{"title":"Relaxation spectrum of poly(styrene-b-isoprene-b-styrene) triblock copolymer","authors":"Hengyu Luo, Zihao Shang, Hui Han, Haiqing Hu","doi":"10.1007/s13726-024-01328-3","DOIUrl":null,"url":null,"abstract":"<div><p>A relatively complete continuous relaxation spectrum <i>H</i>(<i>τ</i>) of poly(styrene-<i>b</i>-isoprene-<i>b</i>-styrene) (SIS) two-phase system was divided into five regions based on the variation of <i>H</i>(<i>τ</i>) strength, which corresponded to: (1) glass transition of PI phase, (2) high elastic state of PI phase, (3) glass transition of PS phase, (4) high elastic state of PS phase, and (5) viscous flow state of the entire SIS molecular chain. Five regions only appeared in SIS1105, because the molecular of SIS1105 experienced glass transition of PI block, PS block, and viscous flow of the whole molecular chain. The stress relaxation of SIS was influenced by the S/I ratios, because the PS microdomains ultimately determined the relaxation characteristics. The stress relaxation of SIS system was also closely related to the viscous flow transition temperature (<i>T</i><sub>f</sub>). When the S/I ratio was low (15/85), forced stress relaxation occurred; when the S/I ratio was high (29/71 and 45/55), the SIS system did not show stress relaxation below the <i>T</i><sub>f</sub>. When the temperature was higher than the <i>T</i><sub>f</sub>, the S/I ratio did not affect the stress relaxation. The relaxation information obtained from the Cole–Cole diagram further verified the analysis of the continuous relaxation spectrum<i> H</i>(<i>τ</i>) and stress relaxation.</p><h3>Graphical abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":601,"journal":{"name":"Iranian Polymer Journal","volume":"33 10","pages":"1411 - 1422"},"PeriodicalIF":2.4000,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Iranian Polymer Journal","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s13726-024-01328-3","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
A relatively complete continuous relaxation spectrum H(τ) of poly(styrene-b-isoprene-b-styrene) (SIS) two-phase system was divided into five regions based on the variation of H(τ) strength, which corresponded to: (1) glass transition of PI phase, (2) high elastic state of PI phase, (3) glass transition of PS phase, (4) high elastic state of PS phase, and (5) viscous flow state of the entire SIS molecular chain. Five regions only appeared in SIS1105, because the molecular of SIS1105 experienced glass transition of PI block, PS block, and viscous flow of the whole molecular chain. The stress relaxation of SIS was influenced by the S/I ratios, because the PS microdomains ultimately determined the relaxation characteristics. The stress relaxation of SIS system was also closely related to the viscous flow transition temperature (Tf). When the S/I ratio was low (15/85), forced stress relaxation occurred; when the S/I ratio was high (29/71 and 45/55), the SIS system did not show stress relaxation below the Tf. When the temperature was higher than the Tf, the S/I ratio did not affect the stress relaxation. The relaxation information obtained from the Cole–Cole diagram further verified the analysis of the continuous relaxation spectrum H(τ) and stress relaxation.
期刊介绍:
Iranian Polymer Journal, a monthly peer-reviewed international journal, provides a continuous forum for the dissemination of the original research and latest advances made in science and technology of polymers, covering diverse areas of polymer synthesis, characterization, polymer physics, rubber, plastics and composites, processing and engineering, biopolymers, drug delivery systems and natural polymers to meet specific applications. Also contributions from nano-related fields are regarded especially important for its versatility in modern scientific development.