			Home About us Contact

Grafted Polymer (grafted + polymer)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Functionalization of multiwalled carbon nanotube via surface reversible addition fragmentation chain transfer polymerization and as lubricant additives

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2008
Xiaowei Pei
Abstract Polymer-grafted multiwalled carbon nanotube (MWCNT) hybrid composite which possess a hard backbone of MWCNT and a soft shell of brush-like polystyrene (PSt) were synthesized. The reversible addition fragmentation chain transfer (RAFT) agents were successfully immobilized onto the surface of MWCNT first, and PSt chains were subsequently grafted from sidewall of MWCNT via RAFT polymerization. Chemical structure of resulting product and the quantities of grafted polymer were determined by Fourier transform infrared, thermal gravimetric analysis, nuclear magnetic resonance, and X-ray photoelectron spectra. Transmission electron microscopy and field emission scanning electron microscopy images clearly indicate that the nanotubes were coated with a polymer layer. Furthermore, the functionalized MWCNT as additives was added to base lubricant and the tribological property of resultant MWCNT lubricant was investigated with four-ball machines. The results indicate that the functionalization led to an improvement in the dispersion of MWCNT and as additives it amended the tribological property of base lubricant. The mechanism of the significant improvements on the tribological properties of the functionalized MWCNT as additives was discussed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3014,3023, 2008 [source]

Grafting Efficiency of Hydroxy-Terminated Poly(methyl methacrylate) with Multiwalled Carbon Nanotubes

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 6 2005
Durairaj Baskaran
Abstract Summary: Poly(methyl methacrylate)s (PMMAs) containing a terminal hydroxy group or multiple hydroxy groups as pendants were grafted to multiwalled carbon nanotubes (MWNTs) by esterification in toluene at 100,°C. The recovered polymer with a low level of MWNTs and the PMMA- g -MWNTs with up to 12 wt.-% grafted polymer were characterized using spectroscopic, microscopic, and thermogravimetric analyses. The percentage of polymer present in the PMMA- g -MWNT samples is very low based upon the concentration of the acid groups in the tubes. The grafting of hydroxy-terminated PMMA to MWNTs by esterification. [source]

Grafting of hyperbranched poly(amidoamine) onto carbon black surfaces using dendrimer synthesis methodology

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10 2001
Norio Tsubokawa
Abstract To modify carbon black surface, the surface grafting of hyperbranched poly(amidoamine) onto the surface by using dendrimer synthesis methodology was investigated. Carbon black having amino groups (initiator sites) was prepared by the reduction of surface nitro groups introduced by nitration of aromatic rings. It was found that hyperbranched poly(amidoamine) was propagated from carbon black surface by repeating two processes: (1) Michael addition of methyl acrylate (MA) to surface amino groups and (2) amidation of the resulting esters with ethylenediamine: the percentage of poly(amidoamine) grafting reached to 96.2% after 10th-generation. The grafting of hyperbranched poly(amidoamine) onto polystyrene-bead as a model compound of carbon black was also achieved by the above procedures. However, the theoretical propagation of poly(amidoamine) dendrimer was not achieved, because of steric hindrance of grafted polymer. Hyperbranched poly(amidoamine)-grafted carbon black gave a stable dispersion in a good solvent for poly(amidoamine). Copyright © 2001 John Wiley & Sons, Ltd. [source]

Reactive grafting of glycidyl methacrylate onto polypropylene

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
Emma-Louise Burton
Abstract This work explored the melt-phase grafting of glycidyl methacrylate (GMA) onto polypropylene on a closely intermeshing corotating twin-screw extruder (16-mm screws, 40 : 1 length/diameter ratio). The modification of the base polypropylene to produce GMA-grafted polypropylene was achieved via peroxide-induced hydrogen abstraction from the polypropylene followed by the grafting of the GMA monomer or by the grafting of styrene followed by copolymerization with the GMA. In this study, both the position and order of the reactant addition were investigated as a route to improving graft yields and reducing side reactions (degradation). For the peroxide,GMA system, adding GMA to the melt before the peroxide resulted in significant improvements in the graft levels because of the improved dispersion of GMA in the melt. The addition of a comonomer (styrene) was explored as a second route to improving the graft yield. Although the addition of the comonomer led to a considerable rise in the level of grafted GMA, altering the order of the reactant addition was not found to contribute to an increase in the grafted GMA levels. However, variable levels of grafted styrene were achieved, and this may play an important role in the development of grafted polymers to suit specific needs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Surface covalent encapsulation of multiwalled carbon nanotubes with poly(acryloyl chloride) grafted poly(ethylene glycol)

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2006
Yan-Xin Liu
Abstract Multiwall carbon nanotube (MWNT) was grafted with polyacrylate- g -poly (ethylene glycol) via the following two steps. First, hydroxyl groups on the surface of acid-treated MWNT reacted with linear poly(acryloyl chloride) to generate graft on MWNT; secondly, the remaining acryloyl chloride groups were subjected to esterification with poly(ethylene glycol) leading the grafted chains on the surface of MWNTs. Thus obtained grafted MWNT was characterized using Fourier transform infrared spectrometer, transmission electron microscopy, and X-ray photoelectron spectroscopy. Thermogravimetric analysis showed that the weight fraction of grafted polymers amounted to 80% of the modified MWNT. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6880,6887, 2006 [source]