Rheological behavior of PMVE-MA aqueous solution with metallic cations

Abstract

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 (f gel ) 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 f gel , pH, metallic valence, and temperature.

Nanoparticles from Gantrez® AN-poly(ethylene glycol) conjugates as carriers for oral delivery of docetaxel

“…The incorporation of calcium enabled us to increase the yield of the preparative process (data not shown). This would be directly related with the presence of ionic interactions between the divalent metal ion (calcium) and two neighbouring carboxylic groups in Gantrez® AN, which induces intrachain associations, promoting the cross-linking of the conjugate (Dong et al, 2011). The obtained poly(anhydride)-PEG2000 conjugate nanoparticles displayed a mean size higher than those in which mPEG2000 was used (around 420 nm vs. 340 nm).…”