Hyperbranched polyethylenes by chain walking polymerization: synthesis, properties, functionalization, and applications

Dong, Zhongmin; Ye, Zhibin

doi:10.1039/c1py00368b

Cited by 181 publications

(184 citation statements)

References 107 publications

Supporting

Mentioning

177

Contrasting

Order By: Relevance

“…The relative accuracy of the quantitative EPR measurements was ±30 %. [18,19,20]. Sun and coworkers have shown that 8-arylimino-5,6,7-trihydroquinolinylnickel chlorides (complexes 1a-1h, Fig.…”

Section: +mentioning

confidence: 99%

NMR and EPR trapping of the active species in the ethylene polymerization and trimerization catalyst systems

Semikolenova¹,

Antonov²,

Bryliakov³

et al. 2016

Catalysis for Sustainable Energy

View full text Add to dashboard Cite

show abstract

Section: +mentioning

confidence: 99%

NMR and EPR trapping of the active species in the ethylene polymerization and trimerization catalyst systems

Semikolenova¹,

Antonov²,

Bryliakov³

et al. 2016

Catalysis for Sustainable Energy

View full text Add to dashboard Cite

show abstract

“…45,46 We expected that the resulting modified GNRs would thus inherit the dispersibility in these solvents. 47 Following the polymerization mechanism, 45,46 all the ionomers should be random copolymers with each chain containing multiple quaternary ammonium groups on average. See Tables 1 and S1 in ESI for their synthesis and macromolecular structural details, and Figure S1 in ESI for representative 1 H NMR spectra.…”

Section: Ionomer Design and Synthesis Of Ctab-coated Gnrsmentioning

confidence: 99%

“…Pd-diimine-catalyzed chain walking polymerization is well known for their unique capability in rendering hyperbranched polyethylenes as well as their functionalized analogues by copolymerization of ethylene with acrylate comonomers. 45 The highly compact dendrimer-like hyperbranched polymer skeleton results from the characteristic chain walking mechanism of the Pd-diimine catalysts. 45,46 We have previously synthesized a large class of such polymers 45,46,[48][49][50][51][52][53][54] and have recently demonstrated, in particular, the synthesis of hyperbranched polyethylene ionomers by direct copolymerization of ethylene with acrylate-type quaternary ammonium-containing ionic liquid comonomers.…”

Section: Ionomer Design and Synthesis Of Ctab-coated Gnrsmentioning

confidence: 99%

Efficient, robust surface functionalization and stabilization of gold nanorods with quaternary ammonium-containing ionomers as multidentate macromolecular ligands

et al. 2016

Self Cite

View full text Add to dashboard Cite

Surface functionalization of gold nanorods (GNRs) is critical to their applications in various fields. While there are several existing strategies, we report in this article a new general strategy for the surface functionalization of GNRs with quaternary ammonium-containing ionomers as a novel class of multidentate macromolecular surface ligands. A range of tetralkylammoniumcontaining hyperbranched polyethylene-and linear poly(n-butyl acrylate)-based ionomers has been specifically designed and employed in the strategy. Acting as multidentate macromolecular analogues of cetyltrimethylammonium bromide (CTAB), the ionomers have been demonstrated to bind onto the GNR surface by displacing the surface-bound CTAB species via ligand exchange to render CTAB-free ionomer-modified GNRs. By properly designing the enabling ionomers, we have shown that the modified GNRs can be endowed with some desired properties, such as excellent dispersibility in various organic solvents, robust stability under multiple rounds (up to 12 investigated) of high-speed centrifugation in organic solvents, amphiphilicity with dispersibility in both aqueous and organic media, fluorescence, and capability in carrying hydrophobic guest species. This strategy thus provides potential new ways for the construction of novel multifunctional GNR nanocomposites.3

show abstract

“…As per their low intrinsic viscosity (see Table S1), the polyethylene skeleton of these ionomers features a spherical dendrimer-like, highly compact hyperbranched chain architecture, resulting from the well-known chain walking mechanism of the Pd-diimine catalyst. 50,51 This hyperbranched architecture is beneficial since it completely disrupts the formation of polyethylene crystals and thus renders the ionomers with good dispersibility/solubility in nonpolar/low-polarity solvents (such as THF, toluene, chloroform, etc. ), which facilitates the subsequent surface modification of CNCs through solution mixing.…”

Section: Synthesis Of Hyperbranched Polyethylene Ionomersmentioning

confidence: 99%

Modification of Cellulose Nanocrystals with Quaternary Ammonium-Containing Hyperbranched Polyethylene Ionomers by Ionic Assembly

Huang

Berry

2016

ACS Sustainable Chem. Eng.

Self Cite

View full text Add to dashboard Cite

We demonstrate in this article the first surface modification of cellulose nanocrystals (CNCs) with quaternary ammonium-containing ionomers by ionic binding of their positively charged ammonium ions onto the negatively charged surface of CNCs. A range of hyperbranched polyethylene ionomers (I1-I6) having different ionic content (0.2-2.3 mol%) has been designed and employed for this purpose. The simple dropwise addition and mixing of the aqueous dispersion of CNCs with the ionomer solution in tetrahydrofuran (THF) conveniently renders the ionomer-modified CNCs (mCNC1-mCNC6). The presence of adsorbed ionomers on the modified CNCs is confirmed with spectroscopic and x-ray diffraction evidence, and quantified through thermogravimetric analysis. The effects of the ionomer to CNC feed mass ratio and the ionomers of different ionic content on the modification have been examined. A study on the morphology of the modified CNCs by atomic force microscopy discloses the occurrence of side-to-side and/or end-to-end assembly of the CNC rods due to the "cross-linking" or bridging effects of the multidentate ionomers.Because of the hydrophobic hyperbranched polyethylene segments in the adsorbed ionomers, the modified CNCs can be dispersed in nonpolar or low-polarity organic solvents (such as THF, toluene, and chloroform). In particular, the THF dispersions of modified CNCs prepared with ionomers having ionic content ≥ 0.7 mol% (I3-I6) behave as thixotropic latexes of poly(styrene-co-butyl acrylate), poly(styrene-co-butadiene), and polybutadiene, [26][27][28][29] etc., have been employed as the compatible polymer matrices for the construction of CNC-reinforced polymer nanocomposites by solution mixing. CNCs can be well dispersed in these polar polymer matrices, which maximizes the reinforcement. However, without proper 4 surface modification, the dispersion of CNCs in nonpolar solvents or hydrophobic polymers, such as polyolefins which are produced in the largest volume, are poor. [1][2][3][4][5][9][10][11]30,31 To broaden their application scope, surface modification of CNCs through both covalent and noncovalent approaches has been attempted to modify their surface properties so as to render their dispersibility in organic solvents (particularly, nonpolar and low-polarity solvents) and hydrophobic polymer matrices. [1][2][3][4][5][9][10][11]30,31 In the covalent approaches, desired organic groups are directly attached onto the surface of CNCs through the hydroxyl groups present on their surface. Various polymers have also been covalently grafted onto the surface of CNCs through both graft-from 32-34 and graft-to strategies. Relative to covalent ones, these noncovalent approaches are more convenient and easier to implement. However, the amount of surfactant required to cover CNCs is often high, along with the highly possible desorption of the adsorbed surfactant given the involvement of only weak monodentate noncovalent interactions, which could undermine the properties of the resulting composites. Synthesis of H...

show abstract

Hyperbranched polyethylenes by chain walking polymerization: synthesis, properties, functionalization, and applications

Cited by 181 publications

References 107 publications

NMR and EPR trapping of the active species in the ethylene polymerization and trimerization catalyst systems

NMR and EPR trapping of the active species in the ethylene polymerization and trimerization catalyst systems

Efficient, robust surface functionalization and stabilization of gold nanorods with quaternary ammonium-containing ionomers as multidentate macromolecular ligands

Modification of Cellulose Nanocrystals with Quaternary Ammonium-Containing Hyperbranched Polyethylene Ionomers by Ionic Assembly

Contact Info

Product

Resources

About