Title:
Preparation and Characterization of Star-Shaped Polycarboxylate Superplasticizer
Author(s):
Xiao Liu, Ziming Wang, Jie Zhu, Ming Zhao, Wei Liu, and Dongjie Yin
Publication:
Symposium Paper
Volume:
302
Issue:
Appears on pages(s):
183-198
Keywords:
polycarboxylate superplasticizer; star-shaped; molecular design; adsorption; fluidity
DOI:
10.14359/51688094
Date:
6/1/2015
Abstract:
A polycarboxylate superplasticizer (PCE) with a novel star-shaped structure was prepared through copolymerization of acrylic acid (AA), isobutenyl polyethylene glycol (IPEG), and star-shaped polymerizable active center by an esterification between polyol and AA. In the first esterification step, the esterification rate reached more than 95% with the catalyst/polyol ratio of 0.07:1, inhibitor/AA ratio of 0.04:1 (or 0.011:1), water-carrying agent dosage of 70g and esterification time of 7 hours. In the second polymerization step, the highest fluidity of cement paste was achieved at the initiator/AA/IPEG ratio of 0.28: 3.3: 1. Infrared spectroscopy (IR) and 1H Nuclear magnetic resonance (1H NMR) measurements were used for structural characterization, and the spectral results confirmed the product’s star-shaped structure. Furthermore, this star-shaped PCE exhibited higher energy efficiency than the conventional comb-shaped PCE, indicated by its excellent paste fluidity and adsorption behavior in cement paste.