Abstract: A metallocene random copolymer of propylene and ethylene in which the ductile/brittle transition temperature of a molded article made from the copolymer may be in the range of from about 20° F. (?7° C.) to about 40° F. (4° C.). The haze level of the molded article may be less than about 10 percent for an 80-mil (0.2 cm) thick plaque. The metallocene random copolymer may further include a clarifier.

Abstract: A solid catalyst component for olefin polymerization comprising a titanium atom, a magnesium atom, a halogen atom, and a cycloheptapolyenedicarboxylic diester; a production method of the solid catalyst component, by contacting with one another a titanium compound, a magnesium compound, and the cycloheptapolyenedicarboxylic diester; a production method of a solid catalyst, by contacting the solid catalyst component with an organoaluminum compound; and a production method of an olefin polymer by polymerizing an olefin in the presence of the solid catalyst.

Abstract: Multi-layer elastic air quenched blown film structures are disclosed which include: a first layer incorporating a propylene-based copolymer and optionally, a linear low density polyethylene or a low density polyethylene; and at least one second layer incorporating a linear low density polyethylene copolymer and optionally, a propylene-based copolymer and/or a low density polyethylene. Alternatively the second layer of the film structures may contain an in-reactor blend of a substantially linear polyethylene (or a homogeneously branched linear polyethylene) and a linear low density polyethylene. The film structures show an excellent balance of Dart impact, Elmendorf tear (in both the machine direction and cross direction), elastic holding force and elastic recovery.

Abstract: The present invention relates to catalyst systems containing solid catalyst components comprising titanium, magnesium, halogen and a 1,8-naphthyl diaryloate internal electron donor compound; organoaluminum compounds and alkyl benzoate derivatives as external electron donors. The present invention also relates to methods of making the catalyst systems, and methods of polymerizing or copolymerizing alpha-olefins using the catalyst systems.

Abstract: Mono-oriented film having a shrink rate at 100° C. of at least 15% and at least one layer of which comprises a propylene copolymer with ethylene and optionally other olefins of formula CH2?CHR in which R is an alkyl group containing from 2 to 10 carbon atoms, having at least 5.5% wt of ethylene, a melt flow rate according to ISO 1133 (230° C., 2.16 Kg) of less than 10, and a fraction of polymer soluble in xylene at 25° C. ranging from 14 to 30% weight based on the total weight of said copolymer. The said films are particularly suited for the manufacturing of shrink labels.

Abstract: Disclosed herein are catalyst compositions and polymers, i.e., propylene-based polymers, produced therefrom. The present catalyst compositions include an internal electron donor with a compounded alkoxyalkyl ester and optionally a mixed external electron donor. The present catalyst compositions improve catalyst selectivity, improve catalyst activity, and/or improve hydrogen response. Propylene-based polymer produced from the present catalyst composition has a melt flow rate greater than 10 g/10 min.

Abstract: Disclosed herein are procatalyst compositions, catalyst compositions and polymers, i.e., propylene-based polymers, produced therefrom. The present procatalyst compositions contain a halo-malonate and a 2-fluoro-malonate in particular. The present catalyst compositions improve catalyst selectivity, improve catalyst activity, and also improve hydrogen response during polymerization. Propylene-based polymer produced from the present catalyst composition has a melt flow rate greater than 50 g/10 min.

Abstract: An ethylenic polymer comprising amyl groups from about 0.1 to about 2.0 units per 1000 carbon atoms as determined by Nuclear Magnetic Resonance and both a peak melting temperature, Tm, in ° C., and a heat of fusion, Hf, in J/g, as determined by DSC Crystallinity, where the numerical values of Tm and Hf correspond to the relationship Tm?(0.2143*Hf)+79.643. An ethylenic polymer comprising at least one preparative TREF fraction that elutes at 95° C. or greater using a Preparative Temperature Rising Elution Fractionation method, where at least one preparative TREF fraction that elutes at 95° C. or greater has a gpcBR value greater than 0.05 and less than 5 as determined by gpcBR Branching Index by 3D-GPC, and where at least 5% of the ethylenic polymer elutes at a temperature of 95° C. or greater based upon the total weight of the ethylenic polymer.

Abstract: A method for extruding transparent and/or translucent article is provided. In one embodiment, the method comprises providing a propylene-based polymer comprising propylene derived units and one or more dienes, the propylene-based polymer having a triad tacticity of from 50% to 99% and a heat of fusion of less than 80 J/g, extruding the propylene-based polymer in the absence of processing oil into an article; and then crosslinking the extruded article.

Abstract: The fiber-reinforced polymer material, in particular for processing in the injection molding and extrusion method, is composed of granular materials having integrated long-fiber reinforcement. The granular materials are designed as wound elements (5), which have continuous fiber strands (3) including continuous reinforcing fibers (1) impregnated with polymer material (2). The wound elements (5) contain more than one turn (6) of the impregnated continuous fiber strands (3), wherein the turns (6) at least partially overlap each other such that the turns are arranged over each other and/or next to each other. The wound elements (5) can be continuously produced by winding and solidifying the impregnated continuous fiber strands (3) around a winding axis (23) or on a winding core (22) and subsequently separating the wound elements from each other, in particular by means of a winding core moved in an oscillating (+x1, ?x1) manner and using melted thermoplastic polymer material (2).

Abstract: A resin composition includes a polyolefin resin. A viscosity of the resin composition is within a range of not less than 500 Pa·s and not more than 2300 Pa·s under measurement conditions of a measurement temperature of 170° C. and a measurement frequency of 1 Hz. A strain hardening rate of the resin composition in uniaxial elongational viscosity measured under measurement conditions of a measurement temperature of 150° C. and a strain rate of 3.0 s?1 is not less than 800%. A foam insulated wire includes a conductor, and a foam insulation of the resin composition extruded on an outer periphery of thereof. A diameter of the conductor is 3.5 to 18 mm, and an outer diameter of the foam insulation is not less than 8 mm.

Abstract: This invention relates to a propylene polymer comprising a component having a crystallinity of 10% or less and a component having a crystallinity of 20% or more, said propylene polymer having: a) a melting point of X° C. or more where X=?0.0038(Tp)2+0.36(Tp)+150, where Tp is the temperature of polymerization in ° C.; b) an Mw of 10,000 g/mol or more; c) a heat of fusion of from 1-70 J/g; d) Stereodefects per 10,000 monomer units of Y or less where Y=2.35(Tp)?100 (where Tp is the temperature of polymerization in ° C.) for the portion of the blend that is insoluble in hexane at 23° C.; e) a dot T-Peel on Kraft paper of 1 N or more; and f) a branching factor of 0.98 or less, where the branching factor is the ratio of g? measured at Mz to g? measured at Mw, and process to produce such polymers.

Abstract: Embodiments of the present invention relate to article comprising 1) a functionalized component, 2) tackifier, and 3) an olefin polymer comprising one or more C3 to C40 olefins, optionally one or more diolefins, and less than 5 mole % of ethylene having a Dot T-Peel of 1 Newton or more, a branching index (g?) of 0.95 or less measured at the Mz of the polymer; and an Mw of 100,000 or less; where the functional component is selected from the group consisting of functionalized polymers, functionalized oligomers and beta nucleating agents; and where the Gardner color of the adhesive does not change by more than 7 Gardner units when the adhesive has been heat aged at 180° C. for 48 hours as compared to the Gardner color of the unaged composition.

Abstract: The invention relates to novel composition comprising hydroxylamine esters and thio compounds, which are suitable for lowering the molecular weight of polypropylene, propylene copolymers or polypropylene blends and result in an excellent degradation performance at temperatures below 220° C.

Abstract: There is described a method of affecting a thermally induced change to a material which comprises the use of a thermocouple or of a resistance temperature detector as a supply of thermal energy.

Abstract: This invention relates to new transition metal complexes for use in olefin polymerization and oligomerization. The active complex is a pyridine amide having a metallocenyl substituent as part of the ligand structure. The invention also relates to novel precursors for the ligand systems of such complexes obtained from metallocenyl-substituted pyridine compounds through sequences involving addition-condensation or lithium-halogen exchange (with subsequent metathesis) reactions.

Abstract: The invention relates to a new process for treatment of residual nucleic acids present on the surface of laboratory consumables. This process combines two treatment phases: i) Treating with ethylene oxide in gaseous phase; then ii) Treating said surface with hydrogen peroxide in liquid phase or in gaseous phase; The effect of this treatment is to avoid the amplification of said residual nucleic acids, in particular during PCR or TMA reactions.

Abstract: A substance and method for treating a subterranean formation using hydraulic fracturing is provided. The method includes treating a formation with a non-metallic deformable proppant that may be substantially deformable, “elastically flexible”, or “plastically compressible.” The method may include the steps of injecting a carrier fluid into the formation at a pressure and a flow rate sufficient to create or open an existing fracture or fracture network in the formation, and placing at least a portion of the deformable proppant in the fracture by way of the carrier fluid so that the deformable proppant forms substantially a partial monolayer in the fracture, and reducing the pressure and/or the flow rate sufficiently to allow the fracture in the formation to at least partially close, wherein at least a portion of the deformable proppant remains in the fracture to prop open at least a portion of the fracture.

Abstract: A polypropylene resin composition contains 2 to 15 wt % of a moldability improver (A) and 85 to 98 wt % of a polypropylene resin (B). The moldability improver (A) is formed of propylene block copolymers (A-1) and (A-2). Each of the propylene block copolymers (A-1) and (A-2) has a crystalline propylene polymer component (A-11), (A-21) and a propylene-ethylene random copolymer component (A-12), (A-22). The propylene block copolymer (A-1) is characterized in that the melt flow rate of the crystalline propylene polymer component (A-11) is high, whereas the propylene block copolymer (A-2) is characterized in that the content ratio of the propylene-ethylene random copolymer component (A-22) is high. The polypropylene resin (B) is formed of a propylene-ethylene block copolymer (B-1), at least one of an ethylene elastomer and a styrene elastomer (B-2) and an inorganic filler (B-3).

Abstract: A composition that may be useful for thermoforming and blow molding applications comprises a metallocene catalyzed propylene-ethylene random copolymer having an ethylene content of from about 0.1 to about 1.5 weight percent based on the copolymer, and exhibits a flexural modulus of at least about 1,100 MPa, a haze of less than about 40 percent, a melt flow of from about 1.0 dg/min to about 3.0 dg/min, and a xylene solubles content from about 0.2 weight percent to about 1.0 weight percent based on the copolymer. A process for preparing the copolymer and articles prepared therefrom are also disclosed. The composition's properties may make it particularly desirable for applications such as bottles, syringes and containers such as those used for food and medical purposes.

Abstract: Multi-branched polypropylene having a g? of less than 1.00.

Abstract: The invention relates to a continuous process for preparing polyolefins having a bimodal or multimodal molar mass distribution in suspension in at least two reactors R1, R2.x, R3.y which are connected in series and in which different reaction conditions are set. In this process, the offgases A1, A2.x, A3.y, A4 and A5 leaving all the reactors connected in series are firstly collected, the collected offgases are then compressed in a compression stage 10, the compressed offgases are subsequently cooled and the cooled material is separated into a gaseous fraction and a liquid fraction. The separated fractions are then recirculated to the polymerization process at different points. The process of the invention allows the total conversion of the polymerization, based on monomer and comonomer used, to be increased to a surprising extent.

Abstract: A production process of a propylene block copolymer, comprising the steps of (I) contacting a solid catalyst component containing titanium atoms, magnesium atoms and halogen atoms with an organoaluminum compound and an external electron donor represented by the defined formula, thereby forming a polymerization catalyst, (II) polymerizing propylene in the presence of the polymerization catalyst, thereby forming a polymer component (1) having an intrinsic viscosity, [?]1, and (III) copolymerizing propylene with an olefin other than propylene in the presence of the polymer component (1), thereby forming a polymer component (2) having an intrinsic viscosity, [?]2, which is three times or more [?]1.

Abstract: The invention is directed to a polypropylene resin, which is suitable for manufacturing an air quenched blown film. The resin has a melt flow rate of greater than 5 g/10 min, less than 2% xylene solubles, a pentad isotacticity of greater than 95%, an isotactic pentad/triad ratio of greater than 95%, a crystallinity of at least 65%, and a crystallization temperature of at least 127° C. The polypropylene resin contains from 500 ppm to 2500 ppm of a nucleator/clarifier additive. An quenched blown film made from resin exhibits a crystallization onset temperature of at least 116° C. and a crystallization half-life time of less 4.1 seconds or less when tested using fast DSC analysis with a scan rate of 200° C./minute.

Abstract: An object of the present invention is to provide a process of producing propylene by contacting ethylene with a catalyst, where propylene is produced with high selectivity. The present invention relates to a production process of propylene, comprising contacting ethylene with a catalyst, wherein the catalyst comprises a zeolite as an active ingredient and an acid content in the outer surface of the zeolite is 5% or less based on an acid content of the entire zeolite.

Abstract: The disclosed invention relates to a process, comprising: conducting unit operations in at least two process zones in a process microchannel to treat and/or form a non-Newtonian fluid, a different unit operation being conducted in each process zone; and applying an effective amount of shear stress to the non-Newtonian fluid to reduce the viscosity of the non-Newtonian fluid in each process zone, the average shear rate in one process zone differing from the average shear rate in another process zone by a factor of at least about 1.2.

Abstract: A method including: (a) selectively reacting a first sugar in a mixture which includes at least one second sugar to form a product mixture comprising a product of said first sugar; (b) separating said product of said first sugar from said product mixture; and (c) separating at least one of said at least one second sugar from said product mixture.

Abstract: A multi-chamber reactor (1) comprises an outer chamber (2) and at least one inner chamber (3), wherein the at least one inner chamber (3) is formed by a reactor/liner (6), which is closed by a closure (7), in particular a septum or a disk that can be penetrated with a needle, and the outer chamber is an autoclave, wherein the autoclave is composed of an autoclave body (4) and an autoclave cover (5), wherein the autoclave cover (5) has at least one first opening (8) for a needle (9), and preferably a second opening (10), which opens into the outer chamber. Said multi-chamber reactor (1) is suited for carrying out reactions with positive or negative pressure and under complete exclusion of air and/or moisture.

Abstract: Uncompounded polyolefin powder which is multimodal and has a particle size distribution such that D95 is less than 355 ?m, D5 is at least 60 ?m, and (D90?D10)/D50 is less than 1.2, where D95, D90, D50 and D10 are defined such that 95 wt %, 90 wt %, 50 wt % and 10 wt % of the polymer particles have a diameter of less than D95, D90, D50 and D10 respectively.

Abstract: There is disclosed a method for producing a highly cross-linked polypropylene material by plasma polymerisation of a carbon containing gas, not specifically propylene, exhibiting low relative permittivity, high thermal stability and enhanced mechanical properties, said method and material being suitable for application not limited to interlayer dielectric deposition in microchip fabrication.

Abstract: The invention relates to doping capsules which have a substance which displays a decreasing transparency with increasing temperature within a defined temperature range due to physicochemical interactions with the polymer matrix to be doped. Likewise, the invention relates to composite systems which have a polymer matrix doped with the doping capsules. The capsules according to the invention are used for sun protection or heat reflection.

Abstract: Group 4 metal complexes comprising a polyvalent, heteroaryl donor ligand and their use as components of olefin polymerization catalysts, especially suited for preparing propylene/ethylene copolymer products having high isotacticity and low molecular weight, are disclosed.

Abstract: Polymer articles formed from a modified propylene based polymer and processes of forming the same are described herein. The modified propylene based polymers generally include a propylene based polymer, a nucleator including a hyper nucleator, and a neutralizer composition, wherein the neutralizer composition includes a first compound selected from stearoyl lactylates, lactates, hydrotalcites, hydroxides and combinations thereof and may optionally include a second compound selected from metal stearates, wherein the lactates are selected from modified calcium salts derived from stearic and lactic acids and calcium lactates.

Abstract: The present invention relates to the development and manufacture of sorbent products and devices suitable for use in hydrocarbon, universal and hazmat applications that are composed of structural components and/or sorbent materials that are fully biodegradable and landfill friendly. The structural components and/or sorbents may be derived from biodegradable polypropylene or biodegradable natural materials and combined in different sizes, shapes and configurations.

Abstract: A material which is excellent in mechanical strength, solar cell sealing properties, transparency, etc., even in an uncrosslinked state and is used in producing a sheet for solar cell sealing. The thermoplastic resin composition for solar cell sealing comprises (A) 0-70 wt. % propylene polymer having a melting point of 100° C. or higher and (B) 30-100 wt. % propylene copolymer satisfying the following requirements (b). (b) The copolymer has an MFR (230° C., 2.16-kg load) in the range of 0.01-100 g/10 min and satisfies at least one of the following requirements (b-1) and (b-2): (b-1) the rr content is 60% or higher; and (b-2) the copolymer comprises 55-90 mol % structural units derived from propylene and 10-45 mol % structural units derived from a C2-20 ?-olefin (excluding propylene) and has an intrinsic viscosity [?] (dL/g) (measured in 135° C. decalin) satisfying a specific relationship with the MFR.

Abstract: A method for treating polymer particles with steam in a steaming vessel downstream a polymerization process, the method comprising contacting polymer particles with a counter-current flow of steam, wherein the flow rate of steam entering said steaming vessel is continuously maintained proportional to the production rate of said polymer in said polymerization process and to the gradient between the temperature (Tout) of the polymer exiting said steaming vessel and the temperature (Tin) of the polymer entering said steaming vessel.

Abstract: A polypropylene for a film capacitor or a polypropylene sheet for a film capacitor which exhibits excellent stretchability when stretched into a film and provides a film having high breakdown voltage and small thermal shrinkage ratio, and which is suitable for a polypropylene film for a film capacitor and a film capacitor comprising the film. The polypropylene for a film capacitor of the present invention is obtained by irradiating a propylene homopolymer with a radiation with an absorbed dose of 0.1 to 500 kGy, the propylene homopolymer having (1) a melt flow rate (MFR) within a range of 1 to 10 g/10 min as determined at 230° C. under a load of 2.16 kg in accordance with ASTM D1238, (2) an isotactic pentad fraction (mmmm fraction) of not less than 94% as determined using 13C-NMR, (3) an ash amount of not more than 30 ppm as obtained by completely burning the propylene homopolymer in air, and (4) a chlorine amount of not more than 10 ppm as determined by ion chromatography.

Abstract: A propylene-based polymer which is suitably applicable to foam molding, sheet molding, blow molding or the like, because of having good flow characteristics, high melt tension, high swell ratio and thus good molding workability. It is attained by a propylene-based polymer or the like characterized by satisfying the following requirements (i) to (vi). Requirement (i): MFR is 0.1 g/10 minutes to 100 g/10 minutes. Requirement (ii): Q value by GPC is 3.5 to 10.5. Requirement (iii): ratio of components with a molecular weight of equal to or higher than 2,000,000, in a molecular weight distribution curve obtained by GPC, is equal to or larger than 0.4% by weight and less than 10% by weight. Requirement (iv): components, which elute at a temperature of equal to or lower than 40° C., are equal to or less than 3.0% by weight, in temperature rising elution fractionation by ODCB. Requirement (v): isotactic triad fraction (mm) measured with 13C-NMR is equal to or higher than 95%.

Abstract: A blown film that comprises polypropylene that has a melt flow rate of 1.8 to 14.0 g/10 min. and a melting point of at least 115° C. The blown film has a haze of less than 10% and a gloss of greater than 70%. The blown film may be co-extruded with a medium density polyethylene or 15 wt % of an impact copolymer. A clarifier may also be incorporated. The blown film that comprises polypropylene is produced on a standard air cooled blown film line.

Abstract: [Object] To provide a propylene homopolymer suitable for capacitor films having high withstand voltage and a stretched film formed by stretching the propylene homopolymer. [Solution] A propylene homopolymer of the present invention for capacitors satisfies the following requirements (i) to (v) and (ix): (i) the MFR is 1 to 10 g/10 minutes; (ii) the meso pentad fraction (mmm) measured by 13C-NMR is 0.940 to 0.995; (iii) the integrted amount of elution at 90° C. by CFC using o-dichlorobenzene is 0.5% by weight or less; (iv) the melting point measured using DSC is 152° C. or more; (v) the chlorine content is 2 ppm by weight or less; and (ix) in an elution temperature-elution volume curve measured by cross-fractionation chromatography (CFC) using o-dichlorobenzene, the maximum peak has a peak top temperature in the range of 105° C. to 130° C. and half width of 7.0° C. or less.

Abstract: This invention relates to an adhesive comprising a polymer composition comprising at least 50 mol % of one or more C3 to C40 olefins where the polymer composition has (a) a Dot T-Peel of 1 Newton or more on Kraft paper; (b) an Mw of at least 7000 to 80,000; (c) a branching index (g?) of from 0.4 to 0.90 measured at the Mz of the polymer composition; (d) a heat of fusion of 1 to 70 J/g; and (e) a heptane insoluble fraction of 70 weight % or less, based upon the weight of the polymer composition, where the heptane insoluble fraction has branching index g? of 0.9 or less as measured at the Mz of the polymer composition.

Abstract: Metal complexes comprising certain polydentate heteroatom containing ligands, catalysts, and coordination polymerization processes employing the same are suitably employed to prepare polymers having desirable physical properties.

Abstract: A flexible material that comprises one or more types of polymers and may be used for drawing surface-adhesive rules having a pre-defined cross-section profile. Wherein the flexible material has attribute to reserve a shape of a profile of an orifice through which it is deposited from.

Abstract: The present invention provides polymer compositions, comprising a random propylene copolymer having an MFR2 value of 70 or more (g/10 min), which is in particular suitable for preparing thin-walled packaging products by injection molding.

Abstract: [Object] To provide a polypropylene resin composition for use in the formation of a microporous membrane having excellent heat resistance and low thermal shrinkage ratio. [Solution] A polypropylene resin composition for use in the formation of a microporous membrane according to the present invention comprises as an essential component a propylene homopolymer (A) that satisfies the following requirements (1) to (4) and (7): (1) the intrinsic viscosity [?] is 1 dl/g or more and less than 7 dl/g; (2) the mesopentad fraction ranges from 94.0% to 99.5%; (3) the integral elution volume during heating to 100° C. is 10% or less; (4) the melting point ranges from 153° C. to 167° C.; and (7) in an elution temperature-elution volume curve, the maximum peak has a peak top temperature in the range of 105° C. to 130° C. and a half-width of 7.0° C. or less.

Abstract: Monomer/solvent separation and recycle processes for continuous supercritical, solution and advanced solution polymerization processes for propylene-containing polymers and their blends are provided. The advantageous monomer/solvent separation and recycle process includes heating a polymer-lean recycle stream coming from a gravimetric separator positioned downstream of the reactor to form a heated polymer-lean recycle stream, and subsequently combining the heated polymer-lean recycle stream with the one or more homogenous reactor effluent streams to form a heated reactor effluent mixed stream. The heated reactor effluent mixed stream may then be passed through a pressure let-down valve followed and a gravimetric separator, such as to provide for reduced fouling propensity of the polymer-rich phase and sufficient heating of the polymer-rich phase to be able to pass through the remainder of the processing steps to form a propylene based polymer product without additional heat.

Abstract: The present invention relates to a process to make alpha olefins comprising: dehydrating ethanol to recover an ethylene stream, introducing said ethylene stream into an oligomerization zone containing an oligomerization catalyst and into contact with said oligomerization catalyst, operating said oligomerization zone at conditions effective to produce an effluent consisting essentially of 1-butene, 1-hexene, optionally heavier alpha olefins and unconverted ethylene if any, introducing the above effluent into a fractionation zone to recover a stream consisting essentially of 1-butene, a stream consisting essentially of 1-hexene, optionally a stream consisting essentially of heavier alpha olefins and an optional ethylene stream. In an advantageous embodiment the 1-hexene or at least one heavier alpha olefins, if any, are isomerized to an internal olefin and subsequently transformed by metathesis with the aid of additional ethylene into different alpha-olefins with even or odd number of carbons.

Abstract: An optical compensation film according to an embodiment of the present invention includes: non-liquid crystal polymers arranged in a tilt alignment, wherein the optical compensation film satisfies the following expressions (1) and (2): 3 [nm]?(nx?ny)×d;??(1) and 5°<?,??(2) where, when an X-axis and a Y-axis, which are plane direction axes of a three-dimensional coordinate system, are perpendicular to each other and an axis vertical to the X-axis and the Y-axis in a thickness direction is defined as a Z-axis, nx and ny indicate a maximum refractive index and a minimum refractive index in an XY-plane of the optical compensation film, respectively, d indicates a film thickness [nm], and ? indicates an angle formed between a direction for providing the minimum refractive index ny and a direction for providing a maximum refractive index nb in a YZ-plane of the optical compensation film.

Abstract: Random propylene/ethylene copolymers are provided characterized by Ethylene content in the range of 4.5-7% wt; Mw/Mn (via GPC) in the range 3.5-5.5; Mz/Mw (via GPC) lower than 4; absence of 2-1 regioinversion, and Melting Temperature (Tm) (non-nucleated grade) lower than 143° C. The said copolymers show an excellent balance of impact and optical properties which is retained even after visbreaking.

Abstract: A fuel cell adhesive comprises a polyolefin adhesive having a bonding strength sufficient to adhere two fuel cell stack components together. The bonding strength of the polyolefin adhesive is less than the cohesive strength of any of the fuel cell stack components such that two adhesively bonded fuel cell stack components can be easily separated and re-joined without causing any mechanical damages to the fuel cell stack components. The polyolefin adhesive may be prepared by polymerizing at least an ?-olefin monomer in the presence of a molecular weight controlling agent.