What is high density polyethylene made of and how does it differ from other kinds of plastics?
HDPE or high density polyethlyne, LDPE or low density polyethylene, and LLDPE or linear low density polyethylene are all different forms of the same type of plastic. Polyethylene is created through the polymerization of ethylene, but it is classified into different categories based mostly on its density and branching. The different forms of polyethylene plastics each have different mechanical properties and degrees of flexibility. For example, HDPE is used to make plastic milk jugs while LDPE and LLDPE are primarily used to make plastic bags. Polypropylene is a plastic with a different molecular structure compared to polyethylene. Most commercial polypropylene has an intermediate level of crystallinity between that of low density polyethylene (LDPE) and high density polyethylene (HDPE). Although it is less tough than HDPE and less flexible than LDPE, it is much more brittle than HDPE. This allows polypropylene to be used as a replacement for engineering plastics. Polypropylene is rugge
