Polyethylene blends with polypropylene

Examples of such compatibilized systems that have been studied include EPDM/PMMA blends compatibilized with EPDM- -MMA, polypropylene/polyethylene blends with EPM or EPDM, polystyrene/nylon-6 blends with polystyrene/nylon-6 block copolymer, and poly(styrene-co-acrylonitrile)/poly(styrene-co-butadiene) blends with butadiene rubber/PMMA block copolymer. 

N.K. Madi, Thermal and mechanical properties of injection molded recycled high density polyethylene blends with virgin isotactic polypropylene. Mater. Des. 46, 435-441 (2013)... 

The low coefficients of friction shown by the polysiloxanes have been exploited in reducing abrasion or wear on a variety of materials. For example, PDMS thin coatings on mica were studied in this regard. PDMS block copolymers have been blended with polypropylene and high-density polyethylene for this purpose. Closely related is the scratch resistance of elastomeric PDMS coatings on materials such as stainless steel. ... 

MA Ramos, FA Belmontes. Polypropylene/low density polyethylene blends with short glass fibers. II. Effect of compounding method on mechanical properties. 

Thus, Clendening and Potts [150] claimed disintegrability of blends of PCL with low-density polyethylene and with polypropylene. Subsequently, Iwamoto and Tokiwa [151] studied blends of PCL with low-density polyethylene and ob-... 

J. Elastomers Plast. 9(7), 281 (1977). Thermoplastic IPNs. Block Copolymers blended with polypropylene. Block copolymers blended with polyethylene. 

W. K. Fischer (see Uniroyal, Inc.), Dynamically Partially Cured Thermoplastic Blend of Monoolefin Copolymer Rubber and Polyolefin Plastic, U.S. Pat. 3,806,558 (1974). EPM or EPDM partly cured, blended with polypropylene or polyethylene. Thermoplastic IPNs. 

The polyolefin block copolymers are lower in cost. Their suggested applications (74) include wire and cable insulation, replacements for PVC and styrenic block copolymers, and blends with polypropylene, either to improve impact resistance or as the soft phase in a hard polymer/elastomer combination. Processing conditions are similar to those for polyethylene, and thermal stability is excellent. 

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]. 

Blends of isobutylene polymers with thermoplastic resins are used for toughening these compounds. High density polyethylene and isotactic polypropylene are often modified with 5 to 30 wt % polyisobutylene. At higher elastomer concentration the blends of butyl-type polymers with polyolefins become more mbbery in nature, and these compositions are used as thermoplastic elastomers (98). In some cases, a halobutyl phase is cross-linked as it is dispersed in the polyolefin to produce a highly elastic compound that is processible in thermoplastic mol ding equipment (99) (see Elastomers, synthetic-thermoplastic). ... 

Polyethylene is sometimes blended with ethylene-propylene rubber (see Chapter 11). In this application it is most commonly used as an additive to the rubber, which in turn is added to polypropylene to produce rubber-modified... 

Other additives. Amorphous polypropylene, waxes and asphalt can be added to decrease the cost of BR formulations. On the other hand, PIB can be blended with NR, styrene-butadiene rubber, EVA and low molecular weight polyethylene to impart specific properties. 

PESA can be blended with various thermoplastics to alter or enhance their basic characteristics. Depending on the nature of thermoplastic, whether it is compatible with the polyamide block or with the soft ether or ester segments, the product is hard, nontacky or sticky, soft, and flexible. A small amount of PESA can be blended to engineering thermoplastics, e.g., polyethylene terepthalate (PET), polybutylene terepthalate (PBT), polypropylene oxide (PPO), polyphenylene sulfide (PPS), or poly-ether amide (PEI) for impact modification of the thermoplastic, whereas small amount of thermoplastic, e.g., nylon or PBT, can increase the hardness and flex modulus of PESA or PEE A [247]. 

Chattopadhyay S., Chaki T.K., and Bhowmick A.K., New thermoplastic elastomers from poly(ethyle-neoctene) (engage), poly(ethylene-vinyl acetate) and low-density polyethylene by electron beam technology structural characterization and mechanical properties. Rubber Chem. TechnoL, 74, 815, 2001. Roy Choudhury N. and Dutta N.K., Thermoplastic elastomeric natural rubber-polypropylene blends with reference to interaction between the components. Advances in Polymer Blends and Alloys Technology, Vol. 5 (K. Finlayson, ed.), Technomic Publishers, Pensylvania, 1994, 161. 

Very low density polyethylenes are relatively soft and transparent, because they are largely noncrystalline in nature. Films made from these materials are resilient with a moderate level of elastic recovery, as long as they are not stretched beyond strain levels of approximately 100%. At their lower densities, they feel tacky and tend to stick to each other. We often blend very-low density polyethylene into higher density grades of polyethylene or isotactic polypropylene to boost their impact resistance. 

Polymer Blends. The miscibility of polyethylene oxide) with a number of other polymers has been studied, eg, with poly(methyl methacrylate) (18—23), poly(vinyl acetate) (24—27), polyvinylpyrrolidinone (28), nylon (29), poly (vinyl alcohol) (30), phenoxy resins (31), cellulose (32), cellulose ethers (33), poly(vinyl chloride) (34), poly(lactic acid) (35), poly(hydroxybutyrate) (36), poly(acrylic acid) (37), polypropylene (38), and polyethylene (39). 

The physical properties of polyallomers are generally intermediate between those of the homopolymers prepared from the same monomers, but frequently represent a better balance of properties than blends of the homopolymers. This is illustrated by comparing the properties of a propylene-ethylene polyallomer containing 2.5% ethylene with polypropylene, high-density polyethylene, and a blend of 5% high-density polyethylene and 95% polypropylene. 

This technology was first commercially applied to polyurethane blend [121] and patented as Rimplast (for Reactive Injection Molding), but many polymers have since been blended with polysiloxane thanks to this method polyethylene [122], polypropylene [122,123], polyamide [124-130], polyesters [128,131-133], poly(phenylene ether) [134], fluorocarbons [135] and many more. Many of them include reinforcing fillers such as fumed silica. The silicone base involved can moreover contain reactive groups such as the epoxy group [136,137]. A typical silicone base useful for these blends was de-... 

Ionomer polymer mixtures can be blended with various products. The materials used to cut the ionomer are paraffins, microcrystalline waxes, plasticizer free vinyl chloride, polymer mixtures of polyethylene, polypropylene as well as natural and synthetic rubber. Finished materials made from uncrosslinked ionomer mixtures may not be used for contact with fatty foods. 

To improve the properties of PLA, plasticizers, special additives such as chain-extenders, polymer blends, and composites are commonly investigated. Martin and Averous (10) have studied the effects of various plasticizers on the properties of PLA. Pilla et al. (11-12) have investigated the effects of chain-extenders on the foaming properties of PLA. In addition, a vast number of studies have been conducted to enhance the properties of PLA by blending it with various polymers such as polyethylene oxide (PEO), polypropylene oxide (PPO), polyvinyl acetate, polyolefins, polystyrene, HIPS (high impact polystyrene), polyacetals, polycarbonate, and acrylonitrile butadiene styrene (ABS) (13-26). 

Shiraishi and Goda [16] reported that allylated wood meals were given thermoplastic properties by blending with appropriate synthetic polymers or low molecular weight plasticizers such as dimethylphthalate or resorcinol. Mere allylation did not render wood thermally meltable. Films from the allylated wood-polyethylene and allylated wood-polypropylene (1 2) blends exhibit tensile strengths of 92.2 and 159.0 MPa and elongations of 14.6 and 3.8% respectively, [16]. 

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