What is the difference between PET, APET, PETE and PETG?What is the difference between PET, APET, PETE and PETG?
PET and PETE are short for polyethylene terephthalate. It can also be referred to as PETP or PET-P. APET and PETG are PET de copolymers, also known as amorphous polyethylene terephthalate, which are heat shrinkable polyester films. Ordinary polyester is generally prepared by esterification and polycondensation of terephthalic acid (PTA) and ethylene glycol (EG), and belongs to crystalline polymer (strictly speaking, it is a polymer coexisting with crystalline and amorphous regions). It is generally milky white or light yellow, highly crystalline polymer, with smooth and glossy surface. The product can be processed even at low temperature, and can remain transparent without adding fillers. It can maintain excellent physical and mechanical properties in a wide temperature range, and the long-term use temperature can reach 120 ℃. Good electrical insulation. Creep resistance, friction resistance, fatigue resistance. It has good dimensional stability.
However, due to its high glass transition temperature, low crystallization rate, difficult processing and molding, high molding temperature, long production cycle and poor impact resistance. Therefore, it is necessary to improve its processing performance through reinforcement, filling, blending and other methods. The use of PET can be divided into fiber (70% of the consumption of synthetic fiber in the early stage) and non-fiber. The latter includes well-known packaging materials (food and beverage containers, vacuum packaging, etc.), insulating materials, tape base, film and photographic film, etc. The so-called copolymerization modification is to introduce the third or even the fourth component in addition to the two main components of terephthalic acid (PTA) and ethylene glycol (EG) to participate in the copolymerization, in order to make it form an asymmetric molecular structure and form an amorphous PET copolymer. For example, the PET copolymer prepared by copolymerization modification with binary carboxylic acid is called APET. Compared with PET, the low temperature toughness (impact resistance and tear resistance) and heat resistance of APET are improved.