Polypropylene and its Blends

The mechanism of MA grafting is related to the mechanism of MA homopolymerisation - in the reactive species is an excited dimer of MA. Since the excited dimer is capable of 

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Recycling of Polypropylene and Its Blends Economic and Technology Aspects... 

Hosier IL, Vaughan AS, Swingler SG (2011) An investigation of the potrmtial of polypropylene and its blends fOT use in recyclable high voltage cable insulation systems. J Matra- Sci 46 4058-4070... 

Deformation Behavior of P-Crystalline Phase Polypropylene and Its Rnhber-Modified Blends... 

Karger-Kocsis, J. (1995) Microstructural Aspects of Fracture in Polypropylene and its Filled, Chopped Fiber and Fiber Mat Reinforced Composites, in Polypropylene Structure, Blends and Composites, Vol. 3, Chap. 4, (ed. J. Karger-Kocsis), Chapman Hall, London, pp. 142-201. 

Mechanical testing (strain-stress, tensile strength, elongation at break, elastic modulus, melt flow, viscoelastic properties, etc), have frequently been used in the study of the photodegradation of polyethylene [711, 1656, 1704, 1750, 1957, 2124, 2128], polypropylene [1750, 1899, 1903], poly(styrene) [748], poly(styrene-co-carbon monoxide) [1429], poly(styrene-co-acrylonitrile) [747], EPDM [896], poly(vinyl chloride) [806,1137,1138,1232,1748,1938], impact modified poly(vinyl chloride) [761, 764,1232], nylon 6 [672, 726, 727, 1395,1396,2300,2305], polyethylene blends with nylon 6 [506], and polyurethanes and its blends with poly(vinyl chloride), poly(vinyl alcohol), poly(vinyl acetate) and poly(vinyl chloride-co-vinyl acetate) [652]. 

Some of the most difficult heterophase systems to characterize are those based on hydrocarbon polymers such as mbber-toughened polypropylene or other blends of mbbers and polyolefins. Eecause of its selectivity, RuO staining has been found to be usehil in these cases (221,222,230). Also, OsO staining of the amorphous blend components has been reported after sorption of double-bond-containing molecules such as 1,7-octadiene (231) or styrene (232). In these cases, the solvent is preferentially sorbed into the amorphous phase, and the reaction with OsO renders contrast between the phases. 

Once a blend has been successfully manufactured, it is possible to describe the properties. A good illustration of these properties can be found with a blend of polypropylene and... 

Substitute for Conventional Vulcanized Rubbers, For this application, the products are processed by techniques and equipment developed for conventional thermoplastics, ie, injection molding, extrusion, etc. The S—B—S and S—EB—S polymers are preferred (small amounts of S—EP—S are also used). To obtain a satisfactory balance of properties, they must be compounded with oils, fillers, or other polymers compounding reduces costs. Compounding ingredients and their effects on properties are given in Table 8. Oils with high aromatic content should be avoided because they plasticize the polystyrene domains. Polystyrene is often used as an ingredient in S—B—S-based compounds it makes the products harder and improves their processibility. In S—EB—S-based compounds, crystalline polyolefins such as polypropylene and polyethylene are preferred. Some work has been reported on blends of liquid polysiloxanes with S—EB—S block copolymers. The products are primarily intended for medical and pharmaceutical-type applications and hardnesses as low as 5 on the Shore A scale have been reported (53). 

Homopolymers are sometimes modified by a mechanical admixture of another homopolymer. As only about 5 % of pairs of all known polymers are mutually miscible, compatibility may be a problem in mixtures (blends). Copolymerization is technically applied to overcome, for example, the brittleness of polystyrene, polypropylene and PVC. It is also applied for improving the curing properties and modifying the viscoelastic properties of rubbers. By copolymerization, the relation between the hydrophobic and hydrophilic properties of macromolecules can also be modified. Their resistance to solvents may be enhanced. 

CINDYE DAC-888 is a butyl benzoate type carrier for the dyeing of polyester, polypropylene, and triacetate fibers and blends containing these fibers. It can be used as a carrier with disperse, cationic, and dyestuffs. 

Blends of Polypropylene and Poly(Methyl Methacrylate). In seeking explanations for the experimental observations in blend degradations, it is important to consider the form in which the polymer is being degraded. Since compatibility, especially in polymers as unlike chemically as PP and PMMA, is the exception rather than the rule and since the blend samples were translucent, it seems most likely that the low concentration component, PMMA, is dispersed as discrete micelles in a matrix of PP. Thus, any interaction between the degradation reactions of the two components must occur across a fairly well defined phase boundary. Because of the severe restrictions on the motion of macromolecules... 

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