Journal of the Brazilian Chemical Society
Print version ISSN 0103-5053
ZHU, Guo-quan; WANG, Fa-gang and 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.
Keywords : effects; reaction condition; grafting percentage; morphology; poly(ethylene glycol)-block-poly(γ-benzyl L-glutamate)-graft-poly(ethylene glycol).