Multigraft copolymers having various structures, e.g., comb and centipede structures, can be prepared from emulsion copolymerization of monomers and macromonomers. The emulsion copolymerization can be initiated by a thermally activated radical initiator or a redox initiation system. The multigraft copolymers can have high molecular weight and/or a large number of branch points. Elastomer or adhesive compositions of the copolymers can be prepared. Also described are poly(n-alkyl acrylate-graft-styrene) multigraft copolymers.

To obtain a hydrophilic macromonomer mixture which is a highly polymerized hydrophilic macromonomer, has few components not bonded to the polymer chain after polymerization, and is less likely to leaching. Provided is a macromonomer mixture containing macromonomer A being a macromonomer having a group obtained by further introducing a polymerizable group into a reactive group derived from a polymerization initiator at an end thereof; and macromonomer B being a macromonomer having a group obtained by further introducing a polymerizable group into a reactive group derived from a chain transfer agent at an end thereof.

A pigment dispersant includes: a polymer having a structural unit represented by General Formula (1); and a structural unit derived from a polystyrene macromonomer.

##STR00001##

In General Formula (1), n represents a positive integer, R.sub.1 represents a hydrogen atom or a methyl group, and X.sub.1 represents a divalent linking group except a single bond.

In an aspect, a method of synthesizing a graft copolymer comprises the steps of: copolymerizing a first macromonomer and a first reactive diluent; wherein said first macromonomer comprises a first backbone precursor directly or indirectly covalently linked to a first polymer side chain group; wherein said reactive diluent is provided in the presence of the first macromonomer at an amount selected so as to result in formation said graft copolymer having a first backbone incorporating said diluent and said first macromonomer in a first polymer block characterized by a preselected first graft density or a preselected first graft distribution of said first macromonomer. In some embodiments of this aspect, said preselected first graft density is any value selected from the range of 0.05 to 0.75. In some methods, the composition and amount of said diluent is selected to provide both a first preselected first graft density and a first preselected first graft distribution.

Metallated aminosilane compounds for use as functional initiators in anionic polymerizations and processes for producing an aminosilane-functionalized polymer using the metallated aminosilane compounds to initiate anionic polymerization of at least one type of anionically polymerizable monomer. Preferred use of the metallated aminosilane compounds results in rubber compositions for use in tires comprising an aminosilane functionalized polymer.

Metallated aminosilane compounds for use as functional initiators in anionic polymerizations and processes for producing an aminosilane-functionalized polymer using the metallated aminosilane compounds to initiate anionic polymerization of at least one type of anionically polymerizable monomer. Preferred use of the metallated aminosilane compounds results in rubber compositions for use in tires comprising an aminosilane functionalized polymer.

Multigraft copolymers having various structures, e.g., comb and centipede structures, can be prepared from emulsion copolymerization of monomers and macromonomers. The emulsion copolymerization can be initiated by a thermally activated radical initiator or a redox initiation system. The multigraft copolymers can have high molecular weight and/or a large number of branch points. Elastomer or adhesive compositions of the copolymers can be prepared. Also described are poly(n-alkyl acrylate-graft-styrene) multigraft copolymers.

Multigraft copolymers having various structures, e.g., comb and centipede structures, can be prepared from emulsion copolymerization of monomers and macromonomers. The emulsion copolymerization can be initiated by a thermally activated radical initiator or a redox initiation system. The multigraft copolymers can have high molecular weight and/or a large number of branch points. Elastomer or adhesive compositions of the copolymers can be prepared. Also described are poly(n-alkyl acrylate-graft-styrene) multigraft copolymers.

Rubber compounds comprising a conjugated diene polymer and a silica filler, wherein the silica filler has a content of SiO.sub.2 of at least 80% by weight based on the weight of the filler and is obtained from a biomass ash comprising rice husk ash and wherein the conjugated diene polymer is a homopolymer of a conjugated diene or a copolymer of at least one conjugated diene selected from the group consisting of butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-butadiene, 1-phenyl-1,3-butadiene, 1,3-hexadiene, and wherein the polymer is functionalized and comprises at least one functional group. Also provided are methods making a vulcanizable rubber compound comprising combining the conjugated diene polymer with the silica, and methods making an article comprising subjecting a curable composition comprising the compound and a curing agent capable of curing the conjugated diene polymer to at least one curing reaction.

The subject matter described herein is directed to molecularly engineered brush-like graft copolymer elastomers and applications thereof. The developed formulation platform is based on the synthesis of brush-like graft copolymer networks with engineered macromolecular architecture composed of brush-like polymers, such as combs and bottlebrush polymers, and block copolymers composed of combinations of brush and linear blocks, with capability of bearing desired chemical functionalities, for example, brush side-chains, chain-ends, and/or brush backbone.