High-density polyethylene and poly vinyl

Structural Components. In most appHcations stmctural foam parts are used as direct replacements for wood, metals, or soHd plastics and find wide acceptance in appHances, automobUes, furniture, materials-handling equipment, and in constmction. Use in the huil ding and constmction industry account for more than one-half of the total volume of stmctural foam appHcations. High impact polystyrene is the most widely used stmctural foam, foUowed by polypropylene, high density polyethylene, and poly(vinyl chloride). The constmction industry offers the greatest growth potential for ceUular plastics. 

J.D.N., and Forte, M.M.C. (2009) Morphology, mechanical and dynamic mechanical properties of recycled high density polyethylene and poly(vinyl alcohol) blends. Polym. Bull., 62, 33-43. 

The book first focuses on commonly used industrial polymers, including polypropylenes, low- and high-density polyethylenes, and poly(vinyl chloride), as well as less widely used polymer types, such as acrylics, ether polymers, cellulosics, sulfide polymers, silicones, polysulfones, polyether ether ketones, and polybenzimidazoles. It then explores polymer derivatives and polymeric combinations that play special and often critical roles in diverse fields of human activities. The polymers covered include liquid crystal, electroactive, ionic, and shape memory polymers hydrogels and nanocomposites. The book concludes with a comprehensive overview of new developments in the use of polymers in a variety of areas. 

Industry estimates indicate that up to 5% of the total resin production finds its way into prototype or mill shape plastic products. By mill shapes is meant those primary uniform configuration subject to established cross-sectional and length tolerances. While this estimate is necessarily conjectural, the best available information indicates that this range is accurate. Modem Plastics magazine estimated mill shape production for 1968 in acrylics, cellulose, nylon, acetal, polycarbonate, high density polyethylene, polypropylene, poly(vinyl chloride), and copolymers to approach 336.4 million pounds. Total United States resin production for 1968 slightly exceeded 16 billion pounds. 

Although the principal application of blow molding has been for bottle fabrication, it is being used increasingly for other parts such as automotive fuel tanks, seat backs, flexible bellows, and toys. High density polyethylene, polypropylene, poly(vinyl chloride) (PVC), and poly(ethylene terephthalate) (PET) are the principal resins molded in this way. For more special applications, however, other thermoplastics such as nylon, polyacetal, ABS, polycarbonate and ultra-high-molecular-weight polyethylene also are used. ... 

A broad range of polymers are produced by polymerization in heterogeneous media, including polyolefins manufactured by slurry (high density polyethylene and isotactic polypropylene) and gas phase (linear low density polyethylene and high density polyethylene) polymerization coatings and adhesives produced by emulsion and miniemulsion polymerization flocculants obtained by inverse emulsion and microemulsion polymerization poly(vinyl chloride) (PVC) and polystyrene produced by suspension polymerization and toners synthesized by dispersion polymerization. As a whole, they represent more than 50% of the polymer produced worldwide [1]. 

Table 6 shows the sales estimates for principal film and sheet products for the year 1990 (14). Low density polyethylene films dominate the market in volume, followed by polystyrene and the vinyls. High density polyethylene, poly(ethylene terephthalate), and polypropylene are close in market share and complete the primary products. A number of specialty resins are used to produce 25,000—100,000 t of film or sheet, and then there are a large number of high priced, high performance materials that serve niche markets. The original clear film product, ceUophane, has faUen to about 25,000 t in the United States, with only one domestic producer. Table 7 Hsts some of the principal film and sheet material manufacturers in the United States.

The even-numbered carbon alpha olefins (a-olefins) from through C q are especially useful. For example, the C, C, and Cg olefins impart tear resistance and other desirable properties to linear low and high density polyethylene the C, Cg, and C q compounds offer special properties to plasticizers used in flexible poly(vinyl chloride). Linear C q olefins and others provide premium value synthetic lubricants linear 145 olefins are used in... 

Various authors—for example, Dole, Milner, and Williams (15) and Lyons (25)—have suggested that the decay of vinyl groups initially present in some types of high density polyethylene involves an end-linking process, these authors disagreeing only about the mechanism involved. If such were the case, some difference in solubility or elastic behavior above 140 °C. would be expected between low and high density poly-... 

Focusing collectors are usually cast acrylic Fresnel lenses, or mirrors of aluminized polyester film in frames of aluminum. These reflectors are either enclosed in a bubble of poly(vinyl fluoride) film, or under polycarbonate glazing, which may be covered with a fluorocarbon film to reduce the reflectivity. The absorbers for active systems are copper or aluminum since the temperatures are too high (325—370°C) for plastics. The frames, however, can be molded ABS, high density polyethylene or polyurethane, either solid or structural foam. Polybutylene or chlorinated PVC can be used for piping hot water, and tanks can be made of either reinforced polyester or blow- or rotational-molded, high density polyethylene (12—15). 

An additive system was developed for poly(vinyl chloride) for medical applications. The additives include primary stabilisers (Ca-Zn stearate and Zn stearate), secondary stabilisers (epoxides) and lubricants (ethylene bisamide and high density polyethylene), to improve melt processing and heat stability. The use of the stabilisers resulted in reduced equipment down-time, increased the level of recycled material which could be incorporated, and enhanced the product characteristics, including colour, clarity, blush, aqueous extractables and particle generation. 5 refs. 

Beret, S. Prausnitz, J. M., "Densities of Liquid Polymers at High Pressure. Pressure-Volume-Temperature Measurementsfor Polyethylene, Polyisobutylene, Poly(vinyl acetate), and Poly(dimethylsiloxane) to 1 kbar," Macromolecules, 8, 536 (1975). 

It is well known from diffusion theory that different types of polymers have different diffusion behaviours. For example, the polyester type polymers like poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN) and polycarbonate (PC) as well as rigid poly(vinyl chloride) (PVC), which have a high glass transition temperature, are low diffusive polymers. The migration of potential contaminants in these polymers will result in low migration values. In contrast, polyolefins like high density polyethylene (HDPE), polypropylene (PP) or low density polyethylene (LDPE), which... 

A great proportion of plastics end its lifetime as a part of the overall solid waste stream where they represent roughly 10 wt%. The typical distribution of plastics in household wastes is shown in Figure 3.1 [3]. The main components are polyolefins low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE) and polypropylene (PP), accounting for about 67% of the total amount of plastic wastes. Other important components in plastic wastes are polystyrene (PS), poly (vinyl chloride) (PVC) and poly (ethylene terephthalate) (PET). 

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