Polymer grafting functional groups

Grafting from involves a polymer with functional groups that initiate polymerization of... 

Homogeneous ion-exchange membranes can be prepared by polymerization of monomers that contain a moiety that either is or can be made anionic or cationic, or by polymerization of a monomer that contains an anionic or a cationic moiety, or by introduction of anionic or cationic moieties into a polymer dissolved in a solvent by a chemical reaction, or grafting functional groups into a preformed polymer film [10]. 

Bhattacharya M., Jacob J., Vaidya U. Method of grafting functional groups to synthetic polymers for making biodegradable plastics. World patent (US) WO9747670 (1997). 

The third method of preparing a graft copolymer is to combine two polymers with functional groups that can react together. An example is the reaction of oxazoline-substituted polystyrene with polymers containing functional groups such as alcohols, amines, and carboxylic acids. 

Thus, during functionalization of PO blends containing styrene polymers, the grafted functionalized groups concentrate within the aliphatic phase. The course of secondary reactions (cross-linking and degradation) is controlled, such as in the case of grafting to neat PO, by variations in the monomer-to-initiator ratios (3). 

In several of the previous techniques, postmodification of polymers with functional groups or by grafting of polymeric chains with functional groups (polymer functionalization) is necessary. These can be generally carried out by abstraction of hydrogen atoms from the polymeric backbone by chemical methods using processes in bulk [8], solution [9], emulsion [10], or miniemulsion [11], via bo-rane compounds [12] and in supercritical conditions (COj),... 

As mentioned above, controlled degradation of polypropylene was one of the earliest reactive extrusion technologies developed. A fairly substantial literature on the subject has appeared in the past 15 years. The mechanism of free radical attack of the polymer backbone is now thought to be well known (3-6). The following sequence of free radical reactions in the extruder provide a summary of key process steps involved in grafting functional groups onto chains of the polypropylene molecules. 

Functionalized monomers. Sinee GTP is a mueh milder process than anionic polymerization, for example, numerous functionalized monomers can be polymerized. Thus trimethylsilyl and 2-(trimethylsiloxy)ethyl, allyl, 2-(ally-loxy)ethyl, and 4-vinylbenzene MA give polymers with functional groups along the chain, which were used for further modifieations (e.g., for the synthesis of graft copolymers) [232,234,251]. 

Amides (emcamide) can be anchored covalently to the surface of ethylene-co-acrylic acid film, which is grafted with amino acid intermediates. Similarly, polymers with functional groups that interact with amide (or with additive of other chemical composition) may affect retention of additive in polymer and its compatibility. 

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