SciELO - Scientific Electronic Library Online

 
vol.21 número4Kinetics of deoxynivalenol degradation by Aspergillus oryzae and Rhizopus oryzae in submerged fermentationAssessment of extractability of Cu, Cr, Ni, Pb and Zn in some chilean biosolid-amended soils by using BCR sequential extraction procedure índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Journal of the Brazilian Chemical Society

versión impresa ISSN 0103-5053

Resumen

ZHU, Guo-quan; WANG, Fa-gang  y  LIU, Yu-ying. Effects of reaction conditions on the grafting percentage of poly(ethylene glycol)-block-poly(γ-benzyl L-glutamate)-graft-poly(ethylene glycol) copolymer. J. Braz. Chem. Soc. [online]. 2010, vol.21, n.4, pp. 715-720. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532010000400019.

In the present work, poly(ethylene glycol)-block-poly(γ-benzyl L-glutamate)-graft-poly(ethylene glycol) (PEG-b-PBLG-g-PEG) copolymer was synthesized by the ester exchange reaction of PEG-block-PBLG copolymer with PEG chain. Structure and properties of PEG-b-PBLG-g-PEG copolymer were investigated by fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and differential scanning calorimeter (DSC). The effects of reaction temperature, reaction time, and the chain length of PBLG segments on the grafting percentage of PEG-b-PBLG-g-PEG copolymer were studied. Experimental results demonstrated that the grafting percentage of PEG-b-PBLG-g-PEG copolymer increased with the increase of both reaction temperature and reaction time, while the increase of the chain length of PBLG segments in block copolymer decreased the grafting percentage.

Palabras llave : effects; reaction condition; grafting percentage; morphology; poly(ethylene glycol)-block-poly(γ-benzyl L-glutamate)-graft-poly(ethylene glycol).

        · resumen en Portugués     · texto en Inglés     · pdf en Inglés