IF 4.1 2区化学

Polymer Pub Date : 2025-05-13 DOI: 10.1016/j.polymer.2025.128545

Leqing He, Shuangbai Li, Chongpin Huang

{"title":"Methanolysis of mixed plastics catalyzed by ionic liquid: PET depolymerization and recycling of PP/PE","authors":"Leqing He, Shuangbai Li, Chongpin Huang","doi":"10.1016/j.polymer.2025.128545","DOIUrl":"10.1016/j.polymer.2025.128545","url":null,"abstract":"<div><div>In the context of composite materials that elude classification via conventional pretreatment methodologies such as crushing, granulating, and flotation—specifically within the domains of food packaging, construction materials, and engineering plastics—this research employed a one-step methanolysis-separation technique for the graded recycling of polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) in mixed plastics. Employing methanol as the reaction solvent, the benign and eco-friendly ionic liquid BMIMOH as the catalyst for the degradation of PET. PET was methanolized to produce dimethyl terephthalate (DMT), while PP and PE remained highly stable, were separated after the reaction, and subjected to subsequent recycling. The stability of PP and PE under methanolysis conditions was revealed through structural and thermodynamic analyses. Single-factor analysis and response surface methodology were employed to determine the optimal conditions for the methanolysis reaction. Additionally, the impact of different contents of PP and PE on the recovery of PET from the mixed plastics during the swelling-condensation process at high temperatures was explored. Under the optimal conditions, the yield of DMT was 94 % for the degradation of single PET, and when the ratio of PET in the mixed plastics was 50 %, the yield of DMT could still reach 90 %.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"331 ","pages":"Article 128545"},"PeriodicalIF":4.1,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143940606","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}

引用次数: 0

Evolution of structure of highly crystalline poly(glycolide-co-lactide) under varying hot stretching rates 不同热拉伸速率下高结晶聚乙二醇-共丙交酯结构的演化

IF 4.1 2区化学

Polymer Pub Date : 2025-05-12 DOI: 10.1016/j.polymer.2025.128540

Yiru Shan, Jin Guo, Congliang Huang, Weijun Miao, Zongbao Wang

{"title":"Evolution of structure of highly crystalline poly(glycolide-co-lactide) under varying hot stretching rates","authors":"Yiru Shan, Jin Guo, Congliang Huang, Weijun Miao, Zongbao Wang","doi":"10.1016/j.polymer.2025.128540","DOIUrl":"10.1016/j.polymer.2025.128540","url":null,"abstract":"<div><div>With the sustained global focus on sustainable development, the utilization of biodegradable polymers as alternatives to traditional plastics has emerged as a significant research topic. Among them, poly(glycolide-co-lactide) (P(GA-<em>co</em>-LA)) has garnered widespread attention in practical applications due to its exceptional biocompatibility and biodegradability. In this study, in-situ synchrotron radiation wide-angle X-ray diffraction (WAXD)/small-angle X-ray scattering (SAXS) techniques were employed to investigate the structural evolution of highly crystalline eutectic P(GA-<em>co</em>-LA) during hot stretching at strain rates ranging from 0.04·min<sup>−1</sup> to 4.00·min<sup>−1</sup>. The research results indicate that the structural evolution primarily encompasses crystal slip, fragmentation, and recrystallization processes, as well as stress-induced formation of new crystals. In the early stage of stretching, as the strain rate decreases, the phenomenon of crystal slip diminishes, effectively inhibiting crystal fragmentation. During the intermediate stage, low-rate stretching leads to a higher degree of order in the molecular chain structure due to the enhanced exclusion effect of LA units. In the later stage of stretching, low-rate stretching conditions are more conducive to the growth of new lamellar crystals and the formation of highly oriented crystals. The crystallite size continues to decrease, and the structural arrangement of P(GA-<em>co</em>-LA) tends to become more regular. It is difficult for LA units to incorporate into the newly formed crystals, thereby enhancing the crystallinity and orientation of P(GA-<em>co</em>-LA). Low-rate stretching further promotes the perfection and evolution of the lamellar structure, facilitating the transition from lamellar crystals to highly oriented fibrous crystals. This reduces the probability of LA units incorporating into the lattice, thus enhancing the regularity of the overall crystal structure.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"331 ","pages":"Article 128540"},"PeriodicalIF":4.1,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143940031","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}

引用次数: 0

In-situ branched Poly (butylene succinate-co-butylene terephthalate) for green preparation of ultralight foams: simultaneous enhanced mechanical and degradation properties 原位支链聚丁二甲酸丁二酯-对苯二甲酸丁二酯绿色制备超轻泡沫：同时增强机械和降解性能

IF 4.1 2区化学

Polymer Pub Date : 2025-05-11 DOI: 10.1016/j.polymer.2025.128519

Wentao Guo, Shaolong Wei, Jie Yuan, Xiulu Gao, Ling Zhao, Dongdong Hu

{"title":"In-situ branched Poly (butylene succinate-co-butylene terephthalate) for green preparation of ultralight foams: simultaneous enhanced mechanical and degradation properties","authors":"Wentao Guo, Shaolong Wei, Jie Yuan, Xiulu Gao, Ling Zhao, Dongdong Hu","doi":"10.1016/j.polymer.2025.128519","DOIUrl":"10.1016/j.polymer.2025.128519","url":null,"abstract":"<div><div>A series of PBST with the branching agent glycerol ranging from 0 mol.% to 1.5 mol.% were synthesized by in-situ polymerization, and different branched PBST foams were prepared using supercritical CO<sub>2</sub>. The introduction of branching structure both improve the rheological, mechanical properties and crystallization behavior of PBST. The crystallinity, relaxation time and tensile modulus of branched PBST increase from 12.7 % to 15.2 %, from 0.0136 s to 2.288 s and from 63.9 MPa to 87.0 MPa, respectively. When the glycerol content was 1.0 mol.%, the degree of branching was optimal and the maximum initial and final expansion ratios of the prepared foams were 38.5 and 21.5, respectively. The addition of branching agent increases the rigidity and entanglement of the molecular chain and provides more hydroxyl groups as degradation sites, resulting in branched PBST foams exhibiting superior compression and degradation properties. Compared to linear PBST, the compressive modulus of branched PBST foams with an expansion ratio of 10 increases from 1.21 MPa to 2.92 MPa. Introduction of branching structure by in-situ polymerization can provide an effective strategy for the preparation of degradable foams with excellent mechanical and degradation properties, and adjustable cell parameters.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"331 ","pages":"Article 128519"},"PeriodicalIF":4.1,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933181","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}

引用次数: 0

Molecular dynamics simulations of stretch-induced crystallization of polyethylene-grafted-graphene/polyethylene system 聚乙烯-接枝石墨烯/聚乙烯体系拉伸诱导结晶的分子动力学模拟

IF 4.1 2区化学

Polymer Pub Date : 2025-05-11 DOI: 10.1016/j.polymer.2025.128534

Yongqiang Ming, Jianlong Wen, Chao Cheng, Tongfan Hao, Juan Yang, Yijing Nie

{"title":"Molecular dynamics simulations of stretch-induced crystallization of polyethylene-grafted-graphene/polyethylene system","authors":"Yongqiang Ming, Jianlong Wen, Chao Cheng, Tongfan Hao, Juan Yang, Yijing Nie","doi":"10.1016/j.polymer.2025.128534","DOIUrl":"10.1016/j.polymer.2025.128534","url":null,"abstract":"<div><div>The stretch-induced crystallization of the polyethylene (PE)-<em>g</em>-graphene/PE system was studied by molecular dynamics simulations. It was found that the stretching effect and the presence of grafted chains can enhance the orientation of segments along the stretching direction and promote the conformational transition of chains, leading to an increase in the content of precursors, thereby improving the crystallization ability of the polymer system. Detailed analysis revealed that the segments near grafting points, due to the strong restriction effect, have a significantly lower degree of orientational order and conformational transformation ability compared to the segments in the middle of the chains. For the segments near the free ends, due to the presence of more entanglements, the degree of orientational order and conformational transition ability are also significantly lower than those of the segments in the middle of the chains. Then, there is a higher precursor content for the segments in the middle of the chains compared to the segments near the ends, resulting in stronger crystallization ability of the segments in the middle of the chains. Additionally, it was found that the segments in the middle of the chains are more likely to form crystal nuclei through the intramolecular nucleation mechanism, while the segments near the ends tend to form crystal nuclei through the intermolecular nucleation mechanism.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"331 ","pages":"Article 128534"},"PeriodicalIF":4.1,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932629","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}

引用次数: 0

Dual-patterned programming of photoactive dynamically cross-linked polyester enabling customizable shape-shifting pathways 光活性动态交联聚酯的双模式编程实现可定制的变形路径

IF 4.1 2区化学

Polymer Pub Date : 2025-05-11 DOI: 10.1016/j.polymer.2025.128538

Yaxin Qiu , Jinxuan Ai , Aiying Liu , Chengkai Yang , Zhifeng Wang , Chong Chen , Xiaozhi Wang

引用次数: 0

Impact of smallest loops and composition fluctuations on the structure of end-linked polymer model networks 最小环和组成波动对末端连接聚合物模型网络结构的影响

IF 4.1 2区化学

Polymer Pub Date : 2025-05-10 DOI: 10.1016/j.polymer.2025.128454

Michael Lang, Reinhard Scholz, Toni Müller

{"title":"Impact of smallest loops and composition fluctuations on the structure of end-linked polymer model networks","authors":"Michael Lang, Reinhard Scholz, Toni Müller","doi":"10.1016/j.polymer.2025.128454","DOIUrl":"10.1016/j.polymer.2025.128454","url":null,"abstract":"<div><div>A self-consistent scheme of differential equations is developed for predicting the frequency of the two smallest loop defects within polymer model networks. Without any adjustable parameter, we obtain excellent agreement with Monte Carlo simulations that sample loop formation only up to the given maximum loop size. The formation of loops of second generation leads to correlations between connected junctions that cannot be treated exactly by considering statistical arguments alone, which is in contrast to reversible networks where equilibrium statistics are sufficient. These correlations and the statistics of the junctions are provided by our model. Comparison with more realistic simulation data in three dimensions indicates that composition fluctuations (CF) of cross-links and chains clearly impact network formation. The differences between the statistics of the network junctions and our mean field predictions provide insight into the size of the domains with a predominance of chains or junctions, and thus, regarding the quality of the mixture. Our results are highly relevant for an accurate modeling of network structure, improved estimates of the elastic properties of polymer networks, and for advanced analysis techniques of the network structure like network disassembly spectrometry or multiple quantum nuclear magnetic resonance.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"330 ","pages":"Article 128454"},"PeriodicalIF":4.1,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931093","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}

引用次数: 0

Corrigendum to “Enhancing thermal conductivity in polypropylene random copolymer through rotational shear processing” [Polymer 325 (2025) 128304] “通过旋转剪切加工提高聚丙烯无规共聚物的导热性”的勘误表[聚合物325 (2025)128304]

IF 4.1 2区化学

Polymer Pub Date : 2025-05-10 DOI: 10.1016/j.polymer.2025.128397

Aerman Abudurezhake , Ran Tian , Jiawei Gong , Ganji Zhong , Zhongming Li , Qiang Fu , Xueqin Gao

引用次数: 0

Challenges of high-temperature melt electrowriting: A study of EVOH printing 高温熔体电解的挑战：EVOH印刷的研究

IF 4.1 2区化学

Polymer Pub Date : 2025-05-10 DOI: 10.1016/j.polymer.2025.128518

Tong Sun , Huali Lu , Simon Luposchainsky , Liu Yang , Xiaoyu Zhang , Akiko Hirano , Yuta Nakano , Yagi Shinichi , Huaizhong Xu

{"title":"Challenges of high-temperature melt electrowriting: A study of EVOH printing","authors":"Tong Sun , Huali Lu , Simon Luposchainsky , Liu Yang , Xiaoyu Zhang , Akiko Hirano , Yuta Nakano , Yagi Shinichi , Huaizhong Xu","doi":"10.1016/j.polymer.2025.128518","DOIUrl":"10.1016/j.polymer.2025.128518","url":null,"abstract":"<div><div>Melt electrowriting (MEW) is an additive manufacturing technique used for creating thermoplastic microfiber scaffolds for tissue engineering with high precision. Most existing research focuses on polycaprolactone (PCL), a material that is commonly studied for its print behavior and is often used to create scaffolds due to its ease of processing. Although PCL is recognized as a bioresorbable polymer, its complete degradation takes multiple years, and its mechanical properties fail to replicate the high stiffness required by certain tissues. While several alternative polymers can be processed using MEW, their printability generally falls short compared to that of PCL. Most polymers have vastly higher processing temperatures, which can lead to swift degradation and rapid jet quenching, negatively impacting print quality. In this study, we explore the use of ethylene vinyl alcohol copolymer (EVOH), which has a melting point of 174 °C, to investigate the principles of printing high-melting-point polymers through MEW. We analyzed the effects of various melt and collector temperature combinations on jet motion, fiber stacking behavior, and the mechanical properties of scaffolds. Our findings indicate that rapid jet quenching leads to jet jumping, whereas a slower quenching printing promotes fiber adhesion, enhancing correct jet landing and improving mechanical properties, including a breaking stress of 0.2 cN/dtex, a modulus of 4 cN/dtex, and an elongation at break of 400 %. Long-term printing indicates that the process can be sustained for at least 15 h, producing fibers with diameters ranging from 8 to 14 μm. This research broadens the range of printable polymers, advancing the application of MEW technology across various fields.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"331 ","pages":"Article 128518"},"PeriodicalIF":4.1,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931096","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}

引用次数: 0

Flame retardancy and thermal and mechanical properties of ternary composites comprising polylactic acid, polyethylene glycol, and bamboo fiber 由聚乳酸、聚乙二醇和竹纤维组成的三元复合材料的阻燃性和热机械性能

IF 4.1 2区化学

Polymer Pub Date : 2025-05-10 DOI: 10.1016/j.polymer.2025.128533

Yu Feng , Yihong Song , Wenfeng Li , Zhenyu Guo , Zhiwei Jiang , Liuwen Ruan , Wenxi Cheng , Weiqiang Song

{"title":"Flame retardancy and thermal and mechanical properties of ternary composites comprising polylactic acid, polyethylene glycol, and bamboo fiber","authors":"Yu Feng , Yihong Song , Wenfeng Li , Zhenyu Guo , Zhiwei Jiang , Liuwen Ruan , Wenxi Cheng , Weiqiang Song","doi":"10.1016/j.polymer.2025.128533","DOIUrl":"10.1016/j.polymer.2025.128533","url":null,"abstract":"<div><div>A ternary composite composed of polylactic acid (PLA), polyethylene glyco (PEG)l, and bamboo fiber (BF) at a weight ratio of 70:10:20 was prepared using a twin-screw extruder, incorporating aluminum diethylphosphinate (ADP) and melamine cyanurate (MCA). Specifically, formulations containing 30 parts ADP alone, 10 parts ADP and 10 parts MCA, or 10 parts ADP and 15 parts MCA improved the UL94 rating from V2 to V0. The corresponding values of limiting oxygen index (LOI) were 29.3 %, 25.5 %, and 26.9 %, respectively. The combination of ADP and MCA exhibited a synergistic effect on flame retardant modification of PLA/PEG/BF. Furthermore, both ADP and MCA altered the thermal behavior of the composite; MCA alone increased the melting temperature (<em>T</em><sub>m</sub>) but decreased the crystallization temperature (<em>T</em><sub>c</sub>), whereas ADP increased both <em>T</em><sub>m</sub> and <em>T</em><sub>c</sub>. The crystallization of PLA in the composite showed coexistence of two-dimensional and three-dimensional growth modes after incorporation of MCA and ADP, although their effects on the rate of PLA crystal growth differed. Composites with 30 parts ADP alone and 10 parts ADP and 10 parts MCA loading demonstrated high mass retention rates at 800 °C.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"330 ","pages":"Article 128533"},"PeriodicalIF":4.1,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931097","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}

引用次数: 0

Melting and transition of isotactic polybutene-1 precipitated from solutions 从溶液中析出的等规聚丁烯-1的熔化和转变

IF 4.1 2区化学

Polymer Pub Date : 2025-05-09 DOI: 10.1016/j.polymer.2025.128530

Jiaxin Huo, Jingqing Li, Shichun Jiang

{"title":"Melting and transition of isotactic polybutene-1 precipitated from solutions","authors":"Jiaxin Huo, Jingqing Li, Shichun Jiang","doi":"10.1016/j.polymer.2025.128530","DOIUrl":"10.1016/j.polymer.2025.128530","url":null,"abstract":"<div><div>The equilibrium concept of conformation is the most important to understand chemical physics, and the non-equilibrium based conformation is the molecular basis underlying essentially all the physical properties of polymers. As a polymer chain with long relaxation time, the conformational memory of isotropic polybutene-1 (iPB-1) could not be completely erased even after it has gone into solution or melt. It is considered that the polymer chains are diluted and the interactions between the chains are reduced in solutions. In this work, the iPB-1 samples with different molecular weight were prepared from solutions by adding various volumes of precipitant or from solutions of various concentrations by adding the same volume of precipitant. The structure, melting and transition of the obtained iPB-1 samples were characterized by DSC, FTIR, WAXS, and SAXS techniques. It was found that the form III increases with the volume of precipitant or solution concentration, and the form III formed from the solution without stirring is more than that formed from the stirred solution. The melting temperature of form III is lower than that of form I′ in the same sample and the transition of solution crystallized iPB-1 is related to the melting of the prepared iPB-1 samples. The temperature for form II formation if iPB-1 prepared from the solutions dominates the form II-form I transition. The crystallization, melting and transition of the iPB-1 prepared from solutions were discussed based on the non-equilibrium chain dynamics and conformation adjustment of polymer chains and clusters, which would be helpful to understand the dynamics and transition of iPB-1.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"330 ","pages":"Article 128530"},"PeriodicalIF":4.1,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931101","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}

引用次数: 0

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