Novel hydrophobic ligand-containing hydrogel membrane matrix: Preparation and application to ?-globulins adsorption

In this study, phenylalanine as a hydrophobic ligand was covalently attached to the co-monomer methacrylochloride. Then, poly(2-hydroxyethylmethacrylate-co-methacrylamidophenyalanine) [poly(HEMA-MAPA)] membranes were prepared by UV-initiated photopolymerization of HEMA and methacrylamidophenyalanine. The ?-globulins adsorption onto these affinity membranes from aqueous solutions containing different amounts of ?-globulins at different pH was investigated in a batch system. The ?-globulins adsorption capacity of the membranes was increased as the ligand density on the membrane surface increase. The non-specific adsorption of the ?-globulins on the pHEMA membranes was negligible. The adsorption phenomena appeared to follow a typical Langmuir isotherm. The maximum adsorption capacity (qm) of the poly(HEMA-MAPA4) membrane for ?-globulins was 2.37 mg g-1dry membrane. The equilibrium constant (kd) value was found to be 1.61×10-1mg ml-1. More than 87% (up to 100%) of the adsorbed ?-globulins were desorbed in 120 min in the desorption medium containing 50% ethylene glycol in 1.0 M NaCl. Copyright © 2001 Elsevier Science B.V

Thermal properties and flame retardance of Al(OH)3/polypropylene composites modified by polypropylene grafting with acrylic acid

The effect of polypropylene grafting with acrylic acid, PP-g-AA (FPP), on crystallization and melting behavior, thermal degradation, and limiting oxygen index of Al(OH)3/PP composites were investigated. The results indicated that crystallization temperature of PP shifted to high temperature with increasing content of Al(OH)3 because of the interfacial heterogeneous nucleation of Al(OH)3 and further increased by the addition of FPP and with increasing FPP content because of the improvement of the dispersion of Al(OH)3 in PP matrix and the increase in the nucleating sites of Al(OH)3. With adding Al(OH)3 and increasing the content of Al(OH)3, limiting oxygen index values of composites increased and further improved by adding FPP. This is attributed to the presence of an interfacial interaction between FPP and Al(OH)3. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci

Functionalization of low molecular weight atactic polypropylene: Part I. Spectroscopic studies

Low molecular weight atactic polypropylene (APP) was functionalized with 4-allyl-2-methoxyphenol (eugenol), 4-allyl-1,2-dimethoxybenzene (DMAB), 4-propenylanisole(trans-anethole), cis-2,4,5-trimethoxypropenylbenzene (?-asarone) and 4-allyl-2,6-dimethoxyphenol (ADMP) in the presence of dicumyl peroxide (DCP) at 170°C. Amount of grafted eugenol, DMAB and anethole on APP and characterization of the products were carried by UV-VIS and FTIR spectroscopies respectively. The effects of the reaction time, concentrations of the functional compounds and DCP on the extent of grafting were examined. © Springer-Verlag 1999