Plastic and their types plan: general information about plastic. Types of plastics

Amorphous plastics and crystalline plastics
Many plastics are completely amorphous (without a highly ordered molecular structure),^[15] including thermosets, polystyrene, and methyl methacrylate (PMMA). Crystalline plastics exhibit a pattern of more regularly spaced atoms, such as high-density polyethylene (HDPE), polybutylene terephthalate (PBT), and polyether ether ketone (PEEK). However, some plastics are partially amorphous and partially crystalline in molecular structure, giving them both a melting point and one or more glass transitions (the temperature above which the extent of localized molecular flexibility is substantially increased). These so-called semi-crystalline plastics include polyethylene, polypropylene, polyvinyl chloride, polyamides (nylons), polyesters and some polyurethanes.
Conductive polymers
Intrinsically Conducting Polymers (ICP) are organic polymers that conduct electricity. While a conductivity of up to 80 kS/cm in stretch-oriented polyacetylene,^[16] has been achieved, it does not approach that of most metals. For example, copper has a conductivity of several hundred kS/cm.^[17]
Biodegradable plastics and bioplastics
Biodegradable plastics
Biodegradable plastics are plastics that degrade (break down) upon exposure to sunlight or ultra-violet radiation; water or dampness; bacteria; enzymes; or wind abrasion. Attack by insects, such as waxworms and mealworms, can also be considered as forms of biodegradation. Aerobic degradation requires that the plastic be exposed at the surface, whereas anaerobic degradation would be effective in landfill or composting systems. Some companies produce biodegradable additives to enhance biodegradation. Although starch powder can be added as a filler to allow some plastics to degrade more easily, such treatment does not lead to complete breakdown. Some researchers have genetically engineered bacteria to synthesize completely biodegradable plastics, such as polyhydroxy butyrate (PHB); however, these are relatively costly as of 2021.^[18]