Commodity resins

Commodity resins Common alum Common clay... 

Over 70% of the total volume of thermoplastics is accounted for by the commodity resins polyethylene, polypropylene, polystyrene, and poly(vinyl chloride) (PVC) (1) (see Olefin polymers Styrene plastics Vinyl polymers). They are made in a variety of grades and because of their low cost are the first choice for a variety of appHcations. Next in performance and in cost are acryhcs, ceUulosics, and acrylonitrile—butadiene—styrene (ABS) terpolymers (see... 

Engineering resins can be combined with either other engineering resins or commodity resins. Some commercially successhil blends of engineering resins with other engineering resins include poly(butylene terephthalate)—poly(ethylene terephthalate), polycarbonate—poly(butylene terephthalate), polycarbonate—poly(ethylene terephthalate), polysulfone—poly (ethylene terephthalate), and poly(phenylene oxide)—nylon. Commercial blends of engineering resins with other resins include modified poly(butylene terephthalate), polycarbonate—ABS, polycarbonate—styrene maleic anhydride, poly(phenylene oxide)—polystyrene, and nylon—polyethylene. 

In addition to the broad categories of TPs and TSs, TPs can be further classified in terms of their structure, as either crystalline, amorphous, or liquid crystalline. Other classes (terms) include elastomers, copolymers, compounds, commodity resins, engineering plastics, or neat plastics. Additives, fillers, and reinforcements are other classifications that relate directly to plastics properties and performance. 

For polymerizing monomers into commodity resins, cost of irradiation would have to be reduced to the cost of catalyst in order to compete economically with the present commercial polymerization processes. For engrafting monomers to finished articles, the cost can be higher, especially when solvents are eliminated. 

There are many polymer chain modification reactions of different types that have been carried out on polymer melts processed in single and twin rotor extruders. This activity, (4-6) in the analysis of polymerization reactors, driven by market forces seeking to create value-added polymers from commodity resins, started in the mid-1960s in industrial research laboratories (7). Indeed much of the early work is to be found in the patent literature.1 Although in recent times more publications, both industrial and academic can be found in the open literature, there is still a good deal of industrial secrecy, because the products of reactive polymer processing are of significant commercial value to industry. Below we will deal briefly with two important examples of such reactions. 

The physical properties and melt processing of PLA are similar to those of conventional packaging resins. It may thus be used as a commodity resin for general packaging application. In many aspects the basic properties of PLA lie between those of crystal PS and PET [ 14]. When plasticized by its own monomer lactic acid, PLA becomes increasingly flexible so that products that mimic PVC, LDPE, LLDPE, PP, and PS can be prepared [15]. Possible applications are espe-... 

TJolypropylene is a versatile and widely used thermoplastic. By 1970, sales volume in the United States should be over one billion pounds, compared with sales of approximately 500 million pounds for 1967, and polypropylene should be well on its way to joining polyethylene, polystyrene, and poly (vinyl chloride) as a commodity resin. 

Commodity resins—High-volume, low-price thermoplastics (polyethylene, polypropylene, poly[vinyl chloride], polystyrene and other styrenics, and polyethylene terephthalate]). 

Most of this growth has concerned the growth of China and suppliers of commodity resins and chemical intermediates to the rapidly growing Chinese market. 

By far the greatest volume of work has involved photodegradation. Although biodegradable has become a popular, overused and much misused word with plastics, the experts know that very few plastic products are truly biodegradable and certainly none of the so-called commodity resins. 

Conversely where less stringent thermal demands are appropriate, choices are broadened to encompass materials more commonly referred to as "commodity resins". Ultimate end product operational environments will impact the material selection process. Where in-service temperatures range from room ambient to moderate thermal extremes, lesser thermally tolerant resins may be considered. Conversely, for hostile environments such as those encountered in "under the hood" automotive, down-hole (geothermal), tropical, or corrosive climatic axtremes, enhanced material properties will be required. 

Batch injection molding machine thermoplastics commodity resins, polyolefins (LDPE, HDPE, PP), styrenics (PS, PMMA. polycarbonates, ABS, PET), and engineered resins for higher impact strength. Continuous extruder thermoplastics. Casting PP fine film 10 to 50 pm cast film 100 to 400 pm thermoformable sheet 200 to 2500 pm. Film blow LDPE, HDPE, PP. Pug mill clay materials for bricks, tiles, and ceramics. 

The five large-volume polymeric families that belong to the Commodity resins are polyethyl-enes (PE), polypropylenes (PP), styrenics (PS), acrylics (PMMA), and vinyls (PVC). Their world market share (see Table 1.1) remains relatively stable — they represent 79% of all plastics. 

Five large-volume polymeric groups belong to this category polyethylenes, polypropylenes, styrenics, acrylics and vinyls. Their world market share remains relatively stable — the commodity resins represent 71% of all consumed plastics. 

Since the anionically polymerized block copolymers are relatively expensive they have been more frequently used in blends with engineering than commodity resins. Owing to miscibility of styrene blocks with PPE, the SBS and SEBS are natural tougheners for this polymer. However, for blending with PEST, PC, POM or PA, the copolymer should be modified by incorporation of acidic, acid anhydride, or epoxy moieties. 

The largest group comprises the impact modified PEST s — these were summarized while discussing commodity resin blends. The commercial blends with, e.g., SMA or acrylic rubber, show good processability, rigidity, impact and tensile strength, as well as excellent weatherability, viz. Arloy 2000, Bexloy , Celanex , Pibiter HI, Rynite , Ultradur KR. 

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