摘要
The rheological properties of aqueous solutions of poly(methyl vinyl ether-co-maleic anhydride)(PMVE-MA)upon addition of metallic cations at different pH values were investigated.Sol-gel transition and shearthickening phenomena at moderate shear rate were observed upon increasing the amount of metallic cations,especially for cupric cation.At certain molar ratio(fgel)of added cupric cations to carboxyl groups in PMVE-MA,the system became gel-like,and the storage modulus(G′)and loss modulus(G′′)were parallel and exhibited a power-law dependence on the frequency,which is consistent with Winter’s hypothesis of determining the gel point of a crosslinking system.The shear-thickening behavior depends on fgel,pH,metallic valence,and temperature.
基金
The authors gratefully acknowledged the“111”Project(Grant No.B08021)
Shanghai Pujiang Talent Project 08PJ14036 for support of this work.
