Effect of chemical structure of backbone in comb-like copolymer dispersants on early properties of concentrated cement suspensions

Title: Effect of chemical structure of backbone in comb-like copolymer dispersants on early properties of concentrated cement suspensions
Author(s): Q.P. Ran, C.W. Miao, J.P. Liu, Y. Shan, J.G.Zhang
Paper category : conference
Book title: International RILEM Conference on Advances in Construction Materials Through Science and Engineering
Editor(s): Christopher Leung and K.T. WAN
ISBN: 978-2-35158-116-2
e-ISBN: 978-2-35158-117-9
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 184 - 190
Total Pages: 7
Nb references: 11
Language: English

Abstract: Comb-like copolymer, consists of backbone with ionizable group and charge neutral poly(ethylene oxide)-based ―teeth‖side chain grafted onto the backbone at frequent intervals, has been widely used as superplasticizer in concrete industry due to its unique properties. It is easy to modify and adapt this molecular structure in order to maximize the targeted properties and also meet specific properties for different applications. However, modification attempts usually focused on side-chain length, charge density, degree of backbone polymerization and composition of functional groups. In fact, the chemical structure in backbone has greatly influence on the early behavior, especially early hydration of cement suspensions. In this study, a serial of comb-like copolymer dispersants with different backbones were produced. The effects of the chemical structure of backbone in comb-like copolymers on the adsorption characteristics and hydration behavior of concentrated cement suspensions, investigated by means of a total organic carbon analyzer(TOC), DSC-TG and calorimetric device and Environmental Scanning Electron Microscope(ESEM). Test results showed that the comb-like copolymer with polyacrylic acid backbone not only accelerate the hydration rate, but also change its crystal shape of hydrated cement. This will help in the understanding of the structure-property relationship of comb-like copolymer and in the designing the molecular structure of new functional superplasticizer.

Online publication: 2011-10-31
Publication type : full_text
Public price (Euros): 0.00