Successive grafting

Various (meth)acrylic monomers have been successfully grafted onto polyolefins. Most studies deal with functional monomers. Grafting yields obtained with PP are usually low (<20%) and are dependent on the particular monomer. Liu et al.jM carried out a comparative study on the grafting of various functional methacrylates onto PP. The experiments were performed in a batch mixer at 180 °C with 7 wt% monomer and 0.05 wt% 22 as an initiator. Grafting levels (wt%) obtained under these conditions were as follows HPMA (I), TBAEMA (1), GMA (0.8), IIEMA (0.4), DMAEMA (0.3), 32 (0.2). Grafting yields to PE appear generally higher. 

A A, and less often MAA or itaconic acid33 5 have been successfully grafted onto polyolefins. In the case of AA, grafting is often accompanied by homopolymerization.333... 

In order to increase the complexity of the peripheral epitopes resulting from the self-assembly process, glycodendrons have been successfully grafted onto various ligands, allowing the formation of dense glycocomplexes. Indeed, in most of the examples, branching of the dendrimers produces a microenvironment that... 

In this paper we describe methods in which polystyrene (PS) and polydimethylsiloxane (PDMS) have been successfully grafted to silica particles, avoiding the dry stage. 

Malto-oligosaccharide aldonolactones react with ethylenediamine to give Ar-(2-aminoethyl)aldonamides (113-115), which have been successfully grafted onto carriers via amide linkages. The malto-oligosaccharides were produced by degradation of amylose with alpha amylase. After purification of the oligosaccharides, they were converted into the lactones by hypoiodite or electrolytic oxidation. 

Tapping-mode atomic force microscopy studies showed that as these hyperbranched PAA films became somewhat less smooth as they increased in thickness through successive grafting stages [24]. For example, a very smooth initial single-crystal Au(lll) surface with a root mean square (RMS) roughness of 0.2 nm (over a 2 xm x 2 im area) had its roughness increased to... 

A series of cyclopentadienyhnolybdenum complexes containing a siloxane functional group, either directly attached to the metal center or to the cy-clopentadienyl moiety, have recently been described and tested imder homogeneous conditions [41], These complexes have been successfully grafted onto MCM-41 and MCM-48 [19,42] (Scheme 5). 

Graft polymers can be obtained by reactive extrusion (47). Likewise, the grafting can be performed in solution. In the solvothermal method, the polymer is dissolved in a solvent and the solution is in a vessel. The material can be heated even above the critical point of the solvent (42). In the past, this method was mostly used in inorganic chemistry, however using this method MA could be successfully grafted onto ABS. 

Several ester monomers have also been studied. In methanol solution, methyl acrylate (16,21), ethyl acrylate (21,54), 2-ethyl hexyl acrylate (55), allyl acrylate (44), glycidyl acrylate (56,57) usually in methanol solution, have been extensively studied. Methyl methacrylate (19, 21, 28, 30, 36, 39, 58) in diversified media composition, has been successfully grafted on polyamides. Vinyl acetate is reported also for grafting on polyamide backbone (19, 28, 35, 58), as well as n-butyl maleate in methanol solution (55). Diallyl maleate as cross-linking agent for polyamide chains is reported (44). Other less usual ester monomers have been mentioned in the literature to form grafts (41,59,60). 

Other monomers have been successfully grafted on polyamide under UV light sources. Hence, organic acids as acrylic (72,73), methacrylic (74), ftimaric (73), itaconic (73), and styrene sulfonic in 25% aqueous solution (73). Methyl acrylate and acrylamide in the presence of photosensitizers (74,75) and acrylonitrile (76) are reported as well. Heterocyclic derivatives as vinyl pyridine and vinyl pyrrolidone under UV light using photosensitizers as benzophenone were grafted on Nylon 66 cloth (77). 

Polymer-linked MWCNT nanocomposites were prepared by reversible addition fragmentation chain transfer (RAFT). The RAFT reagent was successfully grafted on to the surface of MWCNTs and PS chains were grafted from MWCNTs via RAFT polymerization [192], By covalently linking acyl chloride functions of functionalized MWCNTs with living polystyryllithium, Huang et al. succeeded in the preparation of polystyrene-functionalized MWCNTs (Scheme 1.32) [193],... 

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