Thermoplastics polyethylene terephthalate

Friedrich, K. Microstructure and Fracture of Fiber Reinforced Thermoplastic Polyethylene Terephthalate, Center for Composite Materials, University of Delaware, U.S.A., Report No. CCM-80-17, 1980... 

The investigation was performed on commercial polymer sheet blanks having a uniform thickness profile of 2 and 3mm. Four different thermoplastics - polyethylene terephthalate (PET), polyamide (PA), polyvinylchloride (PVC) and polycarbonate (PC), with material structures varying from high-crystalline (PET) to amorphous (PC) -were employed. 

As mentioned earlier, polyethylene terephthalate is an important thermoplastic. However, most PET is consumed in the production of fibers. 

Polyethylene terephthalate (PET) is one of the most important commercial thermoplastic polyesters, which has been on the market since 1977 and is widely used in both industrial and household applications. Under specific conditions, plastics can be converted into their primary components for use in other chemical processes by chemical recycling. PET is a thermoplastic, and so recycling by chemical methods, which converts it into primary components, can be achieved. This study examines the optimal routes of the existing chemical methods. For chemical recycling, acidic hydrolysis is used and PET is converted into terephthalic acid (TPA) and... 

Polyesters, which are a class of engineering thermoplastics, are found in a wide variety of applications including carbonated drink bottles, fibers for synthetic fabrics, thin films for photographic films and food packaging, injection molded automotive parts, and housings for small appliances. In this chapter, we svill explore the synthesis of this class of polymers. We will also look at the typical properties and end uses for the most common of these resins, polyethylene terephthalate and polybutylene terephthalate, which are commonly known as PET and PBT, respectively. 

The workhorse polyester is polyethylene terephthalate) (PET) which is used for packaging, stretch-blown bottles and for the production of fibre for textile products. The mechanism, catalysis and kinetics of PET polymerization are described in Chapter 2. Newer polymerization techniques involving the ring-opening of cyclic polyester oligomers is providing another route to the production of commercial thermoplastic polyesters (see Chapter 3). 

There are two main types of plastics thermoplastics and thermosets. What is the difference between them What is each type of plastic used for Polyethylene terephthalate (PET) can be recycled successfully into new and interesting materials. Research the trade name Ecospun on the Internet. What is this material, what is it made from, and what is it used for ... 

The commodity thermoplastics are the most-used plastics in this sector, accounting for 95% of all thermoplastic packaging. Polyolefins are the most important, accounting for more than 65% of the total plastic weight. Polyethylene terephthalate, polystyrene and PVC are also commonly used. 

Fig. 6.8. Fracture toughness, K, of short glass fiber-thermoplastics injection molded composites as a function of weight fraction of fiber, fVr. (O) and (A) polyethylene terephthalate (PET) matrix ( ) and (A) polycarbonate (PC) matrix. Notches made transverse (O, ) and parallel (A, A) to the mold fill direction,...

TPX does not mix with other thermoplastic resins, e.g., as polyethylene terephthalate) (PET) or PP. It can be used to impart mi-croporous properties in films made from PET and PP. 

Most of the polymer s characteristics stem from its molecular structure, which like POE, promotes solubility in a variety of solvents in addition to water. It exhibits Newtonian rheology and is mechanically stable relative to other thermoplastics. It also forms miscible blends with a variety of other polymers. The water solubility and hot meltable characteristics promote adhesion in a number of applications. PEOX has been observed to promote adhesion comparable with PVP and PVA on aluminum foil, cellophane, nylon, poly(methyl methacrylate), and polyethylene terephthalate), and in composite systems improved tensile strength and Izod impact properties have been noted. 

PC PE PES PET PF PFA PI PMMA PP PPO PS PSO PTFE PTMT PU PVA PVAC PVC PVDC PVDF PVF TFE SAN SI TP TPX UF UHMWPE UPVC Polycarbonate Polyethylene Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde Polyfluoro alkoxy Polyimide Polymethyl methacrylate Polypropylene Polyphenylene oxide Polystyrene Polysulfone Polytetrafluoroethylene Polytetramethylene terephthalate (thermoplastic polyester) Polyurethane Polyvinyl alcohol Polyvinyl acetate Polyvinyl chloride Polyvinyl idene chloride Polyvinylidene fluoride Polyvinyl fluoride Polytelrafluoroethylene Styrene-acrylonitrile Silicone Thermoplastic Elastomers Polymethylpentene Urea formaldehyde Ultrahigh-molecular-weight polyethylene Unplasticized polyvinyl chloride... 

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

Terephthalic Acid (Dimethyl Terephthalate). Terephthalic acid (TPA) and dimethyl terephthalate (DMT) are precursors for polyethylene terephthalate (PET), which in turn is used in the production of polyester fibers and film polyester thermoplastic PET bottles, and other resins. In 1999 the total U.S. production was more than 9 billion lb. In the past, the relative ease of producing high-quality DMT gave it the largest share of the terephthalate market. The trend is now toward TPA, as the result of technological advances that permit better purification of TPA and the use of the acid directly in polymer formation. The capacity is about 3 to 1 split in favor of TPA process. 

Seven families of thermoplastics exceed a billion pounds per year in the United States polyethylenes, polypropylene, PVC, polystyrene and its copolymers, polyethylene terephthalate, acrylonitrile-butadiene-styrene (ABS) and nylon (Table 15.2). 

Saturated polyester (TS polyester) Thermoplastic polyesters Polybutylcne terephthalate (PBT) Polyethylene terephthalate (PET) Unsalurated polyester (TS polyester)... 

Within the family of polyolefins there are many individual families that include low density polyethylenes, linear low density polyethylenes, very low polyethylenes, ultra low polyethylenes, high molecular weight polyethylenes, ultra high molecular weight polyethylenes, polyethylene terephthalates, ethylene-vinyl acetate polyethylenes, chlorinated polyethylenes, crosslinked polyethylenes, polypropylenes, polybutylenes, polyisobutylene, ionomers, polymethylpentene, thermoplastic polyolefin elastomers (polyolefin elastomers, TP), and many others. 

South Korean company SK Chemicals produces SKYGREEN polybutylene succinate (PBS) thermoplastics based on aliphatic polyester and aliphatic/aromatic co-polyesters that were developed from SK Chemicals polyethylene terephthalate (PET) technology. SKYGREEN BDP products offer LDPE-like properties. They are used in films, disposable cutlery, food trays, hairbrush handles and paper coatings. Aliphatic versions biodegrade more rapidly and offer better processing and tensile properties than the aromatic-aliphatic grades, which cost less. 

Polyester fibers, similar to polyamide fibers, represent another important family of fiber. Polyester fiber was discovered in England in 1941 and commercialized in 1950. Two common trade names of polyester are Dacron in the US and Terylene in the UK. The term polyester fiber represents a family of fibers made of polyethylene terephthalate. Dimethyl terephthalate is reacted with ethylene glycol in the presence of a catalyst, antimony oxide, to produce polyethylene terephthalate or polyester. The chain repeat structure of PET is given in Fig. 4.6. Although polyesters can be both thermosetting and thermoplastic, the term polyester has become synonymous with PET. Note that the PET chain structure is different from the simpler structure of nylon or polyethylene. In PET, the aromatic ring and its associated C-C bonds provide a rigidity to the structure. The polyester structure is also bulkier than that of nylon or polyethylene. These factors make polyester less flexible than nylon and polyethylene, and the crystallization rate of PET slower than that of nylon or polyethylene. Thus, when polyester is cooled from the melt, an appreciable amount of crystallization does not result. 

Plastic polymers make up a high proportion of waste and the volume and range used is increasing dramatically. The two main types of plastic are thermoplastics which soften when heated and harden again when cooled and thermosets which harden by curing and cannot be remoulded. The six main plastics in municipal solid waste are, high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC) and polyethylene terephthalate (PET). In addition there are... 

Thermoplastics are polymers that can be melted and then molded into shapes that are retained when the polymer is cooled. Although they have high Tg values and are hard at room temperature, heating causes individual polymer chains to slip past each other, causing the material to soften. Polyethylene terephthalate and polystyrene are thermoplastic polymers. 

Alkyd resins have been the workhorse for the coatings industry over the last half century. The term alkyd was coined to define the reaction product of polyhydric alcohols and polybasic acids, in other words, polyesters. However, its definition has been narrowed to include only those polyesters containing monobasic acids, usually long-chain fatty acids. Thus thermoplastic polyesters typified by polyethylene terephthalate (PET) used in synthetic fibers, films, and plastics and unsaturated polyesters typified by the condensation product of glycols and unsaturated dibasic acids (which are widely used in conjunction with vinylic monomers in making sheet molding compounds or other thermosetting molded plastics) are not considered as part of the alkyd family and are beyond the scope of the present discussion. 

Hahgenated polymers, both brominated and chlorinated, have been developed to yield better polymer compatibility, improve physical properties, and long-term-aging characteristics in many thermoplastic resins, particularly the high-performance engineering thermoplastics, such as nylon, polybutylene terephthalate (PBT) and polyethylene terephthalate (PET). These materials still use antimony oxide as a synergist to achieve the desired flame resistance (31). 

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