitigating screen creases during dynamic folding test. Such enhanced performance originates from its asymmetric architecture, in which the low-<em>v</em> layer accommodates deformation on the compressive side, while the high-<em>v</em> layer maintains integrity on the tensile side. This design strategy offers a promising pathway toward next-generation flexible and foldable display technologies.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129841"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381063","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}
Pub Date : 2026-04-09Epub Date: 2026-02-28DOI: 10.1016/j.polymer.2026.129799
Robrecht Verhelle , Jessica Mangialetto , Joost Brancart , Luk Van Lokeren , Rene Klein , Mark Brennan , Guy Van Assche
The macroscopic properties of polymers are significantly influenced by their macromolecular architecture. Linear polymers are characterized by their molar mass distribution, for branched polymers also the number, degree, and distribution of branching points is needed, while for network polymers a detailed insight into the molecular architecture of the polymer network is essential. Predicting the build-up of the macromolecular structure during polymerization is thus essential for predicting the final material properties, as well as their variation during polymerization or processing. Models currently available show limitations in terms of the computational cost and/or lack of generality of their approach. For this reason, the development of a generalization of the method originally developed by Macosko and Miller is presented. This algorithm can calculate the molar mass averages, including for example the z-average molar mass, gelation and the post-gel properties, such as the sol-, pending- and elastic effective mass fractions and crosslink density. Furthermore, the newly developed algorithm can cope with unequal reactivity of functional groups, substitution effects, competing parallel reactions involving the same or other functional groups, and with homo- and copolymerization alike. The algorithm is validated by comparing the results generated with literature for poly (urethane-isocyanurate) systems. The competing formation of urethane (carbamate) and isocyanurate groups is used to illustrate the capabilities of the algorithm, in view of the industrial relevance thereof.
{"title":"A generalized approach for predicting macromolecular structure formation in linear and cross-linking step-growth (co)polymerizations","authors":"Robrecht Verhelle , Jessica Mangialetto , Joost Brancart , Luk Van Lokeren , Rene Klein , Mark Brennan , Guy Van Assche","doi":"10.1016/j.polymer.2026.129799","DOIUrl":"10.1016/j.polymer.2026.129799","url":null,"abstract":"<div><div>The macroscopic properties of polymers are significantly influenced by their macromolecular architecture. Linear polymers are characterized by their molar mass distribution, for branched polymers also the number, degree, and distribution of branching points is needed, while for network polymers a detailed insight into the molecular architecture of the polymer network is essential. Predicting the build-up of the macromolecular structure during polymerization is thus essential for predicting the final material properties, as well as their variation during polymerization or processing. Models currently available show limitations in terms of the computational cost and/or lack of generality of their approach. For this reason, the development of a generalization of the method originally developed by Macosko and Miller is presented. This algorithm can calculate the molar mass averages, including for example the z-average molar mass, gelation and the post-gel properties, such as the sol-, pending- and elastic effective mass fractions and crosslink density. Furthermore, the newly developed algorithm can cope with unequal reactivity of functional groups, substitution effects, competing parallel reactions involving the same or other functional groups, and with homo- and copolymerization alike. The algorithm is validated by comparing the results generated with literature for poly (urethane-isocyanurate) systems. The competing formation of urethane (carbamate) and isocyanurate groups is used to illustrate the capabilities of the algorithm, in view of the industrial relevance thereof.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"351 ","pages":"Article 129799"},"PeriodicalIF":4.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330253","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号