Grafting polymer modification

Grafting and modification of polymers have been found to have applications in the biomedical field. For example, poly(etherurethane), which has good elastomeric and often mechanical properties and a relatively high compatibility with blood, has been used in the man-... 

An effective method of NVF chemical modification is graft copolymerization [34,35]. This reaction is initiated by free radicals of the cellulose molecule. The cellulose is treated with an aqueous solution with selected ions and is exposed to a high-energy radiation. Then, the cellulose molecule cracks and radicals are formed. Afterwards, the radical sites of the cellulose are treated with a suitable solution (compatible with the polymer matrix), for example vinyl monomer [35] acrylonitrile [34], methyl methacrylate [47], polystyrene [41]. The resulting copolymer possesses properties characteristic of both fibrous cellulose and grafted polymer. 

Polyepichlorohydrin (PECH) is well known as a reactive elastomer. Displacement at the carbon-chlorine bond of PECH has been accomplished with a wide variety of nucleophilic reagents, for the purposes of polymer modification, grafting and crosslinking (1, 2). On the other hand, the PECH structure (1) is hardly optimal from the point of view of its reactivity as a substrate for nucleophilic... 

An important polymer modification reaction is the grafting to or from a polymer backbone by some chemical method to produce a branched structure Q). The characterization of the products of these reactions is often somewhat less well defined than block copolymers (2) due to the complexity of the mixture of products formed. It is therefore useful to prepare and characterize more well defined branched systems as models for the less well defined copolymers. The macromonomer method (3 ) allows for the preparation of more well defined copolymers than previously available. 

Natural Rubber and Synthetic Polyisoprene Polybutadiene and Its Copolymers Polyisobutylene and Its Copolymers Ethylene-Propylene Copolymers and Terpolymers Polychloroprene Silicone Elastomers Fluorocarbon Elastomers Fluorosilicone Elastomers Electron Beam Processing of Liquid Systems Grafting and Other Polymer Modifications... 

This book contains papers presented at the symposium on Polymer Modification held at the National American Chemical Society Meeting in Orlando, Florida, August, 1996. The chemistry presented is broad ranging, and includes grafting and chemical oxidation reactions, and many other chemical modifications. 

In order to limit extensive side reactions (advanced destruction of the support-polymer, modification of grafting monomers structure) which usually accompany grafting reactions in electrical discharge conditions, we have elaborated the solid-solid grafting procedure in cold plasma. Thus, the rayon fabric was grafted with halogen and phosphorus containing polymers in... 

In many experiments, it appears that such drastic solvent extraction can remove the major part of the synthetic polymer, showing that the grafted polymer presents, in point of fact, a good "adhesive" bondability. However, in the case of surface modification, a heavy grafting is not necessary and the degre of permanence is a function of the insolubility of the homopolymer in the solvents used in the common course of subsequent treatments. So it can be inferred that this notion of grafting may be dependent on the efficiency of the solvent extraction. 

The poly-L-lysine derivatives containing pendant nucleic add bases can be prepared alternatively by using a polymer modification reaction69 (Scheme 19). Carboxyethyl derivatives of the bases were grafted onto poly-L-lysine by using the activated ester method . Poly-L-lysine was allowed to react in this case as trifluoroacetate71. ... 

A method for extracting cadmium, copper, europium, and nickel metal ions from aqueous solution using modified polyethyleneimine is described. The polymer modification consists of grafting an imide, diol, triol, carboxylic acid, or thiocar-boxylic acid function to poly(ethyleneimine), which then forms stable metal complexes that are readily removed from solution. 

Modification of surfaces of foils or filaments with stabilizing moieties represents the main application of irradiation induced grafting. Polymers may be irradiated either in solution, emulsion or in the swollen state in the presence of a functionalized monomer or by an indirect procediure involving irradiation of a polymer in an inert atmosphere and subsequent immersion in a monomer. The second process minimize formation of homopolymers from functionalized monomers. 

---