Grafting technique

EG = Capping reagent-derived end group EG2 = Initiator-derived end-group 

Loading with Cu(I) afforded the desired ATRP support [15, 46-48]. Typical metal loadings were about 15 mmol g . Polystyrene (PS) prepared under ATRP conditions with these supports showed comparatively low polydispersity (PDI = 1.55-1.77). The ATRP system consisted of a metal center with one terpyridyl and presumably three acetonitrile ligands, which were at least in part substituted by the monomer. Consequently, in contrast to standard systems [49], the equilibrium M in this type of reaction did not require conformational changes or dissociation of a terpyridyl ligand. Therefore, polymerization proceeded comparatively fast, within 2 h. Unfortunately, presumably due to unfavorable equilibria involving the dormant species, polymer yields were low ( 35%). 

The capability of ROMP for polymerizing even complex functional monomers was demonstrated by the fact that the cationic NHC precursor l,3-di(l-mesityl)-4- [(bicyclo[2.2.1]hept-2-ene-5-ylcarbonyl)oxy]methyl -4,5-dihydro-l//-imidazol-3-ium tetrafluoroborate was polymerized using both ruthenium- and molybdenum-based initiators. Thus, reaction of this monomer with RuCl2(PCy3)2(CHPh) in CH2CI2 at 45 °C resulted in complete consumption of the initiator and formation of an oligomer with a DP of 7. 

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The blending of PPO and polyamides requires special grafting techniques to give a good bond between the two polymers, as otherwise the two polymers are incompatible. Whilst these polymers show the good dimensional stability and toughness of styrenic PPOs, they also have... 

Based on the results of the hydrophobization of po-ly(MA-DP), we applied the hydrophobically grafting technique to poly(maleic acid-fl//-7,l2-dioxaspiro-[5,6]-... 

This grafting technique proved to possess several advantages (1) the initiating macroradicals [shown in... 

Chitosan is the main structural component of crab and shrimp shells. Chitosan contains both reactive amino and hydroxyl groups, which can be used to chemically alter its properties under mild reaction conditions. Al-acyl chitosans were already reported as blood-compatible materials. UV irradiation grafting technique was utilized to introduce obutyrylchitosan (OBCS) onto the grafted SR film in the presence of the photosensitive heterobifunctional cross-linking agent. The platelet adhesion test revealed that films grafted on OBCS show excellent antiplatelet adhesion. 

Trapped radicals on samples with different storage conditions and reaction conditions are usually determined by ESR. Modification of PVC by radiation-grafting technique is an attractive method to improve the mechanical strength, printing ink adhesion, and adhesive receptance. Wang... 

Abstract A review of the thermolytic molecular precursor (TMP) method for the generation of multi-component oxide materials is presented. Various adaptations of the TMP method that allow for the preparation of a wide range of materials are described. Further, the generation of isolated catalytic centers (via grafting techniques) and mesoporous materials (via use of organic templates) is simimarized. The implications for syntheses of new catalysts, catalyst supports, nanoparticles, mesoporous oxides, and other novel materials are discussed. 

Ti-MCM-48 (surface area = 1000-1450 m2/g, pore volume = 0.8-1.1 cm3/g, pore diameter = 2.4-2.7 nm) was synthesized by hydrothermal and postsynthetic grafting techniques from cationic alkylammonium surfactants (22,25,323). 

Gauthier and M oiler [4] described in 1991 the use of anionic polymerization and grafting techniques to prepare poly(styrenes) with a dendritic structure. Styrene is well suited to be incorporated into a synthetic scheme aimed at producing... 

Fig. 13 Hyperbranced graft architecture based on graft-on-graft technique, a Growing tree model (both stem and branch) b Growing hyperbranching model (controlled chain length) c Growing hyperbranching at stem end...

In general, in the field of materials or condensed matter, the preparation of polymer brushes on solid surfaces is of great interest for surface modification and composite material preparation [4-6]. A number of model surface grafting techniques have been used on planar surfaces and particles and have been the subject of previous reviews. While a munber of polymer brush preparation methods have been reported using physisorption or chemisorption or so-called grafting onto methods, the emphasis of this review is on surface-initiated polymerization (SIP) methods or grafting from methods. 

Radiation-induced grafting in its simplest form involves heferogeneous sysfems, with the substrate being film, fiber, or even powder and fhe monomer fo be graffed onto fhe subsfrafe a neaf liquid, vapor, or solufion. 4i Currently, three main radiation grafting techniques are known ... 

Details of the wool used and the grafting techniques have been described (9). The irradiations were carried out in a 1500-curie cobalt-60 room type source. The dose rate could be varied continuously by changing the distance from the source. 

With a polyethylene backbone, this grafting technique will not yield pure poly (ethylene-g-vinyl chloride)—"pure graft copolymer —but a mixture of this compound with PVC homopolymer and unmodified polyethylene. We call this raw graft polymerization product "VC/PE graft copolymer. Sometimes, we add its gross composition between parentheses—for example, VC/PE (50-50) graft copolymer. The same statement applies to the other backbone polymers. 

In this section, we will highlight the use of the grafting technique for designing polymeric biomaterial surfaces that exhibit non-fouling property, selective protein adsorption, enhanced tissue adhesion, and minimum frictional damage to mucosa membranes. 

The energy associated with UV light is in competence with the chemical bond energies associated with any two atoms [104]. Hence, UV radiation often has the potential for retention of the properties of monomers and polymers while the other surface grafting techniques, which use ionisation radiation, cause damage to the substrate polymer due to excessive degradation. 

Self-assembly and grafting techniques have been used to attach both polymeric and monomeric materials to surfaces. The result of this approach is well-ordered monolayers in the case of monomeric precursors (See Section 4.3 above). Polymers... 

Acid Effects in UV Grafting of Styrene. Since styrene is the basic monomer used in the comonomer grafting techniques to be discussed, the UV copolymerization properties of this monomer, particularly in the... 

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