{"title":"Temperature and pH dual dependent conformational transition of polyacrylic acid modified by dehydroabietic alcohol","authors":"Xiufang Zhu, Weihao Liu, Najla AlMasoud, Taghrid S. Alomar, Jiuxiao Sun, Chao Fu, Juying Zhou","doi":"10.1007/s42114-024-01146-4","DOIUrl":null,"url":null,"abstract":"<div><p>A rosin derivative, dehydroabietic alcohol (DHAA), was synthetized and employed to graft onto polyacrylic acid (PAA) via the Steglich esterification reaction, forming a block copolymer consisting of the acrylic acid units and monomer units containing ester groups. The resulted dehydroabietic alcohol grafted polyacrylic acid (DHAA-graft-PAA) demonstrated enhanced pH and temperature sensitivities. The number ratio of the acrylic acid monomer units reacted with the DHAA and the unreacted acrylic acid monomer units was estimated by the NMR results. The number-average molecular weight of DHAA-graft-PAA was determined to be 9290 by an acid-base titration method. The optimal decomposition temperature of DHAA-graft-PAA measured using a thermogravimetric analyzer was approximately 289 °C. The structural characteristics of the DHAA-graft-PAA were analyzed using Fourier transform infrared spectroscopy, ultraviolet (UV) spectroscopy, and proton nuclear magnetic resonance spectroscopy (<sup>1</sup>HNMR). The conformational transition of the DHAA-graft-PAA under different pH and temperature values was investigated. The scattering intensity experiments showed that 7.96 was a critical pH value and 5 °C was a critical temperature. When the pH value was below 7.96, the degree of carboxyl group ionization in the polymer was decreased, leading to a repulsion between the carboxyl groups in the polymer chains and causing the chain contraction. When the temperature dropped to 5 °C, the conformation transitioned from an extended state to a contracted state. This study demonstrates the intelligent applications for a novel pH and temperature-sensitive polymer.</p></div>","PeriodicalId":7220,"journal":{"name":"Advanced Composites and Hybrid Materials","volume":"8 1","pages":""},"PeriodicalIF":23.2000,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Composites and Hybrid Materials","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s42114-024-01146-4","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, COMPOSITES","Score":null,"Total":0}
引用次数: 0
Abstract
A rosin derivative, dehydroabietic alcohol (DHAA), was synthetized and employed to graft onto polyacrylic acid (PAA) via the Steglich esterification reaction, forming a block copolymer consisting of the acrylic acid units and monomer units containing ester groups. The resulted dehydroabietic alcohol grafted polyacrylic acid (DHAA-graft-PAA) demonstrated enhanced pH and temperature sensitivities. The number ratio of the acrylic acid monomer units reacted with the DHAA and the unreacted acrylic acid monomer units was estimated by the NMR results. The number-average molecular weight of DHAA-graft-PAA was determined to be 9290 by an acid-base titration method. The optimal decomposition temperature of DHAA-graft-PAA measured using a thermogravimetric analyzer was approximately 289 °C. The structural characteristics of the DHAA-graft-PAA were analyzed using Fourier transform infrared spectroscopy, ultraviolet (UV) spectroscopy, and proton nuclear magnetic resonance spectroscopy (1HNMR). The conformational transition of the DHAA-graft-PAA under different pH and temperature values was investigated. The scattering intensity experiments showed that 7.96 was a critical pH value and 5 °C was a critical temperature. When the pH value was below 7.96, the degree of carboxyl group ionization in the polymer was decreased, leading to a repulsion between the carboxyl groups in the polymer chains and causing the chain contraction. When the temperature dropped to 5 °C, the conformation transitioned from an extended state to a contracted state. This study demonstrates the intelligent applications for a novel pH and temperature-sensitive polymer.
期刊介绍:
Advanced Composites and Hybrid Materials is a leading international journal that promotes interdisciplinary collaboration among materials scientists, engineers, chemists, biologists, and physicists working on composites, including nanocomposites. Our aim is to facilitate rapid scientific communication in this field.
The journal publishes high-quality research on various aspects of composite materials, including materials design, surface and interface science/engineering, manufacturing, structure control, property design, device fabrication, and other applications. We also welcome simulation and modeling studies that are relevant to composites. Additionally, papers focusing on the relationship between fillers and the matrix are of particular interest.
Our scope includes polymer, metal, and ceramic matrices, with a special emphasis on reviews and meta-analyses related to materials selection. We cover a wide range of topics, including transport properties, strategies for controlling interfaces and composition distribution, bottom-up assembly of nanocomposites, highly porous and high-density composites, electronic structure design, materials synergisms, and thermoelectric materials.
Advanced Composites and Hybrid Materials follows a rigorous single-blind peer-review process to ensure the quality and integrity of the published work.