Pub Date : 2025-04-23DOI: 10.1016/j.polymer.2025.128436
Pingjun Shao, Xinyu Liu, Youxu Chen, Li Pan, Yuesheng Li, Zhe Ma
The self-nucleation effect on crystallization kinetics and polymorphism in poly(propylene-co-ethylene-co-1-butene) terpolymer was investigated using differential scanning calorimetry and wide-angle X-ray diffraction. The incorporation of ethylene and 1-butene comonomers induces the occurrence of self-nucleation, which hardly appears in customary isotactic polypropylene homopolymer. Within the incorporation range of 5.5–12.7 mol%, self-nucleation effect could increase the crystallization peak temperature by around 17 °C with respect to the relaxed melt. However, the temperature window of self-nucleation Domain II decreased with increasing comonomer content, where Domain IIa was absent at 12.7 mol%. The successive self-nucleation and annealing (SSA) analysis revealed that the three terpolymers studied exhibited similar regular sequence lengths but various distributions, where the diminishing of the self-nucleation effect was correlated to the reduction in long regular sequences. Additionally, the incorporation of ethylene and 1-butene comonomers facilitated formation of the triclinic γ form, which could be tuned by self-nucleation temperature Ts. In Domain I, the amount of γ form with respect to α form was kept constant. Interestingly, enhancing self-nucleation by lowering Ts significantly increased the content of γ form, as self-nucleation accelerated crystallization kinetics and increased the cooling crystallization temperature. However, the further reduction of Ts within Domain III favored the formation of α form by preserving crystallites from partial melting and reducing regular sequences for the subsequent crystallization.
采用差示扫描量热法和广角 X 射线衍射法研究了自成核对聚（丙烯-共-乙烯-共-1-丁烯）三元共聚物的结晶动力学和多态性的影响。乙烯和 1-丁烯共聚单体的加入导致了自成核现象的出现，而这种现象在普通的同方向聚丙烯均聚物中几乎不会出现。在 5.5-12.7 摩尔%的掺入量范围内，自核效应可使结晶峰值温度比松弛熔体提高约 17 °C。然而，随着共聚单体含量的增加，自成核域 II 的温度窗口减小，当共聚单体含量为 12.7 摩尔%时，域 IIa 不存在。连续自成核和退火（SSA）分析表明，所研究的三种三元共聚物表现出相似的规则序列长度，但分布各不相同，其中自成核效应的减弱与长规则序列的减少有关。此外，乙烯和 1-丁烯共聚单体的加入促进了三菱γ形的形成，这可以通过自成核温度 Ts 来调节。在域 I 中，γ 形相对于 α 形的数量保持不变。有趣的是，通过降低 Ts 来增强自成核显著增加了 γ 形式的含量，因为自成核加速了结晶动力学并提高了冷却结晶温度。然而，在域 III 内进一步降低 Ts 值有利于形成 α 形，因为这样可以保留结晶颗粒，避免部分熔化，并减少随后结晶的规则序列。
{"title":"Self-Nucleation Effect in Crystallization of Poly(propylene-co-ethylene-co-1-butene) Terpolymers","authors":"Pingjun Shao, Xinyu Liu, Youxu Chen, Li Pan, Yuesheng Li, Zhe Ma","doi":"10.1016/j.polymer.2025.128436","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128436","url":null,"abstract":"The self-nucleation effect on crystallization kinetics and polymorphism in poly(propylene-co-ethylene-co-1-butene) terpolymer was investigated using differential scanning calorimetry and wide-angle X-ray diffraction. The incorporation of ethylene and 1-butene comonomers induces the occurrence of self-nucleation, which hardly appears in customary isotactic polypropylene homopolymer. Within the incorporation range of 5.5–12.7 mol%, self-nucleation effect could increase the crystallization peak temperature by around 17 °C with respect to the relaxed melt. However, the temperature window of self-nucleation Domain II decreased with increasing comonomer content, where Domain IIa was absent at 12.7 mol%. The successive self-nucleation and annealing (SSA) analysis revealed that the three terpolymers studied exhibited similar regular sequence lengths but various distributions, where the diminishing of the self-nucleation effect was correlated to the reduction in long regular sequences. Additionally, the incorporation of ethylene and 1-butene comonomers facilitated formation of the triclinic γ form, which could be tuned by self-nucleation temperature <em>T</em><sub>s</sub>. In Domain I, the amount of γ form with respect to α form was kept constant. Interestingly, enhancing self-nucleation by lowering <em>T</em><sub>s</sub> significantly increased the content of γ form, as self-nucleation accelerated crystallization kinetics and increased the cooling crystallization temperature. However, the further reduction of <em>T</em><sub>s</sub> within Domain III favored the formation of α form by preserving crystallites from partial melting and reducing regular sequences for the subsequent crystallization.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"7 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866144","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128426
Shaobai Wang, Theoni K. Georgiou
Three thermoresponsive BCACB pentablock terpolymers, in which A, B, and C blocks were composed of hydrophilic oligo(ethylene glycol) methyl ether methacrylate (average molar mass = 300 g/mol, OEGMA300), hydrophobic n-butyl methacrylate (BuMA), and less-hydrophilic di(ethylene glycol) methyl ether methacrylate (DEGMA), respectively, were synthesised via one-pot group transfer polymerisation (GTP) with varied chemical compositions. In addition to the thermoresponsive behaviour, a time-dependent evolution was also observed in both microscopic structure and macroscopic performance of the thermo-induced hydrogels formed by these terpolymers. Combined analysis using time-resolved small angle X-ray scattering (TR-SAXS) and rheometry reveals that achieving a balanced ratio of hydrophobic and hydrophilic content is critical for configuring hydrogel networks with optimal performance and stability. Specifically, an excessive hydrophobic content leads to a gradual loss of network storage modulus (G’) over time, while an overwhelming hydrophilic content diminishes the formation of stable elastic-active intermicellar correlations, resulting in the lowest G’.
{"title":"Temperature- and Time-dependent Evolution of Hydrogel Network Formed by Thermoresponsive BCACB Pentablock Terpolymers: Effect of Composition","authors":"Shaobai Wang, Theoni K. Georgiou","doi":"10.1016/j.polymer.2025.128426","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128426","url":null,"abstract":"Three thermoresponsive BCACB pentablock terpolymers, in which A, B, and C blocks were composed of hydrophilic oligo(ethylene glycol) methyl ether methacrylate (average molar mass = 300 g/mol, OEGMA300), hydrophobic <em>n</em>-butyl methacrylate (BuMA), and less-hydrophilic di(ethylene glycol) methyl ether methacrylate (DEGMA), respectively, were synthesised via one-pot group transfer polymerisation (GTP) with varied chemical compositions. In addition to the thermoresponsive behaviour, a time-dependent evolution was also observed in both microscopic structure and macroscopic performance of the thermo-induced hydrogels formed by these terpolymers. Combined analysis using time-resolved small angle X-ray scattering (TR-SAXS) and rheometry reveals that achieving a balanced ratio of hydrophobic and hydrophilic content is critical for configuring hydrogel networks with optimal performance and stability. Specifically, an excessive hydrophobic content leads to a gradual loss of network storage modulus (<em>G</em>’) over time, while an overwhelming hydrophilic content diminishes the formation of stable elastic-active intermicellar correlations, resulting in the lowest <em>G’</em>.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"16 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858146","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128429
Shalini Bhattacharya, Suraj W. Wajge, Shrima Bera, Pradip K. Maji, Shiva Singh, Chayan Das
Metal-ligand coordination bonds have been recognized as promising cross-linkers for elastomeric materials. In this work, the interaction between the carboxylate group of carboxylated nitrile butadiene rubber (XNBR) and the ferric ion (Fe3+) generates a dynamic cross-linked network in XNBR matrix. Furthermore, by introducing, 4-aminopyridine in the system, we are able to control the degree of cross-linking. The dynamic nature of the coordination bonds imparts recyclability feature to the composite when exposed to thermal stimuli. Prepared composites are thoroughly characterized using Fourier transform infrared spectroscopy (FT-IR), Swelling study, Differential scanning calorimetry (DSC), Rheometric Study, and Cyclic stress-strain study to investigate the crosslinking process and evaluation of the composite’s properties. It has been found that variation in the 4-aminopyridine content has a strong influence on the properties including the recycling efficiency and the mechanical strength of the composite. The highest recycling efficiency, after the third recycling, is found as high as 80% for a particular composition (XNBR-AP-1-Fe) while highest tensile strength of 3.81 MPa is shown by another composition (XNBR-AP-1-Fe).
{"title":"Impact of 4-Aminopyridine on Ferric-ion Mediated Cross-linking of Carboxylated Nitrile Butadiene Rubber","authors":"Shalini Bhattacharya, Suraj W. Wajge, Shrima Bera, Pradip K. Maji, Shiva Singh, Chayan Das","doi":"10.1016/j.polymer.2025.128429","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128429","url":null,"abstract":"Metal-ligand coordination bonds have been recognized as promising cross-linkers for elastomeric materials. In this work, the interaction between the carboxylate group of carboxylated nitrile butadiene rubber (XNBR) and the ferric ion (Fe<sup>3+</sup>) generates a dynamic cross-linked network in XNBR matrix. Furthermore, by introducing, 4-aminopyridine in the system, we are able to control the degree of cross-linking. The dynamic nature of the coordination bonds imparts recyclability feature to the composite when exposed to thermal stimuli. Prepared composites are thoroughly characterized using Fourier transform infrared spectroscopy (FT-IR), Swelling study, Differential scanning calorimetry (DSC), Rheometric Study, and Cyclic stress-strain study to investigate the crosslinking process and evaluation of the composite’s properties. It has been found that variation in the 4-aminopyridine content has a strong influence on the properties including the recycling efficiency and the mechanical strength of the composite. The highest recycling efficiency, after the third recycling, is found as high as 80% for a particular composition (XNBR-AP-1-Fe) while highest tensile strength of 3.81 MPa is shown by another composition (XNBR-AP-1-Fe).","PeriodicalId":405,"journal":{"name":"Polymer","volume":"17 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858145","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128434
Moira Foster , Kenneth Steirer , Jason Bernstein , Mark Herynk , Leslie Lamberson
Open-cell polymeric foams are widely used for energy absorption applications due to their unique structural properties. Visualizing the compression behavior of these foams is essential for understanding their viscoelastic response and energy dissipation capabilities. This study investigates the deformation characteristics of an open-cell polyurethane foam, a prospective next-generation material for military combat helmets developed by helmet company Team Wendy. Using micro-computed tomography (CT), two foam samples are scanned at 0 % and 28–29.5 % compression to assess changes in pore geometry. Results show a 10–25 % reduction in pore volume and a 5–10 % decrease in shape uniformity upon compression. Comparative and statistical analyses reveal that initial pore volume significantly influences the sequence of cell collapse. Additionally, pore buckling order is affected by the relative porosity of the material layers, while polydispersity does not play a major role. These findings suggest that both regional density and pore volume are key factors in predicting cell buckling order, providing valuable insights into the structural characteristics that govern open-cell foam deformation under stress.
{"title":"Influence of pore geometry and distribution on buckling under micro computed tomography","authors":"Moira Foster , Kenneth Steirer , Jason Bernstein , Mark Herynk , Leslie Lamberson","doi":"10.1016/j.polymer.2025.128434","DOIUrl":"10.1016/j.polymer.2025.128434","url":null,"abstract":"<div><div>Open-cell polymeric foams are widely used for energy absorption applications due to their unique structural properties. Visualizing the compression behavior of these foams is essential for understanding their viscoelastic response and energy dissipation capabilities. This study investigates the deformation characteristics of an open-cell polyurethane foam, a prospective next-generation material for military combat helmets developed by helmet company Team Wendy. Using micro-computed tomography (CT), two foam samples are scanned at 0 % and 28–29.5 % compression to assess changes in pore geometry. Results show a 10–25 % reduction in pore volume and a 5–10 % decrease in shape uniformity upon compression. Comparative and statistical analyses reveal that initial pore volume significantly influences the sequence of cell collapse. Additionally, pore buckling order is affected by the relative porosity of the material layers, while polydispersity does not play a major role. These findings suggest that both regional density and pore volume are key factors in predicting cell buckling order, providing valuable insights into the structural characteristics that govern open-cell foam deformation under stress.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"328 ","pages":"Article 128434"},"PeriodicalIF":4.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853354","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128433
Xuelian Liu , Qian Li , Yuying Zheng , Weijie Zheng
Antistatic nylon-6 (PA6) composites have attracted considerable attention due to their tailored properties for electronics, textiles, and automotive applications. In this paper, the antistatic PA6 composites comprising with polypropylene (PP), aminated multi-walled carbon nanotubes (MWCNTs-NH2) and aminated carbon black (CB–NH2) were prepared by melt blending and compression molding. In the composite system, PP was used as the co-matrix to assist the phase separation of PA6. MWCNTs-NH2 and CB-NH2 were introduced as conductive fillers. All composites showed good thermal stability with the T5 % higher than 376 °C and the composites containing fillers showed higher residues after thermal degradation due to the good thermal stability of MWCNTs-NH2 and CB-NH2. The DSC and XRD results indicated that the crystallization properties of the composite materials were determined by PA6 and PP rather the conductive fillers. In general, the introduction of conductive fillers decreased the mechanical properties but effectively improved the conductivity of the composites and then the antistatic properties. Besides, the antistatic analysis and mechanical test denoted that MWCNTs-NH2 and CB-NH2 showed synergistic effect on improving the antistatic and mechanical properties of the composites, which was more evident at high MWCNTs-NH2 quantity. The micromorphologies obtained by SEM first confirmed the ductile fracture of these composites, and then disclosed a two-phase structure of PA6 and PP polymer matrix, where the conductive fillers were found in the PA6 phase. Considering both mechanical and antistatic properties, the composite (PCNB-3) containing both 3 phr MWCNTs-NH2 and CB-NH2 was proposed for the antistatic PA6 composite.
{"title":"Polypropylene assisted phase separation nylon-6 antistatic composites: MWCNTs-NH2 and CB-NH2 as hybrid conductive nanofillers","authors":"Xuelian Liu , Qian Li , Yuying Zheng , Weijie Zheng","doi":"10.1016/j.polymer.2025.128433","DOIUrl":"10.1016/j.polymer.2025.128433","url":null,"abstract":"<div><div>Antistatic nylon-6 (PA6) composites have attracted considerable attention due to their tailored properties for electronics, textiles, and automotive applications. In this paper, the antistatic PA6 composites comprising with polypropylene (PP), aminated multi-walled carbon nanotubes (MWCNTs-NH<sub>2</sub>) and aminated carbon black (CB–NH<sub>2</sub>) were prepared by melt blending and compression molding. In the composite system, PP was used as the co-matrix to assist the phase separation of PA6. MWCNTs-NH<sub>2</sub> and CB-NH<sub>2</sub> were introduced as conductive fillers. All composites showed good thermal stability with the T<sub>5 %</sub> higher than 376 °C and the composites containing fillers showed higher residues after thermal degradation due to the good thermal stability of MWCNTs-NH<sub>2</sub> and CB-NH<sub>2</sub>. The DSC and XRD results indicated that the crystallization properties of the composite materials were determined by PA6 and PP rather the conductive fillers. In general, the introduction of conductive fillers decreased the mechanical properties but effectively improved the conductivity of the composites and then the antistatic properties. Besides, the antistatic analysis and mechanical test denoted that MWCNTs-NH<sub>2</sub> and CB-NH<sub>2</sub> showed synergistic effect on improving the antistatic and mechanical properties of the composites, which was more evident at high MWCNTs-NH<sub>2</sub> quantity. The micromorphologies obtained by SEM first confirmed the ductile fracture of these composites, and then disclosed a two-phase structure of PA6 and PP polymer matrix, where the conductive fillers were found in the PA6 phase. Considering both mechanical and antistatic properties, the composite (PCNB-3) containing both 3 phr MWCNTs-NH<sub>2</sub> and CB-NH<sub>2</sub> was proposed for the antistatic PA6 composite.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"328 ","pages":"Article 128433"},"PeriodicalIF":4.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853353","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128425
Marina Doi, Haonan Liu, Shinji Ando
Six types of photoluminescent polyimides (PIs) and co-polyimides (co-PIs) were synthesized to clarify the requirements for PIs that exhibit prolonged UV irradiation-induced delayed luminescence (PIDL). PIDL is a form of phosphorescence (PH) observed after ground-state oxygen (3O2) is gradually excited to singlet oxygen (1O2) via energy transfer from triplet excitons of the phosphor under continuous irradiation. When 4,4'-oxydiphthalic dianhydride (ODPA), which has an ether linkage, is used as a luminescent unit, dilution of the phosphor unit by copolymerization with non-luminescent dianhydrides is effective in exhibiting strong PH as well as PIDL emission. However, PIs derived from ODPA emit only a weak PH without PIDL, which is caused by thermal deactivation owing to their flexible structure. Thus, four types of PIs were synthesized using luminescent dibenzothiophene tetracarboxylic dianhydride (DBSA) having a rigid thiophene core. Two types of PIs exhibited PIDL at room temperature in air when coated with polyvinyl alcohol as an oxygen (O2) barrier. This is the first report of PIs with PIDL emission, indicating that preventing O2 permeation allows sufficient reduction of 3O2, which is necessary for exhibiting PIDL. In addition, these two PIs exhibited different PIDL intensities and induction time, which is the elapsed time required to show the PIDL, depending on the O2 permeability and lifetime of 1O2 within the PI films. These results clarify that PIs derived from a suitable combination of luminescent and non-luminescent dianhydrides can exhibit obvious PIDL while maintaining high thermal resistance and good processability.
{"title":"Photophysical Analysis of Prolonged UV Irradiation-Induced Delayed Luminescence of Semi-Aromatic Polyimides and Its Relation to Oxygen Permeability","authors":"Marina Doi, Haonan Liu, Shinji Ando","doi":"10.1016/j.polymer.2025.128425","DOIUrl":"https://doi.org/10.1016/j.polymer.2025.128425","url":null,"abstract":"Six types of photoluminescent polyimides (PIs) and co-polyimides (co-PIs) were synthesized to clarify the requirements for PIs that exhibit prolonged UV irradiation-induced delayed luminescence (PIDL). PIDL is a form of phosphorescence (PH) observed after ground-state oxygen (<sup>3</sup>O<sub>2</sub>) is gradually excited to singlet oxygen (<sup>1</sup>O<sub>2</sub>) <em>via</em> energy transfer from triplet excitons of the phosphor under continuous irradiation. When 4,4'-oxydiphthalic dianhydride (ODPA), which has an ether linkage, is used as a luminescent unit, dilution of the phosphor unit by copolymerization with non-luminescent dianhydrides is effective in exhibiting strong PH as well as PIDL emission. However, PIs derived from ODPA emit only a weak PH without PIDL, which is caused by thermal deactivation owing to their flexible structure. Thus, four types of PIs were synthesized using luminescent dibenzothiophene tetracarboxylic dianhydride (DBSA) having a rigid thiophene core. Two types of PIs exhibited PIDL at room temperature in air when coated with polyvinyl alcohol as an oxygen (O<sub>2</sub>) barrier. This is the first report of PIs with PIDL emission, indicating that preventing O<sub>2</sub> permeation allows sufficient reduction of <sup>3</sup>O<sub>2</sub>, which is necessary for exhibiting PIDL. In addition, these two PIs exhibited different PIDL intensities and induction time, which is the elapsed time required to show the PIDL, depending on the O<sub>2</sub> permeability and lifetime of <sup>1</sup>O<sub>2</sub> within the PI films. These results clarify that PIs derived from a suitable combination of luminescent and non-luminescent dianhydrides can exhibit obvious PIDL while maintaining high thermal resistance and good processability.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"2 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858144","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}
Face masks are vital in protecting individuals from respiratory viruses but can serve as a source of infection if improperly used or re-used. Herein, we report anti-infective polymer coatings comprised of anti-fouling poly(oligoethylene glycol methacrylate) (POEGMA) functionalized with hydrazide groups for promoting adhesion and a quaternary ammonium compound (QAC) and/or grafted ciprofloxacin as the anti-infective component. The polymers could be functionalized to the surface of spunbonded polypropylene used for face masks using a simple aqueous dip-coating process. The QAC-functionalized coatings demonstrated a 2.0 log reduction against Staphylococcus aureus, a 1.5 log reduction against Escherichia coli, and a 0.8 log reduction against Pseudomonas aeruginosa after five hours of contact time; combination coatings containing both QAC and ciprofloxacin enabled a 2.1 log reduction against S. aureus, a 4.1 log reduction against E. coli, and a 7.3 log reduction against P. aeruginosa. In parallel, the masks maintained their key mechanical properties as well as remained in full compliance with the ASTM standards for barrier face coverings in terms of breathability and particulate filtration efficacy. Thus, this coating strategy offers potential to reduce the risk of infection from mask wear or reuse.
{"title":"An Anti-Infective Polymer Coating to Reduce Surface Transmission of Pathogens on Personal Protective Equipment","authors":"Mya Sharma, Gurpreet Randhawa, Fei Xu, Evelyn Cudmore, Todd Hoare","doi":"10.1016/j.polymer.2025.128428","DOIUrl":"10.1016/j.polymer.2025.128428","url":null,"abstract":"<div><div>Face masks are vital in protecting individuals from respiratory viruses but can serve as a source of infection if improperly used or re-used. Herein, we report anti-infective polymer coatings comprised of anti-fouling poly(oligoethylene glycol methacrylate) (POEGMA) functionalized with hydrazide groups for promoting adhesion and a quaternary ammonium compound (QAC) and/or grafted ciprofloxacin as the anti-infective component. The polymers could be functionalized to the surface of spunbonded polypropylene used for face masks using a simple aqueous dip-coating process. The QAC-functionalized coatings demonstrated a 2.0 log reduction against <em>Staphylococcus aureus</em>, a 1.5 log reduction against <em>Escherichia coli</em>, and a 0.8 log reduction against <em>Pseudomonas aeruginosa</em> after five hours of contact time; combination coatings containing both QAC and ciprofloxacin enabled a 2.1 log reduction against <em>S. aureus</em>, a 4.1 log reduction against <em>E. coli</em>, and a 7.3 log reduction against <em>P. aeruginosa.</em> In parallel, the masks maintained their key mechanical properties as well as remained in full compliance with the ASTM standards for barrier face coverings in terms of breathability and particulate filtration efficacy. Thus, this coating strategy offers potential to reduce the risk of infection from mask wear or reuse.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"328 ","pages":"Article 128428"},"PeriodicalIF":4.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853390","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}
Shape memory polyimide aerogels represent a promising class of next-generation materials for aerospace applications, owing to their intrinsic low density, unique thermo-induced shape memory behavior, and exceptional resistance to extreme environmental conditions. However, aromatic polyimides exhibit poor shape memory performance due to high chain rigidity and strong π-π stacking interactions, while increasing the flexibility of the molecular chains can disrupt the formability of the three-dimensional structure of aerogels. In this study, we successfully synthesized a series of block copolyimide aerogels by systematically manipulating the molecular structure. Through controlling the polymerization degree of soft segments, block copolyimide aerogels demonstrated thermo-induced shape memory behavior at temperatures of approximately 320 °C, with both shape recovery and fixation rates exceeding 97 %. Notably, these block copolyimide aerogels exhibit good formability and lightweight with a low density below 0.19 g cm−3. Furthermore, after more than ten shape memory cycles, the recovery and fixation rates remain consistently above 95 %, indicating excellent long-term stability. This study offers new insights into the development of lightweight and high-temperature shape memory materials, with significant potential for future aerospace applications.
{"title":"Lightweight fluorinated block copolyimide aerogels for high-temperature shape memory","authors":"Dingzheng Zhou, Tiantian Xue, Zhipeng Fu, Shiyang Wang, Xu Zhang, Wei Fan, Tianxi Liu","doi":"10.1016/j.polymer.2025.128430","DOIUrl":"10.1016/j.polymer.2025.128430","url":null,"abstract":"<div><div>Shape memory polyimide aerogels represent a promising class of next-generation materials for aerospace applications, owing to their intrinsic low density, unique thermo-induced shape memory behavior, and exceptional resistance to extreme environmental conditions. However, aromatic polyimides exhibit poor shape memory performance due to high chain rigidity and strong π-π stacking interactions, while increasing the flexibility of the molecular chains can disrupt the formability of the three-dimensional structure of aerogels. In this study, we successfully synthesized a series of block copolyimide aerogels by systematically manipulating the molecular structure. Through controlling the polymerization degree of soft segments, block copolyimide aerogels demonstrated thermo-induced shape memory behavior at temperatures of approximately 320 °C, with both shape recovery and fixation rates exceeding 97 %. Notably, these block copolyimide aerogels exhibit good formability and lightweight with a low density below 0.19 g cm<sup>−3</sup>. Furthermore, after more than ten shape memory cycles, the recovery and fixation rates remain consistently above 95 %, indicating excellent long-term stability. This study offers new insights into the development of lightweight and high-temperature shape memory materials, with significant potential for future aerospace applications.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"328 ","pages":"Article 128430"},"PeriodicalIF":4.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858143","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128432
Sabrine Bentalib , Martin van Drongelen , Edwin T.J. Klompen , Nick G.J. Helthuis , Remko Akkerman
The increased interest in semi-crystalline thermoplastic composites, calls for a profound understanding of the intricate relationship between process parameters and the development of crystalline structures. In this study, the non-isothermal multi-phase crystallization kinetics of PA410 is modelled with the Schneider rate equations. Moreover, the change in crystallization kinetics induced by the addition of carbon-black nanoparticles and glass-fibres to PA410, is quantified by means of Flash-DSC experiments. To this end, a new sample preparation procedure to make unidirectional fibre-reinforced samples, of known fibre volume fraction, suitable for Flash-DSC analysis is introduced and used for the characterization of the reinforced PA410. The investigations showed that the polymorphism of neat PA410 is altered by the introduction of carbon black, which suppresses the formation of β-phase crystals, leading to an α-phase dominant crystalline volume. This finding simplified the crystallization kinetics modelling of both CB-filled and GF-reinforced PA410, for which one single set of Schneider rate equations was sufficient to accurately describe their crystallization behaviour, under isothermal and non-isothermal conditions.
{"title":"Isothermal and non-isothermal crystallization kinetics modelling of neat and composite PA410","authors":"Sabrine Bentalib , Martin van Drongelen , Edwin T.J. Klompen , Nick G.J. Helthuis , Remko Akkerman","doi":"10.1016/j.polymer.2025.128432","DOIUrl":"10.1016/j.polymer.2025.128432","url":null,"abstract":"<div><div>The increased interest in semi-crystalline thermoplastic composites, calls for a profound understanding of the intricate relationship between process parameters and the development of crystalline structures. In this study, the non-isothermal multi-phase crystallization kinetics of PA410 is modelled with the Schneider rate equations. Moreover, the change in crystallization kinetics induced by the addition of carbon-black nanoparticles and glass-fibres to PA410, is quantified by means of Flash-DSC experiments. To this end, a new sample preparation procedure to make unidirectional fibre-reinforced samples, of known fibre volume fraction, suitable for Flash-DSC analysis is introduced and used for the characterization of the reinforced PA410. The investigations showed that the polymorphism of neat PA410 is altered by the introduction of carbon black, which suppresses the formation of β-phase crystals, leading to an α-phase dominant crystalline volume. This finding simplified the crystallization kinetics modelling of both CB-filled and GF-reinforced PA410, for which one single set of Schneider rate equations was sufficient to accurately describe their crystallization behaviour, under isothermal and non-isothermal conditions.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"328 ","pages":"Article 128432"},"PeriodicalIF":4.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858148","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 : 2025-04-21DOI: 10.1016/j.polymer.2025.128435
Jiayong Lu, Ao Wu, Shikai Chen, Binghua Wang, Jingbo Chen, Changyu Shen, Bin Zhang
Atomic force microscopy (AFM) and optical microscopy (OM) were utilized to study the growth kinetics and morphology of the flat-on stereocomplex lamellae in poly(d-lactide)/poly(l-lactide) (PDLA/PLLA) blend ultrathin films at various crystallization temperatures (Tc) and mass ratios. As the Tc increases from 170 to 195 °C, the crystal morphology of PLA stereocomplex (SC-PLA) lamellae transitions from dendrites with curved main and side branches to triangular crystals without curvature, accompanied by a decrease in the early growth rate (Ge). Similarly, increasing the mass ratio of PDLA to PLLA from 1.5:1 to 9:1 results in a decrease in Ge, while the curvature radius of the main branch (ρb) increase. By measuring the width (wd) of the depletion zone ahead of the growing lamellae, we made an intriguing observation that ρb correlates with wd, through a power law relationship: ρb ∼ wdα (α = 1–2, depending on the molecular weight). Furthermore, wd increases over time at higher Tc, leading to a non-linear growth of crystals (Ge continuously decays with time), confirmed a diffusion-controlled growth mechanism. Concurrently, the thickness of stereocomplex lamellar crystals begins to expand as growth rate diminishes to approximately 40 % of Ge. This indicates that the non-equilibrium growth kinetics is the primary factor driving the changes in ρb and thickness of main branches of SC-PLA dendritic crystals within ultrathin films.
{"title":"Influence of growth kinetics on crystal morphology of polylactide stereocomplex in ultrathin films","authors":"Jiayong Lu, Ao Wu, Shikai Chen, Binghua Wang, Jingbo Chen, Changyu Shen, Bin Zhang","doi":"10.1016/j.polymer.2025.128435","DOIUrl":"10.1016/j.polymer.2025.128435","url":null,"abstract":"<div><div>Atomic force microscopy (AFM) and optical microscopy (OM) were utilized to study the growth kinetics and morphology of the flat-on stereocomplex lamellae in poly(<span>d</span>-lactide)/poly(<span>l</span>-lactide) (PDLA/PLLA) blend ultrathin films at various crystallization temperatures (<em>T</em><sub>c</sub>) and mass ratios. As the <em>T</em><sub>c</sub> increases from 170 to 195 °C, the crystal morphology of PLA stereocomplex (SC-PLA) lamellae transitions from dendrites with curved main and side branches to triangular crystals without curvature, accompanied by a decrease in the early growth rate (<em>G</em><sub>e</sub>). Similarly, increasing the mass ratio of PDLA to PLLA from 1.5:1 to 9:1 results in a decrease in <em>G</em><sub>e</sub>, while the curvature radius of the main branch (<em>ρ</em><sub>b</sub>) increase. By measuring the width (<em>w</em><sub>d</sub>) of the depletion zone ahead of the growing lamellae, we made an intriguing observation that <em>ρ</em><sub>b</sub> correlates with <em>w</em><sub>d</sub>, through a power law relationship: <em>ρ</em><sub>b</sub> ∼ <em>w</em><sub>d</sub><sup><em>α</em></sup> (<em>α</em> = 1–2, depending on the molecular weight). Furthermore, <em>w</em><sub>d</sub> increases over time at higher <em>T</em><sub>c</sub>, leading to a non-linear growth of crystals (<em>G</em><sub>e</sub> continuously decays with time), confirmed a diffusion-controlled growth mechanism. Concurrently, the thickness of stereocomplex lamellar crystals begins to expand as growth rate diminishes to approximately 40 % of <em>G</em><sub>e</sub>. This indicates that the non-equilibrium growth kinetics is the primary factor driving the changes in <em>ρ</em><sub>b</sub> and thickness of main branches of SC-PLA dendritic crystals within ultrathin films.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"328 ","pages":"Article 128435"},"PeriodicalIF":4.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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