{"title":"严格线性聚(乙烯-ran-丙烯酸)共聚物的结晶:垂基插入和氢键的影响","authors":"Jian Zhou, Kohei Takahashi, Kyoko Nozaki, Yuta Yamamoto, Takuya Katashima, Naoko Yoshie, Shintaro Nakagawa","doi":"10.1021/acs.macromol.4c01250","DOIUrl":null,"url":null,"abstract":"Functionalized polyolefins hold great promise as a material group for a future society. The hierarchical structure formation process during crystallization and melting of such polymers is greatly influenced by the inter- and intrachain interactions induced by functional groups. Herein, we report the comprehensive structural analysis of strictly linear poly(ethylene-<i>ran</i>-acrylic acid), i.e., polyethylene bearing pendant carboxyl (−COOH) groups randomly along the chain (PE-COOH), during the crystallization and melting processes. Additional use of the corresponding methyl ester (PE-COOMe) and polyethylene (PE) enabled us to separate the effects of hydrogen bonds (H-bonds) among the −COOH groups from those caused by the random insertion of pendant groups. The crystallizable methylene sequences were divided by the randomly inserted pendant groups, giving rise to the sequence-length selective crystallization. That is, longer sequences crystallized at higher temperatures and vice versa. This significantly hindered the crystallization rate, crystal thickness, and crystallinity and led to a strong melt memory effect. The H-bonding between −COOH groups acted as physical cross-linking for the PE chains and hindered the chain motion. This further slowed the crystallization and reinforced the melt memory effect. On the other hand, the H-bonds contributed to increased crystallinity and melting point of PE-COOH crystallized at high temperatures, compared to those of PE-COOMe. Thus, it was found that the H-bonding of −COOH groups stabilized the crystals formed at high temperatures. This work presents a unified view of the crystallization and melting behavior of strictly linear PE with interacting pendant groups, providing the possibility to precisely control the crystalline morphology in scales of both lamella and spherulite by altering the thermal history.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":null,"pages":null},"PeriodicalIF":5.1000,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Crystallization of Strictly Linear Poly(ethylene-ran-acrylic acid) Copolymer: Impacts of Pendant Group Insertion and Hydrogen Bonding\",\"authors\":\"Jian Zhou, Kohei Takahashi, Kyoko Nozaki, Yuta Yamamoto, Takuya Katashima, Naoko Yoshie, Shintaro Nakagawa\",\"doi\":\"10.1021/acs.macromol.4c01250\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Functionalized polyolefins hold great promise as a material group for a future society. The hierarchical structure formation process during crystallization and melting of such polymers is greatly influenced by the inter- and intrachain interactions induced by functional groups. Herein, we report the comprehensive structural analysis of strictly linear poly(ethylene-<i>ran</i>-acrylic acid), i.e., polyethylene bearing pendant carboxyl (−COOH) groups randomly along the chain (PE-COOH), during the crystallization and melting processes. Additional use of the corresponding methyl ester (PE-COOMe) and polyethylene (PE) enabled us to separate the effects of hydrogen bonds (H-bonds) among the −COOH groups from those caused by the random insertion of pendant groups. The crystallizable methylene sequences were divided by the randomly inserted pendant groups, giving rise to the sequence-length selective crystallization. That is, longer sequences crystallized at higher temperatures and vice versa. This significantly hindered the crystallization rate, crystal thickness, and crystallinity and led to a strong melt memory effect. The H-bonding between −COOH groups acted as physical cross-linking for the PE chains and hindered the chain motion. This further slowed the crystallization and reinforced the melt memory effect. On the other hand, the H-bonds contributed to increased crystallinity and melting point of PE-COOH crystallized at high temperatures, compared to those of PE-COOMe. Thus, it was found that the H-bonding of −COOH groups stabilized the crystals formed at high temperatures. This work presents a unified view of the crystallization and melting behavior of strictly linear PE with interacting pendant groups, providing the possibility to precisely control the crystalline morphology in scales of both lamella and spherulite by altering the thermal history.\",\"PeriodicalId\":51,\"journal\":{\"name\":\"Macromolecules\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.1000,\"publicationDate\":\"2024-10-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Macromolecules\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1021/acs.macromol.4c01250\",\"RegionNum\":1,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"POLYMER SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Macromolecules","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.macromol.4c01250","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
Crystallization of Strictly Linear Poly(ethylene-ran-acrylic acid) Copolymer: Impacts of Pendant Group Insertion and Hydrogen Bonding
Functionalized polyolefins hold great promise as a material group for a future society. The hierarchical structure formation process during crystallization and melting of such polymers is greatly influenced by the inter- and intrachain interactions induced by functional groups. Herein, we report the comprehensive structural analysis of strictly linear poly(ethylene-ran-acrylic acid), i.e., polyethylene bearing pendant carboxyl (−COOH) groups randomly along the chain (PE-COOH), during the crystallization and melting processes. Additional use of the corresponding methyl ester (PE-COOMe) and polyethylene (PE) enabled us to separate the effects of hydrogen bonds (H-bonds) among the −COOH groups from those caused by the random insertion of pendant groups. The crystallizable methylene sequences were divided by the randomly inserted pendant groups, giving rise to the sequence-length selective crystallization. That is, longer sequences crystallized at higher temperatures and vice versa. This significantly hindered the crystallization rate, crystal thickness, and crystallinity and led to a strong melt memory effect. The H-bonding between −COOH groups acted as physical cross-linking for the PE chains and hindered the chain motion. This further slowed the crystallization and reinforced the melt memory effect. On the other hand, the H-bonds contributed to increased crystallinity and melting point of PE-COOH crystallized at high temperatures, compared to those of PE-COOMe. Thus, it was found that the H-bonding of −COOH groups stabilized the crystals formed at high temperatures. This work presents a unified view of the crystallization and melting behavior of strictly linear PE with interacting pendant groups, providing the possibility to precisely control the crystalline morphology in scales of both lamella and spherulite by altering the thermal history.
期刊介绍:
Macromolecules publishes original, fundamental, and impactful research on all aspects of polymer science. Topics of interest include synthesis (e.g., controlled polymerizations, polymerization catalysis, post polymerization modification, new monomer structures and polymer architectures, and polymerization mechanisms/kinetics analysis); phase behavior, thermodynamics, dynamic, and ordering/disordering phenomena (e.g., self-assembly, gelation, crystallization, solution/melt/solid-state characteristics); structure and properties (e.g., mechanical and rheological properties, surface/interfacial characteristics, electronic and transport properties); new state of the art characterization (e.g., spectroscopy, scattering, microscopy, rheology), simulation (e.g., Monte Carlo, molecular dynamics, multi-scale/coarse-grained modeling), and theoretical methods. Renewable/sustainable polymers, polymer networks, responsive polymers, electro-, magneto- and opto-active macromolecules, inorganic polymers, charge-transporting polymers (ion-containing, semiconducting, and conducting), nanostructured polymers, and polymer composites are also of interest. Typical papers published in Macromolecules showcase important and innovative concepts, experimental methods/observations, and theoretical/computational approaches that demonstrate a fundamental advance in the understanding of polymers.