摘要:
The invention relates to synthetic branched polyisoprenes having a macrostructure and a microstructure which are very similar to those of natural rubber. According to one aspect of the invention, said polyisoprenes have an apparent stress F/S0 which is equal to or greater than 0.4 MPa for an elongation α of 150 % which is applied to a dumb-bell-shaped test piece containing cross-linkable polyisoprene. According to another aspect of the invention, said polyisoprenes satisfy relation (i) Cotan δ = 0.3761. θinh + 0.15, wherein: cotan δ is the cotangent of the loss angle of a sample of the polyisoprene, which is measured at 130° C using a device with the trade name RPA2000, said sample being shear stressed at 10 % of deformation and at a stress frequency of 0.035 Hz; and θinh is the inherent viscosity of the polyisoprene, which is measured in toluene at 25° C and with a 0.1 g/dl concentration of polyisoprene in the toluene.
摘要:
The invention concerns a catalytic system used for preparing polybutadienes by polymerization, a method for preparing said catalytic system and a method for preparing polybutadienes using said catalytic system. The inventive catalytic system is based on at least: a conjugated diene monomer, a salt of one or more rare earth metals of an organic phosphoric acid, said salt being suspended in at least a saturated inert hydrocarbon solvent of aliphatic or alicyclic type, an alkylating agent consisting of an alkylaluminium of formula AIR3 or HalR2, the mol ratio (alkylating agent/ rare earth salt) being greater than 5, and a halogen donor belonging to the family of alkylaluminium halides other than alkylaluminium sesquihalides, and in accordance with the invention, said catalytic system comprises said rare earth metal(s) in a concentration not less than 0.005 mole/l.
摘要:
A polyurea adhesive composition that is obtainable by reaction of reaction components that include a polyisocyanate comprising isocyanurate rings, the polyisocyanate having a functionality equal to or greater than 3, a polyamine having an average molecular weight greater than about 500 dalton and a carboxylic acid. Additionally, the reaction components may comprise an aromatic diamine chain extender. The molar ratio of the isocyanate groups to whole amine and carboxylic acid functions of the reaction components is between 1.5 and 3.5. Further provided is an article comprising a component bonded to the article with the polyurea adhesive described above. The bonded faces between the component and the article may be of cross- linked rubber composition. The article may be, for example, a tire, a tread band and/or a patch applied to the tire.
摘要:
The invention concerns synthetic polyisoprenes having a high cis-1,4 chaining rate and the method for preparing same. The inventive polyisoprenes have a cis-1,4 chaining rate, measured according to technique of nuclear magnetic resonance of carbon 13 or by means infrared assay, which is of the order ranging between 99.0 % to 99.6 %. The inventive method for preparing said polyisoprenes consists essentially in reacting a catalytic system in the presence of isoprene, and it consists in: a) using, as catalytic system, a system based on at least a conjugate diene monomer, a salt of one or several rare earths of an organic phosphoric acid, an alkylaluminium alkylating agent of formula AIR3 or HAIR2, and, a halogen donor consisting of an alkylaluminium halide, the mol ratio (alkylating agent/rare earth salt) ranging between 1 and 5; and b) carrying out a polymerising reaction of the isoprene at a temperature not higher than 5 °C.
摘要:
A polyurethaneurea system that includes in some embodiments Parts A and B reaction components for a polyurethaneurea, wherein an exemplary embodiment provides a Part A that comprises between 55 and 75 wt.% of an oligomeric polyol, between 3 and 7 wt.% of an aromatic diamine chain extender, and between 0.1 and 1.5 % of a reactivity catalyst; Part B includes between 1 and 15 wt.% of a short aromatic diisocyanate and between 5 and 35 wt.% of an aromatic diisocyanate prepolymer that is the reaction product of a short aromatic diisocyanate and a diol. The polyurethaneurea system may further comprise an elastomer- surface activator comprising a second short aromatic diisocyanate and a second aromatic diisocyanate prepolymer, wherein at least one of the second diisocyanates may be the same as at least one of the diisocyanates of Part B.
摘要:
The invention concerns a method for preparing butadiene and isoprene statistic copolymers essentially consisting in reacting a catalytic system in the presence of butadiene and isoprene, and in: using, as catalytic system, a system based on at least: a conjugated diene monomer, a salt of one or several rare earths of an organic phosphoric acid, an alkylating agent consisting of an alkylaluminium of formula AIR3 or HalR2, and a halogen donor consisting of an alkylaluminium halide, said salt being suspended in at least a saturated inert hydrocarbon solvent of aliphatic or alicyclic type comprised in said catalytic system, and the molar ratio (alkylating agent/rare earth salt) ranges from 1 to 8, and in carrying out a copolymerisation reaction in an inert or mass hydrocarbon polymerizing solvent. Said copolymers are in particular such that the butadiene and isoprene units which they comprise have each a high proportion of cis-1,4 chains.
摘要:
The invention concerns a catalytic system used for preparing by polymerisation diene elastomers comprising polyisoprenes and polybutadienes, a method for preparing said catalytic system and a preparation method, using said catalytic system, of said diene elastomers comprising polyisoprenes with high cis-1,4 chaining rate and polybutadienes. The inventive catalytic system is at least based on: a conjugate diene monomer, a salt of one or several rare earth metals of an organic phosphoric acid, an alkylaluminium alkylating agent of formula AlR3 or HAIR2, and a halogen donor consisting of an alkylaluminium halide, and such that the salt is suspended in at least an inert and saturated hydrocarbon solvent of the aliphatic or alicyclic type, the mol ratio (alkylating agent/rare earth salt) having a value ranging between 1 and 5.
摘要:
The invention concerns a method for preparing butadiene and isoprene statistic copolymers essentially consisting in reacting a catalytic system in the presence of butadiene and isoprene, and in: using, as catalytic system, a system based on at least: a conjugated diene monomer, a salt of one or several rare earths of an organic phosphoric acid, an alkylating agent consisting of an alkylaluminium of formula AIR3 or HalR2, and a halogen donor consisting of an alkylaluminium halide, said salt being suspended in at least a saturated inert hydrocarbon solvent of aliphatic or alicyclic type comprised in said catalytic system, and the molar ratio (alkylating agent/rare earth salt) ranges from 1 to 8, and in carrying out a copolymerisation reaction in an inert or mass hydrocarbon polymerizing solvent. Said copolymers are in particular such that the butadiene and isoprene units which they comprise have each a high proportion of cis-1,4 chains.