Polypropylene-Polyamide

Almeras and co-workers [40] studied the efficiency of various compatabilising agents in intumescent PP-PA-6-APP blends. It was shown that addition of APP and PA-6 

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Many industrial semi-crystalline polymer materials like polypropylene, polyamides, or polyesters contain nucleating agents or clarifiers which form needle-shaped aggregates already in the polymer melt. "For this purpose the pattern is desmeared using the measured primary beam. For a less involved treatment it may be sufficient to know the integral width of the primary beam profile in fiber direction. 

Towflex (Hexcel Composites) is based on carbon, glass or aramid fibres impregnated with polypropylene, polyamide, PPS, polyetherimide, PEEK. Product forms include flexible Towpreg, woven fabric, braided sleeving, UD tape, chopped compression moulding compound, moulded plates, thermoformable laminates. 

SUPreM, Plytron, Quadrax (Gurit Suprem) consolidated tapes or fabrics are made from continuous fibres impregnated with thermoplastic powder. The fibres can be glass, aramid, carbon, steel and the matrices are polyethylene, polypropylene, polyamide, PPS, polyetherimide, PEEK, thermoplastic polyimide, or fluorothermo-plastic. High levels of fibres can be obtained, 65% in volume, for example. 

Y. Tang, Y. Hu, L. Song, R. Zong, Z. Gui, and W. Fan, Preparation and combustion properties of flame retarded polypropylene/polyamide-6 alloys, Polym. Degrad. S(abil., 2006, 91 234—241. 

Tang Y, Hu Y, Song L, Zong RW, Gui Z, Fan WC. Preparation and combustion properties polypropylene-polyamide-6 of flame retarded alloys. Polym. Degrad. Stab. 2006 91 234-241. 

Two main criteria for the membrane selection are pore size and material. As peroxidases usually have sizes in the range of 10-80 kDa, ultrafiltration membranes with a molecular cutoff between 1 and 50 kDa are the most adequate to prevent enzyme leakage [99]. The materials commonly applied to ultrafiltration membranes are synthetic polymers (nylon, polypropylene, polyamide, polysulfone, cellulose and ceramic materials [101]. The adequate material depends on a great number of variables. When enzyme is immobilized into the matrix, this must be prepared at mild conditions to preserve the enzymatic activity. In the case of enzyme immobilization onto the membrane, this should be activated with the reactive groups necessary to interact with the functional groups of the enzyme. If an extractive system is considered, the selection of the hydrophilicity or hydro-phobicity of the membrane should be performed according to the features of reactants, products, and solvents. In any case, the membrane should not interfere with the catalytic integrity of the enzyme. 

Polymeric membranes are prepared from a variety of materials using several different production techniques. Table 5 summarizes a partial list of the various polymer materials used in the manufacture of cross-flow filters for both MF and UF applications. For microfiltration applications, typically symmetric membranes are used. Examples include polyethylene, polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) membrane. These can be produced by stretching, molding and sintering finegrained and partially crystalline polymers. Polyester and polycarbonate membranes are made using irradiation and etching processes and polymers such as polypropylene, polyamide, cellulose acetate and polysulfone membranes are produced by the phase inversion process.f Jf f ... 

Toughened Polypropylene-Polyamide 6 Blends Prepared by Reactive Blending... 

Figure 7.33. Entrance-exit pressure drop in capiUaiy flow of polypropylene, polyamide-6, and commercial PP/PA-6 blend, Orgalloy at 230°C — line computed from Eq 7.132.

Polypropylene-Polyamide Blends with Compatibilizing Agents... 

Eor polypropylene/polyamide/grafted rubber ternary blends, TEM was proved to be a good tool to study their phase morphology. Without grafting, EPR (217) or SEBS (218) formed dispersed particles together with the minor component of the blends separately however, after grafting with maleic anhydride they could encapsulate the dispersed minor component of the blends (214,217-221). 

Both from an applied and from an academic point of view, the polypropylene/ polyamide 6 system is indeed one of the most studied polymer/polymer binary systems, together with the interfacial modification possibilities induced in the morphology of the blend either by mixing during the processing steps or by the presence of interfacial modifiers. 

Isophorone [14.268], [14.269] is an unsaturated cyclic ketone. It consists of a-isophorone [78-59-1] (3,5,5-trimethyl-2-cyclohexen-l-one), which contains about 1-3% of the isomer P-isophorone [471-01-2] (3,5,5-trimethyl-3-cyclohexen-l-one). Isophorone is a stable, water-white liquid with a mild odor that is miscible in all proportions with organic solvents. It dissolves many natural and synthetic resins and polymers, such as poly(vinyl chloride) and vinyl chloride copolymers, poly(vinyI acetate), polyacrylates, polymethacrylates, polystyrene, chlorinated rubber, alkyd resins, saturated and unsaturated polyesters, epoxy resins, cellulose nitrate, cellulose ethers and esters, damar resin (dewaxed), kauri, waxes, fats, oils, phenol-, melamine-, and urea-formaldehyde resins, as well as plant protection agents. However, isophorone does not dissolve polyethylene, polypropylene, polyamides. 

Impact modifiers are added primarily to PVC, polyethylene, polypropylene, polyamides and polyesters. They absorb the energy generated by impact and dissipate it in a non-destructive way. Impact modifiers are physically rubbery and semi-compatible with the polymer. The mechanism of absorbing impact in polymers is not fuUy understood, but these additives increase the tensile strength of the material. The impact modifiers most commonly used include acrylonitrile-butadiene-styrene (ABS) polymers, acrylics and ethylene-vinyl acetate (Carraher, 2000). ABS generates opacity or stress-whitening when used as... 

Polarized light microscopy micrographs of a P-nucleated isotactic polypropylene/polyamide-6 (iPP/PA-6) blend containing 5 wt% PA-6. Isothermal crystallization was carried out at = 135X for (a) t = 0 min, (b) = 21 min, (c) f = 45 min, and (d) = 60 min. (Reproduced from Menyhard, A., Varga, J., Liber, A., and Belina, G. 2005. Polymer blends based on the P-modification of polypropylene. European Polymer Journal 41 669-677 with permission from Elsevier.)... 

Xian-Wu, C., Z. Zi-Cong, X. Ying, and Q. Jin-Ping. 2010. The effect of polypropylene/ polyamide 66 blending modification on melt strength and rheologic behaviors of polypropylene. Polymer Bulletin 64 197-207. 

Variation of Gq with E for polypropylene-polyamide 6 joints reinforced with PP-PA-6-grai id chains [14]. 

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