摘要:
Hydrogenated polymers with a radial structure having a core made up of calixarenes of the general formula (I), to the core of which is linked a number P of hydrogenated linear polymer segments selected from: —hydrogenated homopolymers or co-polymers of conjugated dienes; or —hydrogenated co-polymers of said conjugated dienes and monoalkenyl arenes, and —mixtures thereof said formula (I) in which: —R1, R2, R3 and R4 are independently selected from hydrogen; a group containing carbon and hydrogen; a group also containing heteroatoms in addition to carbon and hydrogen; a group also containing silicon in addition to carbon, hydrogen and heteroatoms; —one of the two substituents R5 and R6 is hydrogen, while the other may be hydrogen or alkyl, with a number of carbon atoms between 1 and 6, preferably methyl and ethyl; —n is an integer in the range between 4 and 16.
摘要:
Hydrogenated polymers with a radial structure having a core made up of calixarenes of the general formula (I), to the core of which is linked a number P of hydrogenated linear polymer segments selected from: —hydrogenated homopolymers or copolymers of conjugated dienes; or —hydrogenated copolymers of said conjugated dienes and monoalkenyl arenes, and —mixtures thereof said formula (I) in which: —R1, R2, R3 and R4 are independently selected from hydrogen; a group containing carbon and hydrogen; a group also containing heteroatoms in addition to carbon and hydrogen; a group also containing silicon in addition to carbon, hydrogen and heteroatoms; —one of the two substituents R5 and R6 is hydrogen, while the other may be hydrogen or alkyl, with a number of carbon atoms between 1 and 6, preferably methyl and ethyl; —n is an integer in the range between 4 and 16.
摘要:
Process for the purification of the solvent deriving from the production of an elastomeric blend comprising the following steps: .(a) optionally, subjecting said solvent to a pre-washing (2) in the presence of at least one acid or basic aqueous solution; .(b) feeding said solvent to a liquid-liquid separation column (7); .(c) feeding the stream leaving the head of said liquid-liquid separation column (7) to an azeotropic distillation column (21); .(d) feeding the stream withdrawn laterally (side-withdrawal) from said azeotropic distillation column (21) to an adsorption section (34a/b); Said process allows to obtain a polymer grade solvent having a quality suitable for being used indifferently and contemporaneously in various types of production plants of elastomeric (co)polymers, i.e. in plants wherein an anionic (co)polymerization is carried out, and also in plants wherein a Ziegler-Natta (co)polymerization is carried out.