Hyperbranched polyethylenes

Morgan S, Ye Z, Subramanian R, Zhu S (2010) Higher-molecular-weight hyperbranched polyethylenes containing crosslinkmg structures as lubricant viscosity-index improvers. 

Dong Z, Ye Z (2012) Hyperbranched polyethylenes by chain walking polymerization synthesis, properties, functionalization, and applications. Polym Chem 3 286-301... 

LIU Liu, H., Chen, Y., and Shen, Z., Thermoresponsive hyperbranched polyethylen-imines with isobutyramide functional groups, J. Polym. Sci. Part A Polym. Chem., 45, 1177, 2007. 

Hyperbranched Polyethylenes from Late Metal Catalysts... 

Mohammad Haj-Abed, Engineering of Hyperbranched Polyethylene and its Future Applications, MSc thesis, McMaster University, (2008). 

Scheme 9. (A) Different dendrimers as macromolecular scaffolds for MRI contrast agents ethylenediamine cored polyamido amine, generation 4 (PAMAM G4), top hyperbranched, ethylenediamine cored polyethylene imine (HB-PEI), bottom left hyperbranched, amino functionalized polyglycerol (HB-PG), bottom right. (B) Different moieties attached to the respective dendrimers via amide or thiourea bonds.

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. 

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... 

Fig. 4 Examples (a) PEGylated monolayer (b) Glucose-modified monolayer (c) Surface-attached hyper-branched polyethylene imine and (d) Surface-attached hyperbranched polyglycerols of surface-coatings that resist the nonspecific adsorption of proteins. (Figure reproduced in part with permission from [41])...

Amphiphilic modification of hyperbranched polyglycerol (1) or polyethylene imine) by partial esterification or, respectively, amidation with fatty acids results in macromolecules with a nonpolar shell and a polar core. Metal nanoparticles are stabilized efficiently by these materials, because the polar moieties are responsible for adsorption to the particle surface and the nonpolar region also convey solubility in nonpolar organic solvents [17,94,95]. 

Hong, Y., Coombs, S. J., Cooper-White, J. J., Mackay, M. E., Hawker, C. J., Malmstrom, E., and Rehnberg, N. 2000. Film blowing of linear low density polyethylene blended with a novel hyperbranched polymer processing aid. Polymer, 41, 7705-7713. 

Hyperbranched water-soluble polyesters containing polyethylene glycol and adipic acid were prepared by Stumbe [1] and used as additives in paints. 

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. 

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