Showing papers on "Plastomer published in 1998"

Fluorinated thermoplastic elastomers

Abstract: Compositions containing fluorinated thermoplastic elastomers with different moelcular weight and with different plastomeric phase/elastomeric phase ratio, essentially formed by: (a) 30-80% by weight, preferably 50-80%, of a fluorinated thermoplastic elastomer, having a block structure of A-B-A type, wherein A is a plastomeric segment and B is an elastomeric segment; (b) 10-50% by weight, preferably 20-40% of a fluorinated thermoplastic elastomer having a block structure of A-B-A type; (c) 0-30% by weight, preferably 0-15%, of a fluorinated plastomer preferably of the same kind as that contained in the component (a) and/or (b).

Effect of elastomeric and plastomeric tougheners on different properties of recycled polyethylene

Abstract: The effect of two elastomers and a newly developed plastomer on rheological, mechanical, and thermal properties of their blends with a commercially available recycled polyethylene were studied. The results show effective improvements in engineering properties of the recycled polyethylene (PE). Low percentages of these modifiers give rise to higher elastic properties of the blends. Addition of all modifiers resulted in decreases in crystallinity and in melting point of the blends. Depending on modifier type the intensity of the changes was different. It is concluded from infrared spectra of the blends that no chemical interaction occurs during melt mixing of the ingredients. These improvements are attributed to morphological changes and physical interactions between modifiers and PE matrix. In melt state, as the modification percentage increases and depending on the nature of modifier, the resulting blends show different rheological behavior: EPDM447 constantly increases the viscosity and elasticity of the corresponding blends; EPDM541 is almost ineffective; and EXACT™ 4041 decreases and then increases these properties, depending on its concentration in the blend. The results presented in terms of weighed relaxation time spectra show different behaviors depending on the additive. For all modifiers, the 7% modification was always found to have the most pronounced effect on almost all properties of the blends. It was also found that EPDM447 shows the best effects on different properties of the recycled PE. © 1998 John Wiley & Sons, Inc. Adv Polym Techn 17: 127–143, 1998

Comparison of EVA and Polyolefin Plastomer as Blend Components in Various Film Applications

Abstract: Ethylene vinyl acetate (EVA) copolymers at various %VA content and AFFINITY** polyolefin plastomers (POP) were evaluated as blend components in various film applications rich in LDPE and LLDPE. The EVA resin miscibility with LDPE or LLDPE decreased as the VA content increased so that high VA EVA resins were partially or completely immiscible with LDPE or LLDPE resins. Both POP resins were miscible with LDPE or LLDPE resins. The blown films of LDPE/POP blends gave lower heat seal initiation temperature and lower haze compared to LDPE/EVA blended films. This is due to immiscibility of Elvax 3165 (18% VA) and Elvax 3128 (9% VA) with the LDPE resin. The impact and tear resistance of the POP based blown films were also superior. Oriented films of blends of POP with LLDPE and ULDPE resins exhibited significantly lower haze compared to blends of 12% VA EVA with LLDPE and ULDPE resins. Again, this is due to partial immiscibility of 12% VA EVA with LLDPE and ULDPE resins. The oriented films of blends of POP with LLDPE and ULDPE resins exhibited similar shrinkage at 90°C compared to blends of 12% VA EVA with LLDPE and ULDPE resins.

Outgassing Rate Measurement of the Electrical Cables and the Elastomer/Plastomer Materials

Abstract: Some kinds of the electrical cables and elastomer/plastomer materials, though having high outgassing rates, are occasionally used in a high vacuum system. In order to evaluate the ultimate pressure of the system in which those materials are to be installed, their outgassing rates have been measured as a function of pumping time by a through-put method. The outgassing rates of the cables and glass-fiber sleevings ranged from 10-9 to 10-5 Pa·m3. s-1. m-1 at 100 h, depending on the insulation materials or varnishing treatment. From the tests of the elastomer/plastomer materials, it was ascertained that the organic materials give high outgassing rates of the orders of 10-5 to 10-3 Pa·m3·s-1·m-2 at 100 h.

The Changes in Ethylene Oxide Sterilization and Their Effect on Thermoplastics

Abstract: Thermoplastics are widely used in the disposable medical device industry. Sterilization of these devices is critical in any application that comes in contact with a body or bodily fluids. Ethylene oxide (EO) and gamma sterilization are the most common sterilization methods for disposable medical instruments. This chapters presents studies of 14 different families of resins: general purpose polystyrene, GPPS, high impact polystyrene, HIPS, advanced styrenic resin, ASR, styrene-acrylonitrile, SAN, acrylonitrile-butadiene-styrene, ABS, polycarbonate, PC, rigid thermoplastic polyurethane (RTPU), high density polyethylene (HDPE), polyolefin plastomer (POP), polyolefin elastomer (POE), polypropylene (PP), polyvinyl chloride (PVC), Nylon, and acrylic. Each resin was exposed to the three gases at two levels of exposure. One cycle represented a typical sterilization cycle and three cycles were selected to model an extreme sterilization situation.

Elastomer composition and its use as gliding agent on elastomer or plastomer profiles

Abstract: of EP0881260Elastomeric composition comprises, in phr (in pts. per 100 pts. total resins and/or elastomers), 5-15 phr EPDM (ethylene propylene diene monomer), 30-50 phr styrene-butadiene rubber (SBR) and 40-60 phr styrenic resin, and up to 2 phr carbon black. Also claimed is a contoured piece coated with the composition.

Composition improved in compression set and instrument made therefrom

Abstract: PROBLEM TO BE SOLVED: To obtain a composition with improved tribological characteristics to reduce morphological changes while it is in service, by making the composition include a mixture of an ethylene/α-olefin metallocene copolymer and styrene/diene block copolymer. SOLUTION: This composition contains (A) an ethylene/3-20C α-olefin metallocene copolymer (e.g. plastomer) and (B) a styrene/diene block copolymer containing 10 to 25 wt.% of styrene (e.g. styrene/butadiene/styrene copolymer), to cross-link the molecules. It is preferable to use the above composition which contains approximately 0.5 to 12.5 wt.% of styrene, and one having a compression set of 70% or less and preferably a durometer hardness of 40 to 60A is preferably used for medical instruments.

Composition comprising metallocene plastomer and ethylene/alkyl (meth)acrylate polymer with their secant moduli ratio greater than 1

Abstract: The invention concerns a composition comprising a metallocene ethylene/alpha-olefin copolymer; and an ethylene/alkyl (meth)acrylate copolymer with their secant moduli ratio greater than 1. The invention also concerns films obtained from said composition, in particular an adhesive film capable of being drawn, and a high temperature extrusion method.

Morphological Studies of Metallocene Plastomer Modified Polypropylenes

Abstract: The dispersion of metallocene plastomers in homopolymer polypropylene varying from low to high melt flow rates were examined by low voltage scanning electron microscopy, LVSEM, using ruthenium tetroxide stained cryomicrotomed samples. Micrographs obtained were used to count the cross-sectional area of several hundred particles. The particles areas were next converted in equivalent diameters. At up to 20 melt flow rate of the base polypropylene, the average particle size remained to be 0.5 μm. Only at high melt flow rate, i.e., 35 MFR did the base polypropylene alter the plastomer dispersion. In this instance, the average particle size was increased to 0.8 μm, but still less than the 1 μm threshold necessary for cold temperature impact modification of polypropylene. Solubility data for ethylene-butene plastomers at varying comonomer content were measured using small angle neutron scattering, SANS. The interfacial tension between plastomer and polypropylene could be then calculated from measured solubility parameters. Low interfacial tensions between ethylene-butene plastomer and polypropylene promoted submicron dispersion of plastomer in both low and high melt flow polypropylenes. The application of Wu's model for predicting plastomer dispersion was not successful.

Plastomer Modified Polypropylene Films for Medical Product Packaging

Abstract: Despite the rapid growth of polypropylene as a material of construction for radiation-sterilized medical devices, polypropylene films have not achieved similar use in packaging either devices or medical solutions. The high ratio of film surface area to mass, combined with the sensitivity of irradiated polypropylene to oxygen-promoted degradation, causes them to be severely embrittled after normal sterilizing doses of radiation. Even resin formulations that yield highly radiation resistant injection molded devices are badly degraded after irradiation in thin film form. This chapter demonstrates, however, that blends of Exact® ethylene plastomers with propylene homo-polymers successfully withstand ϒ-radiation doses in excess of 50 kGy. It is now possible to produce polypropylene film that can be usefully applied to the packaging of radiation-sterilized medical devices.

Roofing sheet with studs

Abstract: A vapour pressure equalisation sealing sheet, for roofs and the like, has upper and lower cover layers (5, 1) with supports (3) on the underside of the lower cover layer (1) which form a connected cavity system between the sheet and the roof to be sealed. The novelty is that a self-adhesive layer (7) is provided on the underside of the lower cover layer (1) and the supports (3). Preferably, the sheet has a supporting inlay (2) in the form of glass fabric or the like, infiltrated with bitumen or polymer bitumen, especially plastomer bitumen. The lower and upper layers (1, 5) preferably consist of filler-stabilised plastomer bitumen.

Preparation of Metallocene Plastomer Modified High Flow Thermoplastic Olefins

Abstract: Metallocene plastomers are ethylene-α-olefin copolymers with a density range from 0.91 to 0.86 and a melt index ranging from less than 1 to 125. The high efficiency single site catalysts provide uniform comonomer insertion, so that at a relatively low comonomer level, the copolymer exhibits both plastics and elastomeric characteristics. In this study, both batch (Banbury) and continuous (extruder) mixing devices were used to melt blend the plastomer into a high flow (35 MFR) homopolymer polypropylene. A mixing device of choice needs to provide both distributive and dispersive mixing as well as adequate mixing time. Examples of good mixing devices are a twin screw extruder or a single screw extruder equipped with a mixing section.

Composition comprising metallocene plastomer of density less than 0.900 and ethylene /alkyl (meth)acrylate copolymer

Abstract: The invention concerns a composition comprising a metallocene ethylene/alpha-olefin copolymer of density less than 0.900 g/cm3; and an ethylene/alkyl (meth)acrylate radical copolymer. The invention also concerns films obtained from said composition, in particular an adhesive film capable of being drawn, and a high temperature extrusion method.

Films comprising metallocene catalyzed plastomer and ethylene/alkyl (meth)acrylate copolymer

Abstract: The invention concerns a composition comprising an ethylene/alpha-olefin metallocene copolymer of density less than 0.900 g/cm 3 and an ethylene/alkyl (meth)acrylate radical copolymer. The invention also concerns films obtained from said composition, in particular a stretchable adhesive film, and a high temperature extrusion method.