A copolymer of ethylene and of isoprene, which comprises from 10 to 35 mol % of isoprene units, at least 70% of which are in the 3,4 configuration and a portion of which is in the 1,2 configuration is provided. A copolymer of this type with a reduced crystallinity is synthesized with a much higher productivity than its homologues of ethylene and of butadiene, and also confers improved curing properties on rubber compositions.

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.

The present invention relates to the use of specific styrene derivatives in the production of an elastomeric copolymer. The invention further relates to methods for producing an elastomeric copolymer and an elastomeric copolymer. Moreover, the invention relates to a method for preparing a rubber comprising vulcanizing the elastomeric copolymer, and a rubber as obtainable according to the method. Further, the invention relates to a rubber composition, a tire component comprising the rubber composition, and a tire comprising the tire component.

The present invention is directed to a stereoregular functionalized elastomer represented by poly(M1 co M2), wherein the functionalized elastomer comprises a microstructure selected from the group consisting of microstructures having at least 90 percent by weight of monomer residues in trans 1,4-configuration, and microstructures having at least 80 percent by weight of monomer residues in cis 1,4-configuration; wherein M1 is selected from the group consisting of isoprene and 1,3-butadiene; and M2 is of formula 4

##STR00001##

wherein R.sup.6 is a covalent bond, phenylene, a linear or branched alkane diyl group containing 1 to 10 carbon atoms, or a combination of one or more phenylene groups and one or more linear or branched alkane diyl groups containing 1 to 10 carbon atoms; R.sup.7 is hydrogen or a linear or branched alkyl group containing 1 to 10 carbon atoms; X.sup.1 is selected from formulas 5 and 6

##STR00002##

wherein R.sup.8 and R.sup.9 are independently trialkylsilyl, phenyl or a linear or branched alkyl group containing 1 to 10 carbon atoms, or one of R.sup.8 and R.sup.9 is hydrogen and the other is phenyl or a linear or branched alkyl group containing 1 to 10 carbon atoms, or R.sup.8 and R.sup.9 taken together with the nitrogen atom represent a nitrogen containing heterocyclic group containing from 4 to 12 carbon atoms; and X.sup.2 is a sulfur atom or a structure of formula 7 or 8

##STR00003##

wherein when X.sup.2 is of formula 8, the S atom of formula 8 is adjacent to the phenyl ring of formula 6 and the N atom of formula 8 is adjacent to R.sup.6.

The present invention is directed to a method of making an amine functionalized elastomer, comprising the steps of polymerizing at least one first monomer selected from the group consisting of 1,3-butadiene and isoprene and a second monomer of formula I in the presence of a polymerization catalyst in a hydrocarbon solvent to form a first copolymer in solution;

##STR00001##

where R.sup.1 is phenylene, a linear or branched alkane diyl group containing from 1 to 10 carbon atoms, or a combination of one or more phenylene groups and one or more linear or branched alkane diyl groups containing from 1 to 10 carbon atoms; and R.sup.2 is methyl or ethyl; and mixing the first copolymer in solution with a protic solvent followed by stirring to convert the first copolymer to a second copolymer given by the formula poly(M1 co M2) wherein M1 is the first monomer and M2 is of formula II

##STR00002##

where R.sup.1 is as previously defined.

A roofing membrane and a method of making the same is provided. The roofing membrane includes a top layer having a flame retardant and a first silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3; a scrim layer; and a bottom layer having a flame retardant and a second silane-crosslinked polyolefin elastomer with a density less than 0.90 g/cm.sup.3. The top and bottom layers of the roofing membrane both exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70 C.).

Fluoroelastomer compositions comprising fluoroelastomers having copolymerized units of a nitrile-containing cure site monomer are cured with certain hydrazone or oxime curatives.

A heterophasic propylene copolymer (HECO) comprising a polypropylene matrix having a melt flow rate MFR.sub.2 (230 C.) in the range of 40 to 120 g/10 min and a comonomer content in the range of 30 to 75 mol-% for the preparation of molded articles with low CLTE.

A heterophasic propylene copolymer (HECO) comprising a polypropylene matrix having a melt flow rate MFR.sub.2 (230 C.) in the range of 40 to 120 g/10 min and a comonomer content in the range of 30 to 75 mol-% for the preparation of molded articles with low CLTE.

A film formed from a polyethylene copolymer using a reduced chromium oxide catalyst, ethylene monomers and a co-monomer selected from butene monomers or 1-hexene, where the polyethylene copolymer has a density in the range of from about 0.935 to about 0.950 g/cm.sup.3 and an I.sub.21/I.sub.5 in a range of about 18.0 to about 30.0. The film formed from the polyethylene copolymer has a dart drop impact (g/.sub.im) that significantly greater as compared to a film of the polyethylene copolymer formed using a silyl chromate catalyst in place of the reduced chromium oxide catalyst. A method of making such films is also provided.