摘要:
A porous polymer of propylene optionally containing up to 15% by weight of an alpha-olefins of formula CH2═CHR wherein R is a hydrogen atom or a C2-C10 alkyl radical having the following characteristics: a) in the Temperature Rising Elution Temperature analysis (TREF) a fraction eluted at a temperature range front 25° C. to 97° higher than 20% of the total polymer eluted; and b) a pore volume (determined by mercury absorption) greater than 0.45 cc/g.
摘要:
A process for preparing porous olefin polymers comprising bringing into contact in a polymerization reactor, at a temperature T1, one or more olefins of the formula (I) CH2═CHR1, R1 being hydrogen, a C1–C20-alkyl or a C6–C12-aryl group, with a catalyst obtained by reacting a solid catalyst component in the form of spheroidal particles comprising a compound of Ti or V not containing metal-π bonds and a Mg halide, optionally containing one or more electron donor compounds, with an aluminum-alkyl (Al-alkyl) compound, then raising the temperature up to the polymerization temperature, said process being characterized in that: a) if the temperature T1 is lower than 40° C., the temperature is raised up to the polymerization temperature is such a way that, for a time of at least one minute after the introduction temperature in such a way that, for a time of at least one minute after the introduction of the catalyst system into the reactor, the temperature of the reaction T2 fulfills the following condition of formula (II) wherein m is the time expressed in minutes employed for reaching the temperature T2; or b) if temperature T1 is 40° C. or higher, the reactor is maintained for a time of at least one minute at a temperature of at least 40° C.
摘要:
A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2=CHL, where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.
摘要:
Described is a thermoplastic composition including: (A) 10 to 99% by weight of a propylene polymer optionally containing from 0.1 to 5% by moles of units derived from an olefin of the formula CH2═CHR, R being hydrogen, a C2-C20-alkyl or a C6-C12-aryl group, having the following characteristics: 50
摘要:
A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2═CHL, where L is an alkyl, cycloalkyl or aryl radical with 1–10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.
摘要:
Disclosed are reverse osmosis anisotropic gel-type membranes having the structure: ##STR1## WHEREIN N IS A WHOLE NUMBER; A is a divalent group derived from piperazine and having the structure: ##STR2## WHEREIN X IS 0 TO 8 AND R is an alkyl group, and Q is at least two divalent organic groups selected from the group consisting of: ##STR3## wherein Y is O or S, ##STR4## Also disclosed are processes for preparing such membranes.
摘要:
Cyclopolyenic 1,3-diethers wherein the carbon atom in position 2 belongs to a particular cyclic or polycyclic structure containing two or three unsaturations, solid catalyst components and catalysts therefrom, the catalysts comprising the reaction product of: i. a solid catalyst component containing an internal donor; ii. an Al-alkyl compound, and optionally iii. an external donor; the internal donor and/or the external donor being cyclopolyenic 1,3-diethers. The catalysts are useful for the polymerization of alpha-olefins.
摘要:
Catalyst system for the polymerization of olefins CH2═CHR, wherein R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, comprising the product of the reaction between (a) a solid catalyst component comprising Mg, Ti, and halogen, (b) dimethylaluminium chloride (DMAC) and (c) an alkylaluinium compound, in which the molar ratio between (b) and (c) is lower than 10. This kind of catalyst system is particularly suitable for the preparation of copolymers of ethylene with &agr;-olefins due to its high capacity for incorporating the comonomer while at the same time maintaining high yields.
摘要:
A debris shedding buoy having a float body with a top and a bottom is provided. The buoy includes a slide rail, adapted for slidable engagement to a mooring line, is attached to the bottom of the float body. The slide rail is located in a generally centered position beneath the float body and is oriented in a first direction. A rudder device is affixed to the float body and adapted to produce a stabilizing force to maintain the float body in a quasi stable orientation with respect to a current direction, with the first direction being generally aligned to the current direction. Debris lodging against the float body overcomes the stabilizing force produced by the rudder device, causing the float body to rotate from the quasi stable orientation to a second orientation to shed the debris whereupon the float body rotates back to the quasi stable orientation.
摘要:
A process for preparing hyperpure propylene (co)polymers comprising polymerizing the monomer(s) in liquid monomer in the presence of a catalyst obtained by reacting an Al-trialkyl compound with a solid catalyst component comprising magnesium dihalide in active form, having supported thereon a titanium chloride or chloroalcoholate, and an ether having the general formula: ##STR1## where R and R" are the same or different and are C.sub.2-18 alkyl, C.sub.3-18 cycloalkyl, C.sub.6-18 aryl, C.sub.7-18 arylalkyl or alkylaryl radicals.