Graft copolymers derivatives

Self-stabilizing polymer emulsions containing a bimodal polymethacrylate solution as a continuous phase and a block or graft copolymer derived from ethylene-polypropylene copolymer and hydroxyethyl methacrylate, Cis i8 alkyl methacrylate, and isodecyl methacrylate were prepared by Rohm GmbH [17] and the emulsions were found to be useful for improving the VI of lubricants. 

Material Protection. The graft copolymers of ethylene sulfide on polyethyleneimine can be used as an antifouHng anticorrosion substrate for iron (439). PEIs or their derivatives are also used in electrolysis baths as brighteners in the electrochemical deposition of metals (440,441). 

Etherification and esterification of hydroxyl groups produce derivatives, some of which are produced commercially. Derivatives may also be obtained by graft polymerization wherein free radicals, initiated on the starch backbone by ceric ion or irradiation, react with monomers such as vinyl or acrylyl derivatives. A number of such copolymers have been prepared and evaluated in extmsion processing (49). A starch—acrylonitrile graft copolymer has been patented (50) which rapidly absorbs many hundred times its weight in water and has potential appHcations in disposable diapers and medical suppHes. 

It was found that the sulfate radical anion S04 produced photochemically in Scheme (46) is responsible for generating the cellulose derivative macroradicals by hydrogen abstraction, which added the vinyl monomer to produce the grafted copolymer. The main disadvantage of this method is the production of large quantities of undesirable homopolymers in addition to the grafted copolymers. 

Interestingly, the first example of a macromonomer, long before the names Macro-mer or macromonomer have been coined 94), is a styrene terminated polydimethyl-siloxane synthesized by the reaction of a Grignard derivative of p-ch loro styrene and an co-chlorodimethylsiloxane oligomer 90) as shown in Reaction Scheme IX. Later, these macromonomers have been reacted with different vinyl monomers such as styrene and acrylates, and relatively well defined graft copolymers have been synthesized. 

Poly(starch-g-(l-amidoethylene)) copolymer is not a polyelectrolyte and will be a smaller molecule in water than an equal molecular weight, partially hydrolyzed poly(l-amidoethylene). Polyelectrolyte effect should, however, cause the graft copolymer to expand in solution in the same way it causes poly(l -amidoethylene) to expand, so a series of hydrolyzed graft copolymers were prepared from poly(starch-g-(l-amidoethylene))(41-43) and these derivatives were tested to determine the effect of hydrolysis on copolymer properties in solution. 

A strain of yeast and a strain of bacterium were co-immobilized to fabricate a biochemical oxygen demand (BOD) sensor based on sol-gel derived composite materials97. This novel type of biosensor was developed for water monitoring and was used to determine the BOD values of OECD synthetic wastewater, domestic wastewater, and lake waters. The microorganisms Trichosporon cutaneum and Bacillus subtilis were coimmobilized in the sol-gel composite material, which was composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)). 

The formation of stable nanoparticles has been studied using various derivatives of thermosensitive PNIPAM, including diblock and graft copolymers, PNIPAM-b-PEO and PNIPAM-g-PEO [165-172], In these copolymers, the role of the PEO chains is to solubilise/stabilise collapsed PNIPAM at temperatures above its cloud point. Both the graft and the block copolymers, PNIPAM-g-PEO and PNIPAM-fr-PEO, form spherical core-shell structures in... 

Ce Ion Initiation. Initiation of grafting with Ce ions was introduced by Mino et al. 7. The process has been widely studied and even applied to industrial production of cellulose and starch graft copolymers. A mechanism is derived from model experiments with low molecular weight vicinal diols in acid aqueous solution. The first step (22) is OH OH... 

Note In the constituent macromolecules of a graft copolymer, adjacent blocks in the main chain or side-chains, or both, are constitutionally different, i.e., adjacent blocks comprise constitutional units derived from different species of monomer or from the same species of monomer but with a different composition or sequence distribution of constitutional units. 

A graft polymer is a polymer comprising molecules with one or more species of block connected to the main chain as side chains, these side chains having constitutional or configurational features that differ from those in the main chain [4]. In a graft copolymer the distinguishing feature of the side chains is constitutional, i.e. the side chains comprise units derived from at least one species of monomer different from those which supply the units of the main chain. 

For a graft copolymer with a backbone derived from monomer A and the graft B what often occurs when B is long ... 

A graft copolymer is a branched polymer containing a polymer chain derived from one monomer to which are attached one or more polymer side chains of another monomer. ATRP produces a graft copolymer when the initiator is a polymer with one or more halogen-containing side groups ... 

New polymeric solid supports have been devised, which include macroporous styrene-divinylbenzene containing large fixed pores, porous glass beads, insoluble carbohydrate polymers, poly(ethylene oxide), cross-linked derivatives of polyacrylamide resins, and graft copolymers of polystyrene and poly(ethylene oxide). The last two have been the most effective and widely used and have competed well with the original copoly(styrene-divi-nylbenzene) beads. 

Figure 5.76 Effect of temperature on shear modulus for random, block, and graft copolymers. Bottom curves are the derivative of the log G curves. Reprinted, by permission, from N. G. McCrum, C. P. Buckley, and C. B. Bucknall, Principles of Polymer Engineering, 2nd ed., p. 173. Copyright 1997 by Oxford University Press.

---