The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I

##STR00001##

wherein R.sup.1 is C1 to C4 linear alkyl, or C1 to C4 branched alkanediyl; X.sup.1, X.sup.2, X.sup.3 are independently O, S, or a group of formula (II) or (III)

##STR00002##

where R.sup.2 is C1 to C18 linear or branched alkyl; and Z is R.sup.3CHCHR.sup.4, where R.sup.3 is a covalent bond or C1 to C18 linear or branched alkanediyl, and R.sup.4 is a hydrogen or C1 to C18 linear or branched alkyl.

A method of preparing a branched polymer comprises the free radical polymerisation of a multivinyl monomer in the presence of a chain transfer agent, using a source of radicals, wherein the extent of propagation is controlled relative to the extent of chain transfer to prevent gelation of the polymer. The average length of each vinyl polymer chain within the product is short.

A method of preparing a polymer comprises the use of free radical vinyl polymerisation to form carbon-carbon backbone segments of the polymer, wherein the longest chains in the polymer comprise vinyl polymer chains interspersed with other chemical groups and/or chains. The product has the characteristics of a step-growth polymer comprising a mixture of polyfunctional step-growth monomer residues formed by vinyl polymerization.

The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I

##STR00001##

where X is Cl, Br, or I;

m is an integer from 0 to 2, n is an integer from 1 to 3, with the proviso that n+m=3;

R.sup.1, R.sup.2 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R.sup.1, R.sup.2 are independently SiR.sub.3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R.sup.1 and R.sup.2 taken together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom to form a five to eight membered ring;

R.sup.3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R.sup.3 is SiR.sub.3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R.sup.3 is R.sup.6R.sup.7, where R.sup.6 is C1 to C3 alkanediyl and R.sup.7 is selected from the following structures

SZ, N(R.sup.8)(R.sup.9), O(Y), or Si(OR.sup.10).sub.3, where R.sup.8 and R.sup.9 are independently C1 to C18 alkyl, aryl, or a combination thereof,

Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyl dimethyl silyl, tert-butyl diphenyl silyl, and isopropyldimethylsilyl, and

R.sup.10 are independently C1 to C4 alkyl;

or when m=1, the polymerization terminator may have the formula II

##STR00002##

where R.sup.4, R.sup.5 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R.sup.4, R.sup.5 are independently SiR.sub.3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, X and R.sup.3 are as defined previously, and k is an integer from 0 to 10.

The present invention is directed to a functionalized elastomer comprising the reaction product of a living anionic elastomeric polymer and a polymerization terminator of formula I

##STR00001##

where X is Cl, Br, or I;
m is an integer from 0 to 2, n is an integer from 1 to 3, with the proviso that n+m=3;
R.sup.1, R.sup.2 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R.sup.1, R.sup.2 are independently SiR.sub.3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R.sup.1 and R.sup.2 taken together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom to form a five to eight membered ring;
R.sup.3 is hydrogen, or C1 to C18 alkyl, aryl, or a combination thereof, or R.sup.3 is SiR.sub.3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R.sup.3 is R.sup.6R.sup.7, where R.sup.6 is C1 to C3 alkanediyl and R.sup.7 is selected from the following structures
SZ, N(R.sup.8)(R.sup.9), O(Y), or Si(OR.sup.10).sub.3, where R.sup.8 and R.sup.9 are independently C1 to C18 alkyl, aryl, or a combination thereof,
Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyl dimethyl silyl, tert-butyl diphenyl silyl, and isopropyldimethylsilyl, and
R.sup.10 are independently C1 to C4 alkyl;
or when m=1, the polymerization terminator may have the formula II

##STR00002##

where R.sup.4, R.sup.5 are independently C1 to C18 alkyl, aryl, or a combination thereof, or R.sup.4, R.sup.5 are independently SiR.sub.3 where R is independently alkyl, aryl, alkoxy, or disubstituted amino, X and R.sup.3 are as defined previously, and k is an integer from 0 to 10.

A modified diene elastomer having a good flow resistance, and imparting to a rubber composition containing the same a good compromise of hysteresis and abrasion properties and a satisfactory processing with a view to a tire application is provided. This modified elastomer comprises: a) at least 70% by weight of a linear diene elastomer predominantly functionalized in the middle of the chain by an alkoxysilane group, optionally partly or completely hydrolyzed to silanol, the alkoxysilane group optionally bearing another function capable of interacting with a reinforcing filler, the silicon atom of the alkoxysilane group lying in the main chain of the diene elastomer; b) more than 0 and up to 30% by weight of a star-branched diene elastomer, the Mooney viscosity of said modified diene elastomer varying from 50 to 80 and the glass transition temperature (Tg) thereof varying from 100 C. to 80 C.

Described is a tri-block prepolymer having a chemical structure of [A]-[B]-[C], comprising at least one monovalent reactive group, wherein segment [A] and [C] independently comprise polymeric segments based on a first hydrophilic monomer comprising functionality selected from the group consisting of hydroxyalkyl, alkylamine, and mixtures thereof and optionally a second hydrophilic monomer, and [B] comprises a polymeric segment of at least one silicone-containing macromer and optionally a third hydrophilic monomer comprising functionality selected from the group consisting of hydroxyalkyl, alkylamine, and mixtures thereof and optionally a silicone-containing monomer. These prepolymers may be used alone or in combination with other components in reactive monomer mixtures for making silicone hydrogels and ophthalmic devices made therefrom, including contact lenses.

Disclosed is a functionalizing method for the end functionalisation of trans-1, 4 stereo-regular polydiene chains obtained by the coordination catalytic polymerisation of at least one conjugated diene monomer. It also relates to a polydiene having a trans-1,4 chain formation rate of at least 85%, preferably at least 90%, and an end functionalisation rate higher than 70%, preferably higher than 80%, and more preferably higher than 90%.

Nanostructures and associated compositions, systems, and methods are provided. In some embodiments, a nanostructure may comprise polymers, intermolecular bonding groups, and a particle. The polymers may be associated with the particle and the intermolecular bonding groups may be associated with at least some of the polymers. In some embodiments, at least some of the intermolecular bonding groups may have a different chemical composition and/or chemical property than the polymers. In some embodiments, nanostructures may reversibly associate with each other via the intermolecular bonding groups to form a material. In some such cases, the intermolecular bonding groups on different nanostructures may reversibly associate with each other. In some embodiments, the nanostructures may be designed, such that the energy required to disassociate at least a portion of the nanostructures in the material is greater than the energy required to dissociate a single association between intermolecular bonding groups.

There is provided a polymeric microsphere comprising a thermally responsive monomer crosslinked with a functional group monomer, wherein the functional group monomer comprises at least one of a carboxylic acid functional group or an amine functional group. The thermally responsive monomer is preferably N-isopropylacrylamide (NIPAM), and the microspheres preferably comprise a coating of polymerized catecholamines (e.g. DOPA). There is also provided a method of preparing the polymeric microsphere and uses of the polymeric microsphere in culturing, harvesting, or expanding stem cells or stromal cells. Preferably, the cells, e.g. hMSCs (human mesenchymal stem/stromal cells), are expanded or harvested in serum-free and xeno-free medium.