著者
Johann Plank Bernhard Sachsenhauser
出版者
公益社団法人 日本コンクリート工学会
雑誌
Journal of Advanced Concrete Technology (ISSN:13473913)
巻号頁・発行日
vol.4, no.2, pp.233-239, 2006 (Released:2006-06-30)
参考文献数
15
被引用文献数
32 106

α-Allyl-ω-methoxypolyethylene glycol - maleic anhydride copolymers were synthesized with side chain lengths nEO from 0-130 and characterized by aqueous GPC. A representation of their molecular conformation (e.g. worm-, brush- or star-like polymers) was developed. The amount of polymer adsorbed on cement rapidly decreases with increasing side chain length nEO. Zeta potential measurements using the electroacoustic method in cement paste with w/c = 0.5 indicate that worm-like copolymers with nEO ≤ 7 adsorb flat (“train” type) and form a densely packed, thin polymer film. In this case, the adsorbed amount of copolymer is high. For star polymers with nEO ≥ 34, preferred orientation of the polymer main chain is perpendicular to the cement surface (“tail” type). The result is a thick polymer layer, with a second electrochemical double layer on top. For star polymers, the adsorbed amount is low because of the higher surface occupancy of horizontally layered side groups.