Abstract:
Processes for producing impact copolymers are provided. Ethylene and at least one copolymer can be polymerized in the presence of one or more catalysts, polypropylene particles, and one or more halocarbon compounds to produce an impact copolymer that includes the polypropylene particles and an ethylene copolymer.
Abstract:
The present disclosure provides a catalyst system comprising the product of a catalyst compound capable of making crystalline material (such as isotactic PP) and a second catalyst compound capable of making non-diene-containing-amorphous material and diene-containing-elastomeric material. The catalyst system of the present disclosure may further comprise a support material (or product thereof) having one or more of: a surface area of from 400 m2/g to 800 m2/g; an average pore diameter of 90 Angstroms or greater; an average particle size of 60 μm or greater; 40% or greater of the incremental pore volume comprising pores having a pore diameter larger than 100 Angstroms or greater; and sub-particles having an average particle size in the range of 0.01 μm to 5 μm. In another embodiment, a propylene polymer composition includes: isotactic polypropylene; 5 wt % or greater of atactic polypropylene, based on the weight of the composition; and an ethylene-propylene-diene terpolymer. The present disclosure further provides methods for forming propylene polymer compositions.
Abstract:
Sequential, double elastomer vulcanization method, system, and composition. First and second immiscible elastomers are mixed together with a first additive package. A first curative system is activated to vulcanize the first elastomer in a dispersed phase of the first elastomer to form a partially vulcanized mixture while maintaining melt flowability of the second elastomer in a continuous phase. Then, a second curative system is activated to vulcanize the second elastomer in the continuous phase. Since the partially vulcanized mixture is melt processable, a second additive package can be introduced to the mixture after activating the first curative system. Or, the second curative system can be activatable at a temperature which is higher than an activation temperature of the first curative system. In this manner, blends of dissimilar elastomers can be vulcanized with independent control of plasticizer, filler and curative distribution.
Abstract:
Pellet-stable olefinic copolymer bimodal rubber is made using parallel reactors, with one reactor synthesizing higher molecular weight (MW) rubber with dual catalysts, with an improved molecular weight split ratio and an improved composition distribution of the moderate and ultra-high MW components, while another reactor synthesizes random isotactic polypropylene copolymer (RCP). The effluents are reactor-blended and result in pellet-stable bimodal rubber (P-SBR), which may be pelletized. When making thermoplastic vulcanizates (TPVs) with P-SBR, the need to granulate rubber bales and subsequently use talc, clay, or other anti-agglomeration agents to prevent granulated rubber crumbs from agglomerating are eliminated. TPVs made with P-SBR have vulcanized rubber particles that are smaller and more uniform in size, resulting in TPVs with higher particle counts and more thermoplastic “ligaments” between the particles, with such ligaments being made stronger by the added RCP. Such thus-produced TPVs have a lower hysteresis and flexural modulus, and better elastic properties.
Abstract:
Methods for the production of heterophasic polymers in gas and slurry phase polymerization processes, and polymer compositions made therefrom, are disclosed herein.
Abstract:
Disclosed is a thermoplastic polyolefin composition useful in automotive components comprising at least a polypropylene having a melting point temperature (Tm) of greater than 130° C. and a melt flow rate (230° C./2.16 kg) within the range from 10 g/10 min to 80 g/10 min; an amorphous ethylene-propylene copolymer comprising within the range from 40 wt % to 80 wt % ethylene derived units and having a melt flow rate (230° C./2.16 kg) within the range from 0.1 g/10 min to 20 g/10 min; and a propylene-based elastomer having within the range from 5 to 25 wt % ethylene derived units and having a Tm of less than 110° C. The composition only partially breaks or there is no break at −29° C. (ASTM D256) with Notched Izod Force of between 10 to 40 ft-lb/in2 at 22° C. (533 to 2,132 J/m2), and between 1.0 to 12 ft-lb/in2 at −29° C. (53 to 636 J/m2).
Abstract:
This invention relates to a thermoplastic polyolefin composition with (a) 45 wt % to 70 wt % of a polypropylene having 70 wt % or more units derived from propylene, having a melting point temperature of greater than 130° C. and a melt flow rate from 2 to 80 g/10 min; (b) 20 wt % to 30 wt % of a bimodal ethylene-propylene copolymer comprising: (i) 80 wt % to 90 wt % of an amorphous ethylene-propylene copolymer having about 30 wt % or more units derived from ethylene; (ii) 5 wt % to 15 wt % of a semi-crystalline ethylene-propylene copolymer having 70 wt % or more units derived from ethylene; and (iii) 1 wt % to 5 wt % of a propylene-based elastomer having within the range from 5 wt % to 25 wt % ethylene derived units and having a melting point temperature of less than 110° C. and a Mw/Mn within the range from 2.0 to 4.0.
Abstract:
Bimodal polypropylene compositions and a process to form melt blended bimodal polypropylene compositions comprising combining at least two polypropylenes in at least a two-pass process, and forming a bimodal polypropylene composition having a Flexural Modulus (190° C., 1% secant) of at least 1700 MPa, as well as one or more other selected properties. These compositions are suitable for thermoformed articles and injection molded articles, any of which may be foamed.
Abstract:
Methods for the production of heterophasic polymers in gas and slurry phase polymerization processes, and polymer compositions made therefrom, are disclosed herein.
Abstract:
Disclosed is the preparation of compatibilized thermoplastic vulcanizates with reduced crosslinked rubber dispersion sizes and dispersity. A cross-linkable ethylene-propylene-diene terpolymer with majority propylene (PEDM) is used to compatibilize a plastic and rubber blend of a polypropylene (PP) and an ethylene-propylene-diene terpolymer rubber, where the propylene content is less than 50 wt % (EPDM), in dynamic vulcanization and preparation of PP/EPDM thermoplastic vulcanizates. The resulting PP/EPDM thermoplastic vulcanizates typically exhibit a weight average equivalent dispersion diameter of less than 3 microns and a particle size polydispersity index (PSDI), or weight average over number average dispersion diameter, of less than 5. This reduction in crosslinked rubber dispersion size in a PP/EPDM TPV by using PEDM compatibilizers enhances the toughness of the vulcanizate product by raising both elongation to break and break stress.