Cross-conjugated copolymers

A plethora of copolymers have been synthesized using many of the other cross-coupling reactions used in earlier sections [310]. Some of the more prominent structure types are shown above in Scheme 65 [315-320]. The possibilities for new Jt-conjugated copolymers seem endless as a huge combination of monomers can be coupled, being restricted only by polymerization-compatible functional groups. 

The synthesis of alternating jt-conjugated copolymers based on this electrochemical preparation of the above mentioned aryldizinc intermediates was obtained by their subsequent cross-coupling with unsaturated dihalogenated compounds using a palladium catalysis [39] ... 

Then, the use of nickel(II) or cobalt(II) complexes as catalyst associated to the sacrificial anode process allows synthesis of functionalized mono- or diorganozinc species in a simple and efficient manner. Alternating Jt-conjugated copolymers, based on this electrochemical preparation of intermediate aryldizinc species and their subsequent palladium-catalyzed coupling with unsaturated dihalogenated compounds, can be synthesized. Furthermore, aromatic ketones are synthesized efficiently via cobalt-catalyzed cross-coupling reaction between arylzinc bromides and acid chlorides. 

NR, styrene-butadiene mbber (SBR), polybutadiene rubber, nitrile mbber, acrylic copolymer, ethylene-vinyl acetate (EVA) copolymer, and A-B-A type block copolymer with conjugated dienes have been used to prepare pressure-sensitive adhesives by EB radiation [116-126]. It is not necessary to heat up the sample to join the elastomeric joints. This has only been possible due to cross-linking procedure by EB irradiation [127]. Polyfunctional acrylates, tackifier resin, and other additives have also been used to improve adhesive properties. Sasaki et al. [128] have studied the EB radiation-curable pressure-sensitive adhesives from dimer acid-based polyester urethane diacrylate with various methacrylate monomers. Acrylamide has been polymerized in the intercalation space of montmorillonite using an EB. The polymerization condition has been studied using a statistical method. The product shows a good water adsorption and retention capacity [129]. 

Nanogels Cross-linked hydrophilic copolymers, e.g., Pluronic-poly(ethylenimine) (PEI) and polyethylene oxide (PEO)-PEI Covalent conjugation of polymers 20,51,52... 

The presence in polyisobutene chains of conjugated unsaturations highly reactive toward free radicals, as it occurs in tire case of isobutene-triene copolymers, induced us to investigate radical cross-linking of these copolymers. 

---