25038-59-9 Usage
Description
Polyethylene terephthalate (PET) is a saturated thermoplastic polyester that belongs to the polyester family of polymers. It is composed of repeating ethylene terephthalate units and is known for its excellent chemical resistance, melt mobility, spinnability, hardness, rigidity, dimensional stability, and lightweight properties. The combination of these properties makes PET a versatile and widely used material in various applications.
Uses
Used in Electrical Parts Industry:
PET is used as a material for electrical parts such as relay bases and lamp sockets, pump housings, gears, and sprockets due to its excellent chemical resistance, dimensional stability, and thermal stability.
Used in Furniture Industry:
PET is used as a material for chair arms, casters, and other furniture components because of its rigidity, lightweight properties, and resistance to wear and tear.
Used in Textile Industry:
PET is used as a material for synthetic fibers that simulate wool, cotton, or rayon. The high strength and durability of PET fibers make them suitable for various textile applications.
Used in Packaging Industry:
PET is used in the production of films such as Mylar? and Melinex?, which are biaxially oriented by cold stretching the extruded sheets in two directions. This increases the crystallinity and reduces the tendency to shrink when heated. PET films are used in capacitors, slot liners for motors, magnetic tape, x-ray film, photographic film, graphic art and drafting applications, and food packaging such as boil-in-bags.
Used in ESD Protection and Cleanliness Applications:
PETG + Multi-wall Carbon Nanotubes (CNTs) compounds are used in critical applications that require electrostatic discharge (ESD) protection and a high level of cleanliness. The benefits of PETG include superior chemical resistance, amorphous nature, low moisture absorption, very low odor emitted during printing, superior ductility, and a wide processing range. The benefits of CNTs include consistent surface resistivity, low additive loading rates, improved retention of impact and elongation, low particulate contamination, and minimal contribution to outgassing and ionic contamination.
Preparation
Poly(ethylene terephthalate) is prepared by the reaction of either terephthalic acid or dimethyl terephthalate with ethylene glycol, and its repeating unit has the general structure
The resin has the ability to be oriented by a drawing process and crystallized to yield a high-strength product.
Synthesis
The synthesis of PET begins with the esterification of either terephthalic acid or dimethyl terephthalate with ethylene glycol, yielding bis(hydroxyethyl)terephthalate (BHET). The BHET is then polymerized up to about 30 repeat units (Awaja and Pavel 2005). Next, to achieve a degree of polymerization (DP) of about 100 repeat units, polycondensation is performed at temperatures > 270°C and pressures > 50 Pa (Ravindranath and Mashelkar 1986). To produce bottle-grade PET, the DP must be > 150 repeat units, which is typically accomplished via solidstate polymerization, a process that requires temperatures > 200°C, pressures > 100 Pa, and incubation times of at least 15 hr (Al-Ghatta et al. 1997).
It is becoming increasingly common for manufacturers to market copolymers for purposes previously filled by homopolymer PET. Copolymer blends, such as polybutylene terephthalate/PET, have certain advantages over homopolymer PET with regard to mechanical properties and resistance to degradation (Grossetête et al. 2000; GuerricaEchevarría and Eguiazábal 2009). In the United States, a clear plastic bottle may be made with copolymers and still be legally marketed as PET, according to applicable federal regulations [e.g., 21 CFR §177.1630 (U.S. Food and Drug Administration 2009).
Check Digit Verification of cas no
The CAS Registry Mumber 25038-59-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,5,0,3 and 8 respectively; the second part has 2 digits, 5 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 25038-59:
(7*2)+(6*5)+(5*0)+(4*3)+(3*8)+(2*5)+(1*9)=99
99 % 10 = 9
So 25038-59-9 is a valid CAS Registry Number.
