Abstract: The reduction of hysteresis in a silica-filled, vulcanized elastomeric compound is produced by mixing diene monomer and optionally monovinyl aromatic monomer with an initiator and a coordinator; effecting polymerization conditions; terminating polymerization with a terminator containing an organo-tin group to form a tin-coupled diene elastomer; compounding the tin-coupled diene elastomer with an amorphous silica filler and a vulcanization agent; and, effecting vulcanization. A pneumatic tire tread stock incorporating the vulcanized elastomer compound exhibits decreased rolling resistance in the tire.

Abstract: Diene polymers or copolymers having improved balance between raw polymer viscosity and mixed compound viscosity, useful in tire tread compositions having highly balanced wet traction, rolling resistance, and traction in ice and snow, and fracture properties in the cured and white carbon reinforced states are provided. These diene polymers or copolymers comprise a mixture of diene polymer or copolymer chains containing carbon-tin bonds in the main polymer or copolymer chains and diene polymer or copolymer chains containing terminals derived from hydrocarboxysilane compounds. The diene polymer or copolymers are prepared by first coupling a portion of the living diene polymer or copolymer chains obtained by anionic polymerization using a tin polyhalide coupling agent and then terminating the remaining living diene polymer or copolymer chains using hydrocarboxysilane compounds.

Abstract: Incorporation of neutral water soluble inorganic salts into a precipitated silica improves the filler dispersion in a compounded rubber, reduces rolling resistance (hysteresis), and improves processability. These properties are achieved without loss of the expected reinforcement effect due to the substitution of inorganic salt for SiO2 in the silica. The properties are seen when a variety of silanes and processing aids are added to the silica.

Abstract: There is disclosed a process for the regulation of the molecular weight of high cis polybutadiene prepared by polymerizing butadiene under solution polymerization conditions employing as the catalyst system a mixture of (a) organoaluminum compounds; (b) organonickel compounds; and (c) fluorine containing compounds; said polymerization being conducted in the presence of alkali or alkaline earth metal salts of organic carboxylic acids.

Abstract: Incorporation of neutral water soluble inorganic salts into a precipitated silica improves the filler dispersion in a compounded rubber, reduces rolling resistance (hysteresis), and improves processability. These properties are achieved without loss of the expected reinforcement effect due to the substitution of inorganic salt for SiO.sub.2 in the silica. The properties are seen when a variety of silanes and processing aids are added to the silica.

Abstract: The reduction of hysteresis in a silica-filled, vulcanized elastomeric compound is produced by mixing diene monomer and optionally monovinyl aromatic monomer with a lithium amine initiator and, optionally, a modifier; effecting polymerization conditions; terminating polymerization with an amino group producing terminator to form an amine functionalized diene elastomer; compounding the amine functionalized diene elastomer with an amorphous silica filler and a vulcanization agent; and, effecting vulcanization. A pneumatic tire tread stock incorporating the vulcanized elastomer compound exhibits improved reduced hysteresis, or highly balanced wet traction, rolling resistance, snow/ice traction, and mechanical strength when compounded with silica filler and vulcanized, in the tire.

Abstract: Depolymerization or molecular weight reduction of polymers and gelled polymers containing internal unsaturation along the polymer backbone is performed in the presence of a molybdenum or tungsten compounds having the structural formula:M(NR.sub.1)(OR.sub.2).sub.2 (CHR.sub.3)wherein M is molybdenum or tungsten;R.sub.1 and R.sub.2 are unsubstituted or halo-substituted alkyl, aryl, aralkyl groups or silicon-containing analogs thereof;R.sub.3 is an alkyl, aryl, aralkyl group of any substituent that results from the initial reaction between the M.dbd.CHR.sub.3 complex and an olefin treating agent.

Abstract: A (halomethyl arene)-modified elastomer is made by reacting a lithium terminated elastomer intermediate with the halogen atoms of a halomethyl vinyl arene compound. A road-contacting tread component for a pneumatic tire is fabricated from vulcanized elastomer made by vulcanizing an elastomer composition of a (halomethyl arene)-modified elastomer, a carbon black reinforcing agent, and a sulfur-based vulcanizing system. A process for making a (halomethyl arene)-modified elastomer includes polymerizing at least one diene monomer with a lithium-containing initiator, capping the lithium terminated elastomer by reaction with a halomethyl arene compound, and recovering the modified elastomer.

Abstract: Modification of lithium-terminated elastomer intermediates by reaction under anionic conditions with 1,3,2-dioxastannolanes provides tin-containing elastomers with improved hysteresis properties. In specific examples, modification of a lithium-terminated styrene-butadiene rubber with a dioxastannolane derived from reaction of dibutyl tin(IV)oxide with an alkyl-substituted 1,3-pentane provides tin-modified SBRs with lowered tan delta properties. Such modified elastomers are useful in making tread portions of pneumatic tires.

Abstract: Increased reactivity of isocyanate terminated polyether prepolymers with metal halide salt complexes of methylenedianiline is obtained when the polyether intermediates are modified to contain an effective amount of ethylene oxide. A desired intermediate is poly(oxypropylene) diol or triol which are modified to contain ethylene oxide units therein and subsequently reacted with a polyisocyanate such as MDI, that is 4,4'-diphenylmethane diisocyanate, or TDI, that is, toluene diisocyanate. A desired metal halide salt complex of methylenedianiline is the sodium chloride salt complex (MDA.sub.3 -NaCl), dispersed in dioctylphthalate (50/50 wt/wt).

Abstract: The present invention relates to a method of preparing linear polyphosphazene polymers by direct synthesis under anhydrous conditions from NH.sub.4 Cl and at least one chlorophosporous compound selected from the group consisting of PCl.sub.5, XPCl.sub.4, or X.sub.2 PCl.sub.3 wherein X is one or more substituents selected from the group consisting of C.sub.6 H.sub.5 -, C.sub.6 H.sub.4 Cl-, C.sub.6 H.sub.4 F-, C.sub.6 H.sub.4 Br-, C.sub.6 H.sub.2 Cl.sub.3 -, C.sub.6 F.sub.5 -, C.sub.6 H.sub.4 CF.sub.3 -, C.sub.6 H.sub.4 NO.sub.2 -, Cl.sub.3 C-, F.sub.3 C-, F.sub.5 C.sub.2 -, F.sub.7 C.sub.3 -, or HC.sub.2 F.sub.4 -. Each of these compounds may be prepared in situ in a reactor. The instant process controls the pressure in the reactor through continuous venting of by-product HCl at elevated pressures. The instant invention also utilizes an excess of of reactive solvent such as PCl.sub.3, XPCl.sub.2, or X.sub.2 PCl as X is defined above.

Abstract: In repairing articles of natural rubber or elastomer predominantly of natural rubber with cured polymer or prepolymer (polyurethane/polyurea), adhering advantages are obtained especially at elevated temperatures when the damaged area is treated with halogen-containing oxidant dissolved in 1,2-dichloroethane instead of other solvents.

Abstract: The invention relates to a process for producing substantially gel-free copolymers of butadiene and isobutylene having number average molecular weights of from about 50,000 to about 200,000 and levels of unsaturation of from about 3 weight percent to about 25 weight percent. The process which is homogeneous in nature involves polymerizing the monomers in an aliphatic solvent or mixture of such solvents in the presence of a BF.sub.3 /ROH catalyst system at a temperature of below -95.degree. C.

Abstract: Conjugated dienes and alpha-olefins, such as butadiene and propylene, are copolymerized by a catalyst system comprising a metal component TiCl.sub.n Br.sub.4-n or VCl.sub.m Br.sub.5-m, a reducing agent of the formula AlR.sub.2 H wherein R is hydrogen or a hydrocarbon group, there being at least one hydrocarbon group per molecule, and a carbonyl-containing compound such as acetophenone. The use of the aluminum hydride compound allows the use of higher and more practical temperatures to obtain desirable molecular weights, yields and microstructure that with aluminum trialkyls require much lower and less practical polymerization temperatures.