摘要:
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).
摘要:
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.
摘要:
A humidification system (A) for humidifying a dry hydrocarbon stream includes a column (10) which defines an interior cavity (20). The cavity is partially filled with a bed (12) of a packing material (40) and a layer of water (20), leaving a headspace above the water. An inlet (52) adjacent a lower end of the cavity receives a dry hydrocarbon stream which is broken up by the packing material and dissolves water as it passes therethrough. Entrained water droplets fall out of the wet blend in a disengagement zone (70) above the water layer leaving the hydrocarbon stream humidified yet substantially free of liquid water in an upper region (72) of the column.
摘要:
A novel method of preparing carboxyl-terminated polymers. A monomer is mixed with an organolithium initiator in a hydrocarbon solvent so as to anionically polymerize linear living polymer lithium chains. A trialkyl aluminum compound is also mixed so as to form polymer lithium: aluminate complexes in equilibrium with the linear living polymer lithium chains. When a cyclic anhydride terminator is mixed, the cyclic anhydride terminator preferentially reacts with the C—Li center on a living polymer lithium chain rather than with the C—Al—Li center on a polymer lithium: aluminate complex.
摘要:
Provided is a method of converting an anionic living end to a protected free radical “living” end in a well-controlled manner, which enables copolymerization by plural mechanisms. The method is particularly useful for copolymerization of anionically polymerizable monomers and free radical polymerizable monomers, and therefore useful for production of PB-g-PS, HIPS, ABS, and MBS etc. Also provided is a reversibly coupled polymer, which, when decoupled, generates “living” free radical for further copolymer chain reaction.
摘要:
A silica-filled, vulcanized elastomeric compound comprises 100 parts by weight of an elastomer; from about 5 to about 100 parts by weight of a reinforcing filler per 100 parts of elastomer, wherein the reinforcing fillers are selected from the group consisting of carbon black and silica filler; from 0 to about 20 percent by weight of a silane, based upon the weight of the silica filler; a cure agent; from about 0 to about 20 parts by weight of a processing aid selected from the group consisting of fatty acid esters of hydrogenated and non-hydrogenated C5 and C6 sugars; from about 0 to about 20 parts by weight of a processing aid selected from the group consisting of polyoxyethylene derivatives of fatty acid esters of hydrogenated and non-hydrogenated C5 and C6 sugars; from about 0 to about 40 parts by weight of an additional filler other than silica or carbon black, with the provisos that at least one of the processing aids or additional fillers are present; that if the processing aid is sorbitan monooleate, then at least one of the polyoxyethylene derivatives or additional fillers is also present and, that the minimal amount for each processing aid and additional filler, if present, is about one part by weight. A process for the preparation of silica filled vulcanizable elastomers is provided as well as pneumatic tires employing tread stock comprising the novel vulcanizable elastomers.
摘要:
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. The resultant diene polymers or copolymers have improved balance between raw polymer viscosity and mixed compound viscosity when compounded with silica and/or carbon black and cured compositions are useful in tire tread having highly balanced wet traction, rolling resistance, and traction in ice and snow. The polymers can be utilized to form elastomer compositions for tire treads having balanced properties of reduced rolling resistance and wet traction and handling or balanced properties of wet traction and handling and traction in snow and ice.
摘要:
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.
摘要:
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.
摘要:
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.