Polyethylene hyperbranched grafts

Fig. 7 Fluorescence spectra of a 5-PAA/PE graft (a) after treatment with 10 (filled squares), (b) after washing with THF in a Soxhlet apparatus for 24 h (open squares)-, (c) after treatment with NaOH (open circles). For comparison purposes, a fluorescence spectrum for an oxidized polyethylene Aim without any hyperbranched graft (but with - CO2H groups) that was also treated with 10 is also shown (filled circles)...

The hyperbranched grafting chemistry used with polyolefin films and wafers was also extended to modification of 200 p.m diameter high density PE powder substrates [19]. However, because of the relatively high surface area of the 200 pm-diameter polyethylene powder (the measured BET surface area was... 

Bannerjee, P., Weissleder, R., Bogdanov, A., Jr. Linear polyethylene-imine grafted to a hyperbranched polyfethylene glycol)-like core a copolymer for gene delivery. Bioconjug. Chem. 2006, 77(1), 125-131. 

Fig. 2 Progress of hyperbranched poly(acrylic acid) graft formation on smooth gold films as measured by ellipsometry ( ) or on polyethylene powders as measured by titration ( ) of the supported - CO2H groups...

Synthesis of Hyperbranched Poly(acrylic Acid) Grafts on Polyethylene Films... 

Scheme 4 Chemistry used to prepare hyperbranched polyfacrylic acid) grafts on polyethylene film, polyethylene powder or polypropylene wafers...

The hyperbranched poly( acrylic acid) graft films -C02H-rich interface on polyethylene can be modified by noncovalent methods just like CO2H-rich interfaces of PAA/Au grafts. This was shown by treating deprotonated 3-PAA/PE films with cationic polyelectrolytes like poly-D-lysine, and amine terminated PAMAM dendrimers at pH 7 [31]. Equation 10 illustrates the entrapment of PAMAM dendrimers in a 3-poly(sodium acrylate)/PE film. In these cases, polyvalent entrapment of the cationic electrolyte was evidenced in the ATR-IR spectriun by the appearance of amide C = O and N - H peaks of the guest dendrimer that were not present in the host 3-poly(sodium acrylate)/PE film. 

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