Acrylated siloxanes

SMITH ETAL. Styrenic- and Acrylic-Siloxane Copolymers... 

Gombert et al. have reported subwavelength structured antireflective surfaces prepared on glass by embossing a nickel master shim on acrylic siloxane layer with UV irradiation (Gombert et al., 1999). Hemispherical reflectance values of <1% are achieved for nonabsorbing planar sheet. 

The most common synthetic thermosetting matrices used for composites preparation via photochemical crosslinking are epoxy-, epoxy acrylates, siloxanes, vinyl esters. 

Poly(dimethyl siloxanc) with vinyl or hydrosilanc (Si-H) chain ends have been converted to ATRP initiator ends e.g. Scheme 9.62) by hydrosilylalion, Bis-functional dimethyl siloxane polymers prepared in this way were used in polymerizations of S, MA, tsobornyl acrylate and BA to form ABA triblock 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. 

Siloxane containing polyester, poly(alkylene oxide) and polystyrene type copolymers have been used to improve the heat resistance, lubricity and flow properties of epoxy resin powder coatings 43). Thermally stable polyester-polysiloxane segmented copolymers have been shown to improve the flow, antifriction properties and scratch resistance of acrylic based auto repair lacquers 408). Organohydroxy-terminated siloxanes are also effective internal mold release agents in polyurethane reaction injection molding processes 409). 

Seeding technique, procedure 130, 131 Sequential addition of monomers 164, 167 Silicon-carbide fibers 8 Silicon-nitride fibers 8 Silicone rubber, crosslinked 4, 7-9, 31, 67 Siloxane, definition of 5 Siloxane-acrylate copolymers 27, 29, 56, 57, 64, 70, 71, 73, 74... 

Siloxane-acrylate copolymers Siloxane-p-methylstyrene copolymers 29 Siloxane oligomers, see reactive siloxane oligomers... 

A water-soluble copolymer of hydrophilic and hydrophobic monomers, acrylamide-acrylate of silane or siloxane... 

In our own research, the functional termination of the living siloxanolate with a chlorosilane functional methacrylate leading to siloxane macromonomers with number average molecular weights from 1000 to 20,000 g/mole has been emphasized. Methacrylic and styrenic monomers were then copolymerized with these macromonomers to produce graft copolymers where the styrenic or acrylic monomers comprise the backbone, and the siloxane chains are pendant as grafts as depicted in Scheme 1. Copolymers were prepared with siloxane contents from 5 to 50 weight percent. 

In this category, the units giving rise to the liquid-crystalline behavior can be in the backbone (as already discussed), in the side chains, or in both [172], Of considerable interest is the orientation of the mesogenic groups and the chain backbones to which they are attached [173,174], Frequently-studied backbones include siloxanes and acrylates [175,176], but a variety of other structures have also been studied, including amphiphilics [177]. 

The same type of reaction has been used just recently by Sonnek and coworkers [17] to get access to di(meth)acrylate structures added to siloxanes via hydrolytically stable silicon-carbon bond formation. 2-Heptamethyltrisiloxanylbut-2-en-l,4-diylbismethacrylate is accordingly prepared in 90 % yield by hydrosilylation of the bismethacrylate of 2-butyne-l,4-diol. 

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