Ester grafting

Observations This group has developed a single-step method for preparing ester-grafted... 

Preparation of 2-aminobenzenesulfonic acid phenyl ester graft copolymer... 

J. Kalbe, H.P. Muller, R. Koch, J. Engelhardt, W. Koch, K. Szablikowski, and G. Weber, Thermoplastic cellulose ether ester graft copolymers and process for their production, US Patent 5 466 794, assigned to Wolff Walsrode Aktiengesellschaft (Walsrode, DE), November 14,1995. 

Polyolefin, 100 parts PO [PE, PP, or EPR], was grafted with 0.01-20 parts of the monomers mixture [consisting of 5-50 mol% of glycidyl (meth) acrylate and 95-50 mol% of acrylamide, vinylpyrrolidone, acrylic acid esters, and/or methacrylic acid esters]. Grafted PO was used as modifier for engineering plastics or as adhesion improver for filled plastics ... 

Coqueret X, El Achari A, Hajaiej A, Lablache-Combier A, Louchenx C, Randrianarisoa L (1991) Some aspects of the reactivity of photo-dimerizable esters grafted onto silicone main chain polymers. Makromol Chem 192(7) 1517 1534... 

Ahn, S., Ahn, S.W., Song, S.C. Thermothickening modification of the poly(ethylene glycol) and amino acid ester grafted polyphosphazenes by monomethyl end-capped poly(ethylene glycol) addition. Colloids Surf. A 333(1-3), 82-90 (2009). doi 10.1016/j.colsurfa.2008.09.045... 

Alkenylsuccinic anhydrides made from several linear alpha olefins are used in paper sizing, detergents, and other uses. Sulfosuccinic acid esters serve as surface active agents. Alkyd resins (qv) are used as surface coatings. Chlorendric anhydride [115-27-5] is used as a flame resistant component (see Flame retardants). Tetrahydrophthalic acid [88-98-2] and hexahydrophthalic anhydride [85-42-7] have specialty resin appHcations. Gas barrier films made by grafting maleic anhydride to polypropylene [25085-53-4] film are used in food packaging (qv). Poly(maleic anhydride) [24937-72-2] is used as a scale preventer and corrosion inhibitor (see Corrosion and corrosion control). Maleic anhydride forms copolymers with ethylene glycol methyl vinyl ethers which are partially esterified for biomedical and pharmaceutical uses (189) (see Pharmaceuticals). 

Another use is of minor proportions of polyfunctional aHyl esters, eg, diaHyl maleate, ttiaHyl cyanurate, and ttiaHyl isocyanurate, for cross-linking or curing preformed vinyl-type polymers such as polyethylene and vinyl chlotide copolymers. These reactions ate examples of graft copolymerization in which specific added peroxides or high energy radiation achieve optimum cross-linking (see Copolymers). 

During mutual graft copolymerization, homopolymerization always occurs. This is one of the most important problems associated with this technique. When this technique is applied to radiation-sensitive monomers such as acrylic acid, methacrylic acid, polyfunctional acrylates, and their esters, homopolymer is formed more rapidly than the graft. With the low-molecular weight acrylate esters, particularly ethyl acrylate, the homopolymer problem is evidenced not so much by high yields as by erratic and irreproducible grafting. 

These thiohydroxamic esters have seen use in grafting of PAN onto PE,iM of PS, PAM and I MPAM onto cellulose127128 and of PS, PMMA, PVP and PAM onto poly(arylene ether sulfone).12 7 The process involves derivitization of a parent carboxy functional polymer to form the thiohydoxamic ester 82 (R=polvmcr) which then behaves as a polymeric transfer agent and/or radical generator. 

Radical induced grafting may be carried out in solution, in the melt phase,292 29 or as a solid state process.296 This section will focus on melt phase grafting to polyolefin substrates but many of the considerations are generic. The direct grafting of monomers onto polymers, in particular polyolefins, in the melt phase by reactive extrusion has been widely studied. Most recently, the subject has been reviewed by Moad1 9 and by Russell.292 More details on reactive extrusion as a technique can be found in volumes edited by Xanthos," A1 Malaika and Baker et a 21 7 The process most often involves combining a frcc-radical initiator (most commonly a peroxide) and a monomer or macromonomer with the polyolefin as they are conveyed through the extruder. Monomers commonly used in this context include MAII (Section 7.6.4.1), maleimidc derivatives and malcate esters (Section 7.6.4.2), (meth)acrylic acid and (meth)acrylate esters (Section 7.6.43), S, AMS and derivatives (Section 7.6.4.4), vinylsilancs (Section 7.6.4.5) and vinyl oxazolines (Section 7.6.4.6). 

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