首页 | 本学科首页   官方微博 | 高级检索  
     


High‐performance carboxylate superplasticizers for concretes: Interplay between the polymerization temperature and properties
Authors:Alireza Tajbakhshian  Mohammad Reza Saeb  Seyed Hassan Jafari  Farhood Najafi  Hossein Ali Khonakdar  Mohammadreza Ayoubi  Farzaneh Hassanpour Asl
Affiliation:1. School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran;2. Department of Resin and Additives, Institute for Color Science and Technology, Tehran, Iran;3. Leibniz Institute of Polymer Research Dresden, Dresden, Germany;4. Chemistry Department, Sharif University of Technology, Tehran, Iran
Abstract:Polycarboxylate superplasticizers based on acrylic acid (AA) and maleic anhydride (MAn) were synthesized via free‐radical copolymerization with an ethylene glycol monomer and characterized. The copolymerization temperature (ranging from 50 to 90 °C) appeared to be the key operating factor governing the chemical structure of the superplasticizers. The chemical structures of the products were analyzed by gel permeation chromatography, whereas an optimized sample was further analyzed by Fourier transform infrared spectroscopy and 1H‐NMR. Superplasticizers of the AA and MAn classes were then incorporated into concrete, and their performances were measured by slump and slump loss tests, where a large dependency of the microstructure on the synthesis temperature was recognized. The optimum temperatures were found to be 50 and 80 °C for the AA and MAn modifiers, respectively. At their own optimum temperatures, the AA and MAn superplasticizer revealed slump losses from 23 to 4 cm and 15 to 5 cm, respectively, after 45 min. The chemical structures of the plasticizers were patterned illustratively to speculate the performance of each superplasticizer according to changes that took place in the backbone length and side‐chain density. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44908.
Keywords:molecular recognition  plasticizer  radical polymerization
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号