Polyethylene EPDM blends having tensile

Morphology of Low Density Polyethylene/ EPDM Blends Having Tensile Strength Synergism... [Pg.361]

Table VI yields the methylene sequence distribution of these two EPDM rubbers. A measure of the fraction of long methylene runs is important to the understanding of physical properties of these and similar materials. Polyethylene blends with EPDM rubbers, having appropriate long runs of ethylene, have been shown ( 1 ,1 ) to have unusually high tensile strengths.

$Table VI yields the methylene sequence distribution of these two EPDM rubbers. A measure of the fraction of long methylene runs is important to the understanding of physical properties of these and similar materials. Polyethylene blends with EPDM rubbers, having appropriate long runs of ethylene, have been shown ( 1 ,1 ) to have unusually high tensile strengths.$

Setua and White (1991 a,b) used CM (chlorinated polyethylene) as a compatibilizer to improve the homogeneity of binary and ternary blends of CR, NBR, and EPR. NBR-EPM and CR-EPDM blends homogenize more rapidly when small amounts of CM are added. The presence of the compatibilizer leads to reductions in both the time needed for mixing, observed by flow visualization, and the domain size of the dispersed phase, observed by SEM. Arjunan et al. (1997) have used an ethylene acrylic acid copolymer and an EPR-g-acrylate as a compatibilizer for blends of EPDM-CR. The addition of the compatibilizer leads to the reduction in the phase size of the dispersed EPDM phase as well as increase in the tensile tear strength of the blend. [Pg.577]

A blend of low-density polyethylene (LDPE) polyethylene (LDPE) with the terpolymer ethylene-propylene-diene monomer rubber (EPDM) exhibits a synergistic effect on tensile strength if EPDM is partially crystalline, but a nonsynergistic effect if the EPDM is amorphous [65]. This example shows the dramatic effect that morphology can have on properties of polymer blends. The synergism apparently arises from a tendency for crystallites in the LDPE to nucleate crystalli2ation of ethylene segments in the EPDM. [Pg.529]

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]. [Pg.569]

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