Abstract:
A polyolefin nanocomposite is prepared by melt blending (a) a polyolefin and (b) a smectite clay in the presence of at least one intercalating agent that is a solid at room temperature and is selected from the group consisting of (a) hydroxy-substituted carboxylic acid esters, (b) amides, (c) hydroxy-substituted amides, and (d) oxidized polyolefins, wherein the ratio of the intercalating agent to the clay is at least 1:3, based on the ash content of the clay.
Abstract:
Process for the preparation of ethylene copolymers comprising the copolymerization of ethylene with olefins CH 2 =CHR,in which R is a hyrdocarbyl radical with 1-12 carbon atoms carried out in the presence of a catalyst comprising (i) a solid catalyst component comprising Mg, Ti, halogen and specific 1,3-diethers of formula (I) in which R is a C 1 -C 10 hydrocarbon group, R 1 is methyl or ethyl, optionally containing a heteroatom, and R 2 is a C4-C12 linear alkyl optionally containing a heteroatom, and (ii) an organo-A1 compound. The obtained copolymers are endowed with good comonomer distribution.
Abstract:
A polyolefin composition suitable for preparing single ply roofing membranes, comprising: (A) from about 15 to 40% by weight of a crystalline copolymer of propylene with at least one alpha-olefin of formula H 2 C=CHR 1 , where R 1 is H or a C 2-8 linear or branched alkyl, containing at least about 90% by weight of propylene, having solubility in xylene at room temperature lower than about 15% by weight; (B) from about 60 to about 85% by weight of an elastomeric fraction comprising: (1) a copolymer of propylene with ethylene containing about 20 to about 35% by weight ethylene, and having solubility in xylene at room temperature greater than about 70% by weight, the intrinsic viscosity of the xylene soluble fraction being higher than about 3.0dl/g; and (2) a copolymer of ethylene with at least one alpha-olefin of formula H 2 C=CHR 2 , where R 2 is a C 2-8 linear or branched alkyl, containing about 15% to 40% by weight alpha-olefin, and having solubility in xylene at room temperature greater than about 25% by weight, the intrinsic viscosity of the xylene soluble fraction ranging from about 0.5 to about 5.0dl/g; the (1) (2) weight ratio ranging from about 1:5 to about 5:1. The polyolefin composition of the invention, preferably prepared by sequential polymerization in at least three stages, has tensile strength at break ≥ 25 Mpa, elongation at break ≥ 700 Mpa and toughness ≥ 150 Mpa.
Abstract:
The present invention relates to a solid catalyst component for the polymerization of olefins CH 2 =CHR in which R is hydrogen or a hydrocarbon radical with 1-12 carbon atoms, comprising Mg, Ti, halogen and an electron donor selected from maleates of a particular formula. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.
Abstract:
The thermal stability of graft copolymers can be improved by blending (1) a graft copolymer comprising a backbone of a propylene polymer material having graft polymerized thereto a monomer selected from the group consisting of (a) an ester of an acrylic acid substituted at the alpha carbon atom by a 1-3 alkyl group and (b) a combination of (i) an ester of an acrylic acid substituted at the alpha carbon atom by a 1-3 alkyl group and (ii) an ester of an unsubstituted acrylic acid, or an acrylic acid substituted at the alpha carbon atom by a 1-3 carbon alkyl group and (2) about 1 weight % to about 25 weight % of a fluorinated olefin polymer, wherein the ratio of the polymerized monomer to the fluorinated olefin polymer is about 25:1 to about 0.5:1.
Abstract:
The molecular weight of a graft copolymer is reduced by carrying out the following steps in a non-oxidizing atmosphere: (1) treating a propylene polymer material with an organic compound that is a free radical polymerization initiator, (2) treating the propylene polymer material with about 2 to about 240 parts per hundred parts of the propylene polymer material, of at least one vinyl-substituted grafting monomer in the presence of about 0.5% to about 5% of a polymerizable chain transfer agent that is a derivative of allyl alcohol, and (3) removing any unreacted monomer, decomposing any unreacted initiator, and deactivating any residual free radicals in the material.
Abstract:
A process for the preparation of alkylidene substituted succinates comprising a step (a) in which is carried out the reaction of a carbonilic compound, a succinic and a base in a reaction medium and a step (b) in which the alkylidene substituted product obtained in (a) is esterified, characterized in that the succinic ester is used in a molar amount substantially equal to, or lower than, the amount of compound carbonilic compound, (ii) the base is used in a molar amount substantially equal to the succinic ester and is selected from metal hydrides and metal and alkoxides, and (iii) the reaction medium comprises an aprotic liquid medium or a protic liquid medium having a Ka, measured in water, lower than that of iPrOH.
Abstract:
A polypropylene resin composition containing (A) a polypropylene resin treatment product obtained by adding from (0.05) to (5) weight parts of an organic peroxide to (100) weight parts of a polypropylene resin with a melt flow rate of from (0.1) to (50) g/10min and carrying out a melt treatment and (B) from (0.01) to (2) weight parts of an oxide of the group (2) or (12) metal of the periodic table or a metal alkoxide of defined formula to (100) weight parts of a resin content of the above polypropylene resin treatment product.
Abstract:
A method of discharging polymer from a continuously operated polymerization reactor, wherein at least a monomer is polymerized to form polymer particles, the method comprising adjusting the discharge rate of the polymer particles by means of a piston valve having a piston element connected to an actuator, said actuator being able to modulate the piston stroke inside said piston valve.
Abstract:
A method for absorbing oxygen from a gas mixture within an enclosure, the method comprising exposing a gas mixture to an oxidized propylene polymer material having a peroxide concentration of about 1 to about 200 mmol total peroxide per kilogram of oxidized propylene polymer material, wherein the oxygen is absorbed by the oxidized propylene polymer material.