Crosslinked graft copolymer

Figure 5. Formation of crosslinked graft copolymer by using polystyryldicar-boxylate anion.

The crosslinked graft-copolymers were contacted with hydrocarbon solvent (n-heptane, toluene) and in the swollen form they were treated with salts of nickel (nickel chloride, nickel acetylacetonate), titanium (dibutoxytitanium dichloride) or zirconium (dibutoxyzirconium dichloride). 

Determination of the Components Modified Rubber + Free Rubber. The dry product (10 g) was placed in a pear-shaped vessel with cyclohexanone in high excess. Stirring continued for 18 hrs at room temperature then the material was filtered on Gooch. The residue was washed with acetone and dried to constant weight. Under these conditions, cyclohexanone dissolved all the PVC homopolymer, and it could dissolve small, insignificant amounts of non-crosslinked grafted copolymer with very high PVC content. 

Certain crosslinked graft copolymers of polysaccharides are found to exhibit salt resistant swelling in different concentrations of salts. Swelling decreases with increase in salt concentration and is found to be cationic charge dependent. Depending upon the cations, swelling is found to follow the order Na > NH/> Mg"2> Ca" > Ba"2>Fe"3... 

Figure 2.10 Electrical stimulus studies (a) under DC voltage (b) under AC voltae ghatti crosslinked graft copolymer [81-83]. Gum...

Meister, J.J. (1991) Soluble or Crosslinked Graft Copolymers of Lignin, Acrylamide and Hydroxymethacrylate, U.S. Patent 5,037,931... 

Sadeghl M, Heidari B (2011). Crosslinked graft copolymer of methacrylic acid and gelatin as a novel hydrogel with pH-responsiveness properties. Materials, 4,543-552. 

If (P ) is terminated by a chain transfer to a solvent or a monomer, a graft copolymer is formed, or, if the termination is from a combination, a crosslinked network polymer is formed. If the pre-existing polymer (B) contains an end group that itself is photosensitive (or can produce a radical by interacting with photoinitiator) and in the presence of a vinyl monomer (A), block copolymer of type AB can be produced if the photosensitive group is on one end of the polymeric chain. Type ABA block copolymer can be produced if the polymer chain (B) contains a photosensitive group on both ends. 

The low quantum yield of the photografting process (0 = 2 X 10 ) provides a good opportunity to control the network formation (curing time control), and accordingly, the desirable properties of the crosslinked or grafted copolymer might be obtained. 

It is well known that block copolymers and graft copolymers composed of incompatible sequences form the self-assemblies (the microphase separations). These morphologies of the microphase separation are governed by Molau s law [1] in the solid state. Nowadays, not only the three basic morphologies but also novel morphologies, such as ordered bicontinuous double diamond structure, are reported [2-6]. The applications of the microphase separation are also investigated [7-12]. As one of the applications of the microphase separation of AB diblock copolymers, it is possible to synthesize coreshell type polymer microspheres upon crosslinking the spherical microdomains [13-16]. 

The epoxy-acrylic resin referred to above is a graft copolymer prepared by the polymerisation of acrylic monomers in the presence of the epoxy resin in such a way that grafting of the acrylic onto the epoxy takes place. Water dispersibility is achieved by neutralising carboxyl groups in the acrylic polymer chain with ammonia or amine. Amino or phenolic resins are used as crosslinkers. Alternatively, solvent-borne epoxy-amino or epoxy-phenolic lacquers can be used. 

Synthesis of comb (regular graft) copolymers having a PDMS backbone and polyethylene oxide) teeth was reported 344). These copolymers were obtained by the reaction of poly(hydrogen,methyl)siloxane and monohydroxy-terminated polyethylene oxide) in benzene or toluene solution using triethylamine as catalyst. All the polymers obtained were reported to be liquids at room temperature. The copolymers were then thermally crosslinked at 150 °C. Conductivities of the lithium salts of the copolymers and the networks were determined. 

Fig. 9. The effect of interpolymer complexation on the correlation length, , and the effective molecular weight between crosslinks, Mc, in P(MAA-g-EG) graft copolymer networks with permanent, chemical crosslinks ( ).

Amphiphilic resin supported ruthenium(II) complexes similar to those displayed in structure 1 were employed as recyclable catalysts for dimethylformamide production from supercritical C02 itself [96]. Tertiary phosphines were attached to crosslinked polystyrene-poly(ethyleneglycol) graft copolymers (PS-PEG resin) with amino groups to form an immobilized chelating phosphine. In this case recycling was not particularly effective as catalytic activity declined with each subsequent cycle, probably due to oxidation of the phosphines and metal leaching. 

Styrene as matrix and polybutadiene as dispersed phase. During this phase inversion the above-mentioned graft copolymers act as polymeric emulsifiers and determine, inter alia, the particle size and particle size distribution of the dispersed polybutadiene phase. This morphology is fixed through another chemical reaction, that is the crosslinking of the polybutadiene phase. Therefore, the reaction mixture at the end of the prepolymerization period (at 30% conversion) does scarcely alter its morphology when it is polymerized to complete conversion, which is done without stirring mostly in bulk in a separate vessel. 

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